Pattern of efflux pump genes in imipenem resistant acinetobacter isolates

Maryam Abbasi shaye,1,* Ghazale amiri,2 Mohammad reza sharifmoghadam,3 Masoumeh bahreini,4

1. Department of Biology, Faculty of Science, Ferdowsi University of Mashhad
2. Department of Biology, Faculty of Science, Ferdowsi University of Mashhad
3. Department of Biology, Faculty of Science, Ferdowsi University of Mashhad
4. Department of Biology, Faculty of Science, Ferdowsi University of Mashhad

Abstract

Introduction

Acinetobacter species are opportunistic pathogens and responsible for various types of nosocomial infections. they are important due to their multidrug resistance phenotype and their ability to acquire antibiotic resistance genes. one of the most important mechanisms of resistance in these bacteria is the overexpression of efflux pumps. the aim of this study is to investigate the frequency and pattern of efflux pumps genes; adeb, adei and abem in imipenem resistant acinetobacter isolates.

Methods

For this purpose, 46 acinetobacter clinical isolates were collected from shahid kamyab and ghaem hospitals in mashhad, iran. the species were identified using biochemical tests. antibiotic susceptibility testing was carried out by disc diffusion method. finally, the presence of adeb, adei and abem genes in imipenem resistant isolates was investigated through polymerase chain reaction(pcr).

Results

Among 48 acinetobacter isolates, 33 isolates were identified as acinetobacter baumannii and 13 isolates identified to be acinetobacter lwoffii. 38 isolates(82.6%) including 30 a.baumannii and 8 a.lwoffii showed resistance to imipenem. pcr results showed that adeb, abem and adei genes were present in 33(86.8%), 32(84.2%) and 31(81.6%) resistant isolates respectively which include both a.baumannii and a.lwoffi isolates.

Conclusion

The results of this study indicate that efflux pump genes are frequently present in acinetobacter isolates whose overexpression could result in high levels of resistance to a wide range of antibiotics including imipenem. moreover, the presence of these genes in a.lwoffii strains is also alarming as it shows the rapid spread of resistance genes among different acinetobacter species as well as a.baumannii.

Keywords

Antibiotic resistance, a.baumannii, a.lwoffii , efflux pump