Microbiological analysis of nosocomial pneumonia at Tanta University Chest Hospital

Background Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) represent a major health problem among hospitalized patients leading to consequent morbidity and mortality specially after Covid-19 era and spread of multidrug-resistance organisms)MDRO) in hospitals. Aim This study aimed to analyze the commonest microorganisms responsible for HAP and VAP at Tanta University Chest Hospital. Methods This prospective observational study was done at Chest Department, Faculty of Medicine, started from June 2022 to February 2023. Fifty HAP patients’ sputum samples and 50 VAP patients (25 endotracheal aspirates and 25 bronchoalveolar lavages) were included. All collected samples were submitted to standard microbiological tests at Microbiology Department, Tanta Faculty of Medicine. Results A total number of 50 HAP and 50 VAP cases were included. Microbial isolates were relatively the same in both groups, where Klebsiella pneumoniae was the predominant isolates (56) followed by Staphylococcus aureus (25), Escherichia coli (14), Pseudomonas aeruginosa (13), Acinetobacter baumannii (5), Streptococcus pneumoniae (4), Enterococci (3), Stenotrophomonas maltophilia (2), Citrobacter freundii (2), Streptococcus pyogenes (2), Providencia stuartii (1), and 7 isolates of Candida . Antimicrobial susceptibility showed predominance of drug-resistance organisms in VAP (78%) versus HAP (28%), P -value: < 0.001. Klebsiella pneumonia showed higher rates of resistance (37 out of 56 isolates, P -value = 0.020). Four out of 5 Acinetobacter baumannii isolates were multidrug resistant, and 2 isolates of Stenotrophomonas maltophilia were polydrug resistant. Multivariate logistic regression analysis showed that intravenous antibiotic administration within last 3 months was associated with risk for MDR-HAP, while univariate regression analysis showed that intravenous antibiotic administration within the last 3 months was the strongest predictor for MDR-VAP. A higher mortality rate was recorded in VAP group (66%), versus (14%) in HAP group ( P -value: < 0.001). Conclusion Microbial isolates were relatively the same in both HAP and VAP, but VAP showed significant predominance of drug-resistant organisms. The most significant predictor for risk of MDRO infection in HAP and VAP was intravenous antibiotic administration within last 3 months; so, raising attention towards antibiotic choice may improve the outcome. Finally, VAP was associated with higher mortality compared to HAP.