Vibrio Cholerae Strains Research Articles

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.

Genomic epidemiology of Vibrio cholerae during a mass vaccination campaign of displaced communities in Bangladesh

Ongoing diarrheal disease surveillance throughout Bangladesh over the last decade has revealed seasonal localised cholera outbreaks in Cox’s Bazar, where both Bangladeshi Nationals and Forcibly Displaced Myanmar Nationals (FDMNs) reside in densely populated settlements. FDMNs were recently targeted for the largest cholera vaccination campaign in decades. We aimed to infer the epidemic risk of circulating Vibrio cholerae strains by determining if isolates linked to the ongoing global cholera pandemic (“7PET” lineage) were responsible for outbreaks in Cox’s Bazar. We found two sublineages of 7PET in this setting during the study period; one with global distribution, and a second lineage restricted to Asia and the Middle East. These subclades were associated with different disease patterns that could be partially explained by genomic differences. Here we show that as the pandemic V. cholerae lineage circulates in this vulnerable population, without a vaccine intervention, the risk of an epidemic was very high.

Sensitivity to antibacterial drugs of biofilms formed by strains of vibrio cholerae of various serogroups.

The ability of Vibrio cholerae to form biofilms may cause ineffectiveness of cholera treatment and prevention. The aim of the study was to determine the antibiotic sensitivity of V.cholerae in biofilms. Material and methods. Sensitivity to 11 antibacterial agents was determined for biofilms of 10 strains of V.cholerae of different serogroups isolated from humans and from water obtained for 48 hours at 37°C on plastic plates in vials with autoclaved tap water infected with a suspension of 104 V.cholerae microbial cells. For this purpose the plates were washed three times in physiological solution and transferred into penicillin vials with double dilutions of antibacterial agents in liquid nutrient medium (Martin's broth, pH 7.7). After 24 hours of cultivation in the thermostat (37°C), the biofilms were imprinted and 0.1 ml of plankton culture was seeded onto plates with Marten's agar (pH 7.7). After 24 hours in the thermostat (37°C), the biofilms were imprinted and 0.1 ml of plankton culture was sown on plates with Marten's agar (pH 7.7). The result was counted after 24 h, determining the minimum suppressive concentrations of preparations by the presence or absence of V.cholerae growth. Results. The strains studied in biofilm communities, in contrast to the planktonic form, were highly resistant to all antibacterial drugs taken in the study, except for ciprofloxacin and ceftazidime. To improve the effectiveness of treatment of cholera and other infections whose causative agents are cholera vibrio, it is necessary to determine the antibiotic sensitivity of V.cholerae biofilms.

Cholera: Analysis and Assessment of Epidemiological Situation around the World and in Russia (2013–2022). Forecast for 2023

The aim of the review was to analyze and assess the epidemiological situation on cholera in the world and Russia in 2013–2022 and to make a forecast for 2023. Over the period of 2013–2022, 500 administrative territories affected by cholera were identified in various regions of 71 countries of Asia, Africa and America (the Caribbean region) with formation of 69 endemic foci in 16, 41 and 12 countries, respectively. In 2022, 1 209 301 cases of cholera were registered in 36 countries of the world. The intensity of epidemic process in Asian countries (Syria, Lebanon) increased. Unfavorable epidemiological situation on the African continent persisted. Epidemics and large outbreaks, which began in 2021–2022 due to emergency situations (ES) of social and natural character, continued. The prediction of the stability of the epidemiological situation on cholera in the territories of constituent entities of the Russian Federation (RF), given for 2022, has been confirmed. In 2022, 43 non-toxigenic strains of Vibrio cholerae О1 were isolated from surface water bodies, 8 V. cholerae nonO1/nonO139 strains – from humans. Similarity of those strains with genetically closely related ones isolated in the course of monitoring in previous years in Russia, Donetsk People’s Republic (DPR) and Zaporozhye Region was demonstrated. In 2023, the risks of importation of the infection into RF are retained. It is associated with the intensification of epidemic processes in Asian, African and Caribbean region countries. The extended border with Ukraine, to where importation of cholera from endemic countries is possible, contributes to increased degree of threat. Bioterrorism is also not excluded. The consequences of a possible cholera epidemic complication in DPR, Lugansk People’s Republic, Zaporozhye and Kherson Regions are exacerbated by social emergencies resulting in disruption of infrastructure, interruptions in water supply, etc. In the absence of implementation of the risks of importation of this infection on the territory of RF, a stable epidemiological situation on cholera will be retained. Detection of non-toxigenic V. cholerae O1 strains (including probability of clonal complexes formation), as well as strains of non-O1/non-O139 serogroups, which can be etiological factors of sporadic cases or outbreaks of diarrheal diseases, in surface water bodies is predicted.

