scholarly journals Features of the Biological Properties of Vibrio cholerae Isolated during the Monitoring of Water Bodies in Rostov-on-Don from 1989 to 2018

Author(s):  
M. I. Ezhova ◽  
D. А. Levchenkо ◽  
I. V. Arkhangelskaya ◽  
V. D. Kruglikov ◽  
N. B. Nepomnyashchaya

The goal is to study the features of the biological properties of Vibrio cholerae strains found in environmental objects (EO) on the territory of Rostov-on-Don from 1989 to 2018.Materials and methods. Bacteriological, molecular biological and statistical methods were used to study 73 strains of cholera vibrios O1, O139 and 1702 strains of nonO1/nonO139 serogroups isolated over a 30-year period.Results and discussion. It was found that in Rostovon-Don, 78.0 % of toxigenic strains were isolated from all isolated from environmental protection in Russia, among which 2 were genetically unchanged. The V. cholerae O1 classical strain and 72 V. cholerae El Tor strains were found, of which 70 % belonged to the Ogawa serovar, and 3 % of the nontoxigenic strains were susceptible to the classical phage. A “very weak direct relationship” was statistically revealed between the isolation of V. cholerae O1, O139 and V. cholerae nonO1/nonO139 strains, in which the dominant serogroups (O67, O76, O75, O53, O16) were identified, and 18 % of the strains showed atypical agglutinability. Revealing the biological characteristics of V. cholerae strains contributes to the optimization of monitoring studies.

Author(s):  
L. V. Mironova ◽  
N. O. Bochalgin ◽  
A. S. Gladkikh ◽  
S. I. Feranchuk ◽  
A. S. Ponomareva ◽  
...  

Objective is analyzing the origin of the ctxAB– tcpA+ Vibrio cholerae О1 El Tor strains isolated from the surface water bodies in the territory that is non-endemic of cholera; as well as investigating their phylogenetic relations to varying by epidemic significance groups of strains, based on the structure of housekeeping genes and whole genome structure. Materials and methods: we examined 25 V. cholerae strains, isolated in Siberia and Far East, including two ctxAB– tcpA+ strains from surface water sources (Altai Territory, 2011; Khabarovsk Territory, 2013). Phylogenetic analysis included genomes of 36 V. cholerae strains from GenBank. Multilocus sequence typing (MLST) was carried out based on dnaE, cat, lap, pgm, recA, gyrB, and chi genes; in silico MLST – adk, gyrB, metE, mdh, pntA, purM and pyrC genes. Reconstruction of phylogeny was performed based on the comparative analysis of core genome SNPs in PhyML 3.0. Results and discussion. MLST of ctxAB– tcpA+ V. cholerae О1 El Tor strains from the surface water bodies revealed that such strains form an individual genotype in the cluster of toxigenic strains and spontaneous mutants of toxigenic strains. According to results of in silico MLST, ctxAB– tcpA+ isolates belong to SТ75, common to US Gulf phylogenetic line. Based on SNP-typing, ctxAB– tcpA+ strains from the surface water sources were assigned to the group, originating from US Gulf V. cholerae, moreover isolate from Khabarovsk (2013) demonstrated high degree of genome homology with US Gulf-like strain from China (2009). For strains from Khabarovsk and China, we also showed the compositional identity of the pathogenicity island VPI-I and the presence of pandemicity island, VSP-1. The results testify to the fact that ctxAB– tcpA+ V. cholerae strains, isolated in Siberia and Far East, originate from the US Gulf phylogenetic line. Furthermore, taking into account the results of epidemiological analysis, we can deduce that these strains are imported ones.


Author(s):  
Dariya Aleksandrovna Levchenko ◽  
Vladimir Dmitrievich Kruglikov ◽  
Natalya Borisovna Nepomnyaschaya ◽  
Oksana Andreevna Podoinitsyna ◽  
Mariya Ivanovna Ezhova

