Abstract
Acinetobacter baumannii is a bacterium found in most places, especially in clinics and hospitals, and an
important agent of nosocomial infections. The presence of class D enzymes such as
OXA-type carbapenemases in A. baumannii is proven to have a key function in resistance to carbapenem. The aim of the current
study is to determine the blaOXA-type
carbapenemase genes and antimicrobial resistance among clinically isolated samples
of A. baumannii. We assessed 100 clinically isolated specimens of A. baumannii from patients in intensive care units of educational hospitals of Hamadan, West of
Iran. The A. baumannii isolates' susceptibility to antibiotics was performed employing disk diffusion method.
Multiplex polymerase chain reaction was used to identify the blaOXA-24-like
, blaOXA-23-like
, blaOXA-58-like
, and blaOXA-51-like
genes. The blaOXA-23-like
, blaOXA-24-like
, and blaOXA-58-like
genes' prevalence were found to be 84, 58, and 3%, respectively. The highest coexistence
of the genes was for blaOXA-51/23
(84%) followed by blaOXA-51/24-like
(58%). The blaOXA-51/23-
like pattern of genes is a sort of dominant gene in resistance in A. baumannii from Hamadan hospitals. The highest resistance to piperacillin (83%) and ciprofloxacin
(81%) has been observed in positive isolates of blaOXA-23-like
. The A. baumannii isolates with blaOXA-58-like
genes did not show much resistance to antibiotics. Based on the results of the phylogenetic
tree analysis, all isolates have shown a high degree of similarity. This study showed
the high frequency of OXA-type carbapenemase genes among A. baumannii isolates from Hamadan hospitals, Iran. Thus, applying an appropriate strategy to
limit the spreading of these strains and also performing new treatment regimens are
necessary.
Keywords
Acinetobacter baumannii
- nosocomial infection -
OXA-type carbapenemase