Evaluating the frequency of carbapenem and aminoglycoside resistance genes among clinical isolates of from Ahvaz, south-west Iran.

is one of the most important opportunistic challenging pathogens as a result of its ability to acquire resistance to broad range of antibiotics and cause a variety of severe nosocomial infections. We investigated the frequency of the aminoglycoside-modifying enzymes (AMEs) and oxacillinase genes among clinical isolates of collected from hospitalized patients in Imam Khomeini Hospital, Ahvaz city, Iran. This prospective cross-sectional study was performed on 80 clinical isolates of collected from patients referred to Imam Khomeini Hospital in Ahvaz, Iran. Initial identification of isolates as was performed using conventional bacteriologic tests, and final confirmation was carried out by PCR of -like gene and multiplex PCR of locus. MICs of different classes of antibiotics against these strains was measured by using VITEK 2 system. After extraction of genomic DNA, two groups of multidrug-resistant genes including AME (, , and ) and oxacillinases ( -like, -like, -like, -like and -like) were detected. According to antibiotic susceptibility testing, among 80 strains, 75 isolates (91.25%) were multidrug resistant. The results showed that colistin and tigecycline, with respective sensitivity rates of 97.5% (78/80) and 56.25% (45/80), had the highest effects. The presence of -like and genes was confirmed in all strains. Furthermore, -like and -like genes were found in 68.75% (55/80) and 20% (16/80) of isolates respectively, while no isolate harbored the -like gene. The frequency of genes encoding the AMEs including , , and were 11.25% (9/80), 16.25% (13/80), 22.5% (18/80) and 30% (24/80) respectively. Our findings indicate that the presence of the and is correlated with high resistance against amikacin and gentamicin. We found a very high resistance rate against most of the antimicrobial agents usually prescribed for severe infections caused by Therefore, because of rapid emergence of resistance even for colistin or tigecycline, monotherapy should be avoided. These results show the importance of providing antibiotics correctly in intensive care units and following antibiotic stewardship protocols as the only effective strategies to attempt to control antibiotic resistance in healthcare settings.