TY  - JOUR
AU  - Albawi, Fatima Abbas Nasser
AU  - Alwash, Mourouge Saadi Abbas
AU  - Mohsen, Liqaa Yehya
PY  - 2026
DA  - 2026/10/11
TI  - Prevalence of AmpC β-Lactamase and MexAB-OprM Efflux Pump Genes Among Multidrug-Resistant <i>Pseudomonas aeruginosa</i> Clinical Isolates from Babylon Province, Iraq
JO  - OBM Genetics
SP  - 363
VL  - 10
IS  - 04
AB  - Multidrug-resistant Pseudomonas aeruginosa is a major cause of hospital-acquired infections and is responsible for high mortality rates due to its intrinsic and acquired resistance mechanisms to various antibiotics. This study aimed to investigate the prevalence of the AmpC beta-lactamase enzyme and the MexAB-OprM efflux pump genes, as well as the effect of the inhibitors cloxacillin and Phe-Arg β-naphthylamide dihydrochloride (PAβN) on its antibiotic resistance. The current cross-sectional study included 227 P. aeruginosa isolates collected from patients hospitalized at AL-Hillah Teaching Hospital, Babil Teaching Hospital, Marjan Medical City, and associated medical microbiology laboratories in Babylon province. The antibiotic resistance pattern, beta-lactamase production, and the effect of inhibitors on these isolates were determined phenotypically, while the prevalence of beta-lactamase and efflux pump genes was investigated using the PCR technique. Of these isolates, 114 (50.2%) were multidrug-resistant. These multidrug-resistant isolates exhibited complete resistance (100%) to aztreonam, cefepime, and ceftazidime-clavulanic acid, but were most susceptible to piperacillin-tazobactam (59.6%). Antibiotic resistance in the multidrug-resistant isolates decreased after adding cloxacillin and PAβN inhibitors, with resistance to several antibiotics markedly reduced (e.g., ceftazidime from 84% to 42% and meropenem from 97% to 48%). Among the genes encoding the beta-lactamase AmpC, the blaDHA was the most prevalent, detected in 55% (17/31) of the isolates, followed by blaFOX (39% (12/31)). The blaACT-1/MIR-1 and blaMOX were each detected in 7% (2/31) of the isolates, while the blaLAT was detected in only one isolate (3%). Among the MexAB-OprM efflux pump systems, the mexB was the most prevalent (48.4% (15/31)) compared to the mexA (16.1% (5/31)), while the oprM was identified in 12.9% (4/31) of isolates. High resistance has been detected in P. aeruginosa isolates, where the use of cloxacillin and PAβN plays a role in decreasing antibiotic resistance. This high resistance is concerning and warrants stricter antibiotic prescribing policies.
SN  - 2577-5790
UR  - https://doi.org/10.21926/obm.genet.2604363
DO  - 10.21926/obm.genet.2604363
ID  - Albawi2026
ER  -