Volume 14, Number 6—June 2008
Letter
Vibrio cholerae O1 Hybrid El Tor Strains, Asia and Africa
Table
Phenotypic and genotypic traits of Vibrio cholerae O1 clinical strains isolated from Asia and Africa, 1991–2004*
Test strain origin (no. examined) or reference strain ID | Year(s) of isolation | rfbO1 | Phenotypic tests |
PCR amplicons |
Cholera toxin type† (no. strains) | |||||
---|---|---|---|---|---|---|---|---|---|---|
CCA | Polymyxin B (50 U) | Voges-Proskauer | tcpA (El Tor) | tcpA (classical) | rtxC | |||||
Japan (6) | 1991–1997 | + | + | Resistant | + | + | – | + | Classical (5), El Tor (1) | |
Hong Kong (18) | 1998–2000 | + | + | Resistant | + | + | – | + | Classical (11), El Tor (7) | |
Zambia (8) | 1996–2004 | + | + | Resistant | + | + | – | + | Classical (5), El Tor (3) | |
China (3) | 1999 | + | + | Resistant | + | + | – | + | Classical (3), El Tor (0) | |
Sri Lanka (1) | 1998 | + | + | Resistant | + | + | – | + | Classical (1), El Tor (0) | |
Vietnam (5) | 1994–2002 | + | + | Resistant | + | + | – | + | Classical (5), El Tor (0) | |
Classical 569B | 1948 | + | – | Sensitive | – | – | + | – | Classical | |
El Tor N16961 | 1971 | + | + | Resistant | + | + | – | + | El Tor |
*rfbO1, O-antigen biosynthesis genes; CCA, chicken cell agglutination; tcp, toxin-coregulated pilus; rtx, repeat in toxin.
†Based on ctxB sequence. GenBank accession nos. for the ctxB sequences are EU156448–EU156488.