PMID(sorted ascending)
culture-independent characterization of the digestive-tract microbiota of the medicinal leech reveals a tripartite symbiosis.culture-based studies of the microbial community within the gut of the medicinal leech have typically been focused on various aeromonas species, which were believed to be the sole symbiont of the leech digestive tract. in this study, analysis of 16s rrna gene clone libraries confirmed the presence of aeromonas veronii and revealed a second symbiont, clone pw3, a novel member of the rikenellaceae, within the crop, a large compartment where ingested blood is stored prior to digestion. the diversit ...200616820471
purification and characterization of cytolytic toxins produced by aeromonas hydrophila and aeromonas veronii biotype sobria strains.cytolytic toxins produced by aeromonas hydrophila and aeromonas veronii biotype sobria strains were partially purified from culture filtrates by two steps of purification: ammonium sulfate precipitation and hydrophobic chromatography using phenyl-sepharose cl-4b. hemolytic activity was detected in one or two peaks in elution profile. purified toxins were also cytotoxic to vero and cho cells. moreover, these toxins revealed cytotonic activity to cho cells.200616878602
mechanistic studies on the mononuclear znii-containing metallo-beta-lactamase imis from aeromonas an effort to understand the reaction mechanism of a b2 metallo-beta-lactamase, steady-state and pre-steady-state kinetic and rapid freeze quench electron paramagnetic resonance (epr) studies were conducted on imis and its reaction with imipenem and meropenem. ph dependence studies revealed no inflection points in the ph range of 5.0-8.5, while proton inventories demonstrated at least 1 rate-limiting proton transfer. site-directed mutagenesis studies revealed that lys224 plays a catalytic role ...200616939225
prevalence of environmental aeromonas in south east queensland, australia: a study of their interactions with human monolayer caco-2 investigate the prevalence of aeromonas in a major waterway in south east queensland, australia, and their interactions with a gut epithelial model using caco-2 cells.200616968308
updated phylogeny of the genus aeromonas.recent phylogenetic studies of the genus aeromonas based on gyrb and rpod gene sequences have improved the phylogeny based on 16s rrna gene sequences first published in 1992, particularly in the ability to split closely related species. these studies did not include the recently described species aeromonas simiae and aeromonas molluscorum and only a single strain of aeromonas culicicola was available for analysis at that time. in the present work, these aeromonas species and newly isolated strai ...200617012583
biochemical and molecular characterization of tetracycline-resistant aeromonas veronii isolates from catfish.eighty-one tetracycline-resistant aeromonas sp. strains were isolated from farm-raised catfish. morphological and biochemical characteristics indicated that 23 of the 81 aeromonads were aeromonas hydrophila, 7 isolates were aeromonas trota, 6 isolates were aeromonas caviae, 42 isolates were aeromonas veronii, and 3 isolates were aeromonas jandaei. however, the alui and mboi restriction fragment length polymorphism (rflp) patterns of the pcr-amplified 1.4-kb 16s rrna gene from all 81 tetracycline ...200617021193
phylogenetic identification of aeromonas strains isolated from carcasses of pig as new members of the species aeromonas allosaccharophila.the first description of the species aeromonas allosaccharophila was only based on two strains (the type strain cect4199, and a duplicate cect4200) isolated from diseased elvers (anguilla anguilla) of an eel-farm located in valencia, spain, and one stool isolate (atcc35942) from a female with diarrhoea and food poisoning in south carolina, u.s.a. in the present study, 17 aeromonas isolates obtained from carcasses of pigs and from the equipment for the cleaning process, and one strain recently is ...200717080292
x-ray absorption spectroscopy of the zinc-binding sites in the class b2 metallo-beta-lactamase imis from aeromonas veronii bv. sobria.x-ray absorption spectroscopy was used to investigate the metal-binding sites of imis from aeromonas veronii bv. sobria in catalytically active (1-zn), product-inhibited (1-zn plus imipenem), and inactive (2-zn) forms. the first equivalent of zinc(ii) was found to bind to the consensus zn(2) site. the reaction of 1-zn imis with imipenem leads to a product-bound species, coordinated to zn via a carboxylate group. the inhibitory binding site of imis was examined by a comparison of wild-type imis w ...200617087519
[postoperative infection of an epigastric hematoma caused by aeromonas veronii biovar sobria].a 52-year-old man with a gastric signet-ring cell carcinoma but without acute symptoms was admitted for reconstructive surgery of the gastrointestinal tract.200617109273
cloning of atp-dependent protease clpxp genes in aeromonas veronii. 200617169116
culturable and vbnc vibrio cholerae: interactions with chironomid egg masses and their bacterial population.vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments. recently, it was found that chironomid (nonbiting midges) egg masses serve as a reservoir for the cholera bacterium and that flying chironomid adults are possible windborne carriers of v. cholerae non-o1 non-o139. chironomids are the most widely distributed insect in freshwater. females deposit egg masses at the water's edge, and each egg mass contains eggs embedded in a gelatinous matrix. hemagglu ...200717186156
detection of conjugation related type four secretion machinery in aeromonas culicicola.background: aeromonas sp. can now be considered relatively common enteropathogens due to the increase of diseases in humans. aeromonas culicicola is a gram negative rod-shaped bacterium isolated for the first time from the mosquito mid-gut, but subsequently detected in other insects and waters also. our previous study discovered that a. culicicola harbors three plasmids, which we designated as pac3249a, pac3249b and pac3249c. we investigated and report here the existence and genetic organization ...200617205119
[rapidly progressive myonecrosis by aeromonas veronii biotype sobria].myonecrosis due to aeromonas spp is exceptional. we report the case of a diabetic patient with liver cirrhosis who developed a rapidly progressive myonecrosis by aeromonas veronii biotype sobria. the portal of entry was an injury after falling down in an irrigation canal. the outcome was not favourable and surgical amputation of left leg was performed in spite of antibiotic treatment with cefotaxime and tobramicin. aeromonas spp can be very aggressive and this microorganism should be considered ...200617222071
