Resistance of Streptococcus pneumoniae Strains Isolated from Clinical Samples to Various Antibiotics

Öz

Objective: It was aimed to determine the antibiotics resistance rates of Streptococcus pneumoniae (S. pneumoniae) strains which are important causes of mortality and morbidity with increasing resistance rates. Methods: Antibiotic susceptibilities of 80 S. pneumoniae specimens identified from samples sent from various clinics in our hospital were analyzed retrospectively. Isolated strains were identified by classical methods and BD Phoenix 100 system (Becton Dickinson Diagnostic, USA) and their antimicrobial susceptibility was evaluated by Kirby-Bauer disc diffusion method according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) document. Penicillin, cefotaxime and meropenem susceptibilities were examined by gradient test; while erythromycin, clindamycin, trimethoprim-sulfamethoxazole, levofloxacin, tetracycline, vancomycin and linezolid resistances were analyzed by disc diffusion method. Results: A total of 80 isolates including 32 blood samples, 29 respiratory samples, 10 cerebrospinal fluid (CSF), 5 vitreous, 3 pleural fluid and 1 abscess aspiration were included in the study. Penicillin resistance in CSF isolates was 70% and there was no resistance to cefotaxime and meropenem. Of 70 non-CSF isolates, 15 (21.4%) were moderately resistant, 14 (20%) were highly resistant and 41 (58.6%) were susceptible to penicillin. Cefotaxime resistance was detected in 2 (2.9%) of these isolates. Intermediate values were found in 2 (2.9%) isolates and remaining 66 (94.2%) isolates were susceptible to cefotaxime. There was no meropenem resistance in non-CSF isolates. Resistance rates of erythromycin, clindamycin, trimethoprim-sulfamethoxazole, levofloxacin and tetracycline in all isolates were 32.5%, 27.5%, 42.5%, 3.7% ve 30% respectively. There was no resistance to vancomycin and linezolid. Conclusion: Penicillin resistance is high in S. pneumoniae strains and penicillin has no place in empirical treatment of pneumococcal meningitis. Periodic monitoring of infectious agents and antibiotic susceptibilities in certain regions may guide clinicians to initiate empirical treatment.

Anahtar Kelimeler

• Antibiotic
• Resistance
• Streptococcus pneumoniae

Kaynakça

1. 1.Henriques-Normark B, Tuomanen EI. Thepneumococcus: epidemiology, microbiology, andpathogenesis. Cold Spring HarbPerspect Med.2013;3: a010215.