Antimicrobial susceptibility of organisms isolated from sputum culture of Karachi, Pakistan.

Our study aims to contribute to developing antibiotics prescription guidelines at a national and a regional level directed by the antibiotics susceptibility patterns and rapidly emerging resistant organisms. This study is designed to observe the antimicrobial susceptibility in sputum culture isolates and drug resistance patterns against various antimicrobials. This was a retrospective cohort study; data was collected from two laboratories from 1st Jan to 15 July 2007. All laboratory reports were analyzed using SPSS version 19.0.The sputum culture was found positive for microbial growth in 217 reports out of 864 total (25.11%). The leading organisms were 25.8% Klebsiella pneumoniae, 23.5% Streptococcus pneumoniae, 18% Pseudomonas aeruginosa and 12.9% Staphylococcus aureus. S.pneumoniae and S.aureus were sensitive to the combination of beta lactam antibiotics and anti-beta lactamase while K.pneumoniae and P. aureginosa were susceptible to fluoroquinolones, macrolides and aminoglycosides. The total yield of sputum culture was 25.11%. The gram positive cocci which were isolated were mostly resistant to beta lactam antibiotics alone i.e. only 45% of S. pneumoniae and 33% of S. aureus were sensitive to Amoxicillin alone. Sensitivity to Co-amoxiclav was still high. 90% and 85% of S. pneumonia and S. aureus respectively were sensitive to Co-amoxiclav. The P. aeruginosa resistance to Amikacin in our study is 10%.