Frequency of Metallo-Beta-Lactamase and Extended- Spectrum Beta-Lactamase genes in Gram-Negative Bacteria Isolated from Ventilator- Associated Pneumonia in the Intensive Care Unit of Imam Reza Hospital in Kermanshah

Ventilator-associated pneumonia is the most common nosocomial infection that is responsible for increasing the mortality of patients admitted to the intensive care unit. The aim of this study was to evaluate the frequency of MBL and ESBL genes and to determine the patterns of antibiotic resistance in gram-negative bacilli isolated from ventilators in the ICU of Imam Reza Hospital in Kermanshah.

After collecting samples and identifying the bacteria by standard biochemical and microbial culture methods, 152 bacterial isolates were identified. ESBL and MBL genes were identified by phenotypic DDCT method and molecular PCR method using specific primers.

The most common microorganism isolated from ventilator-associated pneumonia (VAP) patients was Klebsiella pneumoniae (2.56%). In total, the frequency of ESBL and MBL genes was 113 (74.34%) and 8 (5.26%). The antibiotic resistance pattern showed that 36.53% of the isolates were resistant to ceftazidime, cefotaxime and imipenem. The blaSHVOS gene with a frequency of 75 (49.34%) had the highest genotypic frequency. The blaVIM gene was not found in any of the isolates.

The high resistance of Acinetobacter baumannii and Klebsiella pneumoniae isolates to the mentioned antibiotics and the high prevalence of ESBL-producing genes in Klebsiella pneumoniae isolates is a significant alarm in the ICU of different wards of Imam Reza Hospital. The emergence of the blaPER-1 gene in patients with VAP has raised another worry in patients with VAP in the intensive care unit.