Comprehensive Analysis of Etiological Agents and Drug Resistance Patterns in Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) develops in patients who stay on mechanical ventilation for more than 48 h. In the presence of causative pathogens, the patient develops clinical signs such as purulent tracheal discharge, fever, and respiratory distress. A prospective observational study was carried out in the Intensive Care Unit (ICU) of Max Healthcare Centre, New Delhi, from 2020 to 2023. The study comprised 70 samples from patients diagnosed with VAP. This study thoroughly examined VAP-associated microorganisms and resistance in the hospital ICU. <i>Klebsiella pneumoniae</i>, <i>Acinetobacter baumannii</i>, and <i>Pseudomonas aeruginosa</i> were the most commonly reported pathogens. Significant drug resistance was seen in <i>P. aeruginosa</i>, <i>K. pneumoniae</i>, <i>A. baumannii</i> and <i>Staphylococcus aureus</i>. The heatmap also supported the antibiotic resistance data patterns obtained from conventional and automated systems of determination. Notably, <i>Serratia marcescens</i>, <i>Escherichia coli</i>, <i>Klebsiella pneumoniae</i>, <i>Ralstonia insidiosa</i>, and <i>Ralstonia mannitolilytica</i>, showed 60 to 100% of resistance to a number of antibiotics. Among all VAP patients, 31.42% early-onset and 68.57% late-onset VAP cases were detected. Out of 70 patients, 43 patients died (mortality rate 61.4%); majority of them suffered from late-onset VAP. The study goal was to describe the antibiotic resistance patterns and microbial ecology of the pathogens that were isolated from VAP patients. According to the heatmap analysis, a varied VAP microbiome with high prevalences of MDR in <i>A. baumannii</i>, <i>P. aeruginosa</i>, <i>K. pneumoniae</i>, and <i>S. aureus</i> was identified. To address the increasing prevalence of MDR VAP, the study highlights the critical need for improved VAP monitoring, strong infection control, and appropriate antibiotic usage.