spatial and temporal population dynamics of a naturally occurring two-species microbial community inside the digestive tract of the medicinal leech.the medicinal leech, hirudo verbana, is one of the simplest naturally occurring models for digestive-tract symbioses, where only two bacterial species, aeromonas veronii bv. sobria (gamma-proteobacteria) and a rikenella-like bacterium (bacteroidetes), colonize the crop, the largest compartment of the leech digestive tract. in this study, we investigated spatial and temporal changes of the localization and microcolony structure of the native symbionts in the crop, after ingestion of a sterile blo ...200717277211
induction of apoptosis in vero cells by aeromonas veronii biovar sobria vacuolating cytotoxic factor.recently, a cytotoxin named vacuolating cytotoxic factor (vcf) in aeromonas sobria and aeromonas veronii biovar sobria was described. we have now purified this factor using ion metallic affinity chromatography. the vcf is a nonhemolytic enterotoxin that acts as a serine protease. the toxin can be partially neutralized by serum antiaerolysin and it induced not only cytoplasmatic vacuole formation, but also mitochondrial disorders that must be signaling the apoptotic pathways, leading to vero (afr ...200717286562
aeromonas hemolytic uremic syndrome. a case and a review of the literature.although rarely, hemolytic uremic syndrome can be induced by aeromonas. we report a case in a 40-year-old spanish female produced by aeromonas veronii bv. sobria and review the previous cases described in the literature. this is the 2nd case described in adults.200717300902
importance of flagella and enterotoxins for aeromonas virulence in a mouse model.a genetic characterization of eight virulence factor genes, elastase, lipase, polar flagella (flaa/flab, flag), lateral flagella (lafa), and the enterotoxins alt, act, and ast, was performed using polymerase chain reaction with 55 drinking water and nine clinical isolates. when 16 aeromonas hydrophila strains, seven aeromonas veronii strains, and seven aeromonas caviae strains exhibiting different combinations of virulence factor genes were tested in immunocompromised mice by intraperitoneal inj ...200717496975
interaction between innate immune cells and a bacterial type iii secretion system in mutualistic and pathogenic associations.animals house a community of bacterial symbionts in their digestive tracts that contribute to their well being. the medicinal leech, hirudo verbana, has a remarkably simple gut population carrying two extracellular microbes in the crop where the ingested blood is stored. this simplicity renders it attractive for studying colonization factors. aeromonas veronii, one of the leech symbionts, can be genetically manipulated and is a pathogen of mammals. screening transposon mutants of a. veronii for ...200717517651
characterization of a catalase gene from aeromonas veronii, the digestive-tract symbiont of the medicinal leech.the catalase gene kata of the medicinal leech symbiont aeromonas veronii bv. sobria was cloned, sequenced, and functionally characterized. southern hybridization, using an a. veronii kata-specific hybridization probe, suggested the presence of a single gene copy in many aeromonas species. a. veronii kata consisted of 1446 nt encoding a protein with a high degree of similarity to the small-subunit group iii bacterial catalases. a catalase-null mutant (jg186) was constructed through gene-replaceme ...200717526846
use of the novel phylogenetic marker dnaj and dna-dna hybridization to clarify interrelationships within the genus aeromonas.the interrelationships of 27 aeromonas strains were investigated using dnaj sequences and dna-dna hybridization. dnaj sequence similarities showed a stronger relationship with dna-dna relatedness values than did 16s rrna gene sequence similarities. additionally, dnaj sequence analysis, with interspecies divergence over 5.2 % in most cases, gave better resolution than 16s rrna gene sequences for the differentiation of strains at the species level. relationships among aeromonas species were theref ...200717551035
[isolation and identification of species from the genera aeromonas, vibrio, and plesiomonas from extraintestinal samples in cuba].extraintestinal infections caused by the genera aeromonas, vibrio and plesiomonas have high morbidity and mortality rates in different areas of world. from january 2002 to december 2003, the national reference laboratory for acute diarrhoeal diseases of the pedro kourí tropical medicine institute received 95 gram-negative, facultative anaerobic, oxidase positive bacilli strains from different extraintestinal specimen (blood, ear exudates, infected wounds, conjunctive exudates, urine, and cathete ...200717554439
the role of c-di-gmp signaling in an aeromonas veronii biovar sobria strain.aeromonas is a ubiquitous gram-negative bacterium that persists in the environment. it is shown that all isolates of persistent aeromonas clones show strong biofilm formation ability. c-di-gmp regulates biofilm formation in many bacteria. to investigate the impact of c-di-gmp signaling, we introduced heterologous ggdef and eal domain proteins from salmonella typhimurium to an aeromonas veronii biovar sobria strain. overexpression of the ggdef domain protein adra increased c-di-gmp concentration ...200717573931
convenient test using a combination of chelating agents for detection of metallo-beta-lactamases in the clinical laboratory.although transmissible metallo-beta-lactamases (mbls) are a serious threat to beta-lactam antibiotic therapy, the clsi currently does not recommend testing methods for the detection of mbls. the aim of this study was to evaluate the capability of double-disk tests (ddts) by using disks containing a combination of the chelators 2-mercaptopropionic acid (mpa) and tris-edta (te) to detect mbls. sixteen isolates (4 acinetobacter baumannii isolates, 6 pseudomonas aeruginosa isolates, 1 serratia marce ...200717596358
identification of aeromonas veronii genes required for colonization of the medicinal leech, hirudo verbana.most digestive tracts contain a complex consortium of beneficial microorganisms, making it challenging to tease apart the molecular interactions between symbiont and host. the digestive tract of hirudo verbana, the medicinal leech, is an ideal model system because it harbors a simple microbial community in the crop, comprising the genetically amenable aeromonas veronii and a rikenella-like bacterium. signature-tagged mutagenesis (stm) was used to identify genes required for digestive tract colon ...200717616592
aeromonas veronii, a tributyltin (tbt)-degrading bacterium isolated from an estuarine environment, ria de aveiro in portugal.organotin compounds are used in a variety of industrial processes therefore their subsequent discharge into the environment is widespread. bacteria play an important role in biogeochemical transformations acting as natural decontamination agents. therefore, screening for tributyltin (tbt)-resistant and -degrading bacteria is relevant for the selection of isolates with decontamination ability of these polluted areas. with this purpose, 50 strains were isolated from sediment and water from ria de ...200717719084
