Bacteriology of Sputum Samples: A Descriptive Cross-sectional Study in a Tertiary Care Hospital

Lower respiratory tract infection is a common infection and accounts for a greater burden of disease worldwide. It is a great challenge to the clinician and still more, with increasing antimicrobial resistance. Its empirical treatment may vary according to the type of causative organisms. The objective of this study is to identify the pathogenic microorganisms and their antimicrobial susceptibility pattern from sputum sample.

This descriptive cross-sectional study was conducted in KIST Medical College and Teaching Hospital from February 2015 to January 2016. Ethical approval was taken from institutional review committee prior to the study with reference no. 0051/2014/15. Data on culture and sensitivity of isolates from sputum samples were collected from the records of the hospital. Sample collection, processing, identification of microorganisms and antimicrobial susceptibility tests were performed according to the Clinical and Laboratory Standards Institute guidelines. All the data were tabulated in an Excel sheet and analyzed using SPSS version 20.

Out of 2318 samples, 694 (29.93%) sputum samples at 95% confidence interval (737.21- 650.79) were reported as culture positive. Klebsiella was the most common isolate followed by Pseudomonas, Escherichia coli, Acinetobacter, Staphylococcus aureus, Candida albicans, Streptococcus pneumoniae, Streptococcus pyogenes, and others. Imipenem and vancomycin showed the most sensitivity towards gram-negative and gram-positive bacteria respectively.

Proper diagnosis, identification of causative agents and their antimicrobial susceptibility pattern are important steps to limit the irrational use of antimicrobials. Prescribing antimicrobials empirically in the case of suspected lower respiratory tract infection is difficult.