Vibrio Strains Research Articles

Novel PhoH-encoding vibriophages with lytic activity against environmental Vibriostrains.

Cholera is a devastating diarrheal disease that accounts for more than 10% of children's lives worldwide, but its treatment is hampered by a rise in antibiotic resistance. One promising alternative to antibiotic therapy is the use of bacteriophages to treat antibiotic-resistant cholera infections, and control Vibrio cholera in clinical cases and in the environment, respectively. Here, we report four novel, closely related environmental myoviruses, VP4, VP6, VP18, and VP24, which we isolated from two environmental toxigenic Vibrio cholerae strains from river Kuja and Usenge beach in Kenya. High-throughput sequencing followed by bioinformatics analysis indicated that the genomes of the four bacteriophages have closely related sequences, with sizes of 148,180bp, 148,181bp, 148,179bp, and 148,179bp, and a G + C content of 36.4%. The four genomes carry the phoH gene, which is overrepresented in marine cyanophages. The isolated phages displayed a lytic activity against 15 environmental, as well as one clinical, Vibrio cholerae strains. Thus, these novel lytic vibriophages represent potential biocontrol candidates for water decontamination against pathogenic Vibrio cholerae and ought to be considered for future studies of phage therapy.

Characteristics of Antimicrobial-Resistant Vibrio parahaemolyticus Strains and Identification of Related Antimicrobial Resistance Gene Mutations

Multidrug-resistant (MDR) Vibrio parahaemolyticus strains have become a great threat to public health. The purpose of this study was to investigate differences in biological characteristics and antimicrobial resistance gene (ARG) mutations of V. parahaemolyticus that displayed different levels of antimicrobial resistance. The susceptibility of 74 V. parahaemolyticus strains to 9 common antimicrobials was investigated, of which 88% were resistant to 3-4 antimicrobials and 3% to 5-7 antimicrobials. Interestingly, only 9% were resistant to 1-2 antimicrobials. The MDR strains possessed longer growth lag time than the non-MDR strains and displayed weaker swimming abilities. Whole genome sequencing was performed on strains VP41, VP44, 460, and 469 that were resistant to two to three classes of antimicrobials. ARGs were identified and compared with that of reference strain ATCC17802, and some important mutations were deduced. The Val189Ile mutation emerged in qnr gene of a single strain. Besides, the nonsynonymous mutations existed in four ARGs in different strains, including CatB (Pro165Ser, Gly208Asp), VmeA (Ile313Thr), VmeC (Glu329Ala), and VmeD (Asn205Ser). These results linked resistance gene mutations to enhance resistance in V. parahaemolyticus strains and provide a reference for more effective monitoring and prevention of V. parahaemolyticus infections.

Dynamic Immune Response to Vibriosis in Pacific Oyster Crassostrea gigas Larvae during the Infection Process as Supported by Accurate Positioning of GFP-Tagged Vibrio Strains.

As the immune system is not fully developed during the larval stage, hatchery culture of bivalve larvae is characterized by frequent mass mortality caused by bacterial pathogens, especially Vibrio spp. However, the knowledge is limited to the pathogenesis of vibriosis in oyster larvae, while the immune response to pathogenic microorganisms in this early life stage is still far from being fully elucidated. In this study, we combined green fluorescent protein (GFP)-tagging, histological and transcriptomic analyses to clarify the pathogenesis of experimental vibriosis and the mechanisms used by the host Pacific oyster Crassostrea gigas larvae to resist infection. The Vibrio strains first colonized the digestive system and rapidly proliferated, while only the transcription level of IκB kinase (IKK) and nuclear factor κB (NF-κB) associated with signaling transduction were up-regulated in oyster at 18 h post challenge (hpc). The mRNA levels for integrin β-1, peroxinectin, and heat shock protein 70 (HSP70), which are associated with phagocytosis, cell adhesion, and cytoprotection, were not upregulated until 30 hpc when the necrosis already happened in the larval digestive system. This suggested that the immunity in the early stages of C. gigas is not strong enough to prevent vibriosis and future research may focus on the strengthening of the gastrointestinal immune ability to defend vibriosis in bivalve larvae.

Comparative immunogenicity of outer membrane protein K and whole-cell antigens of Vibrio parahaemolyticus for diagnosis.

