Chloramphenicol-resistant Salmonella typhi in Saigon
J. D. Brown, M. Duong Hong and E. R. Rhoades
Chloramphenicol-resistant Salmonella typhi was detected in Saigon in
September 1971. Subsequently, 163 strains of S typhi were isolated, 46
percent of which were resistant to choramphenicol by the agar-disk method.
Sixty-two strains were studied by the broth-dilution method; 37 percent had
minimal inhibitory concentrations for chloramphenicol greater than
250mug/ml, but all strains were susceptible to 0.4mug/ml of ampicillin and
to a disk of a combination of trimethoprim and sulfamethoxazole (Bactrim).
Persons infected with chloramphenicol-resistant strains of S typhi
responded poorly to chloramphenicol alone, but ampicillin or the
combination drug was effective.
