title: Diversity in the arrangement of the CTX prophages in classical strains of Vibrio cholerae O1.
abstract: This study reports the results of a molecular analysis of the CTX prophages in classical biotype strains of Vibrio cholerae O1 of clinical origin isolated between 1970 and 1979 in India. All strains were sensitive to group IV classical phage and polymyxin B but resistant to group 5 El Tor phage. These phenotypic traits are consistent to that exhibited by the classical biotype. PCR studies reconfirmed their biotype assignment and showed the presence of intact CTX prophages and the presence of the recently described toxin linked cryptic plasmid. Restriction fragment length polymorphism of rRNA genes and pulsed-field gel electrophoresis showed clonal diversity among the strains. The most notable observation was the finding that one strain (GP13) has three CTX prophages while another (GP147) has four CTX prophages. This is the first time heterogeneity is reported in the arrangement of the CTX prophages among classical strains of V. cholerae O1.
authors.affiliation: Department of Microbiology, National Institute of Cholera and Enteric Diseases, P-33, CIT Road, Scheme XM, Beliaghata, Calcutta, India.
authors.forename: A
authors.initials: A
authors.lastname: Basu
authors.forename: A K
authors.initials: AK
authors.lastname: Mukhopadhyay
authors.forename: P
authors.initials: P
authors.lastname: Garg
authors.forename: S
authors.initials: S
authors.lastname: Chakraborty
authors.forename: T
authors.initials: T
authors.lastname: Ramamurthy
authors.forename: S
authors.initials: S
authors.lastname: Yamasaki
authors.forename: Y
authors.initials: Y
authors.lastname: Takeda
authors.forename: G B
authors.initials: GB
authors.lastname: Nair
mesh_terms: D001434:Bacteriophage Typing; D001435:Bacteriophages / Q000235:genetics*; D002771:Cholera / Q000382:microbiology; D002772:Cholera Toxin / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D020459:Genes, rRNA / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011112:Polymyxin B / Q000494:pharmacology; D012335:RNA, Ribosomal / Q000235:genetics; D014734:Vibrio cholerae / Q000145:classification* / Q000187:drug effects / Q000821:virology*
chemical_list: D004275:DNA, Ribosomal; D012335:RNA, Ribosomal; D002772:Cholera Toxin; D011112:Polymyxin B