Vibrio Cholerae Strains Research Articles

Development of a simple allele-specific PCR for the detection of pathogenic Vibrio cholerae O1 and O139 in seafood

This study developed a simple allele specific (AS) PCR assay for the detection of pathogenic Vibrio cholerae strains in seafood. A pair of primers, (1) an AS primer targeting the mutation at site G450 in the hapR2 allele and a (2) common forward primer, were designed to detect the pathogenic O1 and O139 strains. An artificial mismatch was also added to the AS primer to increase its specificity to the target allele. The PCR assays using different DNA polymerases of varying efficiencies were then optimized. The application of the AS primers in both conventional and real-time PCR assays was facilitated with enriched seafood samples spiked with known concentration of pathogenic V. cholerae. The designed AS primers showed high specificity and sensitivity to the hapR2 allele for both conventional and real-time PCR assays. Enrichment of seafood samples for 8 h is recommended to detect viable pathogenic V. cholerae presence in seafood. In this study, we developed an AS-PCR that is simple, rapid, and a low-cost alternative for routine detection of pathogenic V. cholerae in different seafood samples thus aiding in the surveillance and implementation of food safety measures at the seafood post-harvest level.

Development of an INDEL typing system for <i>ctx</i>+ strains of <i>Vibrio cholerae</i> from the seventh pandemic

BACKGROUND: The seventh cholera pandemic is accompanied by the formation of Vibrio cholerae clones with new genetic properties, including those with the ability to spread pandemically and cause diseases with a more severe clinical course. The widespread distribution of such genetic variants of Vibrio cholerae and the possibility of their introduction into the territory of the Russian Federation necessitate constant comprehensive monitoring using modern molecular genetic technologies. AIM: To improve INDEL typing of ctx+ strains of V. cholerae of the seventh pandemic by using additional INDEL loci. Materials and methods: A bioinformatic analysis of 2105 full-genome sequences of toxigenic ctxAB+tcpA+ strains of Vibrio cholerae O1 El Tor from open databases was carried out in order to search for INDEL loci for molecular typing. Based on the convenience criterion for allele size identification, eight INDEL loci were selected. Three loci have been described previously, and five were identified as a result of this work. The designed primers formed amplicons ranging in size from 67 to 390 base pairs, which made it possible to confidently identify them during gel electrophoresis. Results: The distribution of alleles formed 11 unique INDEL clusters, which we designated A-K. Based on the number of strains within the clusters, three types of clusters were identified: major (A, B and C) made up 89% of the total number of sequences studied, intermediate (D, E, F, G and H) 10.5% of the genomes. Three minor clusters (I, J and K) were represented by single strains. Four clusters united strains isolated in the 20th century (A — in 1941, F — in 1957, G — in 1993, E — in 1999), and seven clusters — in the 21st century in the period from 2003 to 2016. In the period from 2019 to 2023, representatives of INDEL clusters were active: A, B, D and E. ConclusionS: The study of the timing of circulation suggested that representatives of different clusters have different epidemic potential, which was manifested in the absence of isolation of strains of some clusters in recent years. A comparative study of INDEL typing with SNP typing in the in silico analysis of 378 genomes of strains isolated on the African continent indicates that the proposed INDEL typing method is not inferior to SNP typing in terms of resolution.

Variations in the Antivirulence Effects of Fatty Acids and Virstatin against Vibrio cholerae Strains.

The expression of two major virulence factors of Vibrio cholerae, cholera toxin (CT) and toxin coregulated pilus (TCP), is induced by environmental stimuli through a cascade of interactions among regulatory proteins known as the ToxR regulon when the bacteria reach the human small intestine. ToxT is produced via the ToxR regulon and acts as the direct transcriptional activator of CT (ctxAB), TCP (tcp gene cluster), and other virulence genes. Unsaturated fatty acids (UFAs) and several smallmolecule inhibitors of ToxT have been developed as antivirulence agents against V. cholerae. This study reports the inhibitory effects of fatty acids and virstatin (a small-molecule inhibitor of ToxT) on the transcriptional activation functions of ToxT in isogenic derivatives of V. cholerae strains containing various toxT alleles. The fatty acids and virstatin had discrete effects depending on the ToxT allele (different by 2 amino acids), V. cholerae strain, and culture conditions, indicating that V. cholerae strains could overcome the effects of UFAs and small-molecule inhibitors by acquiring point mutations in toxT. Our results suggest that small-molecule inhibitors should be examined thoroughly against various V. cholerae strains and toxT alleles during development.

