Publications

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
an escherichia coli biosensor strain for amplified and high throughput detection of antimicrobial agents.	we report here the construction of a bacterial reporter system for high-throughput screening of antimicrobial agents. the test organism is the escherichia coli k-12 strain carrying luciferase genes luxc, luxd, luxa, luxb, and luxe from the bioluminescent bacterium photorhabdus luminescens in a runaway replication plasmid. the replication of the plasmid can be induced, resulting in a change of the plasmid copy number from 1-2/cell to several hundreds per cell within tens of minutes. this increase ...	2002	12006110
a luminescent escherichia coli biosensor for the high throughput detection of beta-lactams.	a group-specific bioluminescent escherichia coli strain for studying the action of beta-lactam antibiotics is described. the strain contains a plasmid, pblalux1, in which the luciferase genes from photorhabdus luminescens are inserted under the control of the beta-lactam-responsive element ampr/ampc from citrobacter freundii. in the presence of beta-lactams, the bacterial cells are induced to express the luciferase enzyme and three additional enzymes generating the substrate for the luciferase r ...	2002	12006111
bacterial infection of a model insect: photorhabdus luminescens and manduca sexta.	invertebrates, including insects, are being developed as model systems for the study of bacterial virulence. however, we understand little of the interaction between bacteria and specific invertebrate tissues or the immune system. to establish an infection model for photorhabdus, which is released directly into the insect blood system by its nematode symbiont, we document the number and location of recoverable bacteria found during infection of manduca sexta. after injection into the insect larv ...	2002	12067318
rapid control of wound infections by targeted photodynamic therapy monitored by in vivo bioluminescence imaging.	the worldwide rise in antibiotic resistance necessitates the development of novel antimicrobial strategies. in this study we report on the first use of a photochemical approach to destroy bacteria infecting a wound in an animal model. following topical application, a targeted polycationic photosensitizer conjugate between poly-l-lysine and chlorin(e6) penetrated the gram (-) outer bacterial membrane, and subsequent activation with 660 nm laser light rapidly killed escherichia coli infecting exci ...	2002	11837327
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
the lumicins: novel bacteriocins from photorhabdus luminescens with similarity to the uropathogenic-specific protein (usp) from uropathogenic escherichia coli.	bacteriocins are proteins produced by bacteria to destroy other bacteria occupying their ecological niche. photorhabdus luminescens is an insect pathogenic bacterium carried by an entomopathogenic nematode and occupies several different niches in its life cycle. the nematode enters the insect and releases a single strain of p. luminescens. the bacteria then kill the host and the bacteria and nematodes replicate within the cadaver. strikingly, at the end of the infection the cadaver is still occu ...	2002	12351238
identification and sequence of an unstable dna element in the entomopathogenic bacteria photorhabdus temperata strain k122.	a search was conducted for a difference in genome composition between phenotypic variants of the insect pathogenic bacteria, photorhabdus temperata.	2002	12100588
diverse bacteria are pathogens of caenorhabditis elegans.	practically and ethically attractive as model systems, invertebrate organisms are increasingly recognized as relevant for the study of bacterial pathogenesis. we show here that the nematode caenorhabditis elegans is susceptible to a surprisingly broad range of bacteria and may constitute a useful model for the study of both pathogens and symbionts.	2002	12117988
a single photorhabdus gene, makes caterpillars floppy (mcf), allows escherichia coli to persist within and kill insects.	photorhabdus luminescens, a bacterium with alternate pathogenic and symbiotic phases of its lifestyle, represents a source of novel genes associated with both virulence and symbiosis. this entomopathogen lives in a "symbiosis of pathogens" with nematodes that invade insects. thus the bacteria are symbiotic with entomopathogenic nematodes but become pathogenic on release from the nematode into the insect blood system. within the insect, the bacteria need to both avoid the peptide- and cellular- ( ...	2002	12136122
identification, characterization, and regulation of a cluster of genes involved in carbapenem biosynthesis in photorhabdus luminescens.	the luminescent entomopathogenic bacterium photorhabdus luminescens produces several yet-uncharacterized broad-spectrum antibiotics. we report the identification and characterization of a cluster of eight genes (named cpma to cpmh) responsible for the production of a carbapenem-like antibiotic in strain tt01 of p. luminescens. the cpm cluster differs in several crucial aspects from other car operons. the level of cpm mrna peaks during exponential phase and is regulated by a rap/hor homolog ident ...	2002	12147472
detection of traces of tetracyclines from fish with a bioluminescent sensor strain incorporating bacterial luciferase reporter genes.	bioluminescent escherichia coli k-12 strain for the specific detection of the tetracycline family of antimicrobial agents was optimized to work with fish samples. the biosensing strain contains a plasmid incorporating the bacterial luciferase operon of photorhabdus luminescens under the control of the tetracycline responsive element from transposon tn10 (korpela et al. anal. chem. 1998, 70, 4457-4462). the extraction procedure of oxytetracycline from rainbow trout (oncorhynchus mykiss) tissue wa ...	2002	12166964
insecticidal toxic proteins produced by photorhabdus luminescens akhurstii, a symbiont of heterorhabditis indica.	we describe the isolation and characterization of an insect pathogenic bacterium from the entomopathogenic nematode heterorhabditis indica (karnataka strain), an isolate from the southern regions of india. the strain has been identified and characterized by phenotypic, biochemical tests and pcr-rflp analysis of the 16s rrna gene as photorhabdus luminescens subsp. akhurstii. the insecticidal toxin complex produced by this bacterium has been purified through a series of steps including ultrafiltra ...	2002	19265903
pathogenomics.	the genomes described this month reflect the overall historical bias of microbial genomics towards pathogenic bacteria. although the balance is now being redressed to some extent, especially through the study of extremophiles, it is still the case that the opportunities provided by genomic studies are primarily taken up by those who study bacterial pathogenicity. this part of the field is, however, being broadened by including the study of pathogens of animals, insects and plants alongside those ...	2003	15035020
