Biofilm Producing Multidrug and Extensive Drug Resistant Bacterial Pathogens from Tracheal Aspirates of Intensive Care Unit Patients – a Threat to Combat

ISSN: 2319-7706 Special Issue-1 (2015) pp. 1-9 http://www.ijcmas.com Antibiotic resistance among Gram negative bacteria (GNB) causing hospital acquired lower respiratory tract infections (LRTI) poses a grave threat in ICU patients. The objective was to assess the prevalence of Gram negative pathogens in ICU patients and their drug resistance profile. Prevalence of extended spectrum βlactamases (ESBLs), AmpC and metallo-β-lactamases (MBL) was also assessed. Tracheal aspirates were collected aseptically from 105 ICU patients from February 2012 to November 2013. They were cultured and identified by standard microbiological techniques. Antimicrobial susceptibility was performed according to CLSI guidelines. MBL were detected phenotypically. ESBLs and AmpC were detected both phenotypically and genotypically. GNB constituted 68 (88.3%) of the total isolates, among them P. aeruginosa 26 (38.2%) were the most frequently isolated species. Gram-positive organisms constituted 4 (5.1%) of the total isolates and all (100%) of them were MDR. Multidrug resistance, extensive drug resistance and biofilm production was observed in 23.9%, 55.2% and 40.6% isolates respectively. Distribution of blaCTX-M gene among MDR and XDR isolates was 17.2% and 11.7% respectively while that of blaAmpC was 13.2% and 29.3%. All the MBL (14.4%) producers were XDR. Prevalence of blaCTX-M and blaAmpC gene in biofilm positive isolates was 10.2% and 27.6% respectively. All the isolates were sensitive to polymixin B and colistin. The average hospital stay of patients positive for biofilm producing isolates was 28 days and was associated with 43.5% mortality. P. aeruginosa was found as the predominant pathogen in tracheal aspirate. AmpC producers were the most frequently isolated GNB producing biofilm and showing extensive drug resistance. In view of significant prevalence of biofilm producing MDR amongst Gram-negative organisms in the ICU, regular surveillance of antibiotic susceptibility patterns plays a crucial role in guiding the clinicians for choosing the empirical or directed therapy of infected patients. K e y w o r d s