Molecular mechanism of plasmid elimination by the DdmDE defense system.

Seventh-pandemic Vibrio cholerae strains contain two pathogenicity islands that encode the DNA defense modules DdmABC and DdmDE. In this study, we used cryogenic electron microscopy to determine the mechanistic basis for plasmid defense by DdmDE. The helicase-nuclease DdmD adopts an autoinhibited dimeric architecture. The prokaryotic Argonaute protein DdmE uses a DNA guide to target plasmid DNA. The structure of the DdmDE complex, validated by in vivo mutational studies, shows that DNA binding by DdmE triggers disassembly of the DdmD dimer and loading of monomeric DdmD onto the nontarget DNA strand. In vitro studies indicate that DdmD translocates in the 5'-to-3' direction, while partially degrading the plasmid DNA. These findings provide critical insights into the mechanism of DdmDE systems in plasmid elimination.

Nucleoid-associated proteins shape the global protein occupancy and transcriptional landscape of a clinical isolate of Vibrio cholerae.

New strains of the bacterial pathogen Vibrio cholerae, bearing novel horizontally acquired elements (HAEs), frequently emerge. HAEs provide beneficial traits to the bacterium, such as antibiotic resistance and defense against invading bacteriophages. Xenogeneic silencers are proteins that help bacteria harness new HAEs and silence those HAEs until they are needed. H-NS is the best-studied xenogeneic silencer; it is one of the nucleoid-associated proteins (NAPs) in gamma-proteobacteria and is responsible for the proper regulation of HAEs within the bacterial transcriptional network. We studied the effects of H-NS and other NAPs on the HAEs of a clinical isolate of V. cholerae. Importantly, we found that H-NS partners with a small and poorly characterized protein, TsrA, to help domesticate new HAEs involved in bacterial survival and in causing disease. A proper understanding of the regulatory state in emerging isolates of V. cholerae will provide improved therapies against new isolates of the pathogen.

Emerging resistome diversity in clinical Vibrio cholerae strains revealing their role as potential reservoirs of antimicrobial resistance.

This is a unique and novel study delineating the genotyping and subsequent prediction of AMR determinants of Vibrio cholerae revealing the potential of contemporary strains to serve as precursors of severe AMR crisis in cholera. Genotyping of representative strains, VC1 and VC2 was undertaken to characterize antimicrobial resistance genes (ARGs) against chloramphenicol, SXT, nalidixic acid and streptomycin against which they were found to be resistant by antibiogram analysis in our previous investigation. strAB, sxt, sul2, qace∆1-sul1 were detected by PCR. Genome annotation and identification of ARGs with WGS helped to detect the presence of almG, varG, strA (APH(3'')-Ib), strB (APH(6)-Id), sul2, catB9, floR, CRP, dfrA1 genes. Signatures of resistance determinants and protein domains involved in antimicrobial resistance, primarily, efflux of antibiotics were identified on the basis of 30-100% homology to reference proteins. These domains were predicted to be involved in other metabolic functions on the basis of 100% identity with 100% coverage with reference protein and nucleotide sequences and were predicted to be of a diverse taxonomic origin accentuating the influence of the microbiota on AMR acquisition. Sequence analysis of QRDR (quinolone resistance-determining region) revealed SNPs. Cytoscape v3.8.2 was employed to analyse protein-protein interaction of MDR proteins, MdtA and EmrD-2, with nodes of vital AMR pathways. Vital nodes involved in efflux of different classes of antibiotics were found to be absent in VC1 and VC2 justifying the sensitivity of these strains to most antibiotics. The study helped to examine the resistome of VC isolated from recent outbreaks to understand the underlying reason of sensitivity to most antibiotics and also to characterize the ARGs in their genome. It revealed that VC is a reservoir of signatures of resistance determinants and serving as precursors for severe AMR crisis in cholera. This is the first study, to our knowledge, which has scrutinized and presented systematically, information on prospective domains which bear the potential of serving as AMR determinants in VC with the help of bioinformatic tools. This pioneering approach may help in the prediction of AMR landfalls and benefit epidemiological surveillance and early warning systems.