the insecticidal toxin makes caterpillars floppy 2 (mcf2) shows similarity to hrma, an avirulence protein from a plant pathogen.	the photorhabdus luminescens w14 toxin encoding gene makes caterpillars floppy (mcf) was discovered due to its ability to kill caterpillars when expressed in escherichia coli. here we describe a homologue of mcf (renamed as mcf1), termed mcf2, discovered in the same genome. the mcf2 gene predicts another large toxin whose central domain, like mcf1, also shows limited homology to clostridium cytotoxin b. however, the n-terminus of mcf2 shows significant similarity to the type-iii secreted effecto ...	2003	14680709
photobactin: a catechol siderophore produced by photorhabdus luminescens, an entomopathogen mutually associated with heterorhabditis bacteriophora nc1 nematodes.	the nematode heterorhabditis bacteriophora transmits a monoculture of photorhabdus luminescens bacteria to insect hosts, where it requires the bacteria for efficient insect pathogenicity and as a substrate for growth and reproduction. siderophore production was implicated as being involved in the symbiosis because an ngra mutant inadequate for supporting nematode growth and reproduction was also deficient in producing siderophore activity and ngra is homologous to a siderophore biosynthetic gene ...	2003	12902261
expression of the photorhabdus luminescens lux genes (luxa, b, c, d, and e) in saccharomyces cerevisiae.	the luxa, b, c, d, and e genes from photorhabdus luminescens were cloned and functionally expressed in saccharomyces cerevisiae to construct a bacterial lux-based yeast bioreporter capable of autonomous bioluminescence emission. the bioreporter was engineered using a series of pbevy yeast expression vectors that allowed for bi-directional constitutive or inducible expression of the individual luxa, b, c, and e genes. the luxd gene, encoding the acyl-acp transferase that ultimately supplies the r ...	2003	14654435
photorhabdus: towards a functional genomic analysis of a symbiont and pathogen.	pathogenicity and symbiosis are central to bacteria-host interactions. although several human pathogens have been subjected to functional genomic analysis, we still understand little about bacteria-invertebrate interactions despite their ecological prevalence. advances in our knowledge of this area are often hindered by the difficulty of isolating and working with invertebrate pathogenic bacteria and their hosts. here we review studies on pathogenicity and symbiosis in an insect pathogenic bacte ...	2003	12586390
photorhabdus species: bioluminescent bacteria as emerging human pathogens?	we report two australian patients with soft tissue infections due to photorhabdus species. recognized as important insect pathogens, photorhabdus spp. are bioluminescent gram-negative bacilli. bacteria belonging to the genus are emerging as a cause of both localized soft tissue and disseminated infections in humans in the united states and australia. the source of infection in humans remains unknown.	2003	12603999
genetic and biochemical characterization of prta, an rtx-like metalloprotease from photorhabdus.	proteases play a key role in the interaction between pathogens and their hosts. the bacterial entomopathogen photorhabdus lives in symbiosis with nematodes that invade insects. following entry into the insect, the bacteria are released from the nematode gut into the open blood system of the insect. here they secrete factors which kill the host and also convert the host tissues into food for the replicating bacteria and nematodes. one of the secreted proteins is prta, which is shown here to be a ...	2003	12777498
development of bespoke bioluminescent reporters with the potential for in situ deployment within a phenolic-remediating wastewater treatment system.	a suite of ecologically relevant, site-specific bioreporters was constructed by transposon mutagenesis of microorganisms isolated from a polluted phenolic-remediating wastewater treatment system. four pseudomonad species were engineered to carry a stable chromosomal copy of the lux operon (luxcdabe) derived from photorhabdus luminescens. these recombinant reporter microorganisms were tested for bioluminescence response to relevant phenol concentrations in the laboratory and to phenolic-containin ...	2003	14607409
identification of photorhabdus asymbiotica in cases of human infection.		2003	15508515
a real-time analysis of qacr-regulated multidrug resistance in staphylococcus aureus.	here we describe the construction and characterization of a biosensing reporter where luxcdabe genes from photorhabdus luminescens, engineered for expression in gram-positive organisms, are under the transcriptional control of qacr repressor from staphylococcus aureus. in non-pathogenic s. aureus model system we analyzed the activity of the regulatory region acting as multidrug-resistance mediator in wild type strains. the use of full-length bacterial luciferase and the measurement of real-time ...	2003	12535635
xenorhabdus nematophila (enterobacteriacea) secretes a cation-selective calcium-independent porin which causes vacuolation of the rough endoplasmic reticulum and cell lysis.	xenorhabdus nematophila and photorhabdus luminescens are two related enterobacteriaceae studied for their use in biological control and for synthesis of original virulence factors and new kinds of antibiotics. x. nematophila broth growth exhibits different cytotoxic activities on insect (spodoptera littoralis, lepidoptera) immunocytes (hemocytes). here we report the purification of the flhdc-dependent cytotoxin, a 10,790-da peptide we have called alpha-xenorhabdolysin (alpha x). we show that pla ...	2003	12441337
specific responses of bacterial cells to dioxins.	five different recombinant bioluminescent strains of escherichia coli that contain the reca (responsive to dna damage related stress), faba (membrane damage), katg (oxidative damage), grpe (protein damage), and lac (constitutive expression, general toxicity) promoters fused to the bacterial lux operon from either vibrio fischeri or photorhabdus luminescens were used to describe the different mechanisms of toxicity that several dibenzo-p-dioxins and dibenzofurans have on bacteria, as well as to d ...	2003	12558152
a hexa homologue from photorhabdus regulates pathogenicity, symbiosis and phenotypic variation.	photorhabdus is a genus of entomopathogenic gram-negative bacteria that belong to the family enterobactericeae. remarkably, at the same time as being pathogenic to insect larvae, photorhabdus also have a mutualistic relationship with entomophagous nematodes of the family heterorhabditiae. photorhabdus can be isolated in two phenotypically distinct forms, termed the primary and secondary variant. both variants grow equally well and are equally virulent when injected into insect larvae. however, o ...	2003	12603747
effect of growth conditions on the motility of photorhabdus temperata.	photorhabdus temperata is a bioluminescent bacterium that lives in mutualistic association with entomopathogenic nematodes of the genus heterorhabditis. the bacterium exists in two morphologically distinguishable phases (primary and secondary). the swimming behavior of p. temperata was investigated. both the primary and secondary variants were able to swim in liquid or semisolid media under appropriate conditions. variation in the oxygen levels had little affect on the chemotaxis and motility of ...	2003	12783158
