| susceptibility of cockroaches (dictyoptera: blattellidae, blattidae) to infection by steinernema carpocapsae. | the susceptibility of american cockroaches, periplaneta americana (l.); smoky brown cockroaches, p. fuliginosa (serville); oriental cockroaches, blatta orientalis l.; german cockroaches, blattella germanica (l.); and brownbanded cockroaches, supella longipalpa (f.), to steinernema carpocapsae weiser (all strain) was evaluated under laboratory conditions. a 1-ml water suspension containing 500,000 nematodes was placed on filter paper in a petri dish or the pad of a bait station. german, brown-ban ... | 1992 | 1517508 |
| pathogenicity of steinernema carpocapsae and s. glaseri (nematoda: steinernematidae) to ixodes scapularis (acari: ixodidae). | the entomopathogenic nematodes steinernema carpocapsae (weiser) and s. glaseri (steiner) are pathogenic to engorged adult, blacklegged ticks, ixodes scapularis (say), but not to unfed females, engorged nymphs, or engorged larvae. nematodes apparently enter the tick through the genital pore, thus precluding infection of immature ticks. the timing of tick mortality, and overall mortality after 17 d, did not differ between infections by s. carpocapsae and s. glaseri. these nematodes typically do no ... | 1995 | 8551517 |
| interaction between ticks (acari: ixodidae) and pathogenic nematodes (nematoda): susceptibility of tick species at various developmental stages. | the virulence of entomopathogenic nematodes (steinernematidae and heterorhabditidae) to tick species under laboratory conditions is reported. the susceptibility of larval, nymphal, and adult stages of the ticks hyalomma excavatum (koch), rhipicephalus bursa (canestrini & fanz), and r. sanguineus (latereille) to 2 strains of steinernema carpocapsae and 3 strains of heterorhabditis bacteriophora were compared in laboratory assays. preimaginal stages of ticks were found to be more resistant to the ... | 1999 | 10593074 |
| mortality rate of adult ticks due to infection by entomopathogenic nematodes. | the mortality of boophilus annulatus, hyalomma excavatum, rhipicephalus bursa, and rhipicephalus sanguineus adult ticks was recorded after their exposure in petri dishes to 5 entomopathogenic nematode strains. the strains used were dt and mexican of steinernema carpocapsae, hb hp88 of heterorhabditis bacteriophora, and is-3 and is-5 of heterorhabditis sp. the most rapid killing rates (lt50 and lt90) were observed for b. annulatus ticks (0.8-5.0 days). most unfed males died 0.3-2.8 days after the ... | 2000 | 10958439 |
| effect of airflow rate on yields of steinernema carpocapse az 20 in liquid culture in an external-loop airlift bioreactor. | maximization of the contact between males and females is a key factor in the production of the nematode steinernema carpocapsae in a bioreactor.%the influence of the airflow rate in male and female distribution and mass production in an external-loop bioreactor with a deceleration zone was studied. when operating at an airflow rate of 0.05 vvm, a high retention of females in the deceleration zone of the bioreactor was observed and a larger nematode productivity was obtained. at this aeration rat ... | 2001 | 11135208 |
| laboratory evaluation of pathogenicity of entomogenous nematodes to african tick species. | five strains of entomogenous nematodes, steinernema carpocapsae strains dd, mexican, sr, and heterorhabditis bacteriophora strains 1s5 and hp88, were tested for their pathogenicity to various developmental stages of five african tick species namely; rhipicephalus appendiculatus, r. evertsi, amblyomma variegatum, a. gemma, and boophilus decoloratus. in engorged female r. appendiculatus, all nematodes at a concentration of 1,000 infective juveniles (ij)/dish, except s. carpocapsae mexican strain, ... | 2000 | 11193637 |
| phylogeny of steinernema travassos, 1927 (cephalobina: steinernematidae) inferred from ribosomal dna sequences and morphological characters. | entomopathogenic nematodes in steinernema, together with their symbiont bacteria xenorhabdus, are obligate and lethal parasites of insects that can provide effective biological control of some important lepidopteran, dipteran, and coleopteran pests of commercial crops. phylogenetic relationships among 21 steinernema species were estimated using 28s ribosomal dna (rdna) sequences and morphological characters. sequences of the rdna internal transcribed spacers were obtained to provide additional m ... | 2001 | 11534654 |
| identification of xenorhabdus nematophila genes required for mutualistic colonization of steinernema carpocapsae nematodes. | one stage in the symbiotic interaction between the bacterium xenorhabdus nematophila and its nematode host, steinernema carpocapsae, involves the species-specific colonization of the nematode intestinal vesicle by the bacterium. to characterize the bacterial molecular determinants that are essential for vesicle colonization, we adapted and applied a signature-tagged mutagenesis (stm) screen to this system. we identified 15 out of 3000 transposon mutants of x. nematophila with at least a 15-fold ... | 2002 | 12207701 |
| differences between the pathogenic processes induced by steinernema and heterorhabditis (nemata: rhabditida) in pseudaletia unipuncta (insecta: lepidoptera). | larvae of pseudaletia unipuncta are moderately susceptible to infections caused by entomopathogenic nematodes, being a desirable host to study pathogenic processes caused by heterorhabditis bacteriophora, steinernema carpocapsae, and steinernema glaseri and their associated bacteria. the ability of the infective stage of these nematodes to invade hosts is quite different. s. carpocapsae invades the highest number of insects and presents the highest penetration rate, followed by h. bacteriophora. ... | 2002 | 12234542 |
| xenorhabdus nematophila requires an intact iscrsua-hscba-fdx operon to colonize steinernema carpocapsae nematodes. | an insertion between isca and hscb of the xenorhabdus nematophila iscrsua-hscba-fdx locus, predicted to encode fe-s assembly machinery, prevented colonization of steinernema carpocapsae nematodes. the insertion disrupted cotranscription of isca and hscb, but did not reduce hscba expression, suggesting that x. nematophila requires coordinated expression of the isc-hsc-fdx locus for colonization. | 2003 | 12775707 |
| xenorhabdus nematophilus inhibits p-bromophenacyl bromide (bpb)-sensitive pla2 of spodoptera exigua. | xenorhabdus nematophilus is a gram-negative symbiotic bacterium of the entomopathogenic nematode, steinernema carpocapsae. the bacteria delivered into the insect hemocoel by the nematodes cause immunodepression of the target insects to protect host nematodes and themselves from the cellular immune reaction. previous reports suggest that the immunodepression is caused by inhibition of the eicosanoid pathway that is known to be critically important to mediate cellular immunity. this study focused ... | 2003 | 14571507 |
| unique organization and regulation of the mrx fimbrial operon in xenorhabdus nematophila. | xenorhabdus nematophila, a gram-negative bacterium belonging to the proteus clade of the family enterobacteriaceae, forms a mutualistic association with the soil nematode steinernema carpocapsae. the nematode invades insects and releases xenorhabdus into the haemolymph, where it participates in insect killing. to begin to understand the role of fimbriae in the unique life cycle of xenorhabdus, the organization and expression of the mrx fimbrial operon was analysed. the mrx operon contained only ... | 2004 | 15133105 |
| identification and functional characterization of a xenorhabdus nematophila oligopeptide permease. | the bacterium xenorhabdus nematophila is a mutualist of steinernema carpocapsae nematodes and a pathogen of insects. presently, it is not known what nutrients the bacterium uses to thrive in these host environments. in other symbiotic bacteria, oligopeptide permeases have been shown to be important in host interactions, and we therefore sought to determine if oligopeptide uptake is essential for growth or symbiotic functions of x. nematophila in laboratory or host environments. we identified an ... | 2004 | 15345451 |
