Epidemiological and pathogenic characteristics of Haitian variant V. cholerae circulating in India over a decade (2000–2018). (December 2020)

• Record Type: Journal Article
• Authors: Narendrakumar, Lekshmi; Jaikumar, Vishnu S.; Chandrika, Sivakumar K.; Thomas, Sabu
• Is Part Of: Microbial pathogenesis. Volume 149(2020)
• Publication Date: 2020-12
• Subjects: Cholera toxin -- Haitian variants -- Genetic diversity -- V. cholerae; Pathogenic microorganisms -- Periodicals; Pathology, Molecular -- Periodicals; Communicable Diseases -- microbiology -- Periodicals; Communicable Diseases -- parasitology -- Periodicals; Micro-organismes pathogènes -- Périodiques; Pathologie moléculaire -- Périodiques; Electronic journals; 616.9041
• DOI: 10.1016/j.micpath.2020.104538
• Languages: English
• ISSNs: 0882-4010

Abstract

Abstract: Vibrio cholerae, causative agent of the water-borne disease cholera still threatens a large proportion of world's population. The major biotypes of the pathogen are classical and El Tor. There have been recent reports of variant V. cholerae strains circulating around the world. In the present study, the epidemiological status of V. cholerae strains circulating in the country over a decade was assessed. Also, a comprehensive analysis of the difference in pathogenicity between the different biotypes of V. cholerae strains was evaluated both in-vitro and in-vivo. The amount of CT produced by different biotypes of V. cholerae strains were analyzed by GM1 ELISA and the probable reasons for the difference in toxin production was discussed. MLST analysis grouped the isolates into a single Sequence Type (ST 69) whereas PFGE analysis clustered the isolates into ten different pulsotypes revealing molecular diversity. The circulating strains were identified to produce cholera toxin and CT mRNA intermediate to the classical and prototype El Tor strains. Also, the circulating strains were identified to possess four ToxR binding sequences. In-vivo pathogenicity analysis by rabbit ileal loop fluid accumulation assay revealed the Haitian variant strains to be more hyperemic than the prototype strains. Highlights: MLST analysis clustered the V. cholerae strains to the seventh pandemic ST69PFGE analysis sub-clustered the strains to ten different pulsotype. Majority of the test isolates were identified to possess CTX-3b allele and few had CTX-3 type genotype. Haitian variant strains circulating in the country produced cholera toxin intermediate to classical and El Tor strains. The Haitian variant strains were identified to be hyperemic than the prototype strains. This study highlights the requisite of understanding the pathogenic potential of V. cholerae strains.