Vibrio cholerae Invasion Dynamics of the Chironomid Host Are Strongly Influenced by Aquatic Cell Density and Can Vary by Strain.

Cholera has been a human scourge since the early 1800s and remains a global public health challenge, caused by the toxigenic strains of the bacterium Vibrio cholerae. In its aquatic reservoirs, V. cholerae has been shown to live in association with various arthropod hosts, including the chironomids, a diverse insect family commonly found in wet and semiwet habitats. The association between V. cholerae and chironomids may shield the bacterium from environmental stressors and amplify its dissemination. However, the interaction dynamics between V. cholerae and chironomids remain largely unknown. In this study, we developed freshwater microcosms with chironomid larvae to test the effects of cell density and strain on V. cholerae-chironomid interactions. Our results show that chironomid larvae can be exposed to V. cholerae up to a high inoculation dose (109 cells/mL) without observable detrimental effects. Meanwhile, interstrain variability in host invasion, including prevalence, bacterial load, and effects on host survival, was highly cell density-dependent. Microbiome analysis of the chironomid samples by 16S rRNA gene amplicon sequencing revealed a general effect of V. cholerae exposure on microbiome species evenness. Taken together, our results provide novel insights into V. cholerae invasion dynamics of the chironomid larvae with respect to various doses and strains. The findings suggest that aquatic cell density is a crucial driver of V. cholerae invasion success in chironomid larvae and pave the way for future work examining the effects of a broader dose range and environmental variables (e.g., temperature) on V. cholerae-chironomid interactions. IMPORTANCE Vibrio cholerae is the causative agent of cholera, a significant diarrheal disease affecting millions of people worldwide. Increasing evidence suggests that the environmental facets of the V. cholerae life cycle involve symbiotic associations with aquatic arthropods, which may facilitate its environmental persistence and dissemination. However, the dynamics of interactions between V. cholerae and aquatic arthropods remain unexplored. This study capitalized on using freshwater microcosms with chironomid larvae to investigate the effects of bacterial cell density and strain on V. cholerae-chironomid interactions. Our results suggest that aquatic cell density is the primary determinant of V. cholerae invasion success in chironomid larvae, while interstrain variability in invasion outcomes can be observed under specific cell density conditions. We also determined that V. cholerae exposure generally reduces species evenness of the chironomid-associated microbiome. Collectively, these findings provide novel insights into V. cholerae-arthropod interactions using a newly developed experimental host system.

Intracellular Expression of CTB in V. cholerae Strains in Laboratory Culture Conditions.

The introduction of the toxT-139F allele triggers the expression of TCP (toxin co-regulated pilus) and CT (cholera toxin) under simple laboratory culture conditions in most Vibrio cholerae strains. Such V. cholerae strains-especially strains that have been used in OCVs (oral cholera vaccines)-can induce antibody responses against TCP in animal models. However, CT produced in these V. cholerae strains is secreted into the culture medium. In this study, V. cholerae strains that can express intracellular CTB under the control of the toxT-139F allele have been constructed for potential application in OCVs. First, we constructed a recombinant plasmid directly linking the ctxAB promoter to ctxB without ctxA and confirmed CTB expression from the plasmid in V. cholerae containing the toxT-139F allele. We constructed another recombinant plasmid to express NtrCTB, from which 14 internal amino acids-from the 7th to the 20th amino acid-of the leader peptide of CTB have been omitted, and we found that NtrCTB remained in the cells. Based on those results, we constructed V. cholerae strains in which chromosomal ctxAB is replaced by ntrctxB or ntrctxB-dimer. Both NtrCTB and NtrCTB-dimer remained in the bacterial cells, and 60% of the NtrCTB-dimer in the bacterial cells was maintained in a soluble form. To develop improved OCVs, these strains could be tested to see whether they induce immune responses against CTB in animal models.

