Bacteriological profile and antimicrobial sensitivity pattern of Ventilator associated pneumonia in a tertiary care hospital

Abstract

Background:Ventilator-associated pneumonia (VAP) is the second most common nosocomial infection and accounts for 15-20% of the total hospital acquired infections. It is the most common cause of death in ICU’s with a mortality rate of up to 40%.VAP rate varies from 1.0 to 46.0 per 1000 mechanical ventilation days, depending on the ICU facility and the hospital.Aims and Objectives:1. To determine the aerobic bacterial pathogens of the patients diagnosed with VAP. 2. To study the antibiogram of isolated bacteria and to detect the drug resistance in the pathogens.Material and methods:Endotracheal aspirates from 120 patients undergoing mechanical ventilation for >48h were collected and processed by semi-quantitative method. Isolates were identified by standard methods and antibiotic susceptibility was done using Kirby Bauer disc diffusion method as per the CLSI guidelines.Results: A total of 120 clinically suspected VAP patients were enrolled for the study who fulfilled our study′s predefined criteria. Among 120 patients, 52 patients (43.3%) showed significant growth of ≥105CFU/ml growth indicating pathogenic bacteria causing VAP and 44 patients (36.6%) with <105CFU/ml classified under NO-VAP group and 24 (20%) showed no growth. This consists of 44 male patients and 8 female patients. Out of which 42/52 (80.7%) showed monomicrobial growth and 10/52 (19.2%) showed polymicrobial growth. The isolation rate of Gram negative bacilli in this study was 54/120 (45%) and Gram positive cocci isolated was 8/120(6.6%).Out of 54 Gram negative bacilli the predominant organism was Klebsiella species 34/54 (62.9%) followed by Acinetobacter sp.10/54 (18.5%) and Pseudomonas aeruginosa 6/54 (11.1%) and Escherichia coli 4/54 (7.4%). Out of 8 Staphylococcus aureus species 4 isolates were MRSA. Out of 54 GNB 28(51.8%) were ESBLs & 10(18.5%) were MBLs.Conclusion: A local antibiogram pattern for each hospital, based on bacteriological profile and susceptibilities is essential for prompt initiation of empirical antimicrobial treatment.Injudicious prophylactic use of antibiotics is not recommended in cases of VAP because exposure to antibiotics is a significant risk factor for colonization and infection with nosocomial multidrug resistant pathogens. The rational use of antibiotics may reduce patient colonization and subsequent VAP with multidrug pathogen.