| microbial control of diamondback moth, plutella xylostella l. (lepidoptera: yponomeutidae) using bacteria (xenorhabdus nematophila) and its metabolites from the entomopathogenic nematode steinernema carpocapsae. | cells and cell-free solutions of the culture filtrate of the bacterial symbiont, xenorhabdus nematophila taken from the entomopathogenic nematode steinernema carpocapsae in aqueous broth suspensions were lethal to larvae of the diamondback moth plutella xylostella. their application on leaves of chinese cabbage indicated that the cells can penetrate into the insects in the absence of the nematode vector. cell-free solutions containing metabolites were also proved as effective as bacterial cells ... | 2004 | 15362188 |
| when mutualists are pathogens: an experimental study of the symbioses between steinernema (entomopathogenic nematodes) and xenorhabdus (bacteria). | in this paper, we investigate the level of specialization of the symbiotic association between an entomopathogenic nematode (steinernema carpocapsae) and its mutualistic native bacterium (xenorhabdus nematophila). we made experimental combinations on an insect host where nematodes were associated with non-native symbionts belonging to the same species as the native symbiont, to the same genus or even to a different genus of bacteria. all non-native strains are mutualistically associated with con ... | 2004 | 15312071 |
| the steinernema carpocapsae intestinal vesicle contains a subcellular structure with which xenorhabdus nematophila associates during colonization initiation. | steinernema carpocapsae infective juvenile (ij) nematodes are intestinally colonized by mutualistic xenorhabdus nematophila bacteria. during ij development, a small number of ingested x. nematophila cells initiate colonization in an anterior region of the intestine termed the vesicle and subsequently multiply within this host niche. we hypothesize that efficient colonization of a high percentage of s. carpocapsae individuals (typically>85%) is facilitated by bacterial adherence to a site(s) in t ... | 2005 | 16309459 |
| insect immunity-effects of factors produced by a nematobacterial complex on immunocompetent cells(1). | during in vitro incubations, the nematobacterial complex steinernema carpocapsae-xenorhabdus nematophilus produces different factors having toxic activities in vitro towards haemocytes, the insect cells responsible for cellular immune defense reactions. among others, two effects were evident on haemocyte monolayers; one of them was a cytotoxic activity while the other was an unsticking effect. the factors responsible for cytotoxic activity and unsticking effect, were separated from each other by ... | 1999 | 12770353 |
| temporal association of entomopathogenic nematodes (rhabditida: steinernematidae and heterorhabditidae) and bacteria. | galleria mellonella l. larvae were infected with three species (seven strains) of steinernema spp. or three species (three strains) of heterorhabditis spp. infected larvae were incubated at 22, 27, and 32 degrees c. larvae were dorsally dissected every 6h over a 48-h period. hemolymph was collected and streaked on tryptic soy agar plates. several non-symbiotic bacterial species were identified from infected insect cadavers: enterobacter gergoviae, vibrio spp., pseudomonas fluorescens type c, ser ... | 2006 | 16448667 |
| the complete mitochondrial genome of the entomopathogenic nematode steinernema carpocapsae: insights into nematode mitochondrial dna evolution and phylogeny. | we determined the complete sequence of the mitochondrial dna of the entomopathogenic nematode steinernema carpocapsae and analyzed its structure and composition as well as the secondary structures predicted for its trnas and rrnas. almost the complete genome has been amplified in one fragment with long pcr and sequenced using a shotgun strategy. the 13,925-bp genome contains genes for 2 rrnas, 22 trnas, and 12 proteins and lacks an orf encoding atpase subunit 8. four initiation codons were infer ... | 2006 | 16474981 |
| early colonization events in the mutualistic association between steinernema carpocapsae nematodes and xenorhabdus nematophila bacteria. | the bacterium xenorhabdus nematophila is a mutualist of the entomopathogenic nematode steinernema carpocapsae. during its life cycle, the bacterium exists both separately from the nematode and as an intestinal resident of a nonfeeding nematode form, the infective juvenile (ij). the progression of x. nematophila from an ex vivo existence to a specific and persistent colonization of ijs is a model to understand the mechanisms mediating the initiation and maintenance of benign host-microbe interact ... | 2003 | 12730175 |
| evolution of culture broth rheological properties during propagation of the entomopathogenic nematode steinernema carpocapsae, in submerged monoxenic culture. | this article presents the evolution of culture broth rheological properties during monoxenic cultures of steinernema carpocapsae in cylindrical bottles agitated orbitally. rheological properties were evaluated in simple-shear flow conditions and were well-modeled by the ostwald-de waele model. rheological properties varied from slightly dilatant, n = 1.2 (-), to moderately pseudoplastic flow behavior, n = 0.6 (-). nematode concentrations increased from 750 +/- 190 to 130 900 +/- 6900 nematodes/m ... | 2003 | 12675580 |
| response of ants to a deterrent factor(s) produced by the symbiotic bacteria of entomopathogenic nematodes. | the production of an ant-deterrent factor(s) (adf) by xenorhabdus nematophila and photorhabdus luminescens, the symbiotic bacteria of the nematodes steinernema carpocapsae and heterorhabditis bacteriophora, respectively, was examined. in addition to an in vivo assay in which bacteria were tested for their ability to produce adf within insect cadavers (m.e. baur, h. k. kaya, and d. r. strong, biol. control 12:231-236, 1998), an in vitro microtiter dish assay was developed to monitor adf activity ... | 2002 | 12450845 |
| characterization of the pleiotropic phenotype of an ompr strain of xenorhabdus nematophila. | xenorhabdus nematophila is an insect pathogen that forms a symbiotic association with the nematode, steinernema carpocapsae. xenorhabdus is carried into the insect host by the nematode, is released into the hemolymph and participates in killing the insect. the bacteria grow to high concentrations supporting the development of the nematode in the hemolymph. ompr is a global regulatory protein involved in the regulation of porin genes, motility, acid tolerance and virulence in several enteric bact ... | 2002 | 12448704 |
| nilr is necessary for co-ordinate repression of xenorhabdus nematophila mutualism genes. | the bacterial mutualist xenorhabdus nematophila colonizes a specific region of its nematode host steinernema carpocapsae. we previously reported the identification of a chromosomal locus encoding three x. nematophila genes of unknown function, nila, b and c, that are each necessary for colonization. subsequent work indicated the global regulator lrp is a repressor of nilc: nilc transcription is elevated in an lrp mutant and lrp interacts directly with the nilc promoter. in this manuscript, we re ... | 2006 | 17076669 |
| submerged monoxenic culture of the entomopathogenic nematode steinernema carpocapsae in an internal-loop airlift bioreactor using two configurations of the inner tube. | this article reports the submerged culture of the entomopathogenic nematode steinernema carpocapsae and its symbiotic bacterium, xenorhabdus nematophila, within an internal-loop airlift bioreactor. two configurations of the inner cylinder were tested: a standard draft tube (sdt) and a static mixer (sm), as well as two production media: mp1 (500 ml/l whey, among other ingredients) and mp2 (82 ml/l agave-juice from agave spp., among other ingredients). three fermentations were carried out: f1 --> ... | 2007 | 17252612 |
