High rates of antimicrobial resistance among clinical isolates of nontyphoidal Salmonella in Taiwan

To assess trends in antimicrobial-resistant Salmonella infections from 1989 to 1996 in southern Taiwan, the minimum inhibitory concentrations (MICs) o f 14 antibiotics or antibiotic combinations were determined by the agar dil ution method for 297 clinical isolates of nontyphoidal Salmonella. The rate s of resistance to ampicillin, chloramphenicol, and tetracycline were 65, 6 7, and 78%, respectively. Resistance to trimethoprim-sulfamethoxazole (TMP- SMX) increased from 25% in 1989-1992 to 35% in 1993-1996 (P = 0.057), For n ew quinolones and extended-spectrum cephalosporins, no resistant strains we re encountered. Multiple resistance to more than five antimicrobial drugs d oubled from 10.6% in 1989-1992 to 19.7% in 1993-1996, Multiply resistant sa lmonellae were isolated more commonly from blood samples than from feces (3 0% vs. 14%, P<0.05), In Taiwan, ampicillin, chloramphenicol, and even TMP-S MX are no longer the drugs of choice for treatment of serious nontyphoidal Salmonella infections. Extended-spectrum cephalosporins are now the preferr ed drugs in Taiwan for treatment of invasive Salmonella infections in child ren.