Penicillin-resistant pneumococci from pediatric patients in the Washington, DC, area.

Objective: To assess the prevalence and antimicrobial susceptibility of penicillin-resistant pneumococci (PRP) isolated from patients in a pediatric hospital.

Methods: All (108) isolates of Streptococcus pneumoniae recovered from usually sterile body sites between June 1, 1992, and May 31, 1993, were screened for susceptibility to penicillin by the E-test method. Minimum inhibitory concentrations of penicillin and other antibiotics were also determined by an agar dilution method for 10 PRP and 22 penicillin-susceptible strains.

Results: Fourteen isolates (12.9%) were PRP by the E-test; nine of these (8.3%) were intermediately resistant and five (4.6%) were highly resistant. All strains were sensitive to rifampin and vancomycin. Increased frequency of resistance to oral and parenteral cephalosporins and carbapenems was found among PRP; for most of these antibiotics, resistance exceeded 40% of the PRP. In addition, 20% of the PRP were resistant to macrolides and all penicillin-susceptible and PRP were resistant to a combination of trimethoprim and sulfamethoxazole.

Conclusions: The decreased susceptibility to oral and parenteral cephalosporins, macrolides, a combination of trimethoprim and sulfamethoxazole, and carbapenems creates a significant problem in the treatment of pneumococcal infections in both ambulatory and hospitalized patients.