January 13, 1975

Chloramphenicol-Resistant Salmonella typhi in Saigon

Author Affiliations

From the Department of Medicine, University of Oklahoma Health Sciences Center (Dr. Brown), the Department of Medicine, Veterans Administration Hospital (Dr. Rhoades), Oklahoma City, and the Department of Pathology, Faculty of Medicine, University of Saigon, Republic of Vietnam (Dr. Duong Hong Mo). Dr. Brown is now at the University of Southern California School of Medicine, Los Angeles.

JAMA. 1975;231(2):162-166. doi:10.1001/jama.1975.03240140022018

Chloramphenicol-resistant Salmonella typhi was detected in Saigon in September 1971. Subsequently, 163 strains of S typhi were isolated, 46% of which were resistant to choramphenicol by the agar-disk method. Sixty-two strains were studied by the broth-dilution method; 37% had minimal inhibitory concentrations for chloramphenicol greater than 250μg/ml, but all strains were susceptible to 0.4μg/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.

(JAMA 231:162-166, 1975)