Antimicrobial susceptibility in community-acquired bacterial pneumonia in adults

OBJECTIVES: To determine the antimicrobial susceptibility patterns of Streptococcus pneumoniae and Haemophilus influenzae, two bacterial pathogens commonly associated with community-acquired pneumonia. DESIGN: Cross-sectional study. SETTING: Bacterial isolates were obtained from adults suspected to have community-acquired pneumonia and who sought treatment at two city council clinics in Nairobi, Kenya. Susceptibility to antimicrobial agents was performed using a microdilution broth method, according to the criteria set by the National Committee for Clinical Laboratory Standards. RESULTS: A total of 277 S. pneumoniae and 58 H. influenzae were obtained from 536 adults examined in the period January 1998 to December 1999. Of the 277 S. pneumoniae, only 56.7% were susceptible to penicillin and 7.6% of strains were resistant to two or more antimicrobial agents. Of the 58 H. influenzae strains, 91.4% were sensitive to ampicillin, with 6.8% resistant to two or more antimicrobial agents. 8.6% were beta-lactamase producers and accounted for the entire ampicillin-resistant population. CONCLUSION: The prevalence of resistance to penicillin and other commonly used antibiotics among pneumococci is high and the large number of multi-resistant strains among H. influenzae is a cause for concern. The prudent use of antibiotics in treatment of pneumonia and other infections should be advocated to minimise spread of resistance.