Antimicrobial Resistance in Haemophilus Influenzae Strains Isolated From Various Clinical Samples in Hacettepe University Children's Hospital (2002-2007)

Aim: To determine the resistance rates to various antimicrobial agents in 861 H. influenzae isolated from various clinical samples between 2001 and 2007 at Hacettepe University Children's Hospital. Material and Method: Susceptibility to ampicillin (Amp), ampicillin/sulbactam (SAM), cefprozil (CPR), cefotaxime (CXM), meropenem (MEM), clarithromycin (CLR), trimethoprim-sulfamethoxazole (T/S), ciprofloxacin (CIP) and tetracycline (TET) were determined in "Haemophilus Test Medium" by the disc diffusion method according to CLSI criteria. beta-lactamase production of strains was investigated using the chromogenic nitrocefin disc method (BD, Sparks, USA). Results: H. influenzae strains were isolated from 450 sputum, 198 eye, 91 bronchoalveolar lavage, 58 pus, 28 adenoid, 12 tonsil, 7 ear, 5 blood, 4 cerebrospinal fluid, 3 deep-tracheal aspirate, and other sterile sites (n=5). Resistance to cefotaxime, meropenem and ciprofloxacin was not observed between 2001 and 2007. Ampicillin, SAM, CPR, CLR, T/S and TET resistance rates were 7.2%, 0.9%, 3.7%, 3.7%, 23% and 1.1% respectively. beta-lactamase production was detected in 6.1% of H. influenzae isolates. Conclusion: Resistance rates by year are significant for the clinicians employing empirical therapy for infections. In this study, the highest resistance rate was observed for T/S. The number of isolates which are ampicillin resistant and beta-lactamase negative is low (1.6%). Diversity in resistance rates according to year was observed. However, a steady increase or decrease in the resistance rates was not shown.