HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by MITRA, RUPAK.K. Articles by NAIR, G. B. Search for Related Content PubMed PubMed Citation Articles by MITRA, RUPAK.K. Articles by NAIR, G. B. Agricola Articles by MITRA, RUPAK.K. Articles by NAIR, G. B.

Molecular characterisation of rough variants of Vibrio cholerae isolated from hospitalised patients with diarrhoea

RUPAK.K. MITRA^*,, RANJAN K. NANDY^*, THANDAVARAYAN RAMAMURTHY^*, SUJIT K. BHATTACHARYA^*, SHINJI YAMASAKI, TOSHIO SHIMADA, YOSHIFUMI TAKEDA and G. BALAKRISH NAIR^*

*National Institute of Cholera and Enteric Diseases, Beliaghata, Calcutta 700 010, India; Research Institute, International Medical Center of Japan, Shinjuku, Tokyo 162-8655, Japan and National Institute of Infectious Diseases, Shinjuku, Tokyo 162-8640, Japan

Corresponding author: Dr G.B. Nair (e-mail: gbnair{at}vsnl.com). Present address: John Hopkins University, 624 N. Broadway, Baltimore, MD 21205, USA.

Received 13 March 2000; revised version received 2 Aug. 2000; accepted 23 Aug. 2000.

Abstract

Seven rough isolates of Vibrio cholerae isolated as the sole infecting agent from patients with cholera-like diarrhoea were examined for the presence of the regulatory element toxR and certain virulence-associated genes of the CTX genetic element and V. cholerae pathogenicity island (VPI). Multiplex PCR analysis with wb-specific genes of either O1 or O139 origin showed that six of the seven isolates produced an O1 wb-specific amplicon and the remaining isolate produced an O139-specific amplicon. Analysis of lipopolysaccharide profiles of smooth variants of V. cholerae revealed the presence of long repeated units of ‘O’ polysaccharide side chains but all the rough variants appeared to be devoid of the latter and possessed only core oligosaccharide. PCR amplification with primers specific to the ctxA, ctxB, tcpA, tagA, int, aldA, toxT, LJ, RJ and toxR genes revealed that six of the seven rough isolates were positive for these genes. One isolate was found to be negative for tagA and RJ, indicating the presence of an altered VPI. Each of these isolates showed media-dependent expression of cholera toxin (CT) and produced more toxin than the reference V. cholerae O1 El Tor strain VC20 or O139 strain SG24 under comparable conditions. Studies on the clonality of these isolates by the analysis of rRNA genes indicated their relatedness to strains of V. cholerae O1 El Tor or O139, isolated during the same time period.

This article has been cited by other articles:

				G. B. Nair, F. Qadri, J. Holmgren, A.-M. Svennerholm, A. Safa, N. A. Bhuiyan, Q. S. Ahmad, S. M. Faruque, A. S. G. Faruque, Y. Takeda, et al. Cholera Due to Altered El Tor Strains of Vibrio cholerae O1 in Bangladesh J. Clin. Microbiol., November 1, 2006; 44(11): 4211 - 4213. [Abstract] [Full Text] [PDF]

				C. Matz, D. McDougald, A. M. Moreno, P. Y. Yung, F. H. Yildiz, and S. Kjelleberg Biofilm formation and phenotypic variation enhance predation-driven persistence of Vibrio cholerae PNAS, November 15, 2005; 102(46): 16819 - 16824. [Abstract] [Full Text] [PDF]

				R. Chakraborty, S. Chakraborty, K. De, S. Sinha, A. K Mukhopadhyay, J. Khanam, T. Ramamurthy, Y. Takeda, S. K Bhattacharya, and G B. Nair Cytotoxic and cell vacuolating activity of Vibrio fluvialis isolated from paediatric patients with diarrhoea J. Med. Microbiol., August 1, 2005; 54(8): 707 - 716. [Abstract] [Full Text] [PDF]

				C.-H. Chen, T. Shimada, N. Elhadi, S. Radu, and M. Nishibuchi Phenotypic and Genotypic Characteristics and Epidemiological Significance of ctx+ Strains of Vibrio cholerae Isolated from Seafood in Malaysia Appl. Envir. Microbiol., April 1, 2004; 70(4): 1964 - 1972. [Abstract] [Full Text] [PDF]