using a dna microarray to investigate the distribution of insect virulence factors in strains of photorhabdus bacteria.	photorhabdus is an insect-pathogenic bacterium in which oral toxicity to insects is found in two distinct taxonomic groups. using a dna microarray and comparative genomics, we show that oral toxicity is associated with toxin complex genes tcaabc and that this locus can be mobilized or deleted within different strains.	2003	12867479
monitoring of recombinant protein production using bioluminescence in a semiautomated fermentation process.	on-line optimization of fermentation processes can be greatly aided by the availability of information on the physiological state of the cell. the goal of our "biolux" research project was to design a recombinant cell capable of intracellular monitoring of product synthesis and to use it as part of an automated fermentation system. a recombinant plasmid was constructed containing an inducible promoter that controls the gene coding for a model protein and the genes necessary for bioluminescence. ...	2003	12892506
for the insect pathogen photorhabdus luminescens, which end of a nematode is out?	the nematode heterorhabditis bacteriophora is the vector for transmitting the entomopathogenic bacterium photorhabdus luminescens between insect larvae. the dauer juvenile (dj) stage nematode selectively retains p. luminescens in its intestine until it releases the bacteria into the hemocoel of an insect host. we report the results of studying the transmission of the bacteria by its nematode vector. cells of p. luminescens labeled with green fluorescent protein preferentially colonized a region ...	2003	12676661
insect resistance conferred by 283-kda photorhabdus luminescens protein tcda in arabidopsis thaliana.	the tcda gene of photorhabdus luminescens encodes a 283-kda protein, toxin a, that is highly toxic to a variety of insects, including some agriculturally important pests. we tested the efficacy of transgenic toxin a in arabidopsis thaliana for control of feeding insects. plants with toxin a expression above about 700 ng/mg of extractable protein were highly toxic to tobacco hornworm (manduca sexta). toxin a isolated from transgenic plants also strongly inhibited growth of the southern corn rootw ...	2003	12949536
breathing new life into insect-resistant plants.		2003	14520396
the genome sequence of the entomopathogenic bacterium photorhabdus luminescens.	photorhabdus luminescens is a symbiont of nematodes and a broad-spectrum insect pathogen. the complete genome sequence of strain tt01 is 5,688,987 base pairs (bp) long and contains 4,839 predicted protein-coding genes. strikingly, it encodes a large number of adhesins, toxins, hemolysins, proteases and lipases, and contains a wide array of antibiotic synthesizing genes. these proteins are likely to play a role in the elimination of competitors, host colonization, invasion and bioconversion of th ...	2003	14528314
bacterial detection of the toxicity of dioxins, polychlorinated diphenyls, and polybrominated diphenyl ethers.	polychlorinated dibenzo-p-dioxins (pcdds), biphenyls (pcbs), and polybrominated diphenyl ethers (pbdes) were found to induce several specific stresses within bacterial cells. four different recombinant escherichia coli with specific stress promoters (i.e., the reca responsive to dna damage, faba responsive to membrane damage, katg responsive to oxidative damage, and grpe responsive to protein damage) that were fused to the lux operon from vibrio fischeri showed very unique specificities in terms ...	2003	14551984
sequence of a symbiont.		2003	14595358
a novel secreted protein toxin from the insect pathogenic bacterium xenorhabdus nematophila.	the bacterium xenorhabdus nematophila is an insect pathogen that produces several proteins that enable it to kill insects. screening of a cosmid library constructed from x. nematophila strain a24 identified a gene that encoded a novel protein that was toxic to insects. the 42-kda protein encoded by the toxin gene was expressed and purified from a recombinant system, and was shown to kill the larvae of insects such as galleria mellonella and helicoverpa armigera when injected at doses of around 3 ...	2004	14707137
in vivo expression of the mannose-resistant fimbriae of photorhabdus temperata k122 during insect infection.	photorhabdus temperata k122 is an entomopathogenic bacterium symbiotically associated with nematodes of the family heterorhabditidae: surface fimbriae are important for the colonization of many pathogenic bacteria, and here we report the nucleotide sequence and analysis of the expression of a 12-kbp fragment encoding the mannose-resistant fimbriae of p. temperata (mrf). the mrf gene cluster contains 11 genes with an organization similar to that of the mrp locus from proteus mirabilis. mrfi (enco ...	2004	14729685
the insecticidal toxin makes caterpillars floppy (mcf) promotes apoptosis in mammalian cells.	photorhabdus bacteria produce a number of toxins to kill their insect hosts. the expression of one of these, makes caterpillars floppy (mcf), is sufficient to allow escherichia coli to persist within and kill caterpillars. mcf causes shedding of the insect midgut epithelium and destructive blebbing of haemocytes suggesting it may trigger apoptosis. to investigate this hypothesis, here we examine the effects of e. coli-expressed mcf on the mammalian cell lines cos-7, nih 3t3 and hela cells. cells ...	2004	15009026
construction and characterization of novel dual stress-responsive bacterial biosensors.	using the genes for the green fluorescence protein and xenorhabdus luminescens luciferase operon and the promoters for the reca and katg genes, two stress-responsive escherichia coli biosensor strains have been constructed that can individually or concurrently respond to oxidative and genotoxic conditions. strain duo-1 carries the prgdk1 plasmid, which has the reca::gfpuv4 and katg::luxcdabe fusion genes oriented divergently with each other, while in duo-2, i.e., prgdk2, they are in a tandem ori ...	2004	15018952
comparison of the bioluminescence of photorhabdus species and subspecies type strains.	natural bioluminescence of all recently accepted photorhabdus species and subspecies type strains (bacterial symbionts of entomopathogenic nematodes) was measured using a commercial luminometer; optimum conditions for the measurement were described. cultures emitted reliably measurable bioluminescence with characteristic level and kinetics for each strain. bioluminescence of all strains was significantly higher at 37 than at 25 degrees c at the beginning of the measurement, no effect of bacteria ...	2004	15702542
enhancement of the multi-channel continuous monitoring system through the use of xenorhabdus luminescens lux fusions.	the enhancement of the multi-channel continuous toxicity monitoring system developed previously was studied. to achieve better and more stable results from the system, the use of thermo-lux fusion strains that express the luxcdabe genes from xenorhabdus luminescens was evaluated. a total of six recombinant escherichia coli strains with the promoters from three oxidative-stress responsive genes, i.e. the katg, soda and pqi-5 genes, fused to either the lux genes from vibrio fischeri or x. luminesc ...	2004	15494228
