scholarly journals Non-toxigenic strains of Vibrio cholerae biovar El Tor, isolated in the territory of Russia: molecular-genetic peculiarities and pathogenic properties

2019 ◽  
pp. 13-24
Author(s):  
E. Yu. Agafonova ◽  
N. I. Smirnova ◽  
Zh. V. Alkhova ◽  
Ya. M. Krasnov ◽  
L. F. Livanova ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Molecular Genetic ◽  
Toxigenic Strains ◽  
El Tor

Molecular-genetic analysis of Vibrio cholerae El Tor strains of epidemic risk isolated in Siberian and Far East regions of Russia

2012 ◽  
Vol 27 (2) ◽  
pp. 61-68 ◽  
Author(s):  
L. V. Mironova ◽  
S. V. Balakhonov ◽  
L. Ya. Urbanovich ◽  
A. S. Kozhevnikova ◽  
V. S. Polovinkina ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Vibrio Cholerae ◽  
Molecular Genetic ◽  
Far East ◽  
Molecular Genetic Analysis ◽  
El Tor ◽  
Epidemic Risk ◽  
Regions Of Russia

scholarly journals 2,3-Butanediol Synthesis and the Emergence of the Vibrio cholerae El Tor Biotype

2006 ◽  
Vol 74 (12) ◽  
pp. 6547-6556 ◽  
Author(s):  
Sang Sun Yoon ◽  
John J. Mekalanos
Keyword(s):  
Vibrio Cholerae ◽  
Diarrheal Disease ◽  
Sharp Decrease ◽  
Aquatic Environments ◽  
Environmental Niche ◽  
Medium Ph ◽  
Toxigenic Strains ◽  
El Tor ◽  
By Products ◽  
Evolutionary Fitness

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.

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

2021 ◽  
pp. 148-151
Author(s):  
M. I. Ezhova ◽  
D. А. Levchenkо ◽  
I. V. Arkhangelskaya ◽  
V. D. Kruglikov ◽  
N. B. Nepomnyashchaya
Keyword(s):  
Environmental Protection ◽  
Vibrio Cholerae ◽  
Statistical Methods ◽  
Direct Relationship ◽  
Biological Properties ◽  
Biological Characteristics ◽  
Water Bodies ◽  
Environmental Objects ◽  
Toxigenic Strains ◽  
El Tor

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.

scholarly journals RS1 Satellite Phage Promotes Diversity of Toxigenic Vibrio cholerae by Driving CTX Prophage Loss and Elimination of Lysogenic Immunity

2014 ◽  
Vol 82 (9) ◽  
pp. 3636-3643 ◽  
Author(s):  
M. Kamruzzaman ◽  
William Paul Robins ◽  
S. M. Nayeemul Bari ◽  
Shamsun Nahar ◽  
John J. Mekalanos ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Sub Saharan Africa ◽  
Host Cells ◽  
Adult Rabbit ◽  
Content Type ◽  
Rabbit Intestine ◽  
Sub Saharan ◽  
Toxigenic Strains ◽  
Ctx Prophage ◽  
El Tor

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.

scholarly journals Construction and Evaluation of a Safe, Live, Oral Vibrio cholerae Vaccine Candidate, IEM108

2003 ◽  
Vol 71 (10) ◽  
pp. 5498-5504 ◽  
Author(s):  
Weili Liang ◽  
Shixia Wang ◽  
Fenggang Yu ◽  
Lijuan Zhang ◽  
Guoming Qi ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Protective Antigen ◽  
Vaccine Candidate ◽  
Rabbit Model ◽  
Housekeeping Gene ◽  
Cholera Vaccine ◽  
Oral Cholera Vaccine ◽  
Toxigenic Strains ◽  
El Tor ◽  
Full Protection

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.

scholarly journals Phylogenetic Affinity and Genome Structure Features of ctxAB– tcpA+ Vibrio cholerae from the Surface Waterbodies in the Territory that is Non-Endemic as Regards Cholera

2020 ◽  
pp. 115-123
Author(s):  
L. V. Mironova ◽  
N. O. Bochalgin ◽  
A. S. Gladkikh ◽  
S. I. Feranchuk ◽  
A. S. Ponomareva ◽  
...  
Keyword(s):  
Surface Water ◽  
Vibrio Cholerae ◽  
In Silico ◽  
Genome Structure ◽  
Far East ◽  
Water Sources ◽  
Water Bodies ◽  
Surface Water Bodies ◽  
Toxigenic Strains ◽  
El Tor

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.

