The evolution of the pathogen and the clinical and epidemiological features of the recent cholera (el tor)

2012 ◽  
Vol 17 (5) ◽  
pp. 31-35
Author(s):  
V. N. Savelyev ◽  
I. V. Savelyeva ◽  
B. V. Babenyshev ◽  
A. N. Kulichenko
Keyword(s):  
Genetic Structure ◽  
Vibrio Cholerae ◽  
Causative Agent ◽  
Genetically Modified ◽  
Causative Factor ◽  
Prevention Measures ◽  
Cholera Outbreak ◽  
The Caucasus ◽  
Epidemiological Features ◽  
El Tor

In a comparative perspective studied cholera outbreak in the Caucasus due to typical toxigenic and genetically modified (hybrid) El Tor variant strains have been studied. Revealed features of the genetic structure of the genome, factors and ways of transmission of the causative agent of modern cholera El tor should be considered when improving the program of epidemiological supervision in terms of enhancing antiepidemic and prevention measures in cholera, the causative factor of which are of hybrid variants of Vibrio cholerae El tor.

scholarly journals El Tor cholera at the contemporary stage of the seventh pandemia: pathogen evolution, clinical and epidemiological features, laboratory diagnostics

2021 ◽  
Vol 11 (5) ◽  
pp. 917-926
Author(s):  
I. V. Savelyeva ◽  
A. N. Kulichenko ◽  
V. N. Saveliev ◽  
D. A. Kovalev ◽  
T. V. Taran ◽  
...  
Keyword(s):  
Genetically Modified ◽  
Epidemiological Surveillance ◽  
Marker Genes ◽  
Laboratory Diagnostics ◽  
Phenotypic Properties ◽  
The Caucasus ◽  
Cholera Vibrio ◽  
Caucasus Region ◽  
Epidemiological Features ◽  
El Tor

The phenotypic and molecular genetic properties of 133 strains of genetically modified (genovariant) Vibrio cholerae O1 El Tor biovar isolated from patients in Dagestan (1993, 1994, 1998), and compared with 246 strains of a typical toxigenic cholera vibrio El Tor biovar isolated in 1970–1990 at the Caucasus Region. It was found that 48.7% of the studied genetically modified strain variants had mixed phenotypic properties of the El Tor and classic biovars that evidences about a need to include the marker genes of the classical biovar (ctxBCl+, rtxC–) and the El Tor biovar (ctxBEl+, rtxC+) into the existing biotyping scheme. The genes of the El Tor biovar, isolated from patients in Dagestan, contain in addition to the El Tor ones, the genes of the classical biovar (ctxBCl and/or rstRCl), as well as the typical toxigenic cholera vibrios of El Tor, islands of persistence (EPI), pathogenicity (VPI-1 and VPI-2) and pandemicity (VSP-I and VSP-II). However, only the El Tor biovar genovariants were found to bear an integrative and conjugative SXT element with antibiotic polyresistance genes. Epidemic cholera outbreaks caused by the El Tor biovar genovariants that occurred in 1993–1998 at the Caucasus Region, correspond to classical (Asian) cholera based on disease severity. The epidemiological features of modern cholera were studied: the main way for transmission via fecal-oral route for typical El Tor cholera vibrio is waterborne, whereas for the El Tor gene variant — household. Primary infections upon water drinking and using domestic water from surface water bodies infected with typical El Tor vibrios occur outside the family hearth. In case of cholera caused by hybrid El Tor variants, infection is transmitted among family members via domestic factors under low sanitary level. The development of laboratory diagnostics and epidemiological surveillance of modern El Tor cholera is based on the development of PCR test systems taking into account the evolutionary genome transformations.

scholarly journals MLVA-TYPING OF CLINICAL STAMPS OF GENETICALLY CHANGED VIBRIO CHOLERAE BIOTYPE EL TOR INSULATED IN RUSSIA AND UKRAINE IN THE PERIOD OF SEVENTH PANDEMIC CHOLERA

2018 ◽  
pp. 37-43
Author(s):  
I. V. Savelieva ◽  
A. N. Kulichenko ◽  
V. N. Saveliev ◽  
D. A. Kovalev ◽  
O. V. Vasilieva ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Vibrio Cholerae ◽  
Genetically Modified ◽  
Cholera Vibrio ◽  
Separate Branch ◽  
Comparative Aspect ◽  
The Russian Federation ◽  
Time Periods ◽  
El Tor ◽  
Mlva Typing

Aim. Conduct in a comparative aspect MLVA-typing of genetically altered cholera vibrio biovar El Tor, isolated from patients during the epidemic (1994) and outbreaks (1993, 1998) in Dagestan with isolates in Mariupol (Ukraine) in 1994-2011 in Moscow (2010, 2012), India (1964, 2006, 2007), Bangladesh 1991, 1994, 2001, 2004) and to establish Phylogenetic connections between strains of cholera vibrios isolated in different years in these territories, to ascertain the source of their drift. Materials and methods. MLVA-tyP-ing was carried out in PCR at 5 variable loci of 35 clinical strains of genetically modified Vibrio cholerae byotyPe El Tor. The obtained amPlicon was studied in the system of automatic caPillary electroPhoresis ExPerion («Bio Rad Laboratories», USA). For Phylogenetic analysis, along with MLVA-genotyPes, 35 strains of Vibrio cholerae from the Institute's collection used Published genotyPes of strains isolated in India, Bangladesh, Haiti. Results. The investigated strains of cholera vibrio are referred to 21 MLVA-tyPes, divided into 2 main clades and 1 seParate branch with clonal clusters and subclusters, each of which contains closely related strains of cholera vibrio genovariants having a different degree of Phylogenetic relationshiP - full or Partial identity of allelic Profiles of five variable loci. The sources of drift of genetically modified Vibrio cholerae byotyPe El Tor to Russia and Ukraine from disadvantaged cholera of India, Bangladesh, Azerbaijan and the countries of the Middle East have been established. Conclusion. The obtained data testify to the PolymorPhism of MLVA-tyPes of genetically altered strains of cholera vibrio of the biologist El Tor, evolved in different years and caused ePidemics or outbreaks of cholera in different territories during different time Periods of the course of the seventh cholera Pandemic, and also suggest the Polyclonal origin of the Vibrio cholerae biovar El Tor and the source of their drift to the territory of the Russian Federation and Ukraine.

