According to World Health Organization (WHO), lower respiratory tract infections are the third most common cause of death worldwide. These infections are mainly caused by multidrug-resistant (MDR) bacteria. Between 8 - 28% of patients receiving mechanical ventilation are affected by ventilator associated pneumonia (VAP).
The aim of current study was to characterize bacteria isolated from VAP patients and to evaluate the effectiveness of some antimicrobial agents. Clinical bacterial isolates were recovered from patients having pneumonia associated with mechanical ventilation from intensive care units of Zagazig University Hospital and identified using conventional microbiological methods. Antimicrobial susceptibility profile of these isolates against various antimicrobials was tested by the disk diffusion method.
A total of 233 isolates were recovered from 153 samples of endo-tracheal aspirates, compromising 203(87.1%) Gram negative and 30 (12.9%) Gram positive bacteria. The major isolates were Klebsiella pneumoniae (36.9%), Escherichia coli (21.04%), Acinetobacter baumannii (14.95%), Pseudomonas aeruginosa (14.16%) and Staphylococcous aureus (12.02%), coagulase negative Staphylococcus spp (0.86%), Serratia mercescens (0.43%). The isolates were highly resistant to antimicrobial agents. Two hundreds and twelve isolates (90.9%) were MDR and one hundred seventy two isolates (73.8%) were extensively drug resistant (XDR). Our study recommends that antimicrobial susceptibility should be performed for bacteria isolated from VAP patients before antimicrobial therapy to avoid emergence of MDR strains.