Clinical characteristics and antimicrobial susceptibility of invasive group B streptococcal infections in nonpregnant adults in Taiwan

To understand group B streptococcal infections other than peripartum events in adults and to provide a regional antimicrobial therapy guide, we conducted a retrospective analysis of invasive diseases caused by group B streptococcus (GBS) in 33 nonpregnant adults treated in a medical center in southern Taiwan, from January 1993 to July 1994. Antimicrobial susceptibility tests were performed using the agar dilution method. The incidence of the disease was 1.6 per 1,000 nonpregnant adult admissions, and the mean age of patients was 58 years (range 17-86 years). Primary bacteremia (13) and soft- tissue infections (11) were the most common manifestations. Nearly all the patients had underlying disease(s) and/or condition(s); the three most common were diabetes mellitus (13), malignancy (5), and liver cirrhosis (5). There were eight nosocomial infections and six patients died. Of 32 GBS strains tested, 27 were susceptible to penicillin G and the rest were intermediately susceptible. All strains were uniformly susceptible to cephalothin, cefotaxime, ofloxacin, and vancomycin; two strains were susceptible to gentamicin and nearly half were intermediately susceptible. Our findings imply a requirement for higher doses of penicillin or combination with an aminoglycoside for treatment of GBS infection. First-generation cephalosporins may be an alternative for the treatment of GBS infections in Taiwan.