Author/Authors :
Pakzad Iraj نويسنده Department of Microbiology and Clinical Microbiology Research Center, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, IR Iran , Sadeghifard Nourkhoda نويسنده Department of Microbiology, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran Sadeghifard Nourkhoda , Soroush Setareh نويسنده Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, IR Iran , Taherikalani Morovat نويسنده Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, IR Iran , Sayehmiri Koroush نويسنده Psychosocial Injuries Research Center, Ilam University of Medical Sciences, Ilam, IR Iran , Khayat Hatef نويسنده Clinical Microbiology Research Center, Ilam University of
Medical Sciences, Ilam, Iran , Azimi Lila نويسنده Pediatric Infections Research Center, Mofid Childeren
Hospital, Shahid Beheshti University of Medical, Sciences, Teharn,
Iran , Delfani Somayeh نويسنده Razi Herbal Medicines Research Center, Department of
Microbiology, School of Medicine, Lorestan University of Medical
Sciences, Khorramabad, Iran , Bogdanovic Lidija نويسنده Department of Public Health, University of Naples, Naples,
Italy
Abstract :
Background Acinetobacter baumannii isolates
resistant to fluoroquinolones, such as levofloxacin and ciprofloxacin
are being increasingly developed every day. Objectives In this study,
ciprofloxacin resistance in A. baumannii isolates was
determined by the presence or absence of efflux pump inhibitors, as the
efflux pumps play an important role in the creation of ciprofloxacin
resistance. Methods One hundred and three
Acinetobacter isolates were collected from
ventilator-associated pneumonia (VAP) and burn patients of Tehran
hospitals, Iran, during six months of 2014. Susceptibility rates of the
isolates to levofloxacin and ciprofloxacin antibiotics were assessed
using the agar disk diffusion and broth microdilution. The effects of
the efflux pump inhibitors including phenylalanine-arginine
β-naphthylamide (PAβN) and 1-(1-naphtylmethyl)-piperazine (NMP) on
ciprofloxacin resistance were investigated. Further, the quinolone
resistance qnrA, qnrB,
qnrS, and adeABC genes were
evaluated using the polymerase chain reaction (PCR) test. Finally, to
examine the mutation in quinolone resistance-determining regions, the
PCR products of the gyrA and parC
genes were sequenced. Results According to the results of the
antibiogram test, 74.7% and 33% of the studied isolates were resistant
to ciprofloxacin and levofloxacin, respectively. Also, there was a
significant relationship between the type of the specimen and resistance
to ciprofloxacin (P = 0.02) and resistance to levofloxacin (P = 0.04).
As for the synergistic study of the inhibitors with ciprofloxacin, the
reduction of minimum inhibitory concentration (MIC) was observed in 40%
and 56.6% of the isolates in the presence of PAβN and NMP, respectively.
The prevalence rates of qnrA,
qnrB, qnrS,
AdeA, AdeB, and
AdeC genes were 0%, 0%, 3.9%, 100%, 100% and 100%,
respectively. In all the resistant isolates, mutation of in the
gyrA gene was observed, but no mutation was seen in
the parC gene. Conclusions The presence of the efflux
pumps and the gyrA gene mutation are still considered
as the most important factors causing fluoroquinolone resistance;
however, identification of the qnr genes for the
first time in Tehran hospitals, Iran, can lead to further concerns in
the future.