virulence potential and genetic diversity of aeromonas caviae, aeromonas veronii, and aeromonas hydrophila clinical isolates from mexico and spain: a comparative study.a comparative study of 109 aeromonas clinical isolates belonging to the 3 species most frequently isolated from patients with diarrhea in mexico and spain was performed to investigate the distribution of 3 prominent toxin genes and the gene encoding flagellin of lateral flagella; 4 well-established virulence factors in the genus aeromonas. the aerolysin-hemolysin toxin genes were the most prevalent, being present in 89% of the total isolates. the ast toxin gene was conspicuously absent from the ...200717898843
tracheobronchitis caused by aeromonas veronii biovar sobria after near-drowning.a 19-year-old man developed an acute tracheobronchitis shortly after having been rescued from a near-drowning in a river where previous investigations had demonstrated the presence of 500 c.f.u. ml(-1) of aeromonas sp. in the water. an isolate of aeromonas veronii biovar sobria was identified as the causative agent of the tracheobronchitis. the causality was supported by the massive growth of a. veronii in bronchial secretion, the presence of a type iii secretion system in the bacterial isolate, ...200717965361
a distinct cause of necrotizing fasciitis: aeromonas veronii biovar sobria.aeromonas veronii biovar sobria (veronii var. sobria) has not been implicated in the pathogenesis of necrotizing fasciitis in north america.200717999586
[identification of closely related bacteria via phylogenetic methods].to differentiate closely related pathogenic bacteria via phylogenetic method on the basis of gyrb gene sequences.200718067224
aeromonas-acanthamoeba interaction and early shift to a viable but nonculturable state of aeromonas by investigate the hypothesis that amoeba may comprise a significant environmental reservoir for aeromonas, acanthamoeba-aeromonas interaction experiments were performed.200818194253
severe diarrhoea caused by aeromonas veronii biovar sobria in a patient with metastasised gist.this report describes the isolation of aeromonas veronii biovar sobria as the causative enteropathogen of diarrhoea in an oncological patient after failure of detection of other infectious agents. the case points out the severe and long course of the infection, the diagnostic dilemma, and the prompt recovery after antibiotic treatment.200718254499
characterization of vibrio cholerae isolated from the aquatic basins of the state of pernambuco, brazil.through a continuous bacteriological monitoring programme carried out by the health secretariat of the state of pernambuco, brazil, two isolates of vibrio cholerae o1 el tor ogawa were discovered in an endemic area in 2001, during a cholera inactive period, along with six v. cholerae non-o1/non-o139 strains and two aeromonas veronii biovar sobria strains showing an unusual characteristic of agglutination with o1 antiserum. between that time and 2005, eight other o1 isolates were found. the virul ...200818258274
effect of packaging atmosphere on the microbial attributes of pearlspot (etroplus suratensis bloch) stored at 0-2 degrees c.effect of packaging atmosphere (air and under different modified atmospheres (mas), 40% co2/60% o2, 50%/50% o2, 60% co2/40% o2, 70% co2/30% o2 and 40% co2/30% o2/30% n2) on the microbial and biochemical attributes of fresh pearlspot (etroplus suratensis bloch) stored at 0-2 degrees c was investigated. trimethylamine nitrogen (tma-n) and thiobarbituric acid (tba) values remained lower than the proposed acceptability limits throughout the storage period. results demonstrated that storage of pearls ...200818355677
pathogenic potential of a collagenase gene from aeromonas veronii.the role of collagenase as a mechanism of bacterial pathogenicity in some pathogenic bacteria has been reported. the information on the role of collagenase in aeromonas spp. pathogenesis is scant. in the present study, a mutant aeromonas veronii ry001 that is deficient in the putative collagenase gene acg was constructed and compared with the wild-type strain for virulence factors. bacterial cells and cell-free extracellular products of the mutant had significantly less collagenolytic activity, ...200818388966
plasmid-mediated qnrs2 determinant from a clinical aeromonas veronii isolate. 200818505860
conformational changes in the metallo-beta-lactamase imis during the catalytic reaction: an epr spectrokinetic study of co(ii)-spin label interactions.metallo-beta-lactamases are responsible for conferring antibiotic resistance on certain pathogenic bacteria. in consequence, the search for inhibitors that may be useful in combating antibiotic resistance has fueled much study of the active sites of these enzymes. there exists circumstantial evidence that the binding of substrates and inhibitors to metallo-beta-lactamases may involve binding to the organic part of the molecule, in addition to or prior to binding to one or more active site metal ...200818528987
[characterization of aeromonas spp isolates from newborns hospitalized].aeromonas spp is recognized as pathogenic to humans after consumption of contaminated water and food. in the present investigation, 2,323 rectal swab samples from newborns hospitalized in rio de janeiro were evaluated with a view to isolating aeromonas. the samples were collected and sent to the national reference laboratory for cholera and other bacterial intestinal infections, at the oswaldo cruz institute of the oswaldo cruz foundation. the swabs were subjected to enrichment in alkaline pepto ...200818545840
ompa is an adhesion factor of aeromonas veronii, an optimistic pathogen that habituates in carp intestinal the present study, we focused on one of the aeromonas veronii isolates that exhibited marked adhesion onto carp intestine and studied its membrane-associated proteins for their possible involvement in mucosal adhesion.200818828791
aeromonas spp. human isolates induce apoptosis of murine macrophages.interactions of aeromonas caviae, aeromonas veronii biotype sobria, and aeromonas hydrophila strains isolated from fecal specimens of humans with gastroenteritis on murine macrophages, j774 cells, were investigated. analyses of cellular morphology and dna fragmentation in phagocytes infected with these strains exhibited typical characteristic features of cells undergoing apoptosis. we observed the morphological changes, including condensation of nuclear chromatin, formation of apoptotic bodies a ...200919005723
[severe pneumonia caused by aeromonas veronii biovar sobria: a case report and review of the literature].to describe the clinical features of severe pneumonitis with aeromonas veronii biovar sobria.200819080598