Spatial constraints and stochastic seeding subvert microbial arms race.

Surface attached communities of microbes grow in a wide variety of environments. Often, the size of these microbial community is constrained by their physical surroundings. However, little is known about how size constraints of a colony impact the outcome of microbial competitions. Here, we use individual-based models to simulate contact killing between two bacterial strains with different killing rates in a wide range of community sizes. We found that community size has a substantial impact on outcomes; in fact, in some competitions the identity of the most fit strain differs in large and small environments. Specifically, when at a numerical disadvantage, the strain with the slow killing rate is more successful in smaller environments than in large environments. The improved performance in small spaces comes from finite size effects; stochastic fluctuations in the initial relative abundance of each strain in small environments lead to dramatically different outcomes. However, when the slow killing strain has a numerical advantage, it performs better in large spaces than in small spaces, where stochastic fluctuations now aid the fast killing strain in small communities. Finally, we experimentally validate these results by confining contact killing strains of Vibrio cholerae in transmission electron microscopy grids. The outcomes of these experiments are consistent with our simulations. When rare, the slow killing strain does better in small environments; when common, the slow killing strain does better in large environments. Together, this work demonstrates that finite size effects can substantially modify antagonistic competitions, suggesting that colony size may, at least in part, subvert the microbial arms race.

Comprehensive in silico analyses of fifty-one uncharacterized proteins from Vibrio cholerae.

Due to the rise of multidrug-resistant strains of Vibrio cholerae and the recent cholera outbreaks in African and Asian nations, it is imperative to identify novel therapeutic targets and possible vaccine candidates. In this regard, this work primarily aims to identify and characterize new antigenic molecules using comparative RNA sequencing data and label-free proteomics data, carried out with essential GTPase cgtA knockdown and wild-type strain of V. cholerae. We identified hitherto 51 characterized proteins from high-throughput RNA-sequencing and proteomics data. This work involved the assessment of their physicochemical characteristics, subcellular localization, solubility, structures, and functional annotations. In addition, the immunoinformatic and reverse vaccinology technique was used to find new vaccine targets with high antigenicity, low allergenicity, and low toxicity profiles. Among the 51 proteins, 24 were selected based on their immunogenic profiles to identify B/T-cell epitopes. In addition, 20 prospective therapeutic targets were identified using virulence predictions and related investigations. Furthermore, two proteins, UniProt ID- Q9KRD2 and Q9KU58, with molecular weight of 92kDa and 12kDa, respectively, were chosen for cloning and expression towards in vitro biochemical characterization based on their range of expression patterns, high antigenic, low allergenic, and low toxicity properties. In conclusion, we believe that this study will reveal new facets and avenues for drug discovery and put us a step forward toward novel therapeutic interventions against the deadly disease of cholera.

Change of antibiotic resistance in Vibrio spp. during shrimp culture in Shanghai

The judicious application of antibiotics in shrimp aquaculture is vital for addressing bacterial infections, yet monitoring bacterial resistance during distinct aquaculture phases remains deficient. This study focused on tracking antibiotic resistance dynamics in Vibrio strains sourced from both shrimp and their breeding settings. Over a standard aquaculture period (day 0, 20, 40, 60, and 80), we isolated eighty-eight Vibrio cholerae and ninety Vibrio parahaemolyticus strains from water, sediment, and shrimp samples. All isolates underwent assessment for antibiotic resistance phenotype and genotype. Both Vibrio species demonstrated resistance to nine antimicrobials. Notably, Vibrio cholerae isolates exhibited resistance rates of up to 46.6% for cephazolin, 30.7% for streptomycin, and 11.4% for ampicillin. Conversely, V. parahaemolyticus isolates displayed pronounced resistance to ampicillin (100%), cephazolin (62.2%), and cefoxitin (36.7%). Moreover, we identified 38 antibiotic resistance genes (ARGs) across all samples, with a higher prevalence observed in the water. Genetic diversity and clonal origins of the Vibrio isolates were quantified using Multilocus Sequence Typing (MLST). New Sequence Types (STs) were predominant among V. cholerae (95.4% of 43 isolates) and V. parahaemolyticus (92.9% of 28 isolates). Predominantly, V. parahaemolyticus isolates formed two extensive clonal groups: CC1420 and CC744. As the shrimp cultivation period progressed, both the resistance development rate among isolates and the average ARG count within the same STs of Vibrios steadily increased. This study underscores the potential role of ARGs transmission in the aquaculture environment as a crucial conduit for Vibrio antibiotic resistance development. Insights gained contribute to understanding the dissemination and transmission of antibiotic resistance in aquaculture, aiding in devising strategies to curb antibiotic resistance in aquatic environments.

