Vibrio cholerae O1 El Tor variant and emergence of Haitian ctxB variant in the strains isolated from South India.
Cholera still continues to be an important cause of human infection, especially in developing countries that lack access to safe drinking water and proper sanitation. In the present study, we report the emergence of new variant form of V. cholerae O1 El Tor biotype with a novel mutation in ctxB in strains isolated from various outbreaks during 2010-2014 in Belgaum situated in north-west Karnataka, India. A total of 14 occurrences of cholera were documented from Belgaum Division of North Karnataka during the 4-year period from 2010 to 2014. All the V. cholerae O1 isolates were subjected to DAMA PCR to detect the three different allelic subtypes of ctxB and PCR-based detection of virulent genes, and subsequently, 14 strains (one strain from each outbreak or sporadic case) were subjected to ctxB gene sequence and pulsed-field gel electrophoresis (PFGE) analysis. A total of 54 V. cholerae O1 strains were obtained of which 21 strains isolated during 2010-2011 had classical ctxB and remaining 33 strains isolated during 2012-2014 belonged to Haitian variant. In the cluster analysis, the PFGE profiles were divided into clades A with and B. Clade A contained eight strains with 94 % similarity and Haitian type of ctxB. Clade B contained six strains and had Haitian type of ctxB except one with classical ctxB. To the best of our knowledge, this is the first report of the Haitian variant of V. cholerae O1 Ogawa causing outbreaks and sporadic cases of cholera in South India.
Regional Medical Research Centre (Indian Council of Medical Research, Department of Health Research, Government of India), Chandrasekharpur, Nandankanan Road, Bhubaneswar, 751023, Odisha, India.|Regional Medical Research Centre (Indian Council of Medical Research, Department of Health Research, Ministry of Health and Family Welfare, Government of India), Nehru Nagar, Belgaum, 590010, India.
Debdutta
http://orcid.org/0000-0001-5199-5288
D
Bhattacharya
Regional Medical Research Centre (Indian Council of Medical Research, Department of Health Research, Ministry of Health and Family Welfare, Government of India), Nehru Nagar, Belgaum, 590010, India.
Shuchismita
S
Dey
Centre for Drug Discovery and Development, Sathabama University, Jeppiaar Nagar, Rajiv Gandhi Road, Chennai, 600 119, Tamil Nadu, India.|Division of Bacteriology, National Institute of Cholera and Enteric Diseases (Indian Council of Medical Research, Department of Health Research, Government of India), P-33, C.I.T. Road, Scheme XM, Beleghata, Kolkata, 700010, West Bengal, India.
Gururaja Perumal
GP
Pazhani
Centre for Drug Discovery and Development, Sathabama University, Jeppiaar Nagar, Rajiv Gandhi Road, Chennai, 600 119, Tamil Nadu, India.
Thandavarayan
T
Ramamurthy
Belgaum Institute of Medical Sciences (Government Medical College), Belgaum, 590010, India.
Mahantesh V
MV
Parande
Regional Medical Research Centre (Indian Council of Medical Research, Department of Health Research, Ministry of Health and Family Welfare, Government of India), Nehru Nagar, Belgaum, 590010, India.
Sanjiva D
SD
Kholkute
Regional Medical Research Centre (Indian Council of Medical Research, Department of Health Research, Ministry of Health and Family Welfare, Government of India), Nehru Nagar, Belgaum, 590010, India. drsubarnaroy@gmail.com.
Subarna
S
Roy
D002771:Cholera / Q000453:epidemiology* / Q000382:microbiology*; D021821:Communicable Diseases, Emerging; D004196:Disease Outbreaks; D005798:Genes, Bacterial; D006801:Humans; D007194:India / Q000453:epidemiology; D010802:Phylogeny; D041241:Vibrio cholerae O1 / Q000145:classification* / Q000302:isolation & purification
Cholera; Classical; Haitian; Variant; ctxB