interaction of aeromonas spp. human isolates with murine macrophages.this study aimed to evaluate phagocytic and bactericidal activity of macrophages originated from murine j774 macrophage cell line against 26 strains of aeromonas caviae, aeromonas veronii biotype sobria and aeromonas hydrophila isolated from human fecal specimens. the analysis of phagocytic index (pi) indicated these strains were phagocytosed in low numbers, below 1.1 x l0(-3) for 65% strains of a. veronii biotype sobria and a. hydrophila. the highest pi value (0.019) was noted in murine macroph ...200819123303
development of imipenem resistance in an aeromonas veronii biovar sobria clinical isolate recovered from a patient with cholangitis.several imipenem-susceptible and -resistant aeromonas veronii biovar sobria isolates with different morphologies and antimicrobial susceptibilities recovered from bile samples of a patient with cholangitis were analysed. these isolates belonged to the same clone and the imipenem-resistant strains showed overexpression of the imis gene, encoding a chromosomal carbapenemase. these results should make clinicians aware of the possible emergence of multidrug-resistant a. veronii biovar sobria, perhap ...200919273640
cloning and expression of an outer membrane protein ompw of aeromonas hydrophila and study of its distribution in aeromonas spp.the main aims of this study were to clone and express an outer membrane protein (omp), ompw, of aeromonas hydrophila and to study its distribution in aeromonas spp.200919426281
new structural variants of homoserine lactones in bacteria.n-acylhomoserine lactones (ahls) are used by a wide variety of bacteria for cell-cell communication in "quorum-sensing". these compounds are derived from l-homoserine lactone and a fatty acid, which varies in chain-length, degree of saturation, and the presence or absence of an oxygen atom at c-3. in this study we describe for the first time the occurrence of acyl chains carrying a methyl branch, and present a gc-ms-based method that can be used to distinguish these compounds from unbranched iso ...200919533714
prevalence of genes encoding the type three secretion system and the effectors aext and aexu in the aeromonas veronii group.the prevalence of important virulence factors, the type iii secretion system (t3ss) and two t3ss-dependent toxins, aext and aexu, was evaluated in the aeromonas veronii group (avg). members of the avg have a broad host range, including vertebrates and invertebrates, and form a variety of associations, spanning from pathogenic to mutualistic. our avg strain collection consists of human, duck, eel, and leech isolates. these isolates were examined for the presence of the t3ss, aext, and aexu throug ...200919534604
aeromonas fluvialis sp. nov., isolated from a spanish river.a gram-stain-negative, facultatively anaerobic bacterial strain, designated 717(t), was isolated from a water sample collected from the muga river, girona, north-east spain. preliminary analysis of the 16s rrna gene sequence showed that this strain belonged to the genus aeromonas, the nearest species being aeromonas veronii (99.5 % similarity, with seven different nucleotides). a polyphasic study based on a multilocus phylogenetic analysis of five housekeeping genes (gyrb, rpod, reca, dnaj and g ...201019648345
plasmid-mediated qnrs2 determinant in an aeromonas caviae isolate recovered from a patient with diarrhoea.a qnrs2 gene was identified in an aeromonas caviae isolate (mics of ciprofloxacin, norfloxacin and ofloxacin >32 mg/l) from a stool sample collected from a patient with gastroenteritis. the analysis of the gyra and parc genes revealed amino acid substitutions ser83-ile and ser80-thr, respectively. in addition, five out of 41 nalidixic acid-resistant aeromonas isolates studied (26 identified as aeromonas veronii bv sobria and 15 identified as a. caviae) showed ciprofloxacin resistance. the identi ...201019863591
mechanisms of quinolone resistance in aeromonas species isolated from humans, water and eels.mechanisms of resistance were determined in 33 quinolone-resistant isolates of the species aeromonas hydrophila, aeromonas caviae, aeromonas media, aeromonas salmonicida, aeromonas popoffii and aeromonas veronii, recovered from humans, freshwater and eels. the quinolone resistance-determining regions (qrdrs) of gyra and parc genes were sequenced in these resistant strains, as well as in 8 quinolone-sensitive aeromonas used as controls. all quinolone-resistant aeromonas carried point mutations in ...201019900538
[isolation and identification of pathogenic aeromonas veronii isolated from infected siberian sturgeon (acipenser baerii)].our study aimed at searching for the pathogenic factor causing siberian sturgeon (acipenser baerii) disease.200920069873
biochemical characterization of three putative atpases from a new type iv secretion system of aeromonas veronii plasmid pac3249a.type four secretion systems (tfss) are bacterial macromolecular transport systems responsible for transfer of various substrates such as proteins, dna or protein-dna complexes. tfsss encode two or three atpases generating energy for the secretion process. these enzymes exhibit highest sequence conservation among type four secretion components.201020144229
detection and characterization of virulence genes and integrons in aeromonas veronii isolated from catfish.the presence of virulence genes and integrons was determined in 81 strains of aeromonas veronii isolated from farm-raised catfish. polymerase chain reaction (pcr) protocols were used to determine the presence of genes for cytotoxic enterotoxin (act), aerolysin (aera), two cytotonic enterotoxins (ast, alt), lipase (lip), glycerophospholipid:cholesterol acyltransferase (gcat), serine protease (ser), dnases (exu), elastase (ahyb) and the structural gene flagellin (fla) in the template dna. oligonuc ...201020227596
clinical isolates of aeromonas veronii biovar veronii harbor a nonfunctional gene similar to the thermostable direct hemolysin-related hemolysin (trh) gene of vibrio parahaemolyticus.thermostable direct hemolysin-related hemolysin encoded by the trh gene is considered a major virulence factor in the pathogenesis of vibrio parahaemolyticus infections. in this study, we report the presence of a trh homolog in three clinical isolates of aeromonas veronii biovar veronii. the presence of a trh homolog in these strains of a. veronii was confirmed by pcr, followed by cloning, sequencing and colony hybridization using a digoxigenin-labelled probe. dna sequence analysis revealed that ...201020636974
