Monitoring the effect of microbial culture on cleaning and sanitizing of the external ventilator circuit

Abstract

This research aimed to investigate the microbial spectrum of microorganisms that cause ventilator-associated pneumonia (VAP) among ICU patients in the selected hospital, antimicrobial susceptibility, genetic diversity of common isolates, and the monitoring effect of microbial culture on cleaning and sanitizing of external ventilator circuits in order to reduce the occurrence of hospital infections. For this purpose, endotracheal aspirate (ETA) specimens were sampled from ICU patients with clinically suspected VAP in the hospital between August 2020 and August 2021 and then investigated for microbiological content. This was followed by Kirby-Bauer testing for determining drug sensitivity and ERIC-PCR for genotyping. Afterward, microbial culture was performed on cleaned, sanitized and dried ventilator external ventilator pipelines and those stored aseptically for 4 weeks to evaluate the cleaning and disinfection effect and measure the bacterial content. Results showed that in the 64 confirmed VAP cases, Klebsiella was the most frequently isolated organism, followed by P. aeruginosa and Acinetobacter baumannii, while Candida is the most widely isolated fungus. The antimicrobial susceptibility spectrum revealed that 40% of the isolates were multidrug-resistant (MDR). ERIC-PCR showed no genetic relationship between pneumococcal isolates. Through microbial culture, no pathogenic bacteria were detected among cleaned and sanitized ventilator external ventilator pipelines and those stored aseptically for 4 weeks, indicating a 100% pass rate. It was concluded that ventilators in intensive care units (ICU) are susceptible to contamination, exposing patients to bacterial contamination and other comorbidities. Gram-negative bacteria are the main pathogens of VAP, which are mostly multidrug-resistant. Clinical care measures for ventilators should be strengthened to reduce the incidence of ventilator microbial contamination and to improve accurate clinical diagnosis and correct antimicrobial therapy.