Purification and Structural Characterization of an Antimicrobial Compound, Lipoxazolidinone a Produced by a Lactobacillus Apis YMP3

ABSTRACT: Strains of Vibrio cholerae are one among the most causative and serious disease causing human pathogenic agents, its infections are caused mostly by ingesting contaminated water and/or food. According to the recent estimates, between 1.3 and 4.0 million individuals are infected all around the world every year. The lactic acid bacteria are an important class of probiotics microbes have their ability to produce diversified bioactive compounds, hence this study focused on the identification of a promising antimicrobial agent from a Lactobacillus apis YMP3. This strain was cultured on MRS broth and the cell free supernatant was ethyl acetate extracted for the antimicrobial agent. The crude extract was further purified with C18 silica gel column chromatography and structurally characterized by FT-IR, NMR, GC and MS/MS spectrum. The chemistry of the compound was confirmed as Lipoxazolidinone A which has the IUPAC name of (2E)-5-butyl-2-[(E)-4-methyl-2-oxoundec-3-enylidene]-1,3-oxazolidin-4-one. This is the first report of Lipoxazolidinone A produced by a bacterium, L. apis YMP3 which was originally isolated from yoghurt. This finding expands the scope of identifying more promising bioactive compounds from probiotic Lactobacillus sp., further, this systematic procedure for purification of this antimicrobial agent stood as the baseline data for more elaborate therapeutic studies in future.

Antibiofilm activity from endophyte bacteria, Vibrio cholerae strains, and actinomycetes isolates in liquid and solid culture

BackgroundBiofilm-associated infections are a global threat to our economy and human health; as such, development of antibiofilm compounds is an urgent need. Our previous study identified eleven environmental isolates of endophyte bacteria, actinomycetes, and two strains of Vibrio cholerae as having strong antibiofilm activity, but only tested crude extracts from liquid culture. Here we grew the same bacteria in solid culture to induce the formation of colony biofilms and the expression of genes that may ultimately produce antibiofilm compounds. This research aimed to compare antibiofilm inhibition and destruction activities between liquid and solid cultures of these eleven environmental isolates against the biofilms of representative pathogenic bacteria.ResultsWe measured antibiofilm activity using the static antibiofilm assay and crystal violet staining. The majority of our isolates exhibited higher inhibitory antibiofilm activity in liquid media, including all endophyte bacteria, V. cholerae V15a, and actinomycetes strains (CW01, SW03, CW17). However, for V. cholerae strain B32 and two actinomycetes bacteria (TB12 and SW12), the solid crude extracts showed higher inhibitory activity. Regarding destructive antibiofilm activity, many endophyte isolates and V. cholerae strains showed no significant difference between culture methods; the exceptions were endophyte bacteria isolate JerF4 and V. cholerae B32. The liquid extract of isolate JerF4 showed higher destructive activity relative to the corresponding solid culture extract, while for V. cholerae strain B32 the solid extract showed higher activity against some biofilms of pathogenic bacteria.ConclusionsCulture conditions, namely solid or liquid culture, can influence the activity of culture extracts against biofilms of pathogenic bacteria. We compared the antibiofilm activity and presented the data that majority of isolates showed a higher antibiofilm activity in liquid culture. Interestingly, solid extracts from three isolates (B32, TB12, and SW12) have a better inhibition or/and destruction antibiofilm activity compared to their liquid culture. Further research is needed to characterize the activities of specific metabolites in solid and liquid culture extracts and to determine the mechanisms of their antibiofilm actions.