molecular mechanisms of quinolone resistance in clinical isolates of aeromonas caviae and aeromonas veronii bv. sobria.mutations in quinolone targets were studied together with quinolone efflux pump activation and plasmid-mediated quinolone resistance determinants in nalidixic-acid-resistant isolates of aeromonas caviae and aeromonas veronii. among 135 clinical aeromonas spp. isolated from stools of patients with gastrointestinal symptoms, 40 nalidixic acid-resistant strains belonging to a. caviae and a. veronii were selected and their susceptibility to different quinolones (ciprofloxacin, norfloxacin, ofloxacin ...201020890847
epithelial cell proliferation in the developing zebrafish intestine is regulated by the wnt pathway and microbial signaling via myd88.rates of cell proliferation in the vertebrate intestinal epithelium are modulated by intrinsic signaling pathways and extrinsic cues. here, we report that epithelial cell proliferation in the developing zebrafish intestine is stimulated both by the presence of the resident microbiota and by activation of wnt signaling. we find that the response to microbial proliferation-promoting signals requires myd88 but not tnf receptor, implicating host innate immune pathways but not inflammation in the est ...201020921418
differential regulation of caspase-1 activation via nlrp3/nlrc4 inflammasomes mediated by aerolysin and type iii secretion system during aeromonas veronii infection.aeromonas spp. are gram-negative bacteria that cause serious infectious disease in humans. such bacteria have been shown to induce apoptosis in infected macrophages, yet the host responses triggered by macrophage death are largely unknown. in this study, we demonstrate that the infection of mouse bone marrow-derived macrophages with aeromonas veronii biotype sobria triggers activation of caspase-1 with the ensuing release of il-1β and pyroptosis. caspase-1 activation in response to a. veronii in ...201021037094
simple and direct detection of aeromonas hydrophila infection in the goldfish, carassius auratus (l.), by dot blotting using specific monoclonal antibodies.a combination of eight isolates of aeromonas hydrophila was used to produce monoclonal antibodies (mabs). ten different groups of mabs specific to aeromonas were selected. the first five groups of mabs demonstrated high specificity and bound to only one or two isolates of a. hydrophila. the sixth and the seventh groups of mabs were a. hydrophila specific. they recognized seven of eight a. hydrophila isolates (ah1, 2, 3, 4, 5, 6, 8); however, the mab in the seventh group also showed cross-reactiv ...201021091724
the type ii secretion system is essential for erythrocyte lysis and gut colonization by the leech digestive tract symbiont aeromonas veronii.hemolysin and the type ii secretion system (t2ss) have been shown to be important for virulence in many pathogens, but very few studies have shown their importance in beneficial microbes. here, we investigated the importance of the type ii secretion pathway in the beneficial digestive-tract association of aeromonas veronii and the medicinal leech hirudo verbana and revealed a critical role for the hemolysis of erythrocytes. a mutant with a minitn5 insertion in exem, which is involved in forming ...201021097598
detection of aaca-aphd, qaced1, mara, flor, and teta genes from multidrug-resistant bacteria: comparative analysis of real-time multiplex pcr assays using evagreen(®) and sybr(®) green i dyes.we have developed multiplex real-time pcr assays that utilize dna-intercalating dyes, sybr green i (sg) and evagreen (eg), with two primer sets (set 1=qaced1, teta and aaca-aphd; set 2=teta, mara, and flor) to simultaneously amplify the qaced1, teta, aaca-aphd, mara, and flor genes. validity of the multiplex pcr assays was confirmed by testing 83 bacterial isolates, including staphylococcus aureus (28 isolates), enterococcus spp. (17 isolates), salmonella enterica serovar typhimurium (8 isolates ...201121256956
complex evolutionary history of the aeromonas veronii group revealed by host interaction and dna sequence data.aeromonas veronii biovar sobria, aeromonas veronii biovar veronii, and aeromonas allosaccharophila are a closely related group of organisms, the aeromonas veronii group, that inhabit a wide range of host animals as a symbiont or pathogen. in this study, the ability of various strains to colonize the medicinal leech as a model for beneficial symbiosis and to kill wax worm larvae as a model for virulence was determined. isolates cultured from the leech out-competed other strains in the leech model ...201121359176
occurrence, abundance and elimination of class 1 integrons in one municipal sewage treatment plant.integrons are elements that encode a site-specific recombination system that recognizes and captures mobile gene cassettes and are closely related to multiple resistances of environmental microorganisms. this study was undertaken to determine the efficiency of an activated sludge process to remove integrons. the prevalence and characteristics of class 1 integrons were investigated for bacterial species isolated from the activated sludge of nanjing jiangxinzhou sewage treatment plant (stp, china) ...201121431316
aeromonas spp. induce apoptosis of epithelial cells through an oxidant-dependent activation of the mitochondrial pathway.we investigated interactions of aeromonas caviae, aeromonas veronii biotype sobria and aeromonas hydrophila strains, isolated from faecal specimens of humans with gastroenteritis, with ht29 intestinal epithelial cells. all strains were found to be cytotoxic to the cells. bacterial infection caused generation of reactive oxygen species (ros) and nitric oxide radical (no(-à)). the maximal levels of ros and no(-à) were 14 and 35 times, respectively, greater in cells infected with aeromonas spp. tha ...201121436367
directed culturing of microorganisms using metatranscriptomics.the vast majority of bacterial species remain uncultured, and this severely limits the investigation of their physiology, metabolic capabilities, and role in the environment. high-throughput sequencing of rna transcripts (rna-seq) allows the investigation of the diverse physiologies from uncultured microorganisms in their natural habitat. here, we report the use of rna-seq for characterizing the metatranscriptome of the simple gut microbiome from the medicinal leech hirudo verbana and for utiliz ...201121467263
phenotypic characteristics of human clinical and environmental aeromonas in western australia.: to determine the phenotypic characteristics of 199 aeromonas strains comprising 146 clinical and 53 environmental isolates.201121519288
medicinal leeches and the microsurgeon: a four-year study, clinical series and risk benefit review.background: there are case reports and small series in the literature relating to the use of medicinal leeches by plastic surgeons; however, larger series from individual units are rare. the aim of this article is to present a comprehensive 4-year case series of the use of medicinal leeches, discuss the current evidence regarding indications, risks, and benefits and highlight the recent updates regarding leech speciation. methods: patients prescribed leeches in a 4-year period (july 2004-2008) w ...201121520265