The immunogenicity of soluble outer membrane protein K (OmpK)- small ubiquitin-like modifier, OmpK inclusion bodies, formalin, and heat-killed Vibrio parahaemolyticus cells were prepared and studied in a mouse model. The results of whole-cell ELISA and Western blot (WB) revealed that the serum against soluble OmpK and OmpK inclusion bodies reacted only with homologous V. parahaemolyticus. Furthermore, recombinant OmpK proteins were not recognized by the serum against whole-cell V. parahaemolyticus antigens. Unexpectedly, the serum against formalin and heat-killed V. parahaemolyticus reacted broadly with homologous (an immunization strain) and heterologous (non-immunization strains) V. parahaemolyticus and Vibrio species. The WB results revealed that the serum against the two V. parahaemolyticus whole-cell antigens primarily reacted with proteins that were approximately 100, 70, 36, 28, and 22kDa in the cell lysates from different Vibrio strains, rather than the recombinant OmpK. The 70 and 28kDa proteins exhibited specificity to Vibrio species, while the 22kDa protein was more specific to V. parahaemolyticus. This study showed the limitation of recombinant OmpK to prepare diagnostic antibodies and revealed several specific Omps of Vibrio sp. and V. parahaemolyticus that were promising in diagnosis and vaccine development.

Screening of anti‐ Vibrio activity of marine fungal methanolic fractions to control vibriosis in white shrimp ( Litopenaeus vannamei )

This study aims to screen and evaluate the antibacterial activity of methanolic extract from marine fungi against pathogenic vibrios. The resazurin-based assay was optimized for high-throughput screening of anti-Vibrio agents. Determination of minimum inhibitory concentrations of the test antibiotics ciprofloxacin and erythromycin against three pathogenic Vibrio strains revealed that the optimized assay can accurately measure antibacterial activity. A total of 1516 methanolic fractions of ethyl acetate extracts from 32 marine fungi were screened by the optimized assay, and four fractions were identified to have significantly inhibitory effect on all three test Vibrio strains. Among these, fraction Z16-17 derived from Schizophyllum commune MCCCZ16 showing strong anti-Vibrio activities and nontoxicity was evaluated for efficacy against experimental Vibrio vulnificus infection in white shrimp (Litopenaeus vannamei). Shrimp fed with fraction Z16-17 supplemented diet at 50, 100 and 200 μg/g for seven days showed notably higher survival rate than the control group fed with unsupplemented diet. Results suggested that the resazurin-based assay can be a reliable method to screen large chemical or natural product libraries for anti-Vibrio activity, and fraction Z16-17 has a good potential to reduce the negative impact of pathogenic vibrios in shrimp aquaculture.

Molecular analysis on Vibrio parahaemolyticus strains isolated from patients in Nanjing, Jiangsu, 2016–2019

Objective To understand the molecular characteristics of Vibrio parahaemolyticus strains in Nanjing, Jiangsu, and provide evidence for the prevention and control of human infection with V. parahaemolyticus. Methods Clinical isolates from diarrhea and food poisoning patients were collected from 2016 to 2019. Virulence genes of tlh, tdh, trh, toxRS/new and ORF8 were detected by polymerase chain reaction (PCR). Molecular types were analyzed by multilocus sequence typing (MLST). Results A total of 93 V. parahaemolyticus strains were collected. O3∶K6 was the predominant serotype (65 strains, 69.9%). Virulence genes screening revealed that all isolates carried tlh gene. 73 strains with tdh+trh-toxRS/new+ were classified as pandemic strains, and 5 non-pandemic strains with tdh-trh- were non-pathogenic strains. A total of 13 STs were detected, of which ST3 was predominant (68/93, 73.1%). Conclusion Molecular analysis on V. parahaemolyticus revealed that ST3 was predominant, and both the pandemic and non-pandemic strains were distributed in Nanjing.

Exogenous autoinducer-2 inhibits biofilm development of Desulfovibrio sp. Huiquan2017.

Sulfate-reducing bacteria (SRB) are culprits for microbiologically influenced corrosion, and biofilms are believed to play essential roles in the corrosion induced by SRB. However, little is known about the regulation of SRB biofilms. Quorum sensing signal molecules acyl-homoserine lactones (AHLs) and autoinducer-2 (AI-2) regulate biofilm formation of many bacteria. In this study, the production of AHLs and AI-2 by one SRB strain, Desulfovibrio sp. Huiquan2017, was detected, and the effect of exogenous AI-2 on bacterial biofilm formation was discussed. It was found that the cell-free supernatants of Desulfovibrio sp. Huiquan2017 induced luminescence in a ∆luxS mutant strain Vibrio harveyi BB170, indicating the production of functional AI-2 by the bacterium. In the presence of exogenous AI-2, the growth of Desulfovibrio sp. Huiquan2017 and early biofilm formation were not affected, but the later stage of biofilm development was inhibited significantly. The biofilms became looser, smaller, and thinner, and contained less bacteria and extracellular polymeric substances (EPS). The inhibition effect of AI-2 on the biofilm development of Desulfovibrio sp. Huiquan2017 was mainly achieved through reducing the amount of EPS in biofilms. These findings shed light on the biofilm regulation of SRB.