Drug resistance and genomic characteristics of a strain of O139 Vibrio cholerae isolated from human bloodstream infection

Objective: To analyze the drug resistance and genomic characteristics of a strain of serogroup O139 Vibrio cholerae producing cholera toxin isolated from the bloodstream of a person with bacteremia. Methods: The broth dilution method and automatic drug sensitivity analyzer were used to determine the antibiotic sensitivity of the strain. The complete genome sequence of the strain was obtained by using second-generation gene sequencing and nanopore sequencing. BLAST software was used for comparison and analysis with CARD, Resfinder, ISfinder, VFDB, and other databases. The drug-resistant genes, insertion sequences and virulence genes carried by the strain were identified. MEGA 5.1 software was used to construct a genetic phylogenetic tree based on the core genomic single nucleotide polymorphisms. Results: V. cholerae SH400, as the toxigenic strain, carried multiple virulence-related genes and four virulence islands. The strain was resistant to streptomycin, tetracycline and cotrimoxazole, carrying corresponding drug-resistant genes. The strain also carried IncA/C plasmid with the size of 172914 bp and contained 10 drug-resistant genes. Combined with the genomic evolutionary relationship, this study found that the drug-resistant genes and drug-resistant plasmids carried among strains showed certain aggregation. The traditional ST type of strain SH400 was ST69, and the cgMLST type was a new type highly similar to cgST-252. Conclusion: This strain of serogroup O139 V. cholerae carries the ctxAB gene, multiple drug-resistant genes and IncA/C plasmid, and there are multiple drug-resistant islands.

Antibiotic Resistance Conferred by Class 1 Integron in Vibrio Cholerae Strains: A Meta-analysis.

Class 1 integron is the most ubiquitous platform among antibiotic resistance bacterial populations, including Vibrio cholerae strains. This meta-analysis aimed to determine the antibiotic resistance conferred by class 1 integron conserved segments (CS); 3'-qacEΔ1 and sul1, and 5'-int1 in V. cholerae strains. An intensive literature search of electronic databases for relevant studies from their starting dates up to April 2019 was conducted by two independent investigators. The electronic databases included; PubMed, Ovid Medline and Google Scholar databases. Only studies that determined antibiotic resistance conferred by class 1 integron in V. cholerae strains isolated from clinical and/or environmental samples using Polymerase Chain Reaction (PCR) assay were included in this study. The random-effects model was selected and performed for all the studies included in this meta-analysis. Fourteen studies consisting of both qacEΔ1 and sul1, and int1 in the class 1 integron of V. cholerae strains were included. The proportions of class 1 integron 3'-CS and 5'-CS were 70.4 % (95%CI: 37.5-94.4) and 52 % (95% CI: 6.3-95.7) respectively. The proportions of class 1 integron in V. cholerae strains significantly contributed to the antibiotic resistances, which are comparable to other gram-negative bacteria clinical isolates. Moreover, the 3'-CS qacEΔ1 and sul1 are highly involved in the antibiotic resistance in comparison to 5'-CS int1. Generally, the study findings provide a general view on antibiotic resistance conferred by class 1 integron in Vibrio cholerae strains.

486: CHOLERA IN THE TIME OF COVID

Introduction: Cholera is endemic to 50 countries with most US cases acquired during international travel. However, several cases have occurred from the ingestion of local oysters, crabs, and shrimp with resident Vibrio cholerae strains on the Gulf Coast. Description: A 52-year-old man with insulin dependent diabetes mellitus and well controlled HIV presented with hypovolemic shock. He reported 4 days of non-bloody diarrhea, poor oral intake, and oliguria. Before symptom onset, he ate crabs and tasted the water they were boiled in. He was prescribed azithromycin outpatient which mildly improved his diarrhea but presented to the hospital due to dizziness. He was initially hypotensive but this improved with 2 liters of normal saline without needing vasopressors. He had a blood glucose of 417 mg/dL, sodium bicarbonate of 13 mmol/L, anion gap of 29, creatinine of 10.5 mg/dL, calcium 8.3 mg/dL and corrected sodium of 124 mmol/L. Lactate and beta-hydroxybutyric acid levels were normal. Prior to admission, he took his insulin despite little oral intake. Given his glucose level and anion gap acidosis, he was placed on an insulin drip for concern of diabetic ketoacidosis (DKA). Stool PCR was positive for Vibrio cholerae and Salmonella enterica. Blood cultures were also positive for S. enterica. He received doxycycline for cholera and 14 days of ciprofloxacin for salmonella bacteremia. During his hospitalization, he got 14 liters of fluids with resolution of electrolyte abnormalities by discharge. Discussion: In this patient, the anion gap acidosis was concerning for DKA but normal ketones made this diagnosis less likely. Cholera infection leads to “rice water” stool outputs up to 200cc/kg/hour in the first 2 days then ending after 4-6 days with profound electrolyte abnormalities. Due to rapid volume loss, patients present in hypovolemic shock with hyponatremia, hypocalcemia and hypoglycemia. Anion gap metabolic acidosis occurs due to acute tubular necrosis as in this patient. Stool culture is the gold standard for diagnosis. Treatment with doxycycline, ciprofloxacin or azithromycin decreases the duration of illness and reduces stool volume by 50%. Despite its rarity in the US, cholera should be considered and promptly treated in patients presenting with copious diarrhea, hypovolemia, and renal failure.