effect of human serum on bioluminescence of natural and recombinant luminescent bacteria.	biphasic modification of bacterial bioluminescence by human serum was revealed: bioluminescence was inhibited at high concentrations of the serum and stimulated at low concentrations. effects of temperature and duration of exposure on bioluminescence manifested in stimulation of the inhibitory effect at higher temperature and longer exposure. the degree of inhibition of bioluminescence under in the presence of serum depends on species characteristics of the microorganism and nature of the lumine ...	2004	15665923
[the effect of clp proteins on dnak-dependent refolding of bacterial luciferases].	a study was made of the refolding of bacterial luciferases of vibrio fischeri, v. harveyi, photobacterium phosphoreum, and photorhabdus luminescens. by reaction rate, luciferases were divided into two groups. the reaction rate constants of fast luciferases of v. fischeri and ph. phosphoreum were about tenfold higher than those of slow luciferases of ph. luminescens and v. harveyi. the order of increasing luciferase thermostability was ph. phosphoreum, v. fischeri, v. harveyi, and ph. luminescens ...	2004	15285621
organ specificity, colonization and clearance dynamics in vivo following oral challenges with the murine pathogen citrobacter rodentium.	citrobacter rodentium belongs to a family of human and animal enteric pathogens that includes the clinically significant enterohaemorrhagic escherichia coli (ehec) and enteropathogenic e. coli (epec). these pathogens use attaching and effacing (a/e) lesions to colonize the host gastrointestinal tract. in this study we have used bioluminescence imaging (bli) to investigate the organ specificity, dynamics of colonization and clearance of mice by c. rodentium in situ and in real time. the biolumine ...	2004	15339271
two new subspecies of photorhabdus luminescens, isolated from heterorhabditis bacteriophora (nematoda: heterorhabditidae): photorhabdus luminescens subsp. kayaii subsp. nov. and photorhabdus luminescens subsp. thracensis subsp. nov.	bacterial isolates from nematodes from turkish soil samples were initially characterized by molecular methods and seven members of the genus photorhabdus identified to the species level, using riboprint analyses and metabolic properties. strain 07-5 (dsm 15195) was highly related to the type strain of photorhabdus luminescens subsp. laumondii dsm 15139t, and was regarded a strain of this subspecies. strains 1121t (dsm 15194t), 68-3 (dsm 15198) and 47-10 (dsm 15197) formed one, strain 39-8t (dsm ...	2004	15053319
champions of versatility.		2004	15058278
identification of a p2-related prophage remnant locus of photorhabdus luminescens encoding an r-type phage tail-like particle.	analysis of the photorhabdus luminescens genome sequence revealed that the pts region is related to the tail synthesis gene core of the p2 phage. the pts locus encodes a dna invertase homologue. pcr-rflp analysis showed the two potential tail fiber regions of the pts locus present dna inversions. electron microscopy revealed a phage tail-like particle, related to the r-type family and named r-photorhabdicin, in the culture supernatant of p. luminescens. mass spectrometry analysis of two sub-unit ...	2004	15063490
bacterial insecticidal toxins.	over the years it has been important for humans to control the populations of harmful insects and insecticides have been used for this purpose in agricultural and horticultural sectors. synthetic insecticides, owing to their various side effects, have been widely replaced by biological insecticides. in this review we attempt to describe three bacterial species that are known to produce insecticidal toxins of tremendous biotechnological, agricultural, and economic importance. bacillus thuringiens ...	2004	15116762
targeted photodynamic therapy of established soft-tissue infections in mice.	the worldwide rise in antibiotic resistance necessitates the development of novel antimicrobial strategies. although many workers have used photodynamic therapy (pdt) to kill bacteria in vitro, the use of this approach has seldom been reported in vivo in animal models of infection. we have previously described the first use of pdt to treat excisional wound infections by gram-(-) bacteria in living mice. however, these infected wound models involved a short timespan between infection (30 min) and ...	2004	15122362
burkholderia cenocepacia phage bcepmu and a family of mu-like phages encoding potential pathogenesis factors.	we have isolated bcepmu, a mu-like bacteriophage whose host range includes human pathogenic burkholderia cenocepacia (formally b. cepacia genomovar iii) isolates, and determined its complete 36748 bp genomic sequence. like enteric bacteriophage mu, the bcepmu genomic dna is flanked by variable host sequences, a result of transposon-mediated replication. the bcepmu genome encodes 53 proteins, including capsid assembly components related to those of mu, and tail sheath and tube proteins related to ...	2004	15184022
cloning and heterologous expression of a novel insecticidal gene (tccc1) from xenorhabdus nematophilus strain.	we have identified and cloned a novel toxin gene (tccc1/xptb1) from xenorhabdus nematophilus strain isolated from korea-specific entomophagous nematode steinernema glaseri mk. the dna sequence of cloned toxin gene (3048 bp) has an open reading frame encoding 1016 amino acids with a predicted molecular mass of 111058 da. the toxin sequence shares 50-96% identical amino acid residues with the previously reported tccc1 cloned from x. nematophilus, photorhabdus luminescens w14 p. luminescens tto1, a ...	2004	15194482
variation in the effectors of the type iii secretion system among photorhabdus species as revealed by genomic analysis.	entomopathogenic bacteria of the genus photorhabdus harbor a type iii secretion system. this system was probably acquired prior to the separation of the species within this genus. furthermore, the core components of the secretion machinery are highly conserved but the predicted effectors differ between photorhabdus luminescens and p. asymbiotica, two highly related species with different hosts.	2004	15205440
purification and characterization of two distinct metalloproteases secreted by the entomopathogenic bacterium photorhabdus sp. strain az29.	photorhabdus sp. strain az29 is symbiotic with an azorean nematode of the genus heterorhabditis in a complex that is highly virulent to insects even at low temperatures. the virulence of the bacteria is mainly attributed to toxins and bacterial enzymes secreted during parasitism. the bacteria secrete proteases during growth, with a peak at the end of the exponential growth phase. protease secretion was higher in cultures growing at lower temperatures. at 10 degrees c the activity was highest and ...	2004	15240252