Toxigenic Vibrio cholerae strains in South-East Queensland, Australian river waterways.

Cholera is a major public health problem in developing and underdeveloped countries; however, it remains of concern to developed countries such as Australia as international travel-related or locally acquired cholera or diarrheal disease cases are still reported. Cholera is mainly caused by cholera toxin (CT) producing toxigenic O1 and O139 serogroup Vibrio cholerae strains. While most toxigenic V. cholerae cases in Australia are thought to be caused by international-acquired infections, Australia has its own indigenous toxigenic and non-toxigenic O1 and non-O1, non-O139 V. cholerae (NOVC) strains. In Australia, in the 1970s and again in 2012, it was reported that south-east Queensland riverways were a reservoir for toxigenic V. cholerae strains that were linked to local cases. Further surveillance on environmental reservoirs, such as riverways, has not been reported in the literature in the last 10 years. Here we present data from sites previously related to outbreaks and surveillance sampling to detect the presence of V. cholerae using PCR in conjunction with MALDI-TOF and whole-genome sequencing. In this study, we were able to detect NOVC at all 10 sites with all sites having toxigenic non-O1, non-O139 strains. Among 133 NOVC isolates, 22 were whole-genome sequenced and compared with previously sequenced Australian O1 and NOVC strains. None of the samples tested grew toxigenic or non-toxigenic O1 or O139, responsible for epidemic disease. Since NOVC can be pathogenic, continuous surveillance is required to assist in theclinical and envir rapid identification of sources of any outbreaks and to assist public health authorities in implementing control measures. IMPORTANCE Vibrio cholerae is a natural inhabitant of aquatic environments, both freshwater and seawater, in addition to its clinical significance as a causative agent of acute diarrhea and extraintestinal infections. Previously, both toxigenic and non-toxigenic, clinical, and environmental V. cholerae strains have been reported in Queensland, Australia. This study aimed to characterize recent surveillance of environmental NOVC strains isolated from Queensland River waterways to understand their virulence, antimicrobial resistance profile and to place genetic current V. cholerae strains from Australia in context with international strains. The findings from this study suggest the presence of unique toxigenic V. cholerae in Queensland river water systems that are of public health concern. Therefore, ongoing monitoring and genomic characterization of V. cholerae strains from the Queensland environment is important and would assist public health departments to track the source of cholera infection early and implement prevention strategies for future outbreaks. The genomics of environmental V. cholerae could assist us to understand the natural ecology and evolution of this bacterium in natural environments with respect to global warming and climate change.