Altered molecular attributes and antimicrobial resistance patterns of Vibrio cholerae O1 El Tor strains isolated from the cholera endemic regions of India.

The present study aimed to document the comparative analysis of differential hypervirulent features of Vibrio cholerae O1 strains isolated during 2018 from cholera endemic regions in Gujarat and Maharashtra (Western India) and West Bengal (Eastern India). A total of 87V. cholerae O1 clinical strains from Western India and 48 from Eastern India were analysed for a number of biotypic and genotypic features followed by antimicrobial resistance (AMR) profile. A novel polymerase chain reaction was designed to detect a large fragment deletion in the Vibrio seventh pandemic island II (VSP-II) genomic region, which is a significant genetic feature of the V. cholerae strains that have caused Yemen cholera outbreak. All the strains from Western India belong to the Ogawa serotype, polymyxin B-sensitive, hemolytic, had a deletion in VSP-II (VSP-IIC) region and carried Haitian genetic alleles of ctxB, tcpA and rtxA. Conversely, 14.6% (7/48) of the strains from Eastern India belonged to the Inaba serotype, polymyxin B-resistant, nonhemolytic, harboured VSP-II other than VSP-IIC type, classical ctxB, Haitian tcpA and El Tor rtxA alleles. Resistance to tetracycline and chloramphenicol has been observed in strains from both regions. This study showed hypervirulent, polymyxin B-sensitive epidemic causing strains in India along with the strains with polymyxin B-resistant and nonhemolytic traits that may spread and cause serious disease outcomes in future. The outcomes of this study can help to improve the understanding of the hyperpathogenic property of recently circulating pandemic Vibrio cholerae strains in India. Special attention is also needed for the monitoring of AMR surveillance because V. cholerae strains are losing susceptibility to many antibiotics used as a second line of defence in the treatment of cholera.

Identification and genomic analysis of a Vibrio cholerae strain isolated from a patient with bloodstream infection

Vibrio cholerae is a bacterium ubiquitous in aquatic environments which can cause widespread infection worldwide. V. cholerae gradually became a rare species of bacteria in clinical microbiology laboratories with the control of the cholera epidemic. In this study, we isolated a V. cholerae strain, named VCHL017, from the blood of an elderly patient without gastrointestinal symptoms. The patient had a history of hookworm infection and multiple myeloma. Furthermore, she was immunocompromised, and received long-term chemotherapy and antimicrobial agents. VCHL017 was inoculated on blood agar and thiosulfate citrate bile salt sucrose plates (TCBS) to observe morphological characteristics. Then this isolate was identified by matrix-assisted laser desorption/ionization time-of-flight spectrometry (MALDI-TOF MS). The minimum inhibitory concentrations (MICs) for cefazolin, ceftazidime, cefepime, meropenem, tetracycline, ciprofloxacin, chloramphenicol, and gentamicin of VCHL017 were determined by the microbroth dilution method. PCR and serum agglutination tests were used to determine whether the serogroups of the isolate belonged to the O1/O139 and cholera toxin encoding genes. Finally, the genomic features and phylogeny of VCHL017 were analyzed by whole genome sequencing (WGS). VCHL017 was a non-O1/O139 V cholerae strain that did not carry the ctxA gene. Antimicrobial susceptibility tests revealed that VCHL017 was susceptive to chloramphenicol and tetracycline. Although it did not carry the genes encoding the cholera toxin, WGS indicated that VCHL017 carried a variety of other virulence factors. By calculating the average nucleotide identity (ANI), we precisely identified the species of VCHL017 as V. cholerae. There are also A171S and A202S missense mutations in gyrA of VCHL017. The phylogenetic analysis indicated that VCHL017 was closely related to V. cholerae strains isolated from aquatic environments. Our results suggest that continuous monitoring is necessary for non-O1/O139 V cholerae strains isolated from outside the digestive tract, which could be pathogenic through multiple virulence factors.