Characterization of a novel shrimp pathogen, Vibrio brasiliensis, isolated from Pacific white shrimp, Penaeus vannamei.

A novel pathogenic strain Vibrio 20190611023 was isolated from the hepatopancreas of moribund cultured Penaeus vannamei suffering from black gill disease. This strain was identified as V.brasiliensis based on the phylogenetic analyses of 16S rDNA gene and five other housekeeping genes (i.e., gapA, ftsZ, mreB, topA and gyrB). Some biochemical features of this strain were determined with an API 20NE system, and its haemolytic activity was determined using a sheep blood agar plate. The pathogenicity of this isolate 20190611023 was confirmed by the experimental challenge tests and histopathological examinations. P.vannamei were challenged via reverse gavage with different doses of bacterial suspensions. The calculated median lethal dose (LD50 ) was (3.16±1.78)×105 CFU/g (body weight). Moreover, antibiotic susceptibility tests were performed, the results of which showed that the strain 20190611023 was sensitive to chloramphenicol, compound sulphamethoxazole, ciprofloxacin, doxycycline and oxacillin, but resistant to erythromycin, kanamycin, gentamicin, cefoperazone, ceftriaxone, cefamezin and piperacillin. To our knowledge, this is the first report for demonstrating V.brasiliensis as a shrimp pathogen, which expands the host range of V.brasiliensis infection. The present study highlights that more attention should be paid to this novel pathogen in intensive shrimp aquaculture.

Characterization and Antimicrobial Susceptibility Patterns of Vibrio cholerae and Vibrio cholerae O 1 Isolated in Tropical Waters: A Contribution to Cholera Disease Prevention in Equatorial Region

The isolation and characterization of Vibrio strains were carried out in Yaounde (equatorial area). Well water characteristic focused on water temperature, pH, dissolved oxygen, dissolved CO2, electrical conductivity, suspended solids. Vibrio cholerae, Vibrio fluvialis, Vibrio mimicus, Vibrio parahaemolyticus and Vibrio vulnificus were identified in all four wells investigated. On 50 strains of Vibrio cholerae tested, 8 agglutinated anti O1 serum; 16% therefore belong to serogroup O1. Antimicrobial susceptibility tests showed that most of the environmental strains of Vibrio cholerae studied are sensitive to the majority of the antibiotics tested. The percentage of sensitivity for most of the antibiotics tested is above 50%. CPR (98%); CTX (94%); GM (84%); AMC (82%); DOX (72%); AMX (70%); NAL (52%). There were 34% cases of resistant to nalidixic acid, 26% to amoxicillin, 24% to chloramphenicol, and 18% to doxycycline. The percentage of sensitivity of Vibrio cholerae O1 is always greater than 50% with GM (100%); AMX and DOX (87.5%); CTX and CPR (75%); AMC and NAL (62.5%); CHL (50%). These results contribute to prevention and control of cholera in equatorial region.

A deep-sea bacterium related to coastal marine pathogens.

SummaryEvolution of virulence traits from adaptation to environmental niches other than the host is probably a common feature of marine microbial pathogens, whose knowledge might be crucial to understand their emergence and pathogenetic potential. Here, we report genome sequence analysis of a novel marine bacterial species, Vibrio bathopelagicus sp. nov., isolated from warm bathypelagic waters (3309 m depth) of the Mediterranean Sea. Interestingly, V. bathopelagicus sp. nov. is closely related to coastal Vibrio strains pathogenic to marine bivalves. V. bathopelagicus sp. nov. genome encodes genes involved in environmental adaptation to the deep‐sea but also in virulence, such as the R5.7 element, MARTX toxin cluster, Type VI secretion system and zinc‐metalloprotease, previously associated with Vibrio infections in farmed oysters. The results of functional in vitro assays on immunocytes (haemocytes) of the Mediterranean mussel Mytilus galloprovincialis and the Pacific oyster Crassostrea gigas, and of the early larval development assay in Mytilus support strong toxicity of V. bathopelagicus sp. nov. towards bivalves. V. bathopelagicus sp. nov., isolated from a remote Mediterranean bathypelagic site, is an example of a planktonic marine bacterium with genotypic and phenotypic traits associated with animal pathogenicity, which might have played an evolutionary role in the origin of coastal marine pathogens.

