Biotype‐specific tcpA genes in Vibrio cholerae

• Published in: FEMS microbiology letters Vol. 121; no. 1; pp. 47 - 54
• Main Authors: Iredell, J.R., Manning, P.A.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.08.1994; Blackwell
• Subjects: Amino Acid Sequence; Antigenic variation; Bacterial Proteins - genetics; Bacterial Typing Techniques; Bacteriology; Base Sequence; Biological and medical sciences; Cholera - microbiology; Fimbriae Proteins; Fimbriae, Bacterial - physiology; Fundamental and applied biological sciences. Psychology; Genes, Bacterial - genetics; Genetic variation; Humans; Microbiology; Molecular Sequence Data; Morphology, structure, chemical composition; Polymerase Chain Reaction; Regulatory Sequences, Nucleic Acid - genetics; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Toxin‐coregulated pilus; Vaccine; Vibrio cholerae; Vibrio cholerae - classification; Vibrio cholerae - genetics; Typing; O antigen; Nucleotide sequence; Gene product; Vibrio cholerae; Sequence alignment; Bacteria; Homology; Vibrionaceae; Pilus; Detection; Comparative study
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.1994.tb07074.x

The tcpA gene, encoding the structural subunit of the toxin‐coregulated pilus, has been isolated from a variety of clinical isolates of Vibrio cholerae, and the nucleotide sequence determined. Strict biotype‐specific conservation within both the coding and putative regulatory regions was observed, with important differences between the El Tor and classical biotypes. V. cholerae O139 Bengal strains appear to have El Tor‐type tcpA genes. Environmental O1 and non‐O1 isolates have sequences that bind an E1 Tor‐specific tcpA DNA probe and that are weakly and variably amplified by tcpA‐specific polymerase chain reaction primers, under conditions of reduced stringency. The data presented allow the selection of primer pairs to help distinguish between clinical and environmental isolates, and to distinguish El Tor (and Bengal) biotypes from classical biotypes from classical biotypes of V. cholerae. While the role of TcpA in cholera vaccine preparations remains unclear, the data strongly suggest that TcpA‐containing vaccines directed at O1 strains need include only the two forms of TcpA, and that such vaccines directed at (O139) Bengal strains should include the TcpA of El Tor biotype.