| purification and characterization of an extracellular protease from xenorhabdus nematophila involved in insect immunosuppression. | xenorhabdus nematophila, a bacterium pathogenic for insects associated with the nematode steinernema carpocapsae, releases high quantities of proteases, which may participate in the virulence against insects. zymogram assays and cross-reactions of antibodies suggested that two distinct proteases were present. the major one, protease ii, was purified and shown to have a molecular mass of 60 kda and an estimated isoelectric point of 8.5. protease ii digested the chromogenic substrate n-tosyl-gly-p ... | 2002 | 11872480 |
| xenorhabdus nematophilus as a model for host-bacterium interactions: rpos is necessary for mutualism with nematodes. | xenorhabdus nematophilus, a gram-negative bacterium, is a mutualist of steinernema carpocapsae nematodes and a pathogen of larval-stage insects. we use this organism as a model of host-microbe interactions to identify the functions bacteria require for mutualism, pathogenesis, or both. in many gram-negative bacteria, the transcription factor sigma(s) controls regulons that can mediate stress resistance, survival, or host interactions. therefore, we examined the role of sigma(s) in the ability of ... | 2001 | 11466270 |
| application of toxins from the entomopathogenic bacterium, xenorhabdus nematophila, for the control of insects on foliage. | larvae of the beet armyworm, spodoptera exigua, and the diamondback moth, plutella xylostella, and nymphs of the desert locust, schistocerca gregaria were controlled by the application of either cell suspensions from the bacterium, xenorhabdus nematophila or filtrates containing cell-free toxins. since there was no significant differences between the two treatments it was concluded that toxins produced by the bacterium were responsible for the lethal effects obtained. cells of xenorhabdus nemato ... | 2006 | 17390798 |
| combining steinernema carpocapsae and bacillus thuringienis strains for control of diamondback moth (plutella xylostella). | the diamondback moth (dbm), plutella xylostella, is a major pest of crucifers and has developed resistance against all chemical insecticides, even against the biological insecticide bacillus thuringiensis (bt). entomopathogenic nematodes (epn) as novel biological insecticide were successfully used against dbm. we investigated the potential of bt to enhance the virulence of epn and the possibility to reduce the application density by exploiting synergistic effects. the interaction between differe ... | 2006 | 17390802 |
| effect of photorhabdus luminescens phase variants on the in vivo and in vitro development and reproduction of the entomopathogenic nematodes heterorhabditis bacteriophora and steinernema carpocapsae. | photorhabdus luminescens (enterobacteriaceae) is a symbiont of entomopathogenic nematodes heterorhabditis spp. (nematoda: rhabditida) used for biological control of insect pests. for industrial mass production, the nematodes are produced in liquid media, pre-incubated with their bacterial symbiont, which provides nutrients essential for the nematode's development and reproduction. particularly under in vitro conditions, p. luminescens produces phase variants, which do not allow normal nematode d ... | 2001 | 11311434 |
| susceptibility of the filbertworm (cydia latiferreana, lepidoptera: tortricidae) and filbert weevil (curculio occidentalis, coleoptera: curculionidae) to entomopathogenic nematodes. | the objective of this study was to determine the susceptibility of the two primary direct insect pests of hazelnuts in oregon to three species of entomopathogenic nematodes. the entomopathogenic nematodes (heterorhabditis marelatus pt. reyes, steinernema carpocapsae all and steinernema kraussei l137) were used in laboratory soil bioassays to determine their virulence against filbertworm, cydia latiferreana (walsingham) (lepidoptera: tortricidae) and filbert weevil, curculio occidentalis (casey) ... | 2007 | 17434523 |
| new insights into the colonization and release processes of xenorhabdus nematophila and the morphology and ultrastructure of the bacterial receptacle of its nematode host, steinernema carpocapsae. | we present results from epifluorescence, differential interference contrast, and transmission electron microscopy showing that xenorhabdus nematophila colonizes a receptacle in the anterior intestine of the infective juvenile (ij) stage of steinernema carpocapsae. this region is connected to the esophagus at the esophagointestinal junction. the process by which x. nematophila leaves this bacterial receptacle had not been analyzed previously. in this study we monitored the movement of green fluor ... | 2007 | 17526783 |
| eicosanoids rescue spodoptera exigua infected with xenorhabdus nematophilus, the symbiotic bacteria to the entomopathogenic nematode steinernema carpocapsae. | xenorhabdus nematophilus is a pathogenic bacterium causing insect haemolymph septicemia, which leads to host insect death. to address the fundamental mechanisms underlying this haemolymph septicemia, or the immunodepressive response of the host insects following bacterial infection, we tested a hypothesis that the insect immune-mediating eicosanoid pathway is blocked by inhibitory action of the bacterium. haemocoelic injection of the bacteria into the fifth instar larvae of spodoptera exigua red ... | 2000 | 10891575 |
| pathogenicity, development, and reproduction of heterorhabditis bacteriophora and steinernema carpocapsae under axenic in vivo conditions. | galleria mellonella larvae cultured axenically were treated with axenic dauer juveniles of heterorhabditis bacteriophora and steinernema carpocapsae. after 3 days s. carpocapsae had killed all insects, with 9.4 +/- 4.3 nematodes per larva. h. bacteriophora were unable to kill g. mellonella, although 13.3 +/- 6.4 nematodes per galleria were found in the hemocoel. invading nematodes of both strains recovered from the dauer stage. h. bacteriophora developed into hermaphrodites with eggs and j1 in t ... | 2000 | 10631058 |
| pathogenicity caused by high virulent and low virulent strains of steinernema carpocapsae to galleria mellonella. | steinernema carpocapsae is an entomopathogenic nematode associated with a symbiotic bacterium, xenorhabdus nematophilus. both components of the complex participate in a pathogenic process in insects. this has raised two questions: how much does each one participate, and what mechanisms are involved? in this paper we compare the virulence of two strains of s. carpocapsae: a high virulent strain (breton) and a low virulent strain (az27), both of which are free of symbiotic bacteria. breton and az2 ... | 2000 | 10631057 |
| suppression of diamondback moth (lepidoptera: plutellidae) with an entomopathogenic nematode (rhabditida: steinernematidae) and bacillus thuringiensis berliner. | we tested the efficacy of the all strain of steinernema carpocapsae (weiser) against larvae of the diamondback moth, plutella xylostella (l.). in laboratory bioassays we found that (1) commercially formulated nematodes produced in vitro were as effective as nematodes produced in vivo, (2) resistance of p. xylostella to bacillus thuringiensis berliner subsp. kurstaki did not confer cross-resistance to nematodes, (3) mortality caused by nematodes was higher for early than late 3rd-instar p. xylost ... | 1998 | 9805498 |
| the laboratory preference of annual legumes by pea weevil sitona lineatus l. (col., curculionidae) and their effect on susceptibility of weevils to entomogenous nematodes. | the activity and natural mortality of sitona lineatus weevils during the egg laying period may be connected with host plant preference. preference of s. lineatus adults for early field pea and other pea cultivars influences their low feeding activity and results in lopff average body weight and higher susceptibility to entomogenous nematodes, steinernema carpocapsae, s. feltiae, and heterorhabditis bacteriophora. | 1998 | 9538029 |