Sensing of intracellular Hcp levels controls T6SS expression in Vibrio cholerae

The type 6 secretion system (T6SS) is a bacterial weapon broadly distributed in gram-negative bacteria and used to kill competitors and predators. Featuring a long and double-tubular structure, this molecular machine is energetically costly to produce and thus is likely subject to diverse regulation strategies that are largely ill defined. In this study, we report a quantity-sensing control of the T6SS that down-regulates the expression of secreted components when they accumulate in the cytosol due to T6SS inactivation. Using Vibrio cholerae strains that constitutively express an active T6SS, we demonstrate that mRNA levels of secreted components, including the inner-tube protein component Hcp, were down-regulated in T6SS structural gene mutants while expression of the main structural genes remained unchanged. Deletion of both hcp gene copies restored expression from their promoters, while Hcp overexpression negatively impacted expression. We show that Hcp directly interacts with the RpoN-dependent T6SS regulator VasH, and deleting the N-terminal regulator domain of VasH abolishes this interaction as well as the expression difference of hcp operons between T6SS-active and inactive strains. We find that negative regulation of hcp also occurs in other V. cholerae strains and the pathogens Aeromonas dhakensis and Pseudomonas aeruginosa This Hcp-dependent sensing control is likely an important energy-conserving mechanism that enables T6SS-encoding organisms to quickly adjust T6SS expression and prevent wasteful build-up of its major secreted components in the absence of their efficient export out of the bacterial cell.

Isolation and characterization of a podovirus infecting the opportunist pathogen Vibrio alginolyticus and Vibrio parahaemolyticus

Bacterial infections have a negative impact on both animal husbandry industry and medicine, and increasing bacterial drug resistance exacerbates this adverse impact. Phages show promise as an alternative to drugs against drug-resistant bacteria. In this study, a novel virulent bacteriophage (phage) vB_ValP_IME234 against Vibrio alginolyticus and Vibrio parahaemolyticus was isolated from freshwater in Beijing, China. Phage vB_ValP_IME234 had an isometric head (59 nm in diameter) and a short tail (10 nm long), belonging to Podoviridae family. Its complete genome is liner double-stranded DNA (dsDNA) with a GC content of 41.6% while encoding 61 putative proteins. Three transfer RNA (tRNA) and no lysogenic gene was detected. vB_ValP_IME234 had a polyvalent infectivity, a burst of 390 PFU/cell, and is stable under different temperatures (4 °C to 50 °C) and pH (6.0 to 10.0) values. Host range test showed that vB_ValP_IME234 has the ability to infect seven strains of Vibrio in total. Phylogenetic analyses based on terminase and capsid suggested that this phage had a close relationship with Vibrio phages. These results indicate that vB_ValP_IME234 could be used as a potential biocontrol agent against V. alginolyticus strains.

The quorum-sensing systems of Vibrio campbellii DS40M4 and BB120 are genetically and functionally distinct.

Vibrio campbellii BB120 (previously classified as Vibrio harveyi) is a fundamental model strain for studying quorum sensing in vibrios. A phylogenetic evaluation of sequenced Vibrio strains in Genbank revealed that BB120 is closely related to the environmental isolate V. campbellii DS40M4. We exploited DS40M4's competence for exogenous DNA uptake to rapidly generate greater than 30 isogenic strains with deletions of genes encoding BB120 quorum-sensing system homologues. Our results show that the quorum-sensing circuit of DS40M4 is distinct from BB120 in three ways: (i) DS40M4 does not produce an acyl homoserine lactone autoinducer but encodes an active orphan LuxN receptor, (ii) the quorum regulatory small RNAs (Qrrs) are not solely regulated by autoinducer signalling through the response regulator LuxO and (iii) the DS40M4 quorum-sensing regulon is much smaller than BB120 (~100 genes vs. ~400 genes, respectively). Using comparative genomics to expand our understanding of quorum-sensing circuit diversity, we observe that conservation of LuxM/LuxN proteins differs widely both between and within Vibrio species. These strains are also phenotypically distinct: DS40M4 exhibits stronger interbacterial cell killing, whereas BB120 forms more robust biofilms and is bioluminescent. These results underscore the need to examine wild isolates for a broader view of bacterial diversity in the marine ecosystem.

Behavior of Vibrio spp. in Table Olives.