complete genome sequence of aeromonas veronii strain b565.aeromonas veronii strain b565 was isolated from aquaculture pond sediment in china. we present here the complete genome sequence of b565 and compare it with 2 published genome sequences of pathogenic strains in aeromonas genus. the result represents an independent step-wise acquisition of virulence factors of pathogenic strains in this genus.201121551296
isolation and characterization of virulent aeromonas veronii from ascitic fluid of oscar astronotus ocellatus showing signs of infectious dropsy.the cichlid oscar astronotus ocellatus has worldwide commercial value in the pet fish industry because of its early maturation, relatively high fecundity, ability to identify its caretaker and also to alter colouration amongst conspecifics. pathogenic strains of aeromonas veronii resistant to multiple antibiotics were isolated from a. ocellatus individuals showing signs of infectious abdominal dropsy. the moribund fish showed haemorrhage in all internal organs, and pure cultures could be obtaine ...201121553566
lactobacillus plantarum (vr1) isolated from an ayurvedic medicine (kutajarista) ameliorates in vitro cellular damage caused by aeromonas veronii.abstract:201121707995
differential immune responses of the green neon shrimp (neocaridina denticulate) to dipropyl phthalate.this study set out to understand the sublethal effect of xenobiotic phthalate esters (paes) on the relationship between the susceptibility of shrimp to bacterial infection and the immune response of the shrimp. neocaridina denticulate were exposed to different concentrations of the pae dipropyl phthalate (dprp), and mortality and six immune parameters were measured on days 1, 3, 5, and 10 after exposure. on days 1 and 3 after exposure, shrimp exposed to 0, 1, 5, 10, and 50 mg/l of dprp and chall ...201121740974
gastrointestinal colonization rates for human clinical isolates of aeromonas veronii using a mouse model.a variety of environment-associated gastrointestinal infections have been associated with the aeromonas group of bacteria which contain both non-virulent strains as well as virulent strains within a particular species. this study monitors the colonization rates of colon tissue in a mouse-streptomycin dose/response model involving isolates of aeromonas veronii biovar sobria obtained from human clinical specimens. the ability to successfully colonize mouse colon tissues by the human clinical isola ...201121779939
pathogenic bacteria in sewage treatment plants as revealed by 454 pyrosequencing.this study applied 454 high-throughput pyrosequencing to analyze potentially pathogenic bacteria in activated sludge from 14 municipal wastewater treatment plants (wwtps) across four countries (china, u.s., canada, and singapore), plus the influent and effluent of one of the 14 wwtps. a total of 370?870 16s rrna gene sequences with average length of 207 bps were obtained and all of them were assigned to corresponding taxonomic ranks by using rdp classifier and megan. it was found that the most a ...201121780772
effects of dietary ß-1,3-glucan, chitosan or raffinose on the growth, innate immunity and resistance of koi (cyprinus carpio koi).this study was performed to determine the efficacy of three immunomodulators viz., ß-1,3 glucan, chitosan and raffinose on the innate immune response of koi, cyprinus carpio koi. kois were divided into 4 groups and each group was fed with diets supplemented with or without immunostimulant for 56 days. total leukocyte counts (wbc), the non-specific humoral (lysozyme, alternative complement pathway and superoxide dismutase) and cellular (phagocytic capacity and respiratory burst activity) response ...201121784160
biochemical and hematological reference intervals for krefft's turtles emydura macquarii krefftii from the burnett river catchment, australia.biochemical and hematological reference intervals have not previously been reported for emydura macquarii krefftii. in 2009, 56 e. m. krefftii were captured by hand from the burnett catchment, clinically assessed to determine health status and blood sampled. reference intervals were calculated from the 35 clinically healthy turtles using techniques established in other chelonid species. aberrant blood results were identified from the 21 clinically unhealthy turtles. low numbers of observed cases ...201121797034
Diversity and antibiotic resistance of Aeromonas spp. in drinking and waste water treatment plants.The taxonomic diversity and antibiotic resistance phenotypes of aeromonads were examined in samples from drinking and waste water treatment plants (surface, ground and disinfected water in a drinking water treatment plant, and raw and treated waste water) and tap water. Bacteria identification and intra-species variation were determined based on the analysis of the 16S rRNA, gyrB and cpn60 gene sequences. Resistance phenotypes were determined using the disc diffusion method. Aeromonas veronii pr ...201121907383
recombinant aexu effector protein of aeromonas veronii bv. sobria disrupts the actin cytoskeleton by downregulation of rac1 and induces direct cytotoxicity to β4-integrin expressing cell lines.aexu is a type three secretion system (ttss) effector of aeromonas hydrophila which has an in vitro adp-ribosyltransferase (art) and gtpase-activating protein (gap) activities on rac1, rhoa and cdc42. here we show that, aexu of aeromonas veronii bv. sobria aeg1 strain disrupts actin cytoskeleton of hela cells during aeg1 infection, aexu transfection or direct application of aexu protein. such cellular disruption was rescued by either inactivation of aexu-gap activity by substitution of arginine ...201121963679
different clinical characteristics among aeromonas hydrophila, aeromonas veronii biovar sobria and aeromonas caviae monomicrobial bacteremia.this study aimed to compare the clinical presentations of aeromonas hydrophila, a. veronii biovar sobria and a. caviae monomicrobial bacteremia by a retrospective method at three hospitals in taiwan during an 8-yr period. there were 87 patients with a. hydrophila bacteremia, 45 with a. veronii biovar sobria bacteremia and 22 with a. caviae bacteremia. compared with a. hydrophila and a. veronii biovar sobria bacteremia, a. caviae bacteremia was more healthcare-associated (45 vs 30 and 16%; p = 0. ...201122065896
a chitinase from aeromonas veronii cd3 with the potential to control myxozoan disease.the class myxosporea encompasses about 2,400 species, most of which are parasites of fish and cause serious damage in aquaculture. due to the concerns about food safety issues and limited knowledge of myxozoa life cycle and fish immune system, no chemicals, antibiotics or immune modulators are available to control myxozoa infection. therefore, little can be done once myxozoa establishment has occurred.201122205999
