Transition of drug susceptibility of vibrio cholerae 01 in Laos and Vietnam

4 strains of Vibrio cholerae 01 E1 Tor (V.cholerae 01) isolated from patients of various areas in Vietnam (20 strains in the year 1995 and 24 in 2000) and 256 strains of V.cholerae 01 isolated from various areas in Laos. (15 strains in 1993-1994 period, 21 in 1995-1996, 91 in 1998, 16 in 1999 and 109 in 2000). The ones from Laos in 1993-1996 years period were sensitive to common antibiotics such as tetracyclin, chloramphenicol, trimethoprim, but the ones of 1998-2000 were resistant to these antibiotics. The strains of V.cholerae 01 isolated in Vietnam in the year 1995 were sensitive to tetracyclin and chloramphenicol, but the ones in the year 2000 were resistant with a medium level. The strains of V.cholerae 01 in Vietnam were resistant to polymycin B, but the ones in Laos were sensitive to polymycin B