The presence of Vibrio species in table olive fermentations has been confirmed by molecular biology techniques in recent studies. However, there has been no report of any foodborne outbreak caused by Vibrio due to the consumption of table olives, and their role as well as the environmental conditions allowing their survival in table olives has not been elucidated so far. The aims of this work were to model the behavior of an inoculated Vibrio cocktail in diverse table olive environments and study the possible behavior of an inoculated Vibrio cocktail in table olives. First, an in vitro study has been performed where the microbial behavior of a Vibrio cocktail was evaluated in a laboratory medium and in olive brines using predictive models at different NaCl concentrations (2–12%) and pH levels (4.0–9.0). Afterward, a challenge testing was done in lye-treated olives inoculated at the beginning of fermentation with the Vibrio cocktail for 22 days. The Vibrio cocktail inoculated in table olives has not been detected in olive brines during fermentation at different pH levels. However, it was observed that this microorganism in a laboratory medium could reach an optimal growth at pH 9 and 2% salt, without time of constant absorbance (tA), and the maximum absorbance value (yend) observed was at pH 8 and 2% salt conditions. The statistical analysis demonstrated that the effect of salt concentration was higher than pH for the kinetic growth parameters (μmax, tA, and yend). On the other hand, it was confirmed that no growth of the Vibrio cocktail on any sample was noticed in lye-treated olive fermentations. Thus, it was concluded that the presence of olive compounds (unknown) did not allow the development of Vibrio strains, so it is a very safety product as it has a natural antimicrobial compound, but the possibility that a native Vibrio sp. is able to acquire the capacity to adapt to this compound should be considered in further studies.

Draft Genome Sequences of Vibrio vulnificus Strains Recovered from Moribund Tilapia.

ABSTRACTPotentially zoonotic Vibrio vulnificus strains were isolated from vibriosis outbreaks occurring on eastern Mediterranean tilapia farms between 2016 and 2019. In this work, the draft genome sequences of three representative isolates are presented.

Pan-Genome Analysis of Vibrio cholerae and Vibrio metschnikovii Strains Isolated From Migratory Birds at Dali Nouer Lake in Chifeng, China.

Migratory birds are recently recognized as Vibrio disease vectors, but may be widespread transporters of Vibrio strains. We isolated Vibrio cholerae (V. cholerae) and Vibrio metschnikovii (V. metschnikovii) strains from migratory bird epidemic samples from 2017 to 2018 and isolated V. metschnikovii from migratory bird feces in 2019 from bird samples taken from the Inner Mongolia autonomous region of China. To investigate the evolution of these two Vibrio species, we sequenced the genomes of 40 V. cholerae strains and 34 V. metschnikovii strains isolated from the bird samples and compared these genomes with reference strain genomes. The pan-genome of all V. cholerae and V. metschnikovii genomes was large, with strains exhibiting considerable individual differences. A total of 2,130 and 1,352 core genes were identified in the V. cholerae and V. metschnikovii genomes, respectively, while dispensable genes accounted for 16,180 and 9,178 of all genes for the two strains, respectively. All V. cholerae strains isolated from the migratory birds that encoded T6SS and hlyA were non-O1/O139 serotypes without the ability to produce CTX. These strains also lacked the ability to produce the TCP fimbriae nor the extracellular matrix protein RbmA and could not metabolize trimetlylamine oxide (TMAO). Thus, these characteristics render them unlikely to be pandemic-inducing strains. However, a V. metschnikovii isolate encoding the complete T6SS system was isolated for the first time. These data provide new molecular insights into the diversity of V. cholerae and V. metschnikovii isolates recovered from migratory birds.

Virulence of Vibrio harveyi ORM4 towards the European abalone Haliotis tuberculata involves both quorum sensing and a type III secretion system.

Environmental Vibrio strains represent a major threat in aquaculture, but the understanding of their virulence mechanisms heavily relies on the transposition of knowledge from human-pathogen vibrios. Here, the genetic bases of the virulence of Vibrio harveyi ORM4 towards the European abalone Haliotis tuberculata were characterized. We demonstrated that luxO, encoding a major regulator of the quorum sensing system, is crucial for the virulence of this strain, and that its deletion leads to a decrease in swimming motility, biofilm formation, and exopolysaccharide production. Furthermore, the biofilm formation by V. harveyi ORM4 was increased by abalone serum, which required LuxO. The absence of LuxO in V. harveyi ORM4 yielded opposite phenotypes compared with other Vibrio species including V. campbellii (still frequently named V. harveyi). In addition, we report a full type III secretion system (T3SS) gene cluster in the V. harveyi ORM4 genome. LuxO was shown to negatively regulate the promoter activity of exsA, encoding the major regulator of the T3SS genes, and the deletion of exsA abolished the virulence of V. harveyi ORM4. These results unveil virulence mechanisms set up by this environmentally important bacterial pathogen and pave the way for a better molecular understanding of the regulation of its pathogenicity.