In connection with the development of the epidemic process of coronavirus infection on the territory of Russia in 2020, monitoring studies of environmental objects for the presence of Vibrio cholerae in surface water bodies and drains were carried out against the background of restrictive measures, the volumes and time of introduction of which were not the same in different regions of Russia. The purpose of the study was to assess the implementation of cholera monitoring tasks in 2020, in the context of the introduction of restrictive measures associated with the new coronavirus infection. Materials and methods. We used 25 nontoxigenic strains of Vibrio cholerae isolated from water bodies of the environment in 2020 on the territory of Russia. Identification was carried out in accordance with MUK 4.2.2218–07 «Laboratory diagnostics of cholera», including using the MALDI-TOF method to establish the genus and species of the isolated cultures. PCR genotyping was performed using an extended spectrum of genes. Cluster analysis was performed using the UPGMA method. Results and discussion. Against the background of the introduction of restrictive measures, the intensity of monitoring studies did not decrease. On the territory of four federal districts in seven constituent entities of Russia, 25 strains of cholera vibrios O1 and R-variant were isolated from environmental objects, which is comparable to the indicators of previous years. A comprehensive study of biological properties was carried out that revealed the distribution of isolates into groups according to the criterion of combined distinctive features (phenotypic and genotypic), as a result of which the isolated V. cholerae O1 strains were divided into seven groups. It was shown that the largest number of V. cholerae O1 strains isolated from water bodies fell on the territory of the Southern Federal District. Relationships have been established between a certain group of Vibrio cholera strains and the place of their isolation. Thus, the restrictive measures introduced in Russia in 2020 in connection with the COVID-19 pandemic did not affect the intensity and effectiveness of monitoring studies, the tasks of monitoring cholera in the country were implemented.


2006 ◽  
Vol 74 (12) ◽  
pp. 6547-6556 ◽  
Author(s):  
Sang Sun Yoon ◽  
John J. Mekalanos

ABSTRACT Vibrio cholerae is an aquatic bacterium that causes the severe diarrheal disease cholera. V. cholerae strains of the O1 serogroup exist as two biotypes, classical and El Tor. Toxigenic strains of the El Tor biotype emerged to cause the seventh pandemic of cholera in 1961 and subsequently displaced strains of the classical biotype both in the environment and as a cause of cholera within a decade. The factors that drove emergence of the El Tor biotype and the displacement of the classical biotype are unknown. Here, we show a unique difference in carbohydrate metabolism between these two biotypes. When grown with added carbohydrates, classical biotype strains generated a sharp decrease in medium pH, resulting in loss of viability. However, growth of El Tor biotype strain N16961 was enhanced due to its ability to produce 2,3-butanediol, a neutral fermentation end product, and suppress the accumulation of organic acids. An N16961 mutant (SSY01) defective in 2,3-butanediol synthesis showed the same defect in growth that classical biotype strains show in media rich in carbohydrates. Importantly, the SSY01 mutant was attenuated in its ability to colonize the intestines of infant mice, suggesting that host carbohydrates may be available to V. cholerae within the intestinal environment. Similarly, the SSY01 mutant failed to develop biofilms when utilizing N-acetyl-d-glucosamine as a carbon source. Because growth on N-acetyl-d-glucosamine likely reflects the ability of a strain to grow on chitin in certain aquatic environments, we conclude that the strains of classical biotype are likely defective compared to those of El Tor in growth in any environmental niche that is rich in chitin and/or other metabolizable carbohydrates. We propose that the ability to metabolize sugars without production of acid by-products might account for the improved evolutionary fitness of the V. cholerae El Tor biotype compared to that of the classical biotype both as a global cause of cholera and as an environmental organism.


2014 ◽  
Vol 82 (9) ◽  
pp. 3636-3643 ◽  
Author(s):  
M. Kamruzzaman ◽  
William Paul Robins ◽  
S. M. Nayeemul Bari ◽  
Shamsun Nahar ◽  
John J. Mekalanos ◽  
...  

ABSTRACTIn El Tor biotype strains of toxigenicVibrio cholerae, the CTXϕ prophage often resides adjacent to a chromosomally integrated satellite phage genome, RS1, which produces RS1ϕ particles by using CTX prophage-encoded morphogenesis proteins. RS1 encodes RstC, an antirepressor against the CTXϕ repressor RstR, which cooperates with the host-encoded LexA protein to maintain CTXϕ lysogeny. We found that superinfection of toxigenic El Tor strains with RS1ϕ, followed by inoculation of the transductants into the adult rabbit intestine, caused elimination of the resident CTX prophage-producing nontoxigenic derivatives at a high frequency. Further studies usingrecAdeletion mutants and a clonedrstCgene showed that the excision event wasrecAdependent and that introduction of additional copies of the clonedrstCgene instead of infection with RS1ϕ was sufficient to enhance CTXϕ elimination. Our data suggest that once it is excised from the chromosome, the elimination of CTX prophage from host cells is driven by the inability to reestablish CTXϕ lysogeny while RstC is overexpressed. However, with eventual loss of the additional copies ofrstC, the nontoxigenic derivatives can act as precursors of new toxigenic strains by acquiring the CTX prophage either through reinfection with CTXϕ or by chitin-induced transformation. These results provide new insights into the role of RS1ϕ inV. choleraeevolution and the emergence of highly pathogenic clones, such as the variant strains associated with recent devastating epidemics of cholera in Asia, sub-Saharan Africa, and Haiti.