bundle-forming pilus locus of aeromonas veronii bv. sobria.little is known about the colonization mechanisms of aeromonas spp. previous work has suggested that the type iv bundle-forming pilus (bfp) is an aeromonad intestinal colonization factor. this study provides the first genetic characterization of this structure. to define the role of bfp in aeromonas veronii bv. sobria adherence, a 22-kb locus encoding the bundle-forming pilus was isolated; this contained 17 pilus-related genes similar to the mannose-sensitive hemagglutinin (msha) of vibrio chole ...201222311923
distribution and phenotypic and genotypic detection of a metallo-β-lactamase, cpha, among bacteraemic aeromonas isolates.the objectives of the study were to investigate the distribution of cpha-related genes (cpha) encoding a cpha metallo-β-lactamase (mbl) among 51 consecutive aeromonas blood isolates and to compare different phenotypic methods for detecting cpha. the presence of cpha was detected by pcr. four phenotypic methods, the imipenem-edta combined disc test, imipenem-edta mbl etest, agar dilution test and modified hodge test (mht), were used to detect imipenem susceptibility and mbl production. the result ...201222322339
broad diversity of conjugative plasmids in integron-carrying bacteria from wastewater this study we assessed the occurrence, diversity and conjugative potential of plasmids in integron-carrying aeromonas and enterobacteriaceae from wastewaters. sixty-six strains were included as donors in mating assays using rifampicin-resistant escherichia coli and pseudomonas putida recipient strains. the diversity of plasmids from donors and transconjugants (resistant to tetracycline or streptomycin) was evaluated by restriction analysis and replicon typing targeting 19 incompatibility grou ...201222409355
structural analysis of the o-specific polysaccharide from the lipopolysaccharide of aeromonas veronii bv. sobria strain k49.the o-specific polysaccharide obtained by mild-acid degradation of the lipopolysaccharide from aeromonas veronii bv. sobria strain k49 was studied by sugar and methylation analyses along with (1)h and (13)c nmr spectroscopy. the sequence of the sugar residues was determined using (1)h,(1)h noesy and (1)h,(13)c hmbc experiments. the o-specific polysaccharide was found to be a high molecular mass polysaccharide composed of repeating units of the structure: →2)-β-d-quip3nac-(1→3)-α-l-rhap-(1→3)-α-l ...201222483338
recombinant aeromonas hydrophila outer membrane protein 48 (omp48) induces a protective immune response against aeromonas hydrophila and edwardsiella tarda.the gene coding for an outer membrane protein omp48 of aeromonas hydrophila isolated from an infected fish was cloned and sequenced. analysis of nucleotide sequence showed the omp48 gene to be an adhesin encoding a protein of 426 amino acids with high identity to the omp48 gene of aeromonas veronii, another fish pathogen. the gene belonged to the maltoporin group of porins and had high similarity to lamb porins of a. hydrophila, aeromonas salmonicida and vibrio parahaemolyticus. the expressed pu ...201222564558
bacterial symbioses of the medicinal leech hirudo verbana.gastrointestinal microbiomes play important roles in the health and nutrition of animals and humans. the medicinal leech, hirudo verbana, serves as a powerful model for the study of microbial symbioses of the gut, due to its naturally limited microbiome compared with other popular models, the ability to cultivate the most abundant microbes, and genetically manipulate one of them, aeromonas veronii. this review covers the relevance and application of leeches in modern medicine as well as recent d ...201722572874
a variant quorum sensing system in aeromonas veronii mtcc 3249.we have investigated the quorum sensing control in aeromonas veronii mtcc 3249, originally isolated as a. culicicola from the midgut of culex quinquefasciatus. based on biosensor assays, the bacterium showed constant production of multiple acyl-homoserine lactones (ahls) with increasing cell-density. the luxri gene homologs, acur (a. culicicola transcriptional regulator) and acui (a. culicicola autoinducer) were successfully amplified by inverse-pcr. sequence analysis indicated acuri were diverg ...201222666003
identity and virulence properties of aeromonas isolates from diseased fish, healthy controls and water environment in investigate the species distribution in aeromonas isolates from diseased fish, healthy controls and water environment in china; to evaluate the frequency of the aerolysin (aer), cytotonic enterotoxin (alt), cytotoxic enterotoxin (act), temperature-sensitive protease (eprcai) and serine protease (ahp) genes in aeromonas isolates; and to determine the potential pathogenicity of these isolates.201222725694
characterization and virulence potential of phenotypically diverse aeromonas veronii isolates recovered from moribund freshwater ornamental fishes of kerala, the present study, we investigated the involvement of aeromonas spp. in eliciting disease outbreaks in freshwater ornamental fishes across the state of kerala, india. we investigated three incidences of disease, in which the moribund fishes exhibited clinical signs such as haemorrhagic septicemia (in gouramy, trichogaster sp.), dropsy (in oscar, astronotus ocellatus) and tail rot/fin rot (in gold fish, carassius carassius). pure cultures (n = 20 from each fish; 60 in total) of aeromonas spp. ...201322903451
effects of marine silages enriched with lactobacillus sakei 5-4 on haemato-immunological and growth response in pacific red snapper (lutjanus peru) exposed to aeromonas veronii.combined effects of marine silages enriched with lactobacillus sakei 5-4 were evaluated on growth performance, immune activity and disease resistance of pacific red snapper (lutjanus peru) against aeromonas veronii infection. the experimental fish were divided into three groups which were fed with each one of the following diets: silage-probiotic-free diet (control, c group), pacific creole-fish silage diet supplemented with live l. sakei (10(6) cfu g(-1)) (fslact group) and humboldt squid silag ...201222940556
investigation into the physiologies of aeromonas veronii in vitro and inside the digestive tract of the medicinal leech using microbial communities are widespread in nature and vital to the health and fitness of the host. deciphering the physiology of the microbiome in vivo is critical to understanding the molecular basis of the symbiosis. recently, the development and application of high-throughput sequencing techniques, particularly rna-seq, for studying microbial communities has enabled researchers to address not only which microbes are present in a given community but also how the community function ...201222983040