interference competition and parasite virulence.	within-host competition between parasites, a consequence of infection by multiple strains, is predicted to favour rapid host exploitation and greater damage to hosts (virulence). however, the inclusion of biological variables can drastically change this relationship. for example, if competing parasite strains produce toxins that kill each other (interference competition), their growth rates and virulence may be reduced relative to single-strain infections. bacteriocins are antimicrobial toxins p ...	2004	15255095
cloning serratia entomophila antifeeding genes--a putative defective prophage active against the grass grub costelytra zealandica.	serratia entomophila and serratia proteamaculans (enterobacteriaceae) cause amber disease in the grass grub costelytra zealandica (coleoptera: scarabaeidae), an important pasture pest in new zealand. larval disease symptoms include cessation of feeding, clearance of the gut, amber coloration, and eventual death. a 155-kb plasmid, padap, carries the genes sepa, sepb, and sepc, which are essential for production of amber disease symptoms. transposon insertions in any of the sep genes in padap abol ...	2004	15262948
two new bacterial pathogens of colorado potato beetle coleoptera: chrysomelidae).	other than bacillus thuringiensis berliner, few bacteria are lethal to the colorado potato beetle (leptinotarsa decemlineata [say]), a major pest of potatoes and eggplant. expanded use of biologicals for the control of colorado potato beetle will improve resistance management, reduce pesticide use, and produce novel compounds for potential use in transgenic plants. using freeze-dried, rehydrated artificial diet in pellet form to screen bacteria lethal to other insects, we determined that strains ...	2004	15279252
comparison of proteolytic activities produced by entomopathogenic photorhabdus bacteria: strain- and phase-dependent heterogeneity in composition and activity of four enzymes.	twenty strains (including eight phase variant pairs) of nematode-symbiotic and insect-pathogenic photorhabdus bacteria were examined for the production of proteolytic enzymes by using a combination of several methods, including gelatin liquefaction, zymography coupled to native and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and activity measurement with two chromogen substrate types. four protease activities (approximately 74, approximately 55, approximately 54, and approximately ...	2004	15574931
specificity of association between paenibacillus spp. and the entomopathogenic nematodes, heterorhabditis spp.	endospore-forming bacteria, paenibacillus spp., have recently been isolated in association with insect pathogenic nematodes heterorhabditis spp. sporangia adhere to nematode infective juveniles (j3) and are carried with them into insects. paenibacillus proliferates in the killed insect along with heterorhabditis and its obligate bacterial symbiont, photorhabdus, despite the antibiotic production of the latter. nematode infective juveniles leave the insect cadaver with paenibacillus sporangia att ...	2004	15692861
human infection with photorhabdus asymbiotica: an emerging bacterial pathogen.	the three currently recognised photorhabdus species are bioluminescent bacteria that are pathogenic to insects. p. luminescens and p. temperata form a symbiotic relationship with nematodes that infect insects. p. asymbiotica, on the other hand, has only been isolated from human clinical specimens from the usa and australia. the bacterium has been associated with locally invasive soft tissue and disseminated bacteraemic infections. an invertebrate vector for p. asymbiotica has not yet been identi ...	2004	15049334
astr-asts, a new two-component signal transduction system, mediates swarming, adaptation to stationary phase and phenotypic variation in photorhabdus luminescens.	photorhabdus luminescens is an insect-pathogenic bacterium that forms a symbiosis with specific entomopathogenic nematodes. in this bacterium, a symbiosis-'deficient' phenotypic variant (known as the secondary variant or form ii) arises at a low frequency during prolonged incubation. a knock-out mutant was generated of the regulator of a newly identified two-component regulatory system, designated astr-asts. interestingly, this mutation altered the timing of phenotypic switching. variant cells a ...	2004	15073299
taxonomy of australian clinical isolates of the genus photorhabdus and proposal of photorhabdus asymbiotica subsp. asymbiotica subsp. nov. and p. asymbiotica subsp. australis subsp. nov.	the relationship of photorhabdus isolates that were cultured from human clinical specimens in australia to photorhabdus asymbiotica isolates from human clinical specimens in the usa and to species of the genus photorhabdus that are associated symbiotically with entomopathogenic nematodes was evaluated. a polyphasic approach that involved dna-dna hybridization, phylogenetic analyses of 16s rrna and gyrb gene sequences and phenotypic characterization was adopted. these investigations showed that g ...	2004	15280306
insect cellular and chemical limitations to pathogen development: the colorado potato beetle, the nematode heterorhabditis marelatus, and its symbiotic bacteria.	this research examines possible factors limiting pathogen development and reproduction in a novel host insect. the nematode heterorhabditis marelatus and its symbiotic bacterium, photorhabdus luminescens, kill 98% of nematode-treated colorado potato beetle (cpb) prepupae, but the nematode reproduces in only 1-6% of beetles. we examined nematode/bacterial inhibition at each step of the normal developmental pathway to determine host feature(s) limiting nematode reproduction. we found that in vivo ...	2004	15579320
effect of the insect pathogenic bacterium photorhabdus on insect phagocytes.	photorhabdus are insect pathogenic bacteria that replicate within the insect haemocoel following release from their entomopathogenic nematode symbionts. to investigate how they escape the cellular immune response we examined the effects of two strains of photorhabdus, w14 and k122, on manduca sexta phagocytes (haemocytes), in vitro and in vivo. following injection of esherichia coli into manduca larvae, these non-pathogenic bacteria are rapidly cleared from the haemolymph and the number of free ...	2004	14678333
microbial infection causes the appearance of hemocytes with extreme spreading ability in monolayers of the tobacco hornworm manduca sexta.	the ability to adhere to and spread on a surface is a common property of insect blood cells. spreading on a glass surface by insect hemocytes is often used as a measure of immune fitness that can be inhibited by some insect pathogens and parasites. here, we report that upon infection of the tobacco hornworm manduca sexta with either a fungus (beauveria bassiana) or a bacterium (photorhabdus luminescens), a new type of hemocyte, not previously observed in healthy insects, was found in hemocyte mo ...	2004	15043939
enzymic characterization with progress curve analysis of a collagen peptidase from an enthomopathogenic bacterium, photorhabdus luminescens.	a proteolytic enzyme, php-b ( photorhabdus protease b), was purified from the entomopathogenic bacterium, photorhabdus luminescens. the enzyme is intracellular, and its molecular mass is 74 kda. tested on various peptide and oligopeptide substrates, php-b hydrolysed only oligopeptides, with significant activity against bradykinin and a 2-furylacryloyl-blocked peptide, fua-lgpa (2-furylacryloyl-leu-gly-pro-ala; kcat=3.6x10(2) s(-1), k(m)=5.8x10(-5) m(-1), ph optimum approx. 7.0). the p k(a1) and ...	2004	14744262