| the xenorhabdus nematophila nilabc genes confer the ability of xenorhabdus spp. to colonize steinernema carpocapsae nematodes. | members of the steinernema genus of nematodes are colonized mutualistically by members of the xenorhabdus genus of bacteria. in nature, steinernema carpocapsae nematodes are always found in association with xenorhabdus nematophila bacteria. thus, this interaction, like many microbe-host associations, appears to be species specific. x. nematophila requires the nila, nilb, and nilc genes to colonize s. carpocapsae. in this work, we showed that of all the xenorhabdus species examined, only x. nemat ... | 2008 | 18390667 |
| mechanisms of specificity of association between the nematode steinernema scapterisci and its symbiotic bacterium. | we suggest a new mechanism for the maintenance of specificity of the association between the entomopathogenic nematode steinernema scapterisci and its symbiotic bacteria. we evaluated the development and reproduction of infective and non-infective juvenile s. scapterisci in monoxenic combinations with its symbiotic bacteria, xenorhabdus sp. 's' and with the bacterial symbiont of steinernema carpocapsae and steinernema riobravis. although development of non-infective stages occurred on all xenorh ... | 1997 | 9149419 |
| effect of cucurbitacin d on in vitro growth of xenorhabdus and photorhabdus spp., symbiotic bacteria of entomopathogenic nematodes. | in vitro assays were conducted to determine the effect of cucurbitacin d, an oxygenated tetracyclic triterpenoid found in cucurbits, on the growth of xenorhabdus isolated from steinernema carpocapsae (all, mexican, agriotos strains), steinernema riobravis, steinernema glaseri (nc strain, strain 27), and photorhabdus from heterorhabditis bacteriophora (nc, lewiston strains), and heterorhabditis sp. (fl2122 strain). cucurbitacin d inhibited the growth of four isolates, had no effect on the growth ... | 1996 | 8858910 |
| ecology of anti-microbials produced by bacterial associates of steinernema carpocapsae and heterorhabditis bacteriophora. | based on the ability of bacterial associates of entomopathogenic nematodes to produce antibiotic compounds on artificial media, it has been commonly accepted that xenorhabdus sp. and photorhabdus sp. inhibit a wide range of invading microorganisms in insects infected with steinernema spp. or heterorhabditis spp. therefore, the question of whether antibiotic compounds produced by the primary form of bacterial symbionts associated mutualistically with s. carpocapsae and h. bacteriophora explain wh ... | 1996 | 8684829 |
| characterization of the gut bacterial community in manduca sexta and effect of antibiotics on bacterial diversity and nematode reproduction. | the tobacco hornworm, manduca sexta, is a model lepidopteran insect used to study the pathogenic and mutualistic phases of entomopathogenic nematodes (epns) and their bacterial symbionts. while intestinal microbial communities could potentially compete with the epn and its bacterial partner for nutrient resources of the insect, the microbial gut community had not been characterized previously. here, we show that the midgut of m. sexta raised on an artificial diet contained mostly gram-positive c ... | 2008 | 18647359 |
| susceptibility and behavioral response of red imported fire ant (hymenoptera: formicidae) to selected entomogenous nematodes (rhabditida: steinernematidae & heterorhabditidae). | pathogenicity of infective juveniles of selected steinernema spp. and heterorhabditis spp. toward developing and reproductive stages of the red imported fire ant, solenopsis invicta buren, was tested under laboratory conditions. at 10(3)-10(5) infective juveniles per petri dish, mortality of reproductive larvae, pupae, and alates ranged from 28 to 100% at higher doses after 96 h at 23-25 degrees c. steinernema carpocapsae all was the most consistent species tested; this nematode caused mortality ... | 1992 | 1593012 |
| acetylcholinesterases of the nematode steinernema carpocapsae. characterization of two types of amphiphilic forms differing in their mode of membrane association. | we analyzed the molecular forms of acetylcholinesterase (ache) in the nematode steinernema carpocapsae. two major aches are involved in acetylcholine hydrolysis. the first class of ache is highly sensitive to eserine (ic50 = 0.05 microm). the corresponding molecular forms are: an amphiphilic 14s form converted into a hydrophilic 14.5s form by mild proteolysis and two hydrophilic 12s and 7s forms. reduction of the amphiphilic 14s form with 10 mm dithiothreitol produces hydrophilic 7s and 4s forms ... | 1992 | 1323459 |
| effect of phenotypic variation in xenorhabdus nematophila on its mutualistic relationship with the entomopathogenic nematode steinernema carpocapsae. | the entomopathogenic nematode steinernema carpocapsae is mutualistically associated with the bacterium xenorhabdus nematophila. infective juveniles (ijs) transport x. nematophila cells that provide them with good conditions to reproduce within the insect. in the laboratory, long term stationary-phase culture conditions sometimes lead x. nematophila's variant 1 cells, which were previously isolated from the worms, to spontaneously and irreversibly change into a new phenotypic variant (variant 2). ... | 2005 | 16255827 |
| analysis of xenorhabdus nematophila metabolic mutants yields insight into stages of steinernema carpocapsae nematode intestinal colonization. | xenorhabdus nematophila colonizes the intestinal tract of infective-juvenile (ij) stage steinernema carpocapsae nematodes. during colonization, x. nematophila multiplies within the lumen of a discrete region of the ij intestine termed the vesicle. to begin to understand bacterial nutritional requirements during multiplication in the ij vesicle, we analysed the colonization behaviour of several x. nematophila metabolic mutants, including amino acid and vitamin auxotrophs. x. nematophila mutants d ... | 2005 | 16164547 |
| pathogenicity of bacterium, xenorhabdus nematophila isolated from entomopathogenic nematode (steinernema carpocapsae) and its secretion against galleria mellonella larvae. | the entomopathogenic bacterium, xenorhabdus nematophila was isolated from the hemolymph of galleria mellonella infected with steinernema carpocapsae. the bacterial cells and its metabolic secretions have been found lethal to the galleria larvae. toxic secretion in broth caused 95% mortality within 4 d of application whereas the bacterial cells caused 93% mortality after 6 d. when filter and sand substrates were compared, the later one was observed as appropriate. similarly, bacterial cells and s ... | 2005 | 15909327 |
| monoxenic production of the entomopathogenic nematode steinernema carpocapsae using culture media containing agave juice (aguamiel) from mexican maguey-pulquero (agave spp). effects of the contents of nitrogen, carbohydrates and fat on infective juvenile production. | the production of infective juvenile stages (ij) of the entomopathogenic nematode steinernema carpocapsae in the presence of its symbiotic bacterium xenorhabdus nematophilus was carried out in orbitally agitated bottles. four complex culture media (m1-m4) were used, containing from 8% to 28% (by vol.) agave juice (aguamiel) from mexican maguey-pulquero (agave spp) as the main carbohydrate source. after 20 days of fermentation, a maximum viable ij concentration of 249,000 ij/ml and an initial nem ... | 2005 | 15650850 |
| identification of an antibacterial compound, benzylideneacetone, from xenorhabdus nematophila against major plant-pathogenic bacteria. | an entomopathogenic bacterium, xenorhabdus nematophila, is known to have potent antibiotic activities to maintain monoxenic condition in its insect host for effective pathogenesis and ultimately for optimal development of its nematode symbiont, steinernema carpocapsae. in this study we assess its antibacterial activity against plant-pathogenic bacteria and identify its unknown antibiotics. the bacterial culture broth had significant antibacterial activity that increased with development of the b ... | 2004 | 15476972 |