Cholera outbreak investigation, Bhadola, Delhi, India, April–May 2018

2020 ◽  
Vol 114 (10) ◽  
pp. 762-769
Author(s):  
Akhileshwar Singh ◽  
Rakesh Gupta ◽  
Tanzin Dikid ◽  
Ekta Saroha ◽  
Naresh Chand Sharma ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Fecal Coliforms ◽  
Prevention Measures ◽  
Cholera Outbreak ◽  
Public Health Action ◽  
The North ◽  
Municipal Water ◽  
Health Action ◽  
Vibrio Cholerae O1 ◽  
Stool Samples

Abstract Background In the Gangetic plains of India, including Delhi, cholera is endemic. On 10 May 2018, staff at the north Delhi district surveillance unit identified a laboratory-confirmed cholera outbreak when five people tested positive for Vibrio cholerae O1 Ogawa serotype in Bhadola. We investigated to identify risk factors and recommend prevention measures. Methods We defined a case as ≥3 loose stools within 24 h in a Bhadola resident during 1 April–29 May 2018. We searched for cases house-to-house. In a 1 : 1 unmatched case control study, a control was defined as an absence of loose stools in a Bhadola resident during 1 April–29 May 2018. We selected cases and controls randomly. We tested stool samples for Vibrio cholerae by culture. We tested drinking water for fecal contamination. Using multivariable logistic regression we calculated adjusted ORs (aORs) with 95% CIs. Results We identified 129 cases; the median age was 14.5 y, 52% were females, 27% were hospitalized and there were no deaths. Symptoms were abdominal pain (54%), vomiting (44%) and fever (29%). Among 90 cases and controls, the odds of illness were higher for drinking untreated municipal water (aOR=2.3; 95% CI 1.0 to 6.2) and not knowing about diarrhea transmission (aOR=4.9; 95% CI 1.0 to 21.1). Of 12 stool samples, 6 (50%) tested positive for Vibrio cholerae O1 Ogawa serotype. Of 15 water samples, 8 (53%) showed growth of fecal coliforms. Conclusions This laboratory-confirmed cholera outbreak associated with drinking untreated municipal water and lack of knowledge of diarrhea transmission triggered public health action in Bhadola, Delhi.

scholarly journals Molecular characterization reveals involvement of altered el tor biotype Vibrio cholerae O1 strains in cholera outbreak at Hyderabad, India

2011 ◽  
Vol 49 (2) ◽  
pp. 280-284 ◽  
Author(s):  
Ajay Kumar Goel ◽  
Meenu Jain ◽  
Pramod Kumar ◽  
Pennagaram Sarguna ◽  
Meera Bai ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Molecular Characterization ◽  
Cholera Outbreak ◽  
Vibrio Cholerae O1 ◽  
El Tor

scholarly journals Evolution of Vibrio cholerae El Tor and Detection of Their Gene-Variants in the Caucasus

2012 ◽  
pp. 58-60
Author(s):  
V. N. Savel’Ev ◽  
I. V. Savel’Eva ◽  
O. V. Vasil’Eva ◽  
B. V. Babenyshev ◽  
D. A. Kovalev ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Gene Variants ◽  
Genotype I ◽  
The Caucasus ◽  
El Tor

, rstC genes), and 7 strains – to the genotype I. Genotypes I and II (genetically altered ones) are the hybrid variants of the El Tor biovar producing CT of the first type.

scholarly journals A large cholera outbreak due to a new cholera toxin variant of the Vibrio cholerae O1 El Tor biotype in Orissa, Eastern India

2009 ◽  
Vol 58 (2) ◽  
pp. 234-238 ◽  
Author(s):  
P. Kumar ◽  
M. Jain ◽  
A. K. Goel ◽  
S. Bhadauria ◽  
S. K. Sharma ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Dna Analysis ◽  
Novel Mutation ◽  
Consensus Sequence ◽  
Eastern India ◽  
Cholera Outbreak ◽  
Pathogenic Genes ◽  
Serological Studies ◽  
El Tor

A total of 32 Vibrio cholerae isolates were collected during a recent large cholera outbreak in Eastern India. Biochemical and serological studies revealed that all of the isolates belonged to serogroup O1, biotype El Tor, serotype Ogawa. Two multiplex PCR assays confirmed the presence of various toxigenic and pathogenic genes – ace, ctxAB, hlyA, ompU, ompW, rfbO1, rtx, tcp, toxR and zot – in all of the isolates. Sequencing of the ctxB gene from the isolates revealed a novel mutation in the gene. Sequencing also confirmed the presence of altered cholera toxin B of the classical biotype in all of the El Tor isolates, suggesting infection of isolates by classical CTXΦ. The molecular diversity of V. cholerae isolates studied by enterobacterial repetitive intergenic consensus sequence PCR, BOX-PCR and randomly amplified polymorphic DNA analysis uniformly showed the clonal relationship among the outbreak V. cholerae O1 isolates. The results of this study suggest that cholera-causing V. cholerae strains are constantly evolving in epidemic areas, highlighting the potential of the emergence of more virulent strains.

Sign in / Sign up

Export Citation Format

Share Document