Association between ESBL Production and the Presence of magA Gene among the Clinical Isolates of Klebsiella pneumoniae

Background: Klebsiella pneumoniae (K. pneumoniae) causes a wide range of nosocomial and community-acquired infections. In recentdecades, K. pneumoniae has been known as the agent of community-acquired primary pyogenic liver abscess. In attempts to find the causes ofthis disease, researchers found a new virulence gene called magA (mucoviscosity-associated gene A). The present study was performed todetermine the prevalence rate of magA gene among the extended-spectrum beta lactamase (ESBL)-positive and ESBL-negative K.pneumoniae strains.Materials and Methods: The current cross-sectional study was conducted on 130 K. pneumoniae isolates collected from patients in ImamReza hospital and its associated clinics in Mashhad city (Iran) from May 2011 to July 2012. The presence of K. pneumoniae species wasconfirmed by conventional microbiological methods. Samples were tested for the production of ESBLs by the double disk diffusion (DDS)test. PCR was performed to detect magA gene. The hypermucoviscosity (HV) phenotype of Klebsiella isolates was characterized by the stringtest.Results: magA gene was detected in 11(8.5%) out of 130 isolates of K. pneumoniae. Of 11 isolates with positive result for magAgene, three cases were HV+, and 8 cases were HV- phenotype. Of 130 K. pneumoniae isolates, 56 isolates were ESBL-positive, and 74isolates were ESBL-negative. The magA gene was detected in 4 out of 56 (7.14%) ESBL-positive, and 7 out of 74 (9.46%) ESBLnegativesamples.Conclusion: In the present study, no correlation was observed between the presence of magA gene and the production of ESBL in K.pneumoniae strains isolated from different clinical samples in Mashhad.

کلیدواژه ها:

Klebsiella pneumoniae ، Extended-spectrum beta-lactamase (ESBL) ، magA gene