Alkyl Sulfatase of Cholera Vibrios

The aim of the work was to study the structure of the alkyl sulfatase (asu) gene in Vibrio cholerae strains of various serogroups, as well as to compare nucleotide and amino acid sequences of alkyl sulfatases using various methods of bioinformatic analysis.Materials and methods. 483 strains of V. cholerae O1, O139 and nonO1/nonO139 serogroups were employed in the work. The search for the gene, its recurrence, and localization was carried out applying the Blast software. The nucleotide and corresponding amino acid sequences of the gene, as well as its structure, were studied using bioinformatic analysis. Sequencing was performed on the MiSeq (Illumina) platform. The enzymatic activity was detected using a medium, confirming the presence/absence of the gene by PCR in vitro and in silico.Results and discussion. Bioinformatic analysis of the nucleotide and corresponding amino acid sequences of the asu gene has been carried out and its structure investigated. Four functional domains have been identified. In the beta-lactamase domain, a conservative amino acid sequence -HAHADH- has been found in all strains of cholera vibrios, which is part of the Zn2+ binding motif. It has been established that the alkyl sulfatase of cholera vibrios belongs to the family of Zn2+-dependent β-lactamases. Blast analysis has revealed the similarity of nucleotide and amino acid sequences of alkyl sulfatases in representatives of V. cholerae O1 and O139 serogroups (ctxAB+tcpA+) and representatives of the genera Aeromonas and Pseudomonas, which is in the line with the data of 3D modeling of the amino acid sequence structures of the alkyl sulfatase enzyme in these microorganisms. The bioinformatic analysis of nucleotide and amino acid sequences of alkyl sulfatases in cholera vibrios has showed the conservativeness of these sequences in toxigenic strains and the presence of a number of single mutations in the asu gene in atoxigenic ones. The presence or absence of the asu gene has been established by PCR in vitro and in silico and confirmed by the results obtained using the Blast program. It is demonstrated that the presence/absence of the asu gene correlates with the ability/inability of O139 strains to hydrolyze SDS on the medium. These results can be used in studying mechanisms of cholera vibrios adaptation, persistence and pathogenicity.

Duped by dumping syndrome: non-endemic Vibrio cholerae bacteremia in an immunocompetent host with gastric bypass surgery, a case report

Extra-intestinal infection with non-O1/non-O139 strains of Vibrio cholerae (NOVC) is rare, though bacteremia and hepatobiliary manifestations have been reported. Reduced stomach acid, or hypochlorhydria, can increase risk of V. cholerae infection. We describe a 42-year-old woman with hypochlorhydria due to untreated Helicobacter pylori infection, gastric-bypass surgery, and chronic proton pump inhibitors (PPI) exposure, who developed acute diarrhoea following raw oyster consumption. Her symptoms were attributed to rapid gastric emptying (dumping syndrome) after a negative limited stool work-up. She had persistent diarrhoea, weight loss, and after 5 months was admitted with acute cholecystitis and NOVC bacteremia, requiring cholecystectomy. This is the first reported case of NOVC bacteremia and cholecystitis in a patient with gastric bypass. This case highlights the potential for NOVC biliary carriage, the role of hypochlorhydria as a risk factor for Vibrio infection, and the importance of excluding infectious diarrhoea in patients with new onset of symptoms compatible with dumping syndrome and a relevant travel history.

Ancestral Origin and Dissemination Dynamics of Reemerging Toxigenic Vibrio cholerae, Haiti.

The 2010 cholera epidemic in Haiti was thought to have ended in 2019, and the Prime Minister of Haiti declared the country cholera-free in February 2022. On September 25, 2022, cholera cases were again identified in Port-au-Prince. We compared genomic data from 42 clinical Vibrio cholerae strains from 2022 with data from 327 other strains from Haiti and 1,824 strains collected worldwide. The 2022 isolates were homogeneous and closely related to clinical and environmental strains circulating in Haiti during 2012-2019. Bayesian hypothesis testing indicated that the 2022 clinical isolates shared their most recent common ancestor with an environmental lineage circulating in Haiti in July 2018. Our findings strongly suggest that toxigenic V. cholerae O1 can persist for years in aquatic environmental reservoirs and ignite new outbreaks. These results highlight the urgent need for improved public health infrastructure and possible periodic vaccination campaigns to maintain population immunity against V. cholerae.

