Efflux pumps encoding genes (adeA and adeS) in relation to antibiotic resistance pattern in Acinetobacter baumannii strains isolated from Benha university hospital

Background

Acinetobacter baumannii become a growing problem in hospitals as a predominant multidrug-resistant (MDR). This resistance capacity is generated by various mechanisms including efflux pumps that can direct antibiotics outwards and prevent antibiotics from affecting the bacteria.


Methods
Clinical samples were cultured on blood agar and MacConkey agar medium, identified by Gram stain and biochemical reactions, and then identified to the species level by Vitek2 automated system. The adeA and adeS genes among isolated strains were detected by conventional PCR. This study included 50 A. baumannii strains to assess the antibiotic resistance pattern of A. baumannii.


Results
A. baumannii strains were fully resistant to Piperacillin (100%) and lowest resistance to Imipenem (54%) was observed. Out of 50 isolates, 41 (82%) of A. baumanii isolates had adeA gene and 32 (64%) had adeS gene. The clinical strains that had adeA gene and adeS gene showed significantly higher resistance to Ciprofloxacin (92.7%) and (100%), respectively. Additionally, borderline significant differences were reported regarding Gentamycin (P = 0.065), Ceftazidime (P = 0.08), and Meropenem (P = 0.08), with the resistance being higher in the adeA positive group.


Conclusion
Efflux pumps genes (adeA, adeS) played a key role in antibiotic resistance of A. baumanii.