Comparative Analysis of Expression of the Main Virulence Genes in Various <i>Vibrio cholerae</i> О1 Strains

The aim of the work was a comparative study of the expression of the main virulence genes in Vibrio cholerae strains of the classical biovar, typical and genetically modified strains of V. cholerae, El Tor biovar.Materials and methods. Natural toxigenic strains of V. cholerae O1, classical biovar (J89, Pakistan, 1969), typical (M-887, Astrakhan, 1970) and genetically modified (301, Taganrog, 2011) strains of the El Tor biovar were used as model ones. The strains were grown under optimum conditions for the production of cholera toxin and toxin-coregulated pili. The assessment of strain growth was carried out in LB broth at room temperature with determination of the cells number on a Biowave DNA spectrophotometer (Biochrome Ltd., UK). Determination of gene expression was performed using real-time PCR with reverse transcription.Results and discussion. The expression of structural (ctxA, tcpA) and regulatory (toxR, toxT, tcpP, tcpH) virulence genes has been investigated in V. cholerae strains of the classical biovar, typical and genetically modified strains of the El Tor biovar. Significant differences have been revealed in terms of time and level of maximum expression of these genes in strains of classical and El Tor biovars. It was found that ctxA and toxR genes expression in the genovariant strain reached its maximum 1–3 h earlier than in the other strains. At the same time, the level of ctxA gene expression corresponded to the level of the classical strain. The maximum expression of the toxR gene in the genovariant strain was higher than in typical El Tor and classical strains, and also had a clear inverse correlation with ctxA gene expression. Expression of the tcpA, toxT, and tcpH genes in the classical biovar strain reached its maximum 1–2 h earlier than in the El Tor biovar strains. These differences should be taken into account when conducting research work related to the study of the expression of the main virulence genes.

Systematic Review on the Antibacterial Resistance of Vibrio Cholerae

Background: Vibrio cholerae is the causative agent of cholera illness. Antibacterial resistance of V. cholerae is frequently experienced due to the environmental pressure from human and animal overuse and misuse of antibacterials. Among such antibacterials include Tetracycline, Chloramphenicol, Furazolidone, Ampicillin, and Trimethoprim-Cotrimoxazole as used against V. cholerae O1, O139 and non O1, O139 strains. Objectives: This systematic review was aimed at providing an overview of Antibacterial resistant strains of Vibrio cholerae in terms of year, location and factors responsible for the resistance. Material and Method: Systematic Electronic database search of PubMed (NCBI) by means of the key terms MeSH “Antimicrobial resistance of Vibrio cholerae” between the period of January 2000 to October 2018 was used. Results: From the findings it showed that many factors are responsible for Antibacterial resistance of Vibrio cholerae which include genetic composition, mutation, enzymes. Also V. cholerae, both O1, O139, environmental and non O1/ non O139 such as V. anginiloticus, paraheamolytcus were incriminated in transferring resistance genes from one another. Antimimicrobial Susceptibility Testing phenotypic and Polymerase Chain Reaction (PCR) molecular procedure were employed in detecting the resistance and equally the use of Global Antimicrobial Surveillance System (GLASS) and Centre for Disease control (CDC) AR threat report 2019 was used successfully in the management of Vibrio cholerae epidemic. Conclusions: Drug-resistant Vibrio cholarae is a problem that needs to be dealt with as soon as possible