Molecular characterization of Vibrio species isolated from dairy and water samples

Vibrio species can cause foodborne infections and lead to serious gastrointestinal illnesses. The purpose of this research was to detect the Vibrio cholerae and Vibrio parahaemolyticus in raw milk, dairy products, and water samples. Also, it investigated the virulence factors, antibiotic resistance and biofilm formation in isolated bacteria. Conventional and molecular approaches were used to identify the isolates in this study. Vibrio species were detected in 5% of the samples. Vibrio cholerae and Vibrio parahaemolyticus were isolated from 1.25 and 1.5%, respectively, of the total samples. Penicillin resistance was detected in all strains of Vibrio cholerae and Vibrio parahaemolyticus, with a MAR index ranging from 0.16 to 0.5. Four isolates were moderate biofilm producer and three of them were MDR. When Vibrio cholerae was screened for virulence genes, ctxAB, hlyA, and tcpA were found in 80, 60, and 80% of isolates, respectively. However, tdh + /trh + associated-virulence genes were found in 33.3% of Vibrio parahaemolyticus isolates.

An oral cholera vaccine in the prevention and/or treatment of inflammatory bowel disease.

The oral cholera vaccine WC-rBS consists of 4 different inactivated strains of Vibrio cholerae (LPS source) admixed with recombinant cholera toxin B subunit. Because of its unique composition and anti-inflammatory properties reported for both CTB and low doses of LPS from other Gram-negative bacteria, we speculated that WC-rBS might have anti-inflammatory potential in a chronic autoimmune disease such as inflammatory bowel diseases. First in vitro endotoxin tolerance experiments showed the surprising WC-rBS potential in the modulation of inflammatory responses on both PBMCs and THP1 cells. WC-rBS was further evaluated in the Dextran Sodium Sulfate colitis mouse model. Administrated orally at different dosages, WC-rBS vaccine was safe and showed immunomodulatory properties when administered in a preventive mode (before and during the induction of DSS colitis) as well as in a curative mode (after colitis induction); with improvement of disease activity index (from 27 to 73%) and histological score (from 65 to 88%). Interestingly, the highest therapeutic effect of WC-rBS vaccine was observed with the lowest dosage, showing even better anti-inflammatory properties than mesalamine; an approved 5-aminosalicylic acid drug for treating IBD patients. In summary, this is the first time that a prophylactic medicine, safe and approved for prevention of an infectious disease, showed a benefit in an inflammatory bowel disease model, potentially offering a novel therapeutic modality for IBD patients.

Expression of Cholera Toxin (CT) and the Toxin Co-Regulated Pilus (TCP) by Variants of ToxT in Vibrio cholerae Strains.

The expression of the two major virulence genes of Vibrio cholerae-tcpA (the major subunit of the toxin co-regulated pilus) and ctxAB (cholera toxin)-is regulated by the ToxR regulon, which is triggered by environmental stimuli during infection within the human small intestine. Special culture methods are required to induce the expression of virulence genes in V. cholerae in the laboratory setting. In the present study, induction of the expression of virulence genes by two point mutations (65th and 139th amino acids) in toxT, which is produced by the ToxR regulon and activates the transcription of the virulence genes in V. cholerae, under laboratory culture conditions has been investigated. Each of the four toxT alleles assessed displayed different transcriptional activator functions in a given V. cholerae strain. Although the ToxR regulon has been known to not be expressed by El Tor biotype V. cholerae strains cultured under standard laboratory conditions, the variant toxT alleles that we assessed in this study enabled the expression virulence genes in El Tor biotype strains grown under simple culture conditions comprising shake culture in LB medium, suggesting that the regulation of virulence gene expression may be regulated more complexly than previously thought and may involve additional factors beyond the production of ToxT by the ToxR regulon.

Dynamics of a reaction-advection-diffusion model for cholera transmission with human behavior change

Cholera is a virulent intestinal infection caused by Vibrio cholerae strains. To explore multiple effects of spatial structure, seasonality and human behavior change on cholera transmission, we establish a reaction-advection-diffusion model with a general boundary condition at the downstream end of the river. We derive the basic reproduction number R0 and discuss its asymptotic behaviors. We further show that R0 is a strictly decreasing function of the bacterial loss c, which reveals that the bacterial loss at the downstream end of the river due to water flux reduces the risk of cholera transmission. Then we derive a threshold-type result in terms of R0. More precisely, (i) if R0<1, the disease-free periodic solution is globally attractive; (ii) if R0>1, the disease is uniformly persistent; (iii) if R0=1, the disease-free steady state is globally asymptotically stable in the absence of the advection term, in which the proof is quite challenging due to the introduction of human behavior change, involving some subtle inequalities and estimates. Numerically, an application is demonstrated by investigating the cholera outbreak in Somalia from 1995 to 2016.