the phop-phoq two-component regulatory system of photorhabdus luminescens is essential for virulence in insects.	photorhabdus luminescens is a symbiont of entomopathogenic nematodes. analysis of the genome sequence of this organism revealed a homologue of phop-phoq, a two-component system associated with virulence in intracellular bacterial pathogens. this organism was shown to respond to the availability of environmental magnesium. a mutant with a knockout mutation in the regulatory component of this system (phop) had no obvious growth defect. it was, however, more motile and more sensitive to antimicrobi ...	2004	14973084
liquid culture mass production of biocontrol nematodes, heterorhabditis bacteriophora (nematoda: rhabditida): improved timing of dauer juvenile inoculation.	heterorhabditis bacteriophora is used in biological control of soil-borne insect pests in horticulture and turf. mass production is carried out in monoxenic liquid cultures pre-incubated with the symbiont of the nematodes, the bacterium photorhabdus luminescens, before nematode dauer juveniles (dj) are inoculated. as a response to bacterial food signals, the dj recover from the developmentally arrested dauer stage, grow to adults and produce dj offspring. variable dj recovery after inoculation i ...	2004	14727090
effects of paenibacillus nematophilus on the entomopathogenic nematode heterorhabditis megidis.	the insect parasitic nematodes heterorhabditis spp. are mutualistically associated with entomopathogenic bacteria, photorhabdus spp. a novel association has been detected between h. megidis isolate eu17 and the endospore-forming bacterium paenibacillus nematophilus. p. nematophilus sporangia adhere to infective juveniles (ijs) of h. megidis and develop in insect hosts along with the nematodes and their symbiont. we tested the effects of p. nematophilus on h. megidis. the yield and quality (size, ...	2004	15707868
[conditions that influence bacterial luminescence in the presence of blood serum].	conditions that influence the luminescence of natural and recombinant luminescent bacteria in the presence of blood serum were studied. in general, blood serum quenched the luminescence of the marine photobacterium phosphoreum and the recombinant escherichia coli strains harboring the luminescent system genes of photobacterium leiognathi, but enhanced the luminescence of the soil bacterium photorhabdus luminescens zm1 and the recombinant e. coli strain harboring the lux operon of p. luminescens ...	2005	15938395
the gene stla encodes a phenylalanine ammonia-lyase that is involved in the production of a stilbene antibiotic in photorhabdus luminescens tt01.	photorhabdus is a genus of gram-negative bacteria from the family enterobacteriaceae. members of photorhabdus have a complex life cycle during which the bacterium has a pathogenic interaction with insect larvae whilst also maintaining a mutualistic relationship with nematodes from the family heterorhabditidae. during growth in the insect, photorhabdus bacteria produce a broad-spectrum antibiotic identified as 3,5-dihydroxy-4-isopropylstilbene (st). the biochemical pathway responsible for the pro ...	2005	16079333
occurrence and regulation of the ferric citrate transport system in escherichia coli b, klebsiella pneumoniae, enterobacter aerogenes, and photorhabdus luminescens.	in escherichia coli k-12, transcription of the ferric citrate transport genes fecabcde is initiated by binding of diferric dicitrate to the outer membrane protein feca which elicits a signaling cascade from the cell surface to the cytoplasm. the feci sigma factor is only active in the presence of fecr, which transfers the signal across the cytoplasmic membrane. in other bacteria, fecira homologues control iron transport gene transcription by siderophores other than citrate. however, in most case ...	2005	16193283
on the mechanisms of photodynamic effect of sensitizers and improvement of methods of their primary selection for photodynamic antimicrobial therapy.		2005	16392758
oral toxicity of photorhabdus toxins against thrips species.	the oral toxicity of excretion products of several photorhabdus and xenorhabdus strains was tested on two thrips species: frankliniella occidentalis and thrips tabaci. out of 46 photorhabdus isolates and six xenorhabdus isolates only six north american p. temperata isolates were toxic to the thrips species. after 7 days of drinking from p. temperata supernatant a mortality of 90% could be reached. thrips were also killed after sucking from leaves covered with the toxins. toxins have a negative e ...	2005	15955338
two groups of entomopathogenic bacteria, photorhabdus and xenorhabdus, share an inhibitory action against phospholipase a2 to induce host immunodepression.	photorhabdus and xenorhabdus are two genera of entomopathogenic bacteria having a mutualistic relationship with their respective nematode hosts, heterorhabditis and steinernema. one of the pathogenic mechanisms of these bacteria includes host immunodepression, which leads to lethal septicemia. it has been known that x. nematophila inhibits phospholipase a2 (pla2) to induce host immunodepression. here, we tested the hypothesis of pla2 inhibition using another bacterial species involved in other g ...	2005	15979640
photorhabdus asymbiotica, a pathogen emerging on two continents that proves that there is no substitute for a well-trained clinical microbiologist.	a 54-year-old ranch hand presented to the emergency room with an alleged spider bite and multiple abscesses. both wound and blood cultures grew photorhabdus asymbiotica, an enteric gram-negative rod that was initially misidentified by the hospital's rapid identification system. clinical laboratories should be aware of the limitations of their rapid identification systems and always use them as an adjunct to analysis of morphological and phenotypic traits.	2005	16081963
the family of serratia type pore forming toxins.	the serratia marcescens hemolysin represents the prototype of a growing family of pore forming toxins. the available bacterial genome sequences reveal serratia hemolysin homologues in additional species. however, only s. marcescens hemolysin has been studied in great molecular detail. this family of toxins has nothing in common with the pore forming toxins of e. coli type (rtx toxins), the staphylococcus aureus alpha-toxin or the thiol activated toxin of group a beta-hemolytic streptococci (stre ...	2005	16101433
specialization of the entomopathogenic nematode steinernema scapterisci with its mutualistic xenorhabdus symbiont.	the level of specialization of the entomopathogenic nematode steinernema scapterisci with its native xenorhabdus symbiont was investigated by testing (1) the influence of non-native bacterial strains on nematode fitness within an insect-host (galleria mellonella) and (2) specificity of the association between the nematode infective juveniles and non-native bacteria. all non-native xenorhabdus spp. or photorhabdus spp. strains tested were mutualistically associated with other entomopathogenic nem ...	2005	16163505
