Table 2. Phenotypic, genotypic and drug resistance properties of V. cholerae O1 isolated in Thailand (n = 35) between 2003 and 2011.
| Strains | Year of isolation | No. of isolates | Source* | Serotype | rfbO1 | Phenotypic properties† | Genetic screening by PCR | Resistance pattern§ | |||||||||
| CCA | Sensitivity | ctxA | tcpA type | ctxB type‡ | rstR type | rtxC | rstC | tlc | |||||||||
| PMB (50 U) | CL-specific phage IV | ET-specific phage V | |||||||||||||||
| Thai isolates | 2003 | 1 | Clin | Inaba | + | + | R | R | S | + | ET | CL | CL | + | − | − | E, AMP |
| 2003 | 1 | Env | Inaba | + | + | R | R | S | + | ET | CL | CL | + | − | − | E, AMP | |
| 2003 | 1 | Clin | Inaba | + | + | R | R | S | + | ET | CL | CL | + | − | − | E | |
| 2003 | 2 | Clin | Inaba | + | + | R | R | S | + | ET | CL | CL | + | − | − | E | |
| 2004 | 1 | Clin | Inaba | + | + | R | R | S | + | ET | CL | CL | + | − | − | E, AMP | |
| 2004 | 1 | Clin | Inaba | + | + | R | R | S | + | ET | CL | CL | + | − | − | E | |
| 2004 | 1 | Clin | Inaba | + | + | R | R | S | + | ET | CL | CL | + | − | − | E | |
| 2007 | 1 | Clin | Ogawa | + | + | R | R | S | + | ET | CL | CL | + | − | − | E, TE, SXT, AMP | |
| 2007 | 2 | Clin | Ogawa | + | + | R | R | S | + | ET | CL | ET | + | + | + | E, TE, SXT, AMP | |
| 2007 | 2 | Clin | Ogawa | + | + | R | R | S | + | ET | CL | ET | + | + | + | E, TE, SXT | |
| 2010 | 1 | Clin | Ogawa | + | + | R | R | S | + | ET | CL | ET | + | + | + | TE, SXT | |
| 2010 | 1 | Clin | Ogawa | + | + | R | R | S | + | ET | CL | ET | + | + | + | E | |
| 2010 | 1 | Clin | Ogawa | + | + | R | R | S | + | ET | CL | ET | + | + | + | TE, SXT | |
| 2010 | 3 | Clin | Inaba | + | + | R | R | S | + | ET | CL | ET | + | + | + | E, SXT | |
| 2010 | 3 | Clin | Inaba | + | + | R | R | S | + | ET | CL | ET | + | + | + | SXT | |
| 2010 | 1 | Clin | Inaba | + | + | R | R | S | − | ET | − | − | + | − | + | E | |
| 2010 | 1 | Clin | Ogawa | + | + | R | R | S | + | ET | CL | ET | + | + | + | E, TE, SXT | |
| 2010 | 2 | Clin | Ogawa | + | + | R | R | S | − | ET | − | − | + | − | + | E, AMP | |
| 2010 | 1 | Clin | Ogawa | + | + | R | R | S | − | ET | − | − | + | − | + | Sensitive to all | |
| 2010 | 1 | Clin | Ogawa | + | + | R | R | S | + | ET | CL | ET | + | + | + | SXT | |
| 2010 | 1 | Clin | Inaba | + | + | R | R | S | + | ET | CL | ET | + | + | + | SXT | |
| 2010 | 1 | Clin | Ogawa | + | + | R | R | S | − | ET | − | − | + | − | + | Sensitive to all | |
| 2010 | 2 | Env | Inaba | + | + | R | R | S | + | ET | CL | ET | + | + | + | E | |
| 2010 | 1 | Clin | Inaba | + | + | R | R | S | + | ET | CL | ET | + | + | + | E, AMP, SXT | |
| 2011 | 1 | Clin | Ogawa | + | + | R | R | S | + | ET | CL | ET | + | + | + | AMP, SXT | |
| 2011 | 1 | Clin | Ogawa | + | + | R | R | S | − | − | − | − | + | − | − | E, AMP, SXT | |
| Reference strains | |||||||||||||||||
| O395 | 1965 | – | Clin | Ogawa | + | − | S | S | R | + | CL | CL | CL | − | − | + | – |
| N16961 | 1971 | – | Clin | Inaba | + | + | R | R | S | + | ET | ET | ET | + | + | + | – |
*
Clin, Clinical; Env, environmental.
†
CCA, Chicken cell agglutination; PMB, polymyxin B; R, resistant; S, sensitive.
‡
Determined by MAMA-PCR.
§
AMP, ampicillin; E, erythromycin; SXT, trimethoprim/sulfamethoxazole; TE, tetracycline.