Volume : 3, Issue : 4, April - 2014

Sputum Gram Stain Assessment in Relation to Sputum Culture for Respiratory Tract Infections in A Tertiary Care Hospital

Dr . V. P. Amudha, Dr. B. Cinthujah, Dr. G. Sucilathangam

Abstract :

For diagnosis of Lower respiratory tract infections (LRTIs), expectorated sputum is the most commonly received sample in the laboratory. Normal resident bacteria of the oropharynx contaminate the sputum sample. The value of sputum microscopy and culture in the diagnosis of LRTIs is a matter of controversy. The following study was conducted to evaluate the correlation of Gram’s stain and culture in sputum samples from LRTIs. A total of 50 sputum samples were processed. All the samples were processed through Gram’s stain and culture. The Gram’s smear was examined for the presence of polymorphs, epithelial cells and bacterial forms. Sputum samples were evaluated based on Bartlett’s grading system. The cultures were identified by standard protocols and antibiotic susceptibility performed by Kirby Bauer disk diffusion method. Out of 50 sputum samples processed, 21 (42%) were acceptable and 29 (58%) were not meeting the standard criteria of Bartlett. Potential pathogens were obtained from 17 of 21 acceptable samples (80.95 %), and from11 of 29 non-acceptable samples (27.58%). The most common organisms isolated in the present study include: Klebsiella pneumoniae (22%) and Pseudomonas aeruginosa (8%). we recommend initial screening of sputum samples for clinically relevant results, and reject the non-acceptable samples, and re-order for fresh and correct specimens.