Multiresistant Salmonella Organisms in India

To the Editor. —In developing countries, multiresistant Salmonella organisms are being increasingly reported. 1-3 From April 1990 to April 1991 we isolated 190 strains of Salmonella typhi from blood cultures of patients in and around the city of Bombay, India. Of these, 141 were multiresistant to chloramphenicol, ampicillin, co-trimoxazole, tetracycline, and streptomycin (by Kirby Bauer disk diffusion) giving an incidence of resistance of 74%. Minimum inhibitory concentration (MIC) done on 50 representative strains by agar dilution technique (modified National Committee for Clinical Laboratory Standards) confirmed the disk diffusion result in 40 of 50 strains, wherein an MIC value above break point was considered resistant. Resistance was found to be plasmid-mediated (100 megadalton, plasmid isolated). Salmonella typhi remains sensitive to nalidixic acid and the fluoroquino lones ciprofloxacin, oflaxacin, and norfloxacin. These drugs have been used successfully in epidemics of enteric fever caused by multiresistant organisms. 3,4 However, a decrease in