| characterization of a lipoprotein, nilc, required by xenorhabdus nematophila for mutualism with its nematode host. | xenorhabdus nematophila is a gamma-proteobacterial mutualist of an insect-pathogenic nematode, steinernema carpocapsae. x. nematophila requires nilc, a gene predicted to encode an outer membrane lipoprotein of unknown function, for colonization of its nematode host. characterization of nilc, described here, demonstrated it is a 28 kda lipoprotein directed to the periplasm by an n-terminal signal sequence. lipidation and processing of nilc occurs by a mechanism that is conserved in proteobacteria ... | 2004 | 15469517 |
| compatibility of entomopathogenic nematodes with fipronil. | the survival and infectivity of infective juveniles (ijs) of three species of entomopathogenic nematodes, steinernema carpocapsae weiser, s. arenarium (artyukhovsky) (rhabditida: steinernematidae) and heterorhabditis bacteriophora poinar (rhabditida: heterorhabditidae), were determined after exposure to different concentrations (250, 500, 1000 and 2000 ppm) of fipronil, an insecticide acting on the gaba receptors to block the chloride channel. heterorhabditis bacteriophora was very tolerant to a ... | 2005 | 16336717 |
| monoxenic liquid culture of the entomopathogenic nematode steinernema carpocapsae using a culture medium containing whey kinetics and modeling. | the submerged culture of the entomopathogenic nematode steinernema carpocapsae and its symbiotic bacterium, xenorhabdus nematophila, was carried out in orbitally agitated bottles using a culture medium containing whey (in grams per litre: 500 whey, 20 yeast extract, 10 dried egg yolk-food grade, 3 sodium chloride, 37 corn oil-food grade). maximum total viable nematode concentrations of 198,333ml(-1) were achieved within fermentations of 24 days with 64% of the nematode population within the infe ... | 2006 | 16516997 |
| parasitism of subterranean termites (isoptera: rhinotermitidae: termitidae) by entomopathogenic nematodes (rhabditida: steinernematidae; heterorhabditidae). | in laboratory bioassays, steinernema riobrave cabanillas, poinar and raulston (355 strain), steinernema carpocapsae (weiser) (mexican 33 strain), steinernemafeltiae (filipjev) (uk76 strain), and heterorhabditis bacteriophora poinar (hp88 strain) were all capable of infecting and killing three termite species, heterotermes aureus (snyder), gnathamitermes perplexus (banks), and reticulitermes flavipes (kollar) in laboratory sand assays. s. riobrave and s. feltiae caused low levels of reticuliterme ... | 2006 | 16937662 |
| biological control of the pecan weevil, curculio caryae (coleoptera: curculionidae), with entomopathogenic nematodes. | steinernema carpocapsae (weiser) strain a11, s. feltiae (filipjev) strain sn, and heterorhabditis bacteriophora poinar strains hp88 and georgia were tested for their efficacy as biological control agents of the pecan weevil, curculio caryae (horn), in pecan orchard soil-profile containers under greenhouse conditions. percentage c. caryae parasitism by s. carpocapsae and h. bacteriophora strain hp88 and georgia was consistently poor when applied either prior to or following c. caryae entry into t ... | 1993 | 19279746 |
| stability of entomopathogenic bacteria, xenorhabdus nematophila and photorhabdus luminescens, during in vitro culture. | the entomopathogenic nematode-bacteria complexes heterorhabditis bacteriophora/photorhabdus luminescens and steinernema carpocapsae/xenorhabdus nematophila are mass produced for use as biological insecticides. stability of the bacterial partner in culture is essential for maintaining traits important for both biological control and production. two geographically distinct strains of each bacterial species were isolated from their nematode partners and serially subcultured on in vitro media to ass ... | 2007 | 16941119 |
| effect of bacterial symbionts xenorhabdus on mortality of infective juveniles of two steinernema species. | steinernema species are entomopathogenic nematodes associated with xenorhabdus bacteria. the life cycle of these associations is composed of two stages: (1) a free stage in the soil, where infective juveniles (ijs), which carry bacteria in their guts, search for new insect hosts; and (2) a parasitic stage, where the ijs infect insects, release their xenorhabdus symbionts and reproduce in order to produce new ijs. previous studies clearly showed benefits to the association for several steinernema ... | 2007 | 16944202 |
| potentiating effect of bacillus thuringiensis subsp. kurstaki on pathogenicity of entomopathogenic bacterium xenorhabdus nematophila k1 against diamondback moth (lepidoptera: plutellidae). | xenorhabdus nematophila is the symbiotic bacterium of an entomopathogenic nematode, steinernema carpocapsae. when the nematode enters a target insect, the symbiotic bacteria are released into the hemocoel. after inducing host immunosuppression, the bacteria multiply in the hemocoel and cause fatal septicemia. for optimal field application to control insect pests, culturing mass numbers of the nematodes would be costly. in this study, bacillus thuringiensis (bt) was chosen as an alternative natur ... | 2007 | 17370835 |
| influence of nematode age and culture conditions on morphological and physiological parameters in the bacterial vesicle of steinernema carpocapsae (nematoda: steinernematidae). | steinernema spp. third-stage infective juveniles (ijs) play a key role in the symbiotic partnership between these entomopathogenic nematodes and xenorhabdus bacteria. recent studies suggest that steinernema carpocapsae ijs contribute to the nutrition and growth of their symbionts in the colonization site (vesicle) [martens, e.c. and goodrich-blair, h., 2005. the s. carpocapsae intestinal vesicle contains a sub-cellular structure with which xenorhabdus nematophila associates during colonization i ... | 2007 | 17376477 |
| diversity in pathogenicity of steinernema carpocapsae and its symbiotic bacterium for spodoptera spp. | pathogenicity of five isolates of steinernema carpocapsae (ger: germany, buw: becker underwood, kop: koppert, cz: czech republic, bel: belgium) were tested against the fourth instar larvae of the cotton leaf worm, spodoptera littoralis and the beet armyworm, spodoptera exigua (lepidoptera: noctuidae) at different concentrations (0, 5, 10, 25, and 50 infective juveniles/cm2) in petri dishes (9 cm dia.) lined with filter paper. results obtained after 48 h exposure indicated that the pathogenicity ... | 2006 | 17390810 |
| they've got a ticket to ride: xenorhabdus nematophila-steinernema carpocapsae symbiosis. | the association between the bacterium xenorhabdus nematophila and the nematode steinernema carpocapsae is emerging as a model system to understand mutually beneficial symbioses. x. nematophila, but not other xenorhabdus species, colonize a discrete region of a specific developmental stage of s. carpocapsae nematodes. recent progress has led to the identification of bacterial genes necessary for colonization. furthermore, new details have been elucidated regarding the morphology and physiology of ... | 2007 | 17553732 |
| cold tolerance of an antarctic nematode that survives intracellular freezing: comparisons with other nematode species. | panagrolaimus davidi is an antarctic nematode with very high levels of cold tolerance. its survival was compared with that of some other nematodes (p. rigidus, rhabditophanes sp., steinernema carpocapsae, panagrellus redivivus and ditylenchus dipsaci) in both unacclimated samples and those acclimated at 5 degrees c. levels of recrystallization inhibition in homogenates were also compared, using the splat-cooling assay. the survival of p. davidi after the freezing of samples was notably higher th ... | 2008 | 17712562 |
| cpxra regulates mutualism and pathogenesis in xenorhabdus nematophila. | the cpxra signal transduction system, which in escherichia coli regulates surface structure assembly and envelope maintenance, is involved in the pathogenic and mutualistic interactions of the entomopathogenic bacterium xenorhabdus nematophila. when deltacpxr1 cells were injected into manduca sexta insects, the time required to kill 50% of the insects was twofold longer than the time observed for wild-type cells and the deltacpxr1 cells ultimately killed 16% fewer insects than wild-type cells ki ... | 2007 | 17951441 |
