Antimicrobial resistance pattern among aerobic gram-negative bacilli of lower respiratory tract specimens of intensive care unit patients in a neurocentre.

ABSTRACT

BACKGROUND: Analysis of the tracheal and bronchial isolates from the lower respiratory tract specimens of the intensive care unit (ICU)-admitted patients, was carried out for the year 2002 with a perspective of looking at the antibiotic resistance pattern. METHODS: Lower respiratory tract secretions (tracheal or bronchoscopic aspirates) of 370 patients were cultured, identified and antimicrobial susceptibility performed by standard methods. RESULTS: Out of samples obtained from 370 patients, 274 (74%) were culture positive. A total of 489 bacterial isolates were recovered from 270 patients; 451 were gram-negative bacilli (GNB) and 38 were Staphylococcus aureus. In four of the patients, Candida spp was isolated. The common GNB isolates were non-fermentative gram-negative bacilli (NFGNB, 31.9%), followed by Pseudomonas aeruginosa (21.5%) and Klebsiella spp (19%). Elderly (24.8%) and adults (19.2%) showed increased rate of GNB isolation. In both tracheal and bronchial GNB isolates, the highest mean resistance was to cefazolin (98.8%) and ampicillin (97.6%) while the lowest mean resistance was to amikacin (48.5%). Isolation of two organisms per specimen (41.4%) was commonly seen. Multidrug resistance to the tested antimicrobials was more frequent in NFGNB (6.6%) and Pseudomonas aeruginosa (5%). There were no remarkable differences in the overall mean drug resistance among tracheal and bronchial GNB isolates. CONCLUSIONS: Isolation practices, antibiotic policies, effective surveillance, maintenance of epidemiological trends of infections and, rapid molecular diagnosis are the need of hour in improved and speedy management of lung infections with resistant organisms.