Studies on Phytochemical, Antimicrobial activity and Micro propagation of Medicinal plants from Eastern Ghats of Andhra Pradesh

The aim of the present study was to investigate the presence of phyto chemical, antimicrobial activities and micro propagation of the selected medicinal plants i.e. Rauwolfia serpentina, Adhatoda vasica and Alstonia scholaris. These endemic plants belong to Apocynaceae and were collected from higher altitudes of Eastern Ghats, Lambasingi forest region, Andhra Pradesh India. To determine the total phenolic and flavonoid contents, Soxhlet apparatus was used for this study. Solvents used were in this study are water, ethyl acetate, chloroform and methanol. Among them the solvent methanolic extract of Rauwolfia serpentina (57.15±1.2) and Alstonia scholaris (55.06±0.7) showed high content of saponins. The test microrganism which were studied against the efficacy of selected medicinal plant extracts were, two bacterial strians i.e., Streptococcus pyogenes, Pseudomonas aeruginosa and two fungal strains Aspergillus niger and Vibrio cholera. The antimicrobial activity was proved that the methanol extracts was found to be maximum antimicrobial growth inhibition. The simple and effective protocol was developed to propagate the Rauwolfia plant from nodal explants. Maximum no of 95% plantlets regenerated successfully. These propagated plantlets were hardened to survive in vivo conditions.

Effects of crude oil and aromatic compounds on growth and bioluminescence of Vibrio campbellii FS5.

Fifteen native luminescent bacteria were isolated from the Gulf of Thailand, and their sensitivity for the detection of toxicity of crude oil and its aromatic components was investigated. Of these isolates, Vibrio campbellii strain FS5 was one of the two most highly inhibited bacteria at all crude oil concentrations. This bacterium showed a decrease in luminescence intensity of between 10.7 and 80.2% after a 15-min exposure to 0.0001-10mg/L of crude oil. The degree of bioluminescence inhibition increased with increasing concentrations of crude oil. The presence of crude oil at all concentrations had negative effects on the log bioluminescence per log number of viable cells after 15- to 105-min exposure. About 10 to 100 times, lower half maximal effective concentration (EC50) values were observed for polycyclic aromatic hydrocarbons (PAHs) than those for benzene, toluene, ethylbenzene, and xylene (BTEX). In the presence of each individual BTEX and PAH, the bioluminescence inhibition increased with increasing exposure time (1-32h). This indigenous bacterium can be used as a simple and general indicator of oil contamination and its impact on coastal waters as well as for assessing potential toxicity during oil bioremediation.

Genetic Characteristics of Antibiotic Resistance Gene of Vibrio cholerae Isolated

Vibrio cholerae is the factor of cholera disease in human and it has been becoming a serious problem in human health. This study was conducted to identify the genetic characteristics and antibiotic resistance of V. cholerae isolated in Tra Vinh Province. From the results, twenty-five (25) Vibrio spp. were isolated, including 6 strains of Vibrio (V.) cholerae (24%), 8 strains of V. paraheamolyticus (32%), 4 strains of V. vulnificus (16%), 5 strains of V. fluvialis (20%), and 2 strains of V. alginolyticus (8%). The serogroup results showed that all the 6 V. cholerae belonged to serogroup O1, with 50% positive to serotype Inaba, and 50% positive to Ogawa. No strain belonged to serogroup O139. The results also showed that 50% of V. cholerae were resistant to streptomycin and 33% were resistant to tetracycline and trimethoprim-sulfamethoxazole. Two of the 6 strains had an antibiotic resistance gene (gene tetA) encoding for a tetracycline-resistant factor. Gene blaSHV, gene aac(3)-IV and gene dhfrI encoding for β-lactam, aminoglycoside, trimethoprim resistant factors were not detected. Additionally, the results showed that adhesion indexes of V. cholerae strains T1 and T3 in the intestinal mucosa of rabbits shared the same antigens with the bacteria used to produce cholera vaccine (mORCVAX) available in Vietnam. V. cholerae was prevalent in the environment and clams in Tra Vinh province. Information from this research may be useful for further studies.