Study on induction of Allium sativum L. hairy roots with antibacterial activity against Vibrio

Allium sativum L. has long been used to improve the health of humans and other species due to its antibacterial activity. Applying biotechnology to create a stable and large-scale production process for Allium sativum L., medicinal herbs by hairy root culture technology are essential. However, Allium sativum L. is a monocotyledonous plant, so its ability to induce hairy roots is lower than that of dicotyledonous plants, which requires more research investment. In this study, we succeeded in inducing hairy roots in monocotyledonous plants Allium sativum L, by evaluating parameters impacting hairy root induction such as plant organs, acetosyringone concentration, infection time and co-culture time. The results showed that the optimal procedure for induction of Allium sativum L. hairy roots by Agrobacterium rhizogenes ATCC 15834 was as follows: 10 day old in vitro Allium sativum L. sprouts were wound and soaked in 100 μM acetosyringone solution for 10 min, infection time was 5 minutes, co-culture time was 48 hours cultured on B5 medium (Gamborg B5 medium) having the induction rate of hairy roots reaching 64.4% after 14 days of culture. Allium sativum L. hairy roots had good antibacterial effect against all three strains of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus because the MBC/MIC ratios are all less than or equal to 2. Especially, for V. cholerae (MIC = 1.84 mg/ml, MBC = 2.11 mg/ml), hairy roots have antibacterial activity equivalent to tetracycline antibiotics and better than non-infectious roots.

Vibrio Cholerae Colonisation in a Case of Bilateral Cystic Bronchiectasis in an Immunocompetent Male

Non O1 and non O139 strains of Vibrio cholerae are often nontoxigenic and tend to cause extraintestinal infections such as wound infections, external ear infection, sepsis, epidural and subdural abbesses. We herein describe an unusual presentation where there is colonisation of Vibrio cholerae in a case of bilateral cystic bronchiectasis in an immunocompetent male.

Bacteremia Caused by a Serotype Ob5 Vibrio cholerae Strain in a Cirrhotic Patient in China.

The increasing incidence of non-O1/non-O139 Vibrio cholerae (NOVC) has been observed worldwide. However, septicemia caused by NOVC remains a rare condition that has received limited attention. Currently, there are no established treatment guidelines for bloodstream infections caused by NOVC, and the understanding of this condition mainly relies on individual case reports. Although NOVC bacteremia can be fatal in a small percentage of cases, knowledge about its microbiological features remains limited. Here, we present a case of V. cholerae septicemia caused by NOVC in a 46-year-old man with chronic viral hepatitis and liver cirrhosis. The isolated strain, named V. cholerae VCH20210731 and classified as a new sequence type (ST), ST1553, was found to be susceptible to most of the antimicrobial agents tested. O-antigen serotyping of V. cholerae VCH20210731 revealed that it belonged to serotype Ob5. Interestingly, the ctxAB genes, which are typically associated with V. cholerae, were absent in VCH20210731. However, the strain possessed 25 other potential virulence genes, such as hlyA, luxS, hap, and rtxA. The resistome of V. cholerae VCH20210731 included several genes, including qnrVC4, crp, almG, and parE. Nevertheless, susceptibility testing demonstrated that the isolate was susceptible to most of the antimicrobial agents tested. Phylogenetic analysis indicated that the closest strain to VCH20210731 was strain 120 from Russia, differing by 630 single-nucleotide polymorphisms (SNPs). Our findings contribute to the understanding of the genomic epidemiological characteristics and antibiotic resistance mechanisms of this invasive bacterial pathogen. IMPORTANCE This study highlights the discovery of a novel ST1553 V. cholerae strain in China, providing valuable insights into the genomic epidemiology and global transmission dynamics of V. cholerae. It is important to note that clinical presentations of NOVC bacteremia can vary significantly, and the isolates demonstrate genetic diversity. Consequently, health care professionals and public health experts should remain vigilant about the potential for infection with this pathogen, particularly considering the elevated prevalence of liver disease in China.