Оценка экспрессии гена ctxA штамма Vibrio cholerae 569В при производстве холерной вакцины

Cultivation of production strains of Vibrio cholerae is one of the most important stages in the production of cholera bivalent chemical vaccines. In the production of immunobiological preparations, it is necessary to use producer strains with stable properties that persist in a number of generations. The aim of this study was to evaluate the expression of the ctxA gene using molecular genetic methods of the V. cholerae 569B producing strain. By PCR with electrophoretic accounting of the results, the presence of this strain of the ctxA gene in the chromosome was established. The expression of this gene in all hourly samples of culture fluid was recorded by the method of PCR with reverse transcription, taking into account the results in real time and digital drip PCR. Immunochemical methods confirmed the presence of cholera toxin in the samples, with a maximum mark at the ninth hour, which corresponded to the maximum indicators of the “concentration of microbial cells”. Thus, molecular genetic methods have shown the stability of the production strain V. cholerae 569B in samples of 4 independent cultivations.

Development of a Low-Cost Lateral Flow Assay for Rapid Detection of Vibrio Cholerae

Cholera is an acute, often fatal diarrheal disease that primarily affects areas with poor sanitation and unclean water. Cholera is caused by toxigenic strains of Vibrio cholerae (V. cholerae), which cause the body to rapidly dehydrate upon colonizing the intestine. The WHO estimates that 2.9 million people contract cholera each year, resulting in approximately 95000 deaths [1].Current methods for detection of V. cholerae are either inferential (detection of fecal coliforms or monitoring weather patterns) or diagnosed after an infection (stool tests) [2]. Even methods that have been developed for direct detection of V. cholerae fall short of detecting environmental concentrations of the bacterium (10-104 CFU/mL) [3]; a lateral flow assay (LFA) using gold nanoparticle-labelled antibodies for the simultaneous detection of O1 and O139 strains of V. cholerae achieved a limit of detection of 108 CFU/mL for O1 and 107 CFU/mL for O139 [4]. The current work aims to develop an LFA for the detection of V. cholerae at environmental conditions in drinking water under limited resource settings. By incorporating novel aptamers as antigen detecting agents, carbon nanoparticles as colorimetric indicators, and N-acetylglucosamine (GlcNAc)–a known chemoattractant for V. cholerae –in the sample pad, the limit of detection will be improved without the need for lengthy preprocessing steps or costly reagents.The antigen detection agent employed in the LFA is the aptamer V.ch27 which was identified by Mojarad and Gargaria [5]. This aptamer was shown to have a favourable secondary structure at 21°C and high binding affinity to the surface of V. cholerae bacteria. Aptamers are a synthetic alternative to conventionally used antibodies for this application. They exhibit specificities comparable to those of monoclonal antibodies, are cheaper to synthesize, and can be easily immobilized to surfaces via biotin-avidin complexing.Amorphous carbon nanoparticles (ACNPs) were chosen as the colorimetric indicator for the assay due to their strong black color and low cost [6]. For instance, carbon nanoparticles have shown a 100-fold decrease in the limit of detection for dengue fever antigen when compared to gold nanoparticles [7]. The ACNPs were synthesized by collecting the soot from burning candles followed by size selection by centrifugation, as previously described Zhang et al [8].The chemotaxis of V. cholerae to GlcNAc is well documented in literature [9]. The sample pad of the LFA contains a GlcNAc solution which diffuses into the water sample. V. cholerae swim up the GlcNAc concentration gradient and accumulate in high concentrations at the sample pad. This in turn results in a high concentration of analyte entering the assay, and consequently, a greater signal intensity. Previous studies have shown that chemotaxis can be exploited to collect nearly all of the bacteria in a 100 mL water sample [10,11].The fabricated LFA device will provide a rapid, accessible, and low-cost platform for V. cholerae detection in the water sources available to rural and low-income communities, without the need for technical training or well-established laboratory infrastructure. Successful implementation of the device will result in the overall reduction of global deaths due to cholera, as well as provide the framework for future preventative initiatives aimed towards cholera outbreak prediction and monitoring.