2003 ◽  
Vol 71 (10) ◽  
pp. 5498-5504 ◽  
Author(s):  
Weili Liang ◽  
Shixia Wang ◽  
Fenggang Yu ◽  
Lijuan Zhang ◽  
Guoming Qi ◽  
...  

ABSTRACT IEM101, a Vibrio cholerae O1 El Tor Ogawa strain naturally deficient in CTXΦ, was previously selected as a live cholera vaccine candidate. To make a better and safer vaccine that can induce protective immunity against both the bacteria and cholera toxin (CT), a new vaccine candidate, IEM108, was constructed by introducing a ctxB gene and an El Tor-derived rstR gene into IEM101. The ctxB gene codes for the protective antigen CTB subunit, and the rstR gene mediates phage immunity. The stable expression of the two genes was managed by a chromosome-plasmid lethal balanced system based on the housekeeping gene thyA. Immunization studies indicate that IEM108 generates good immune responses against both the bacteria and CT. After a single-dose intraintestinal vaccination with 109 CFU of IEM108, both anti-CTB immunoglobulin G and vibriocidal antibodies were detected in the immunized-rabbit sera. However, only vibriocidal antibodies are detected in rabbits immunized with IEM101. In addition, IEM108 but not IEM101 conferred full protection against the challenges of four wild-type toxigenic strains of V. cholerae O1 and 4 μg of CT protein in a rabbit model. By introducing the rstR gene, the frequency of conjugative transfer of a recombinant El Tor-derived RS2 suicidal plasmid to IEM108 was decreased 100-fold compared to that for IEM101. This indicated that the El Tor-derived rstR cloned in IEM108 was fully functional and could effectively inhibit the El Tor-derived CTXΦ from infecting IEM108. Our results demonstrate that IEM108 is an efficient and safe live oral cholera vaccine candidate that induces antibacterial and antitoxic immunity and CTXΦ phage immunity.


2017 ◽  
Vol 22 (1) ◽  
pp. 25-30
Author(s):  
L. A Egiazaryan ◽  
N. A Selyanskaya ◽  
I. B Zakharova ◽  
M. V Podshivalova ◽  
E. A Bereznyak ◽  
...  

Aim of the study. The analysis of antibiotic resistance and molecular mechanisms of the persistence of Vibrio cholerae О1 El Tor strains, isolated from patients and environmental objects on the territory of the Russian Federation in 2006-2015. Material and Methods. The susceptibility of 34 V. cholerae El Tor strains to 13 antibacterial drugs was determined by the method of serial dilutions in a rich culture medium (Instructional Guidelines (МUК) 4.2.2495-09). Results. The strains showed resistance to 1-5 antibiotics (levomicetin, streptomycin, nalidixic acid, furazolidone, trimethoprim/sulfamethoxazole) and harbored SXT-element with antibiotic resistance genes. The emergence of quinolone resistance in V. cholerae O1 El Tor strains with accompanying multiple drug resistance limits the choice for drugs for etiotropic therapy and aggravates the possibility of unfavourable cholera outcome.


2020 ◽  
Vol 25 (6) ◽  
pp. 246-252
Author(s):  
Nadechda Selynskaya ◽  
Daria Alexandrovna Levchenko ◽  
Liana Egiazarjan ◽  
Nina Pasyukova

