The Journal of Association of Chest Physicians (Jan 2018)
Prevalence of Multidrug-Resistant Pathogens and Their Antibiotic Susceptibility Pattern from Late-Onset Ventilator-Associated Pneumonia Patients from a Tertiary-Care Hospital in North India
Abstract
Background: Ventilator-associated pneumonia (VAP) is seen as being most common in critically ill patients in intensive care units. Diagnostic protocol is challenging and the treatment is often difficult. Incorrectly selected antibiotic therapy further leads to the emergence of multidrug-resistant (MDR) organisms. Materials and Methods: The present prospective study was conducted to study patients of VAP with the aim of determining the aerobic bacterial etiological agents, antimicrobial susceptibility patterns, and molecular detection of MBL (metallo beta lactamase) genes. The antimicrobial susceptibility of the isolates by the disc diffusion method and the detection of various drug-resistance mechanisms was done. The minimum inhibitory concentration (MIC) based on E-test was determined along with the molecular analysis by polymerase chain reaction for detection of MBL genes (IMP and VIM). Results: Out of a total of 372 patients admitted in intensive care unit during the time period (March 2010 to February 2013), 40 patients were finally diagnosed as having late-onset VAP. Among the study isolates (69, due to polymicrobial infection), the maximum isolates were Acinetobacter spp. (32) followed by Pseudomonas aeruginosa (18), Klebsiella pneumoniae (8), and others. MDR was high with 34% of Acinetobacter and 50% of Pseudomonas strains being MBL producers. Among Staphylococcus aureus, 50% strains were methicillin resistant. On molecular analysis, eight of the Acinetobacter and six of the Pseudomonas isolates came out to be positive for VIM 2 gene, whereas IMP was not detected in any of the isolates. Conclusion: The present study emphasizes the threat of MDR in VAP patients from ICU as the treatment options are limited. The knowledge of prevailing organisms, resistance mechanisms, and their antibiotic profile can go a long way in deciding appropriate empirical therapy.
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