| kinetics of infective juvenile production of the entomopathogenic nematode steinernema carpocapsae in submerged monoxenic culture. | the effects of culture medium formulations on the kinetics of infective juvenile (ij) production of the entomopathogenic nematode steinernema carpocapsae in submerged monoxenic culture, were studied at the cylindrical-bottle scale using six culture media containing agave juice from agave spp. among other ingredients. the ij production kinetics was well modelled through a re-parameterised 3-parameter gompertz model with kinetic parameters: ij-lag phase lambda (ij) (day), maximum ij-stage producti ... | 2008 | 18074155 |
| pathogenic effect of entomopathogenic nematode-bacterium complexes on terrestrial isopods. | in this study, we evaluated the effect of entomopathogenic nematodes (epns) steinernema carpocapsae, steinernema feltiae and heterorhabditis bacteriophora, symbiotically associated with bacteria of the genera xenorhabdus or photorhabdus, on the survival of eight terrestrial isopod species. the epn species s. carpocapsae and h. bacteriophora reduced the survival of six isopod species while s. feltiae reduced survival for two species. two terrestrial isopod species tested (armadillidium vulgare an ... | 2008 | 18346756 |
| manifold aspects of specificity in a nematode-bacterium mutualism. | coevolution in mutualistic symbiosis can yield, because the interacting partners share common interests, to coadaptation: hosts perform better when associated with symbionts of their own locality than with others coming from more distant places. however, as the two partners of a symbiosis might also experience conflicts over part of their life cycle, coadaptation might not occur for all life-history traits. we investigated this issue in symbiotic systems where nematodes (steinernema) and bacteri ... | 2009 | 19732258 |
| establishment, persistence, and introgression of entomopathogenic nematodes in a forest ecosystem. | entomopathogenic nematodes (epn) are currently marketed worldwide for use in inundative biological control, where the applied natural enemy population (rather than its offspring) is expected to reduce insect numbers. unlike classical biological control, in inundative control natural enemy establishment is not crucial in order to achieve pest suppression. field trials in irish forestry provided the opportunity to test predictions regarding the establishment of two exotic (steinernema carpocapsae ... | 2008 | 18488631 |
| the hmshfrs operon of xenorhabdus nematophila is required for biofilm attachment to caenorhabditis elegans. | the bacterium xenorhabdus nematophila is an insect pathogen and an obligate symbiont of the nematode steinernema carpocapsae. x. nematophila makes a biofilm that adheres to the head of the model nematode caenorhabditis elegans, a capability x. nematophila shares with the biofilms made by yersinia pestis and yersinia pseudotuberculosis. as in yersinia spp., the x. nematophila biofilm requires a 4-gene operon, hmshfrs. also like its yersinia counterparts, the x. nematophila biofilm is bound by the ... | 2008 | 18515487 |
| low migration decreases interference competition among parasites and increases virulence. | competition among different parasite genotypes within a host is predicted to affect virulence. the direction of this effect, however, depends critically on the mechanisms that parasites use to compete or to cooperate with each other. one mechanism that bacteria use to compete with each other is via the production of bacteria-killing toxins, called bacteriocins. this warfare among parasites within a host is predicted to reduce the rate of host exploitation, resulting in lower virulence. by contra ... | 2008 | 18636975 |
| group selection on population size affects life-history patterns in the entomopathogenic nematode steinernema carpocapsae. | selection is recognized to operate on multiple levels. in disease organisms, selection among hosts is thought to provide an important counterbalance to selection for faster growth within hosts. we performed three experiments, each selecting for a divergence in group size in the entomopathogenic nematode, steinernema carpocapsae. these nematodes infect and kill insect larvae, reproduce inside the host carcass, and emerge as infective juveniles. we imposed selection on group size by selecting amon ... | 2009 | 19187254 |
| purification, biochemical and molecular analysis of a chymotrypsin protease with prophenoloxidase suppression activity from the entomopathogenic nematode steinernema carpocapsae. | a chymotrypsin serine protease (designated sc-chym) was purified by gel filtration and anion-exchange chromatography from excretory-secretory products of parasitic stage steinernema carpocapsae. the purified protease had an apparent molecular mass of 30kda and displayed a pi of 5.9. this protease demonstrated high activity against the chymotrypsin-specific substrate n-succinyl-ala-ala-pro-phe-p-nitroanilide and was highly sensitive to the inhibitor aprotinin. this protease digested the chromogen ... | 2009 | 19249304 |
| imd pathway is involved in the interaction of drosophila melanogaster with the entomopathogenic bacteria, xenorhabdus nematophila and photorhabdus luminescens. | xenorhabdus nematophila/steinernema carpocapsae and photorhabdus luminescens/heterorhabditis bacteriophora are nemato-bacterial complexes highly pathogenic for insects. using a syringe as artificial vector, we have analyzed the effects of the two bacteria, x. nematophila and p. luminescens on the genetic tool insect, drosophila melanogaster. both bacteria were found to kill adult flies in a dose dependent manner with x. nematophila being the fastest. on the other hand, when an injection of non-p ... | 2010 | 20627393 |
| control of the oriental fruit moth, grapholita molesta, using entomopathogenic nematodes in laboratory and fruit bin assays. | the oriental fruit moth (ofm), grapholita molesta (busck), which is among the most important insect pests of peaches and nectarines, has developed resistance to a wide range of insecticides. we investigated the ability of the entomopathogenic nematodes (epn) steinernema carpocapsae (weiser), s. feltiae (filipjev), s. riobrave (cabanillas et al.), and heterorhabditis marelatus (liu and berry) to control ofm under laboratory and fruit bin conditions. at a dosage of 10 infective juveniles (ij)/cm(2 ... | 2006 | 19259443 |
| cloning, characterisation and heterologous expression of an astacin metalloprotease, sc-ast, from the entomoparasitic nematode steinernema carpocapsae. | steinernema carpocapsae is a parasitic nematode that is high virulent to insects. the parasitic juvenile reaches the insect haemocoelium by passing through mid-gut barriers and develops there. during invasion, the nematode was predicted to express a large set of proteases, including metalloproteases, one of which was sequenced and expressed in this work. a 1583-nucleotide cdna encoding a putative metalloprotease containing a 28-aa signal peptide, a 79-aa propeptide and a 311-aa mature protease w ... | 2010 | 20670659 |
| recycling potential and fitness of steinernematid nematodes cultured in curculio caryae and galleria mellonella. | the recycling potential of entomopathogenic nematodes in the pecan weevil, curculio caryae, following inundative applications is an important factor in considering whether nematodes could be incorporated into a c. caryae management strategy. our objective was to determine the recycling potential and fitness of steinernema carpocapsae and s. riobrave cultured in c. caryae. to estimate fitness and quality, we reared nematodes in larvae of c. caryae and in the commonly used standard host, the great ... | 2005 | 19262838 |
| effects of four nematode species on fitness costs of pink bollworm resistance to bacillus thuringiensis toxin cry1ac. | evolution of resistance by pests can reduce the efficacy oftransgenic crops that produce insecticidal toxins from the bacterium bacillus thuringiensis berliner (bt). in conjunction with refuges of non-bt host plants, fitness costs can delay the evolution of resistance. furthermore, fitness costs often vary with ecological conditions, suggesting that agricultural landscapes can be manipulated to magnify fitness costs and thereby prolong the efficacy of bt crops. in the current study, we tested th ... | 2010 | 21061986 |