The Evolution of Phenotypic Properties and Molecular Genetic Organization of Genomes of Vibrio Cholerae O1 El Tor Variant Strains Isolated from Patients and Environmental Objects in the Caucasus in 1970–1998

2020 ◽  
pp. 56-61
Author(s):  
VN Savelyev ◽  
DA Kovalev ◽  
IV Savelyeva ◽  
TV Taran ◽  
EI Podoprigora ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Molecular Genetic ◽  
Laboratory Diagnosis ◽  
Classical Type ◽  
Phenotypic Properties ◽  
The Caucasus ◽  
Genetic Characteristics ◽  
Environmental Objects ◽  
Vibrio Cholerae O1 ◽  
El Tor

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.

scholarly journals THE INFLUENCE OF SOME FACTORS ON THE FORMATION OF BIOFILM BY TOXIGENIC AND NON-TOXIGENIC VIBRIO CHOLERAE EL TOR STRAINS

2012 ◽  
Vol 17 (5) ◽  
pp. 36-40
Author(s):  
O. A. Tatarenko ◽  
L. P. Alekseeva ◽  
N. R. Telesmanich ◽  
I. S. Shestialtynova ◽  
O. C. Chemisova ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Biofilm Formation ◽  
Culture Medium ◽  
Microtiter Plate ◽  
Medium Composition ◽  
Medium Temperature ◽  
Exopolysaccharide Production ◽  
Medium Interface ◽  
Toxigenic Strains ◽  
El Tor

The early stages of biofilm formation on polystyrene surface were studied in 14 Vibrio cholerae El Tor strains, all of which carried genes of vps cluster, mshA, and hapR genes. 13 Vibrio cholerae El Tor strains were shown to be capable of adsorption on the walls of microtiter plate wells and of ring formation at the "polystyrene-medium" interface. One of the Vibrio cholerae El Tor strains tested was defective in this ability. The use of different media - modified M1 medium and 1 per cent peptone - failed to reveal sufficient influence of culture medium composition on the ability of Vibrio cholerae to form multilayer biofilm at the phase boundary "polystyrene-medium". Temperature reduction from 37°C to 25°C also didn t result in statistically significant enhancement of monolayer formation in both media. Quantitative evaluation of biofilm formation showed that this ability was clearly marked only in two toxigenic and two non-toxigenic strains of Vibrio cholerae El Tor. Monolayer comparison in ELISA demonstrated that only two toxigenic and two non-toxigenic strains possessed the ability for exopolysaccharide production.

scholarly journals RETROSPECTIVE ANALYSIS OF BIOLOGICAL AND MOLECULAR-GENETIC PROPERTIES OF STRAINS - CAUSATIVE AGENTS OF CHOLERA - ISOLATED IN UKRAINE IN 1994 - 2011

2017 ◽  
pp. 49-55
Author(s):  
I. V. Savelieva ◽  
S. N. Tikhonov ◽  
V. N. Saveliev ◽  
D. A. Kovalev ◽  
S. V. Pisarenko ◽  
...  
Keyword(s):  
Retrospective Analysis ◽  
Vibrio Cholerae ◽  
Molecular Genetic ◽  
Test System ◽  
Personal Genome ◽  
International Database ◽  
Cholera Vibrio ◽  
Causative Agents ◽  
Pcr Method ◽  
El Tor

Aim. Retrospective analysis of biological and molecular-genetic properties of strains - causative agents of cholera - isolated in the period of epidemics in Ukraine in 1994 - 2011. Materials and methods. Phenotypic and molecular-genetic properties of 5 strains of cholera vibrios, biovar El Tor isolated from cholera patients and 4 strains from the environmental samples were studied using traditional bacteriological and genetic methods. Detection of DNA for toxigenicity genes and genes characteristic for El Tor and classic biovar were carried out by PCR method using reagent kits «AmpliSens- Vibrio cholerae FRT» and «.Vibrio cholerae ctxB-rstR-rstC genes, REF» (an experimental test system). Sequencing of genomes of 4 strains of causative agents of cholera was carried out in genetic analyzer Ion Torrent Personal Genome Machine. Results. Strains of cholera vibrios identified in Ukraine in 1994 and 2011 such as a typical toxigenic biovar El Tor (V cholerae 01, El Tor, Ogawa, Hly-, ctxA+, tcpA+) contain genes of the classic cholera vibrio in their genome and are genetically altered (hybrid) variants of cholera vibrio biovar El Tor producing enterotoxin CT1 and having increased virulence, that was clinically manifested in predominance of severe forms of cholera in Mariupol of Donetsk region in 2011. Genome sequences of the 4 studied strains were deposited into the international database DDBJ/EMBL/GenBank. Conclusion. The studied isolates were established to belong to a clade of strains associated with cholera outbreaks in Haiti and Asian continent, from where genetically altered strains of cholera vibrios biovar El Tor were introduced to Haiti in 2010, based on results of comparison of genomic sequences of the studied strains with genomes of V. cholera strains from the international database GenBank.

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