a severe case of aeromonas veronii biovar sobria travellers' diarrhoea characterized by vibrio parahaemolyticus co-isolation.we report a severe case of travellers' diarrhoea in a patient returning from ecuador to italy with the concomitant presence of aeromonas veronii biovar sobria and vibrio parahaemolyticus in their faeces. based on diagnostic results, epidemiological information and the clinical outcome, we conclude that the real aetiological agent was a. veronii biovar sobria, while v. parahaemolyticus was only transient in the intestine of the patient.201323002063
infections following the application of leeches: two case reports and review of the literature. 201223098279
detection of aerolysin gene in aeromonas hydrophila isolated from fish and pond water.aerolysin is a hemolytic toxin encoded by aerolysin gene (1482 bp) that plays a key role in the pathogenesis of aeromonas hydrophila infection in fish. new speciesspecific primers were designed to amplify 326 bp conserved region of aerolysin gene for a. hydrophila. twenty-five isolates of a. hydrophila recovered from fish and pond water were studied for detection of aerolysin gene. aerolysin gene was detected in 85% of the isolates during the study. the designed primers were highly specific and ...200823100746
resistance characterization, virulence factors, and eric-pcr fingerprinting of aeromonas veronii strains isolated from diseased trionyx sinensis.aeromonas veronii (av) is an important pathogen causing severe diseases in aquaculture. fifteen a. veronii strains isolated from diseased trionyx sinensis from four aquafarms was characterized by enterobacterial repetitive intergenic consensus-polymerase chain reaction (eric-pcr), antibiotic susceptibility testing, and identification of virulence factors. a. veronii strains were grouped into nine eric types with discriminatory ability (d) of 91.43 based on 90% similarity. the virulence genes wer ...201223134287
aeromonas australiensis sp. nov., isolated from irrigation water.a gram-negative, facultatively anaerobic bacillus, designated strain 266(t), was isolated from an irrigation water system in the south-west of western australia. analysis of the 16s rrna gene sequence confirmed that strain 266(t) belonged to the genus aeromonas, with the nearest species being aeromonas fluvialis (99.6% similarity to the type strain, with 6 nucleotide differences) followed by aeromonas veronii and aeromonas allosaccharophila (both 99.5%). analysis of gyrb and rpod sequences sugge ...201323159749
aeromonas caviae is the most frequent pathogen amongst cases of aeromonas bacteremia in japan.aeromonas species can cause various infections including bacteremia, gastroenteritis, cholangitis, and wound infections. to date, most studies on aeromonas species have been reported from countries other than japan. the aim of this study, therefore, was to evaluate aeromonas bacteremia in japan.201323163893
tissue distribution, expression, and antimicrobial activity of anas platyrhynchos avian β-defensin this study, a novel avian β-defensin (avbd) was isolated from the chaohu duck. the complete nucleotide sequence of the gene contained a 204-bp open reading frame that encoded 67 amino acids (aa), including a signal peptide of 20 aa, a propiece of 5 aa, and a mature peptide of 42 aa. the homology, characterization, and comparison of this gene with avbd from other avian species confirmed that it was duck avbd6. also, the preproprotein of avbd6 from chicken, goose, and duck was highly conserved ...201323243235
bacterial pathogens and flora isolated from farm-cultured eels (anguilla japonica) and their environmental waters in korean eel farms.the purpose of this study was to investigate bacterial pathogens and flora in both sick and clinically healthy eels, anguilla japonica, and the environmental rearing waters of korean eel farms. between 2003 and 2010, a total of 621 sick eels were submitted for diagnosis, while 216 healthy eels and 87 environmental water samples were collected during a survey of 26 eel farms in korea. seven different bacterial species were obtained from 183 isolates, which were recovered from the internal organs ...201223357049
suicide plasmid-dependent is1-element untargeted integration into aeromonas veronii bv. sobria generates brown pigment-producing and spontaneous pelleting mutant.foodborne gram-negative pathogens belonging to the genus aeromonas are variable in harboring insertion sequence (is) elements that play an important role in the generation of dysfunctional relatives of known genes. using suicide plasmids carrying an is1-element, untargeted integration is a common problem during experimental trials to generate specific mutations by homologous recombination. in this work, different strains of aeromonas veronii bv. sobria (aeg1 and atcc 9071t), a. hydrophila atcc 1 ...201323436029
identification of a bacteriovorax sp. isolate as a potential biocontrol bacterium against snakehead fish-pathogenic aeromonas veronii. 201423745946
high-yield production of a chitinase from aeromonas veronii b565 as a potential feed supplement for warm-water aquaculture.chitin, present in crustacean shells, insects, and fungi, is the second most plentiful natural organic fiber after wood. to effectively use chitin in a cost-saving and environmentally friendly way in aquaculture, crustacean shells (e.g., shrimp-shell meal) are supplemented into aquafeed after degradation by chemical methods. herein, we describe a chitinase from aeromonas veronii b565, designated chib565, which potently degrades shrimp-shell chitin and resists proteolysis. we isolated recombinant ...201423775269
protective efficacy of plga microspheres loaded with divalent dna vaccine encoding the ompa gene of aeromonas veronii and the hly gene of aeromonas hydrophila in the present study, poly (lactic-co-glycolic) acid (plga) was used as a carrier for a divalent fusion dna vaccine encoding the aeromonas veronii outer membrane protein a (ompa) and aeromonas hydrophila hemolysins (hly) protein. the recombinant pet-28a-ompa-hly was constructed by inserting the ompa gene and hly gene into a pet-28a expression vector. loading of ompa-hly antigen module on plga microspheres were accomplished by water-in-oil-in-water (w/o/w) encapsulation. the molecular weight and ...201324012571
characterization of pathogenic aeromonas veronii bv. veronii associated with ulcerative syndrome from chinese longsnout catfish (leiocassis longirostris günther).273 bacterial strains were isolated from 20 chinese longsnout catfish samples. the biochemical characteristics of all strains conformed to the species description of aeromonas veronii bv. veronii on the basis of vitek gni+ card. furthermore, 16s rdna, gyrb and rpod sequences of the representative strain py50 were sequenced and showed high similarity with a. veronii bv. veronii in genbank. antibiotic-resistance of the representative strain py50 was assessed by the kirby-bauer disk diffusion metho ...201224031843
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