| effect of entomopathogenic nematodes and trichoderma harzianum on the strawberry black root rot pathogens pratylenchus penetrans and rhizoctonia fragariae. | the effects of inundative releases of entomopathogenic steinernema carpocapsae and s. feltiae infective juveniles and applications of the biological control fungus trichoderma harzianum t-22 (rootshield) on pratylenchus penetrans and strawberry black root rot caused by rhizoctonia fragariae were determined in field microplots and small plots. entomopathogenic nematodes were applied as a soil drench at rates of 7.4 or 14.8 billion per ha in may or august for 3 years. rootshield was applied as cro ... | 2002 | 19265955 |
| effects of fertilizers on suppression of black cutworm (agrotis ipsilon) damage with steinernema carpocapsae. | the ability of steinernema carpocapsae to reduce damage to seedling corn by the black cutworm, agrotis ipsilon, in soil amended with three fertilizers (fresh cow manure, composted manure, and urea) was determined. total nitrogen was standardized among the fertilizers at 280 kg/ha and 560 kg/ha. black cutworm damage was assessed by the percentage of cut corn plants in small field plots. relative to a control (no nematodes), nematode applications resulted in reduced black cutworm damage in all tre ... | 1999 | 19270937 |
| the xnp1 p2-like tail synthesis gene cluster encodes xenorhabdicin and is required for interspecies competition. | xenorhabdus nematophila, the mutualistic bacterium of the nematode steinernema carpocapsae, produces the r-type bacteriocin called xenorhabdicin that is thought to confer a competitive advantage for growth in the insect host. we have identified a p2-like tail synthesis gene cluster (xnp1) that was required for xenorhabdicin production. the xnp1 genes were expressed constitutively during growth and were induced by mitomycin c. deletion of either the sheath (xnps1) or fiber (xnph1) genes eliminate ... | 2011 | 21602326 |
| foliar sprays with steinernema carpocapsae against early-season apple pests. | persistence and field efficacy of the entomopathogenic nematode steinernema carpocapsae a11 strain applied by foliar sprays were evaluated against the apple sawfly hoplocampa testudinea and the plum curculio conotrachelus nenuphar, two early-season pests in quebec apple orchards. from 1992 to 1995, bioassays with galleria mellonella larvae were conducted to assess the persistence of s. carpocapsae on leaves, flower clusters, and twigs up to 4 days after evening application. s. carpocapsae juveni ... | 1998 | 19274253 |
| activity and persistence of steinernema carpocapsae and spodoptera exigua nuclear polyhedrosis virus against s. exigua larvae on soybean. | experiments were conducted to assess the effects of the entomopathogenic nematode steinernema carpocapsae and spodoptera exigua multinucleocapsid nuclear polyhedrosis virus (semnpv), alone and in combinations, on mortality of the beet armyworm, s. exigua, larvae on soybean. in 1991 tests, field-grown soybean plants were treated with s. carpocapsae at 0.3 and 0.6 nematodes/cm(2) of leaflet, semnpv at 20 and 40 polyhedral inclusion bodies (pib)/cm(2), and all possible combinations. treated leaflet ... | 1996 | 19277347 |
| entomopathogenic nematodes for control of insect pests above and below ground with comments on commercial production. | entomopathogenic nematodes (epns) have been utilized in classical, conservation, and augmentative biological control programs. the vast majority of applied research has focused on their potential as inundatively applied augmentative biological control agents. extensive research over the past three decades has demonstrated both their successes and failures for control of insect pests of crops, ornamental plants, trees and lawn and turf. in this paper we present highlights of their development for ... | 2012 | 23482993 |
| quantification of invasion of two strains of steinernema carpocapsae (weiser) into three lepidopteran larvae. | studies with last instar larvae of the fall armyworm, spodoptera frugiperda (j. e. smith), the black cutworm, agrotis ipsilon (hufnagel), and the greater wax moth, galleria mellonella (l.) were used to quantify the invasive ability of two strains (all and mexican) of steinernema carpocapsae and to determine how factors in the bioassay procedure affect both nematode invasion and host mortality. nematode invasive ability was variable, with 10-50% of nematodes successfully infecting the host. the p ... | 1993 | 19279755 |
| in vivo flow 31p ft-nmr spectroscopy of a nematode parasite. | 31p nmr spectroscopy of a parasitic nematode. steinernema carpocapsae, is described. in vivo spectra were generated from nematode suspensions continuously circulating through the spectrometer. by flowing the organism, saturation effects were avoided and short interpulse delays significantly reduced spectral generation time. to maximize sensitivity, 90 degrees pulses were employed. changes in energetic status in response to oxygen availability were easily and rapidly monitored in circulating nema ... | 2008 | 2266853 |
| natural occurrence of entomogenous nematodes in tennessee nursery soils. | to isolate potential insect biocontrol agents, entomogenous nematodes were surveyed in tennessee plant nurseries in 1991. soil samples from 113 nursery sites were baited with greater wax moth (galleria mellonella) larvae, house cricket (acheta domesticus) adults, lesser mealworm (alphitobius diaperings) adults, and house fly (musca domestica) larvae. heterorhabditis bacteriophora and steinernema carpocapsae were each recovered from 17 soil samples. heterorhabditis bacteriophora was more common i ... | 1993 | 19279756 |
| comparative analysis of xenorhabdus koppenhoeferi gene expression during symbiotic persistence in the host nematode. | species of xenorhabdus and photorhabdus bacteria form mutualistic associations with steinernema and heterorhabditis nematodes, respectively and serve as model systems for studying microbe-animal symbioses. here, we profiled gene expression of xenorhabdus koppenhoeferi during their symbiotic persistence in the newly formed infective juveniles of the host nematode steinernema scarabaei through the selective capture of transcribed sequences (scots). the obtained gene expression profile was then com ... | 2016 | 26745883 |
| use of low temperature scanning electron microscopy to observe frozen hydrated specimens of nematodes. | frozen hydrated specimens of pratylenchus agilis and dauer larvae of steinernema carpocapsae were observed with low-temperature field emission scanning electron microscopy. this new technique provides information about the surface features of nematodes and also allows specimens to be fractured to reveal their internal structure. furthermore, both halves of fractured specimens can be retained, examined, and photographed either as two-dimensional micrographs or as three-dimensional images for ster ... | 1993 | 19279761 |
| influence of irrigation and heterorhabditis bacteriophora on plant-parasitic nematodes in turf. | daily irrigated, 80% pan replacement, and nonirrigated field plots of kentucky bluegrass (poa pratensis l.) were inoculated with a mixture of steinernema carpocapsae (all strain) and heterorhabditis bacteriophora (hp-88 strain) in 1988. in 1989, daily irrigated and nonirrigated plots were inoculated with hp-88 alone. the turf and associated soil contained populations of tylenchorhynchus dubius, t. nudus, pratylenchus penetrans, paratylenchus projectus, and criconemella rustica. in irrigated plot ... | 1992 | 19283039 |
| biological control of soil pests by mixed application of entomopathogenic and fungivorous nematodes. | in greenhouse experiments, massive application of the fungivorous nematode, aphelenchus avenae, in summer at 26-33 c (1 x l0 nematodes/500 cm(3) autoclaved soil) or in autumn at 18-23 c (5 x 10 nematodes/500 cm(3) autoclaved soil) suppressed pre-emergence damping-off of cucumber seedlings due to rhizoctonia solani ag-4 by 67% or 87%, respectively. application of 2 x l0 a. avenae to sterilized soil infested with r. solani caused leafminer-like symptom on the cotyledons, which did not occur in mix ... | 1991 | 19283109 |
