title: Rugose atypical Vibrio cholerae O1 El Tor responsible for 2009 cholera outbreak in India.
abstract: Vibrio cholerae causes cholera outbreaks in endemic regions where the water quality and sanitation facilities remain poor. Apart from biotype and serotype changes, V. cholerae undergoes phase variation, which results in the generation of two morphologically different variants termed smooth and rugose. In this study, 12 rugose (R-VC) and 6 smooth (S-VC) V. cholerae O1 Ogawa isolates were identified in a cholera outbreak that occurred in Hyderabad, India. Antimicrobial susceptibility results showed that all the isolates were resistant to ampicillin, furazolidone and nalidixic acid. In addition, R-VC isolates were resistant to ciprofloxacin (92 %), streptomycin (92 %), erythromycin (83 %), trimethoprim-sulfamethoxazole (75 %) and tetracycline (75 %). Based on the ctxB gene analysis, all the isolates were identified as El Tor variant with mutation in two positions of ctxB, similar to the classical biotype. The R-VC isolates specifically showed excessive biofilm formation and were comparatively less motile. In addition, the majority of these isolates (~83 %) displayed random mutations in the hapR gene, which encodes haemagglutinin protease regulatory protein. In the PFGE analysis, R-VC and S-VC were placed in distinct clusters but remained clonally related. In the ribotyping analysis, all the R-VC isolates exhibited R-III pattern, which is a prevailing type among the current El Tor isolates. A hapR deletion mutant generated using an S-VC isolate expressed rugose phenotype. To our knowledge, this is the first report on the association of rugose V. cholerae O1 in a large cholera outbreak with extended antimicrobial resistance and random mutations in the haemagglutinin protease regulatory protein encoding gene (hapR).
authors: Department of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors: Goutam
authors: G
authors: Chowdhury
authors: Infectious Diseases and Immunology Division, CSIR - Indian Institute of Chemical Biology, Kolkata, India.
authors: Rupak K
authors: RK
authors: Bhadra
authors: Infectious Diseases and Immunology Division, CSIR - Indian Institute of Chemical Biology, Kolkata, India.|Center for Human Microbial Ecology, Translational Health Science and Technology Institute, Faridabad, India.
authors: Satyabrata
authors: S
authors: Bag
authors: National Institute of Pharmaceutical Education and Research, Kolkata, India.
authors: Gururaja P
authors: GP
authors: Pazhani
authors: Center for Human Microbial Ecology, Translational Health Science and Technology Institute, Faridabad, India.
authors: Bhabatosh
authors: B
authors: Das
authors: Infectious Diseases and Immunology Division, CSIR - Indian Institute of Chemical Biology, Kolkata, India.
authors: Pallabi
authors: P
authors: Basu
authors: Division of Microbiology, Gandhi Medical College, Secunderabad, India.
authors: K
authors: K
authors: Nagamani
authors: Department of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors: Ranjan K
authors: RK
authors: Nandy
authors: Department of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors: Asish K
authors: AK
authors: Mukhopadhyay
authors: Center for Human Microbial Ecology, Translational Health Science and Technology Institute, Faridabad, India.|Department of Bacteriology, National Institute of Cholera and Enteric Diseases, Kolkata, India.
authors: Thandavarayan
authors: T
authors: Ramamurthy
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms; D002771:Cholera / Q000453:epidemiology / Q000382:microbiology*; D004196:Disease Outbreaks; D005838:Genotype; D006801:Humans; D007194:India / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D041241:Vibrio cholerae O1 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins