First quinolone resistant typhoid salmonella

ABSTRACT

The susceptibility of typhoid salmonellae to one of the quinolones [OFLOXACIIM] was first reported in 1986. Since then more than 1500 blood culture isolates have been tested in various Armed Forces Laboratories, for their susceptibility to different quinolones. As yet resistance to quinolones has not been reported from anywhere though we have reported that S.paratyphi A strains generally possessed higher MICs of the quinolones as compared to S.typhi. During May 1 992, a strain of S.paratyphi A was isolated from the blood of a clinically suspencpted typhoid case who had failed to respond to the empirical use of adequate dose of ofloxacin for eight days. This isolate of S.paratyphi A was subjected to extensive investigation as regards its susceptibility to the conventional antityphoids, as well as to all the available quinolones. The disk diffusion, broth dilution and agar dilution methods were used. The isolate was found to be fully sensitive to trimethoprim [TMP] and sulphamethoxazole [SMX]. Consequently the patient was successfully managed with cotrimoxazole [TMP + SMX]. Some of the recently isolated and lyophilized strains of S.paratyphi A were also re-evaluated. The susceptibility pattern of the isolate to various quinolones is discussed