homologues of insecticidal toxin complex genes in yersinia enterocolitica biotype 1a and their contribution to virulence.	yersinia enterocolitica is an enteric pathogen that consists of six biotypes: 1a, 1b, 2, 3, 4, and 5. strains of the latter five biotypes can carry a virulence plasmid, known as pyv, and several well-characterized chromosomally encoded virulence determinants. y. enterocolitica strains of biotype 1a lack the virulence-associated markers of pyv-bearing strains and were once considered to be avirulent. there is growing epidemiological, clinical, and experimental evidence, however, to suggest that s ...	2005	16177365
evolutionary relationships of three new species of enterobacteriaceae living as symbionts of aphids and other insects.	ecological studies on three bacterial lineages symbiotic in aphids have shown that they impose a variety of effects on their hosts, including resistance to parasitoids and tolerance to heat stress. phylogenetic analyses of partial sequences of gyrb and reca are consistent with previous analyses limited to 16s rrna gene sequences and yield improved confidence of the evolutionary relationships of these symbionts. all three symbionts are in the enterobacteriaceae. one of the symbionts, here given t ...	2005	15933033
the pbgpe operon in photorhabdus luminescens is required for pathogenicity and symbiosis.	photorhabdus is a genus of gram-negative enterobacteriaceae that is pathogenic to insect larvae while also maintaining a mutualistic relationship with nematodes from the family heterorhabditis, where the bacteria occupy the gut of the infective juvenile (ij) stage of the nematode. in this study we describe the identification and characterization of a mutation in the pbge1 gene of photorhabdus luminescens tt01, predicted to be the fifth gene in the pbgpe operon. we show that this mutant, bmm305, ...	2005	15601690
calibration and deployment of custom-designed bioreporters for protecting biological remediation consortia from toxic shock.	we have previously described the development of a panel of site-specific lux-based bioreporters from an industrial wastewater treatment system remediating coking effluents. the pseudomonad strains carry a stable chromosomal copy of the luxcdabe operon from photorhabdus luminescens and display proportional responses in bioluminescence decay with increasing phenol concentration up to 800 mg l-1. in this work we describe their deployment to provide a strategic sensing network for protecting bacteri ...	2005	15658993
the broadly insecticidal photorhabdus luminescens toxin complex a (tca): activity against the colorado potato beetle, leptinotarsa decemlineata, and sweet potato whitefly, bemisia tabaci.	toxin complex a (tca), a high molecular weight insecticidal protein complex produced by the entomopathogenic bacterium photorhabdus luminescens, has been found to be orally toxic to both the colorado potato beetle, leptinotarsa decemlineata, and the sweet potato whitefly, bemisia tabaci biotype b. the 48 hour lc50 for tca against neonate l. decemlineata was found to be 2.7 ppm, and the growth of 2nd instar l. decemlineata exposed to tca for 72 hours was almost entirely inhibited at concentration ...	2005	17119614
codon optimization of bacterial luciferase (lux) for expression in mammalian cells.	expression of the bacterial luciferase (lux) system in mammalian cells would culminate in a new generation of bioreporters for in vivo monitoring and diagnostics technology. past efforts to express bacterial luciferase in mammalian cells have resulted in only modest gains due in part to low overall expression of the bacterial genes. to optimize expression, we have designed and synthesized codon-optimized versions of the luxa and luxb genes from photorhabdus luminsecens. to evaluate these genes i ...	2005	15761767
the photorhabdus pir toxins are similar to a developmentally regulated insect protein but show no juvenile hormone esterase activity.	the genome of the insect pathogen photorhabdus luminescens strain tt01 contains numerous genes predicting toxins and proteases. within the p. luminescens tt01 genome, the products of two loci, plu 4093-plu 4092 and plu 4437-plu 4436, show oral insecticidal activity against both moth and mosquito larvae. the proteins encoded by these loci, here termed 'photorhabdus insect related' (pir) proteins a and b, show similarity both to delta-endotoxins from bacillus thuringiensis (bts) and a developmenta ...	2005	15796978
characterization of cry34/cry35 binary insecticidal proteins from diverse bacillus thuringiensis strain collections.	bacillus thuringiensis crystal proteins of the cry34 and cry35 classes function as binary toxins showing activity on the western corn rootworm, diabrotica virgifera virgifera leconte. we surveyed 6,499 b. thuringiensis isolates by hybridization for sequences related to cry35a genes, identifying 78 strains. proteins of the appropriate molecular mass (ca. 44 kda) for cry35 were observed in 42 of the strains. full-length, or nearly full-length, sequences of 34 cry34 genes and 16 cry35 genes were al ...	2005	15811999
the exbd gene of photorhabdus temperata is required for full virulence in insects and symbiosis with the nematode heterorhabditis.	photorhabdus are bacteria found colonizing the gut of a specialized stage of the nematode heterorhabditis, called the infective juvenile (ij). the ij is a free-living stage of the nematode that seeks out and infects insect larvae. once inside the insect the ij release photorhabdus into the haemolymph where the bacteria rapidly proliferate, killing the insect within 48-72 h. the nematodes grow and reproduce in the insect cadaver by feeding on the photorhabdus biomass. in this study we use photorh ...	2005	15819630
random mutagenesis of bacterial luciferase: critical role of glu175 in the control of luminescence decay.	bacterial luciferases (luxab) can be readily classed as slow or fast decay luciferases based on their rates of luminescence decay in a single turnover assay. luciferases from vibrio harveyi and xenorhabdus (photorhabdus) luminescens have slow decay rates, and those from the photobacterium genus, such as photobacterium fisheri, p. phosphoreum and p. leiognathi, have rapid decay rates. by substitution of a 67-amino-acid stretch of p. phosphoreum luxa in the central region of the luxa subunit, the ...	2005	15352872
site-specific antiphagocytic function of the photorhabdus luminescens type iii secretion system during insect colonization.	photorhabdus is an entomopathogenic bacterium belonging to the enterobacteriaceae. the genome of the tt01 strain of photorhabdus luminescens was recently sequenced and a large number of toxin-encoding genes were found. genomic analysis predicted the presence on the chromosome of genes encoding a type three secretion system (ttss), the main role of which is the delivery of effector proteins directly into eukaryotic host cells. we report here the functional characterization of the ttss. the locus ...	2005	15679839
