Outcome of Acinetobacter baumannii Ventilator Associated Pneumonia in Upper Egypt: does the resistance profile play a role?

Abstract

Abstract Background Ventilator-associated pneumonia (VAP) due to drug resistant Acinetobacter baumannii (A. baumannii) is a challenging nosocomial problem associated with increased morbidity and risk of mortality. Objective This study aimed to investigate plasmid mediated quinolone resistance genes (PMQR) as a mechanism of resistance transmission, risk factors and outcome of A. baumannii VAP. Methods This prospective cohort study included 100 VAP patients between October 2020 and December 2022. Microbiological confirmation of A. baumannii. was done and PMQR genes were exposed by polymerase chain reaction (PCR). Pneumonia severity index (PSI), risk factors for developing drug resistant A. baumannii VAP, and the outcome were studied. Results The proportions of drug sensitive (DS), multidrug (MDR), extensive drug (XDR), and pan drug (PDR) resistant A. baumannii were 14%, 35%, 50%, and 1%, respectively. Majority of PSI classes IV and V showed XDR (66%) and PDR (100%) isolates. Detection of qnrA, qepA and aac(6′)-Ib-cr genes was predominant in PSI classes IV and V. The in-hospital mortality for MDR, XDR, and PDR was 22.7%, 70.5%, and 2.3%, respectively. ICU duration, prior use of carbapenems and use more than 2 antibiotics prior to VAP were risk factors for developing MDR A. baumannii while septic shock, multilobar chest radiography (CXR) infiltration and PSI class were predictors of in-hospital mortality. Conclusions VAP caused by MDR, XDR and PDR isolates of A. baumannii which harbors qnrA, qepA and aac(6’)-Ib-cr PMQR genes showed higher PSI classes and increased in-hospital mortality. The number of PMQR genes in A. baumannii isolates, ICU days, use of more than 2 antibiotics, and use of carbapenem prior to VAP, were independent risk factors for the development of drug resistant A. baumannii VAP.