Prediction of Antibiotic Susceptibility Profiles of Vibrio cholerae Isolates From Whole Genome Illumina and Nanopore Sequencing Data: CholerAegon.

During the last decades, antimicrobial resistance (AMR) has become a global public health concern. Nowadays multi-drug resistance is commonly observed in strains of Vibrio cholerae, the etiological agent of cholera. In order to limit the spread of pathogenic drug-resistant bacteria and to maintain treatment options the analysis of clinical samples and their AMR profiles are essential. Particularly, in low-resource settings a timely analysis of AMR profiles is often impaired due to lengthy culturing procedures for antibiotic susceptibility testing or lack of laboratory capacity. In this study, we explore the applicability of whole genome sequencing for the prediction of AMR profiles of V. cholerae. We developed the pipeline CholerAegon for the in silico prediction of AMR profiles of 82 V. cholerae genomes assembled from long and short sequencing reads. By correlating the predicted profiles with results from phenotypic antibiotic susceptibility testing we show that the prediction can replace in vitro susceptibility testing for five of seven antibiotics. Because of the relatively low costs, possibility for real-time data analyses, and portability, the Oxford Nanopore Technologies MinION sequencing platform—especially in light of an upcoming less error-prone technology for the platform—appears to be well suited for pathogen genomic analyses such as the one described here. Together with CholerAegon, it can leverage pathogen genomics to improve disease surveillance and to control further spread of antimicrobial resistance.

OPTIMAL CONTROL ON CHOLERA DISEASE SPREADING MODEL WITH THREE VARIABLES CONTROL VARIATION

Cholera is an infection of the small intestine by some strains of the bacterium Vibrio Cholerae. This disease is a deadly disease that necessitates efficient prevention and control measures. In this research, the optimal control of the cholera spread model with variations of three control variables is discussed. There are four controls to minimize the spread of diseases such as sanitation, treatment consisting of quarantine, increased education, and chlorination. The dynamic system is formed with three controls variation. Then it is compared and analyzed for the most effective result. The optimal control solution is derived using the Pontryagin Minimum Principle and solved using the Runge-Kutta method.

Etiological and epidemiological characteristics of Vibrio cholerae in Beijing, 2015-2021

Objective: To analyze the etiological and epidemiological characteristics of Vibrio cholerae in Beijing during 2015-2021 and provide evidence for the prevention and control of cholera. Methods: The V. cholerae strains isolated in Beijing during 2015-2021 were analyzed by serotyping and virulence genes detection. Pulsed field gel electrophoresis (PFGE) was performed for the molecular typing of the strains. Based on the collected epidemiological and clinical data of cholera cases,the epidemiological characteristics of cholera were analyzed by descriptive epidemiology method. Results: A total of 76 Vibrio cholerae O1 strains were isolated in Beijing during 2015-2021, including 61 strains from human, 10 strains from environment and 5 strains from seafood. The 76 strains consisted of 68 Ogawa strains and 8 Inaba strains. Six Ogawa strains isolated from sporadic cases carried ctxAB. After NotⅠ digestion, 76 strains were divided into 33 PFGE patterns. From 2015 to 2021, a total of 38 cholera epidemics were reported in Beijing, most of them were sporadic ones, accounting for 92.11% (35/38). A total of 45 cases were reported, and the cases occurred during June-September accounted for 97.78% (44/45). Cholera cases occurred in 9 districts of Beijing, and the cases reported in Chaoyang district accounted for 42.22% (19/45) and in Changping district accounted for 31.11% (14/45). The age of the cholera cases ranged from 19 to 63 years. Except for one case with unknown clinical symptoms, 44 cases had diarrhea symptoms with 84.09% (37/44) of the cases reporting diarrhea (3-9 times/day), followed by yellow watery stool (95.45%, 42/44), abdominal pain (68.18%, 30/44), nausea and vomiting (40.91%, 18/44) and fever (36.36%, 16/44). Conclusion: Vibrio cholerae strains isolated in Beijing during 2015-2021 were mainly O1 serotype Ogawa,most of which were non-toxigenic. The PFGE of the strains varied. Cholera epidemics occurred in 9 districts of Beijing, but most were sporadic ones with incidence peak during June-September.