| transcripts analysis of the entomopathogenic nematode steinernema carpocapsae induced in vitro with insect haemolymph. | steinernema carpocapsae is an insect parasitic nematode widely used in pest control programs. the efficacy of this nematode in controlling insects has been found to be related to the pathogenicity of the infective stage. in order to study the parasitic mechanisms exhibited by this parasite, a cdna library of the induced s. carpocapsae parasitic phase was generated. a total of 2500 clones were sequenced and 2180 high-quality ests were obtained from this library. cluster analysis generated a total ... | 2009 | 19836423 |
| serine proteases of parasitic helminths. | serine proteases form one of the most important families of enzymes and perform significant functions in a broad range of biological processes, such as intra- and extracellular protein metabolism, digestion, blood coagulation, regulation of development, and fertilization. a number of serine proteases have been identified in parasitic helminths that have putative roles in parasite development and nutrition, host tissues and cell invasion, anticoagulation, and immune evasion. in this review, we de ... | 2015 | 25748703 |
| microbial population dynamics in the hemolymph of manduca sexta infected with xenorhabdus nematophila and the entomopathogenic nematode steinernema carpocapsae. | xenorhabdus nematophila engages in a mutualistic association with the nematode steinernema carpocapsae. the nematode invades and traverses the gut of susceptible insects. x. nematophila is released in the insect blood (hemolymph), where it suppresses host immune responses and functions as a pathogen. x. nematophila produces diverse antimicrobials in laboratory cultures. the natural competitors that x. nematophila encounters in the hemolymph and the role of antimicrobials in interspecies competit ... | 2014 | 24814780 |
| influence of cell density and phase variants of bacterial symbionts (xenorhabdus spp.) on dauer juvenile recovery and development of biocontrol nematodes steinernema carpocapsae and s. feltiae (nematoda: rhabditida). | the rhabditid nematodes steinernema carpocapsae and steinernema feltiae are used in biological control of insect pests. mass production is done in liquid culture media pre-incubated with their bacterial symbionts xenorhabdus nematophila and xenorhabdus bovienii, respectively, before nematode dauer juveniles (djs) are inoculated. as a response to food signals produced by the bacterial symbionts, the djs exit from the developmentally arrested dauer stage (they recover development) and grow to adul ... | 2009 | 19319521 |
| complete mitochondrial genomes of four entomopathogenic nematode species of the genus steinernema. | nematodes belonging to the genus steinernema are insect parasites and are used as effective biological agents against soil-dwelling insect pests. although the full nuclear genomes of multiple steinernema species have become available recently, mitochondrial genome information for the genus is limited. in this study, we sequenced the complete mitochondrial genomes of four species of steinernema and analysed their structure, codon usage and phylogenetic relationships. | 2016 | 27494995 |
| cpxra influences xenorhabdus nematophila colonization initiation and outgrowth in steinernema carpocapsae nematodes through regulation of the nil locus. | the gammaproteobacterium xenorhabdus nematophila mutualistically colonizes an intestinal region of a soil-dwelling nematode and is a blood pathogen of insects. the x. nematophila cpxra two-component regulatory system is necessary for both of these host interactions (e. herbert et al., appl. environ. microbiol. 73:7826-7836, 2007). mutualistic association of x. nematophila with its nematode host consists of two stages: initiation, where a small number of bacterial cells establish themselves in th ... | 2009 | 19376901 |
| adaptation by western corn rootworm (coleoptera: chrysomelidae) to bt maize: inheritance, fitness costs, and feeding preference. | we examined inheritance of resistance, feeding behavior, and fitness costs for a laboratory-selected strain of western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), with resistance to maize (zea maize l.) producing the bacillus thuringiensis berliner (bt) toxin cry3bb1. the resistant strain developed faster and had increased survival on bt maize relative to a susceptible strain. results from reciprocal crosses of the resistant and susceptible strains indicate ... | 2012 | 22928323 |
| effect of temperature on the development of steinernema carpocapsae and steinernema feltiae (nematoda: rhabditida) in liquid culture. | for commercial use of the entomopathogenic nematodes steinernema carpocapsae and steinernema feltiae in biological control of insect pests, they are produced in liquid culture on artificial media pre-incubated with their symbiotic bacteria xenorhabdus nematophila and xenorhabdus bovienii, respectively. after 1 day of the bacterial culture, nematode dauer juveniles (djs) are inoculated, which recover development. the adult nematodes produce dj offspring, which are harvested and can be sprayed. th ... | 2009 | 19455323 |
| influence of inoculum density on population dynamics and dauer juvenile yields in liquid culture of biocontrol nematodes steinernema carpocapsae and s. feltiae (nematoda: rhabditida). | for improvement of mass production of the rhabditid biocontrol nematodes steinernema carpocapsae and steinernema feltiae in monoxenic liquid culture with their bacterial symbionts xenorhabdus nematophila and xenorhabdus bovienii, respectively, the effect of the initial nematode inoculum density on population development and final concentration of dauer juveniles (djs) was investigated. symbiotic bacterial cultures are pre-incubated for 1 day prior to inoculation of djs. djs are developmentally a ... | 2010 | 19597815 |
| role of secondary metabolites in establishment of the mutualistic partnership between xenorhabdus nematophila and the entomopathogenic nematode steinernema carpocapsae. | xenorhabdus nematophila engages in a mutualistic partnership with the nematode steinernema carpocapsae, which invades insects, migrates through the gut, and penetrates into the hemocoel (body cavity). we showed previously that during invasion of manduca sexta, the gut microbe staphylococcus saprophyticus appeared transiently in the hemocoel, while enterococcus faecalis proliferated as x. nematophila became dominant. x. nematophila produces diverse secondary metabolites, including the major water ... | 2015 | 25398871 |
| characterization of xenorhabdus isolates from la rioja (northern spain) and virulence with and without their symbiotic entomopathogenic nematodes (nematoda: steinernematidae). | eighteen xenorhabdus isolates associated with spanish entomopathogenic nematodes of the genus steinernema were characterized using a polyphasic approach including phenotypic and molecular methods. two isolates were classified as xenorhabdus nematophila and were associated with steinernema carpocapsae. sixteen isolates were classified as xenorhabdus bovienii, of which fifteen were associated with steinernema feltiae and one with steinernema kraussei. two x. bovienii phase ii were also isolated, o ... | 2009 | 19682458 |
| examination of xenorhabdus nematophila lipases in pathogenic and mutualistic host interactions reveals a role for xlpa in nematode progeny production. | xenorhabdus nematophila is a gammaproteobacterium and broad-host-range insect pathogen. it is also a symbiont of steinernema carpocapsae, the nematode vector that transports the bacterium between insect hosts. x. nematophila produces several secreted enzymes, including hemolysins, lipases, and proteases, which are thought to contribute to virulence or nutrient acquisition for the bacterium and its nematode host in vivo. x. nematophila has two lipase activities with distinct in vitro specificitie ... | 2010 | 19880652 |