Salmonella typhi and applicability of Etest

The in vitro antibacterial activity of various antibiotics incfucling cefrxime against 73 clinical isolates o/Salmonella typhi from a vetriety of sources was evaluated by conventional agar-dih.uion metlod and Eîest. lB strains of these 73 strains were chloratnphenicol and cotrimoxazole (sulfcuttelhoxazole-trimetlnprtm) resistant arul I2 of these I8 strains were ttlso resistant to anroxicillin due to p-Lttctamase protluction. Cefixitne slnwed excellent activity against all 73 strains with the MICgI value of 0.25 1tg/nil. ReJlecting its high b-lactamase stabilily, CeJixime also lnd excellent activity against chloramplrcnicol-resistant strains inchrclirtg p-lactamase-proclucing amoxicillin-resistant strctitls. Antibacterial ctctivity of ceftxime was comparable to ceftriaxone, ofloxacin, antl ciprofloxacin, which are cl.rrently often usecl for llæ trealment of typhoid fever The MIC values obtainetl front the Etest correlatecl well with th.e results of cotrventional agar-diltttion ntetlncl, suggesting the usefulness of the Etest as a new easy MIC detenninarion methocl. In conclttsion, oral cefixinre can provicle a safe and effective allernative for nnnagement of tylthokl fetter even in cases of ntulticlrug-resistant S. typhi. Suppl I l99B Antibacterial activity of"€efTxime against INTRODUCTION Typhoid fever continlles to be one of the major public health problems in developing countries. Chloramphenicol was used as the first choice drug for typhoid fever until recently. However, causative organism Salmonella typhi is developing resistance to conventional antibiotics chloramphenicol, cotrimoxazole and ampicillin in many countries. Consequently, treatment of typhoid fever with conventional agents can frequently cause clinical treatment failures or bacterial relapses. Frequencies of these strains called MDR (Multi Drug Resistance) are repofted to be 78.4Vo (1990) in Indiar, 75Vo (1995) inEgyptz,77Vo (1995) in Pakistan3 and 86Vo (1995) in Vietnama. ReDept of Infections Diseases, M edicinal Biology Research Laboratories, Ftlisewa Phannaceutical Co., Ltd., Osaka, Japan. Therapy 189