potentiation and cellular phenotypes of the insecticidal toxin complexes of photorhabdus bacteria.	the toxin complex (tc) genes of bacteria comprise a large and growing family whose mode of action remains obscure. in the insect pathogen photorhabdus, tc genes encode high molecular weight insecticidal toxins with oral activity against caterpillar pests. one protein, tcda, has recently been expressed in transgenic plants and shown to confer insect resistance. these toxins therefore represent alternatives to toxins from bacillus thuringiensis (bt) for deployment in transgenic crops. levels of tc ...	2005	15679840
construction and evaluation of nagr-nagaa::lux fusion strains in biosensing for salicylic acid derivatives.	the nagr protein is a response regulatory protein found in the bacterium ralstonia sp. u2 that is involved in sensing for salicylic acid and the subsequent induction of the operon just upstream of its gene. the genes encoded for in this operon are involved in the degradation of salicylic acid. escherichia coli strain rfm443 carrying a fusion of the photorhabdus luminescens luxcdabe operon with the nagr gene and upstream region of the nagaa gene was constructed and characterized with respect to i ...	2005	15767693
cloning and sequencing of a genomic island found in the brazilian purpuric fever clone of haemophilus influenzae biogroup aegyptius.	a genomic island was identified in the haemophilus influenzae biogroup aegyptius brazilian purpuric fever (bpf) strain f3031. this island, which was also found in other bpf isolates, could not be detected in non-bpf biogroup aegyptius strains or in nontypeable or typeable h. influenzae strains, with the exception of a region present in the type b eagan strain. this 34,378-bp island is inserted, in reference to h. influenzae rd kw20, within a choline transport gene and contains a mosaic structure ...	2005	15784532
regulation and biosynthesis of carbapenem antibiotics in bacteria.	carbapenem antibiotics are members of the beta-lactam family of antibiotics, the most important class of antibiotics currently in clinical use. they are active against many important gram-positive and gram-negative pathogens. one important feature of carbapenem antibiotics is their resistance to several beta-lactamases. thienamycin, isolated from streptomyces cattleya, was the first carbapenem described. other well-studied carbapenems were isolated from the gram-negative bacteria erwinia carotov ...	2005	15759042
on-line determination of serum bactericidal activity using recombinant luminescent bacteria.	intensity of luminescence quenching in recombinant strains of escherichia coli with cloned lux-operones by human blood serum is directly proportional to the degree of bactericidal effect assessed by nephelometric and bacteriological methods. this correlation was most characteristic of e. coli with luminescence genes from photobacterium leiognathi, which substantiates its use in the development of the kinetic bioluminescent method to determine of serum bactericidal activity. the possibility of us ...	2006	17369948
nematode symbiont for photorhabdus asymbiotica.	photorhabdus asymbiotica is an emerging bacterial pathogen that causes locally invasive soft tissue and disseminated bacteremic infections in the united states and australia. although the source of infection was previously unknown, we report that the bacterium is found in a symbiotic association with an insect-pathogenic soil nematode of the genus heterorhabditis.	2006	17176572
ytxr, a conserved lysr-like regulator that induces expression of genes encoding a putative adp-ribosyltransferase toxin homologue in yersinia enterocolitica.	yersinia enterocolitica causes human gastroenteritis, and many isolates have been classified as either "american" or "non-american" strains based on their geographic prevalence and virulence properties. in this study we describe identification of a transcriptional regulator that controls expression of the y. enterocolitica ytxab genes. the ytxab genes have the potential to encode an adp-ribosylating toxin with similarity to pertussis toxin. however, a ytxab null mutation did not affect virulence ...	2006	16997967
comparison of bulb syringe and pulsed lavage irrigation with use of a bioluminescent musculoskeletal wound model.	despite the fact that wound irrigation is a common surgical procedure, there are many variables, including delivery device, irrigant type, and fluid volume, that have yet to be optimized. the purpose of this study was to compare, with use of transgenic bioluminescent bacteria and standard quantitative microbiological methods, the efficacy of pulsed lavage and bulb syringe irrigation in reducing wound bacterial counts.	2006	17015593
pleiotropic role of quorum-sensing autoinducer 2 in photorhabdus luminescens.	bacterial virulence is an integrative process that may involve quorum sensing. in this work, we compared by global expression profiling the wild-type entomopathogenic photorhabdus luminescens subsp. laumondii tt01 to a luxs-deficient mutant unable to synthesize the type 2 quorum-sensing inducer ai-2. ai-2 was shown to regulate more than 300 targets involved in most compartments and metabolic pathways of the cell. ai-2 is located high in the hierarchy, as it controls the expression of several tra ...	2006	17021191
development of bioluminescent edwardsiella ictaluri for noninvasive disease monitoring.	edwardsiella ictaluri is a facultative intracellular bacterium that causes enteric septicemia of catfish (esc). in this study, we aimed to develop bioluminescent e. ictaluri that can be monitored by noninvasive bioluminescence imaging (bli). to accomplish this, the luxcdabe operon of photorhabdus luminescens was cloned downstream of the lacz promoter in the broad host range plasmid pbbr1mcs4. edwardsiella ictaluri strain 93-146 transformed with the new plasmid, paklux1, was highly bioluminescent ...	2006	16842347
identification and phylogenetic analysis of arsenophonus- and photorhabdus-type bacteria from adult hippoboscidae and streblidae (hippoboscoidea).	this is the first report of arsenophonus- and photorhabdus-type bacteria from streblidae (bat flies) and hippoboscidae (louse flies, keds). strains were detected by means of polymerase chain reaction of 16s rdna, and phylogenetic analysis determined the relationship of the obtained sequences to previously reported sequences in genbank. phylogenetic analysis by means of maximum parsimony revealed that all isolated arsenophonus spp. 16s rdna sequences formed a monophyletic sub-clade within other i ...	2006	16289111
nitric oxide production by hemocytes of larva and pharate prepupa of galleria mellonella in response to bacterial lipopolysaccharide: cytoprotective or cytotoxic?	nitric oxide production by the hemocytes of the last instar larvae and sessile pharate prepupa of galleria mellonella (lepidoptera: pyralidae) was demonstrated in vitro in response to preparations of bacterial lipopolysaccharide (lps) from escherichia coli using the griess reaction. augmented, dose dependent nitric oxide production was observed in the pharate prepupal hemocytes compared with larval hemocytes. this was partially reversed in a dose dependent manner with s-methyl thiourea (smt), a ...	2006	16316786