Prevalence and susceptibility patterns of bacteria causing respiratory tract infections in North Waziristan, Pakistan

Respiratory tract infections (RTIs) are the most common infectious diseases in humans and are the major cause of mortality and morbidity in Pakistan. These infections are the leading causes of consultations in primary care in Pakistan. Therefore, this study was aimed at determining bacterial pathogens of respiratory tract infections and the susceptibility patterns of bacterial isolates to antibiotics. The study was conducted between February, 2013 and March, 2014 in North Waziristan region of Pakistan. Sputum specimens were collected aseptically from 227 patients and cultured on the appropriate bacteriological media. Bacterial isolates were identified by biochemical tests and their antibiotics susceptibility patterns were determined by standard methods. Out of 227, various species of bacteria were isolated from 152 (75%) specimens. The prevalence of bacteria species isolated were as follows Pseudomonas aeruginosa (42.8%), Streptococcus pneumoniae (26.7%), Corynebacterium diphtheria (10.6%), Staphylococcus aureus (5.9%), Proteus vulgaris (4.6%), Micrococcus species (3.3%), Klebsiella pneumoniae (2.6%) and Bacillus species (2.6%). The susceptibility patterns varied among bacterial species depending on the antibiotics. For the susceptibility test 11 commercially available antibiotics against bacterial isolates were used. The results revealed that generally the bacterial isolates were susceptible to gentamicin (80.9%), meropenem (75 %), ceftazidime (62.5%), cefotaxime (57.9%) and ceftriazone (57.9%) and resistant to penicillin (84.9%) and doxycycline (78.9%). The antibiotics gentamicin (100%) meropenem (100%), ceftriaxone (58.5%), ciprofloxacin (60%) trimethoprim (60%), ceftazidime (66.2%) and cefotaxime (64.6%) were observed effective against the P. aeruginosa isolates. The findings of our study provide significant information for empiric therapy of patients with RTIs in North Waziristan region of Pakistan.