Prevalence and Molecular Characterization of β- Lactamases among Pathogens Isolated from Surgical Site Infections

Ghaleb Adwan, Nael Abu Hasan,
Raya Abubaker and Marah Al-Arda

Department of Biology and Biotechnology, An-Najah
National University, Nablus, Palestine

ABSTRACT

Surgical site infections (SSIs) considered a worldwide problem associated with a significant morbidity and mortality, prolonged hospitalization and consequently increasing healthcare expenditures. Thirty bacterial isolates were recovered from SSIs at Rafidia Hospital-Nablus during February-April 2016. The study was conducted to assist the prevalence and molecular characterization β-lactamases and integron classes among the isolated pathogens using multiplex PCR. The results showed that the prevalence of β-lactamase genes was 83.3%. The prevalence of ESBLs, MBLs and AmpC β-lactamases was 83.3%, 23.3 and 13.3%, respectively. The prevalence of ESBLs within isolated bacterial species was 76.5% for E. coli; 88.9% for S. aureus and100% for each of Klebsiells sp., Enterobacter sp. and Acinatobacter sp. The most prevalent gene was blaTEM (100%). The prevalence of AmpC genes was 11.8% for E. coli, 11.1% for S. aureus, 100% for Enterobacter and 0% for both Klebsiells sp. and Acinatobacter sp.. MBL genes were detected only in 41.2% of E. coli isolates. The most prevalent gene among MBLproducer E. coli was blaSPM (85.7%). In addition, 30% of the tested isolates harbor at least another type of β-lactamases. With respect to integron classes, 40% of SSIs bacterial isolates harbored class 1 integrons, and none of the isolates expressed classes 2 or 3. All class I integrons expressed in association with β-lactamases, particularly those carrying blaTEM genes. The finding of high level of β-lactamases among pathogens causing SSIs in the area is expected to complicate management protocols of these infections and could be associated with higher SSI rates, prolonged hospitalization and increased number of used antimicrobial agents. Appropriate surgical antibiotic prophylaxis and continuous monitoring systems are absolutely required and can reduce the risk of such infections at surgical sites in the region.

Keywords: Surgical site infections, β- lactamases, AmpC β- lactamases, MBLs, ESBLs, Palestine