Prevalence of Genes Encoding Aminoglycoside Modifying Enzymes in Clinical Isolates of Klebsiella Pneumoniae in the Hospitals of Borujerd

Background and Aims: Given the importance of aminoglycoside resistance in nosocomial and community infections caused by bacterial pathogenes such as Klebsiella pneumoniae (K. pneumoniae), the aim of this study was to determine the frequency of aac (۶')- Ib and aac (۳)- IIa, the genes encoding aminoglycoside modifying enzymes involved in aminoglycoside resistance. Material and Methods: A total of ۱۰۰ K. pneumonia isolates were collected from hospitalized patients from April to September ۲۰۱۵ in Borujerd hospitals. Conventional microbiological tests were carried out to detect and confirm K. pneumonia isolates. Antibiotic susceptibility of isolates was detected by disk diffusion methods. The presence of the aac(۶')-Ib and aac(۳)-IIa genes which encode aminoglycoside modifying enzymes was determined by polymerase chain reaction. Results: Among ۱۰۰ K. pneumonia isolates, ۳۴% showed resistance to gentamicin and ۲۱% to amikacin. Resistance to both gentamicin and amikacin was detected in ۱۸% of the isolates. Multi-resistance phenotypes were detected in ۷۱% of the isolates. The aac (۳)-IIa and aac(۶ʹ)-Ib genes were found in ۷۱% (n=۲۴) and ۵.۸% (n=۲) of aminoglycoside resistant isolates, respectively. Simultaneous carriage of aac (۳)-IIa and aac(۶ʹ)-Ib was detected in ۶۴% (n=۲۲) of the aminoglycoside resistant isolates. Conclusions: The results of this study showed the presence of aac (۳)-IIa genes in more than ۷۰% of the aminoglycosides resistant K. pneumoniae strains; this may be due to the transmission of this gene through mobile genetic elements that create a high risk of rapid spread of these genes in hospitals.

کلیدواژه ها:

aac (۳)-IIa ، aac (۶')- Ib ، Klebsiella pneumonia ، آمینوگلیکوزید ، کلبسیلا پنومونیه ، ژن aac(۳)-II ، ژن aac(۳)-II