BACKGROUND: Waterborne diseases kill 3.4 million people worldwide each year. Cholera is one such disease. Up to 4 million cases of this infection occur in the world every year, leading to more than 100,000 deaths. The plasticity of the genome of the causative agent of cholera, the mobility of genetic elements carrying factors of pathogenicity and antibiotic resistance, contribute to the variability and unpredictability of the spectrum of resistance, the formation of new pheno- and genotypes. A single Vibrio cholerae isolate can contain up to 40 different genes that can confer resistance to 22 antibiotics, representing nine different classes of antimicrobial drugs. The ability of Vibrio cholerae to long-term survival in aquatic ecosystems in which there is an active exchange of genetic information and new ecological lines may arise that have potential advantages in the adaptation of microorganisms to adverse conditions, emphasizes the complexity of the ways of transmission of this infection and the need for studies at the environmental level. Periodic deliveries of cholera to the territory of the Russian Federation with (without) the spread of the infectious agent, V. cholerae contamination of surface water bodies used as sources of water supply and for recreational water use, the possibility of implementing the main route for cholera (water) the pathway for the spread of the pathogen of the infection indicate the need for conducting annual monitoring of antimicrobial resistance as part of the epidemiological surveillance of cholera in order to obtain information on the distribution, nature and dynamics of resistance in a specific period of time in a given territory. AIM: Analysis of the spectrum of antibiotic resistance of Vibrio cholerae O1 serogroup strains isolated from environmental objects in various territories of the Russian Federation in 2020. MATERIALS AND METHODS: 25 strains V. cholerae О1 El Tor, isolated from environmental objects in the Russian Federation in 2020. The sensitivity / resistance of the studied strains to 13 antibacterial drugs was determined by the method of serial dilutions on a solid nutrient medium in accordance with guidelines. PCR-genotyping of strains V. cholerae El Tor was performed for 14 target genes, followed by cluster analysis. RESULTS: The strains showed resistance markers to furazolidone, trimethoprim/sulfamethoxazole, ampicillin, nalidixic acid, ceftriaxone, which formed 5 phenotypes. PCR-genotyping genotyping of 14 target genes divided the strains into five genotypes (A1A5), corresponding to certain territories. The antibiotic resistance profiles within the same genotype in V. cholerae О1 El Tor belonging to different territories were both the same and different. CONCLUSION: The genotypic diversity of isolated strains was revealed, the variability of resistance markers even in one region, which indicates both changes in the V. cholerae population and the possibility of circulation of various geno- and phenotypes, which emphasizes the importance of constant monitoring of these pathogens.


Author(s):  
N.A. Selyanskaya ◽  
L.A. Egiazaryan ◽  
A.V. Trishina ◽  
E.A. Bereznyak ◽  
I.R. Simonova

The paper presents the analysis of Vibrio cholerae El Tor strains antibiotic resistance gathered from environmental objects on the territory of the Russian Federation during 2007–2016. We determined the sensitivity of 268 strains of V. cholerae El Tor to 12 antibacterial drugs by the method of serial dilutions in a dense nutrient medium. The strains showed resistance to 1–7 antibacterial drugs. The emergence of quinolone resistance in polyresistant strains of V. cholerae E.


Author(s):  
VN Savelyev ◽  
DA Kovalev ◽  
IV Savelyeva ◽  
TV Taran ◽  
EI Podoprigora ◽  
...  

Summary. Introduction: The formation of highly pathogenic strains of Vibrio cholerae resistant to antibiotics determines the pathogenesis, clinical picture, epidemiology, and laboratory diagnosis of cholera. It is necessary to study the structure of the genome of V. cholerae of any serological groups isolated during routine monitoring of environmental objects or patients with acute intestinal infections in order to detect toxigenic genes inherent to epidemic strains of V. cholerae O1. Our objective was to study changes in phenotypic properties and molecular genetic bases of persistence, epidemic and pathogenetic potential of El Tor variant of Vibrio cholerae O1 isolated from patients and environmental objects in the Caucasus in 1970–1998. Materials and methods: We studied phenotypic and molecular genetic characteristics of 32 V. cholerae O1 strains isolated from patients and environmental objects in the Caucasus (1970–1998) using a microbiological assay and PCR test, respectively. Results: We established that the following biotypes of V. cholerae O1 were found in the Caucasus: a) El Tor, ctxA–, and Hly+ nontoxigenic strains of V. cholerae O1, typical in their phenotypic and molecular genetic properties. Their toxigenic potential is represented by exo- and endotoxins different from the enterotoxin of toxigenic V. cholerae; b) toxigenic El Tor, ctxABEL+, rtхC+, and Hly– variant biotypes of V. cholerae O1, typical in their phenotypic, molecular and genetic properties during outbreaks of invasive cholera, producing a CT-2 enterotoxin and containing genes responsible for persistent, pathogenic and pandemic potential, and c) typical in terms of their main phenotypic characteristics but molecularly genetically altered variants (hybrids) of El Tor variant of Vibrio cholerae O1 including El Tor ctxABCL+, rtxC+, Hly–. Conclusions: The main manifestation of evolutionary changes in a typical toxigenic vibrio of the El Tor variant biotype was the replacement of the ctxBEl gene in its genome with the ctxBCL gene encoding the classical type of enterotoxin (CT-1), which significantly increased the persistent, toxic, epidemic, and pandemic potential of genetically modified variants of El Tor biotype Vibrio cholerae. The genome of these strains contains an integrative and conjugative element SXT with genes for antibiotic multiresistance.


Sign in / Sign up

Export Citation Format

Share Document