Multidrug Resistance Patterns, Gene Overexpression, and Genetic Diversity of Acinetobacter baumannii Isolates from Clinical Specimens

Background : The adeJ, Omp33-36, and oprD are vital genes for the resistance of Acinetobacter baumannii. , by regulating the permeability of the membrane and carbapenem resistance in the clinical isolates. Objective : To detect the adeJ, Omp33-36, and oprD, on the way to antibiotic resistance, that could developbetter treatment for A. baumannii infections. Material and Methods: The study was based on 300 clinical specimens that were collected from Al-Hilla Teaching Hospital from January–to June 2024. The specimen types taken were wounds (40%), Burns 40% Blood 12% and Urine 8%. They were grown on blood agars, identified as Acinetobacter baumannii (8.33%) by Epi-20E. PCR was done to detect the presence of blaoxa-51 and genes (adeJ, Omp33-36, and oprD, ), while gene expression by RT-qPCR. PCR-ERIC facilitated the differentiation of the strains due to the different bands produced. Results and Discussion: Multidrug resistance to antibiotics was observed among isolates and high resistance was observed against, β-lactams, carbapenems, and aminoglycosides with colistin being effective. All isolates were adej positive Overexpression of OperD (80%) and adej (44%) was observed, with consistent downregulation of the Omp33-36 gene (100%).The result of PCR-ERIC, Group A: Thus, isolates 7, 9, 10, 17, 5, 8,6, 11, 12, 2, 4, and 19 for Group A; 18 for Group B; 3 for Group C; 1 and 13 for Group D; and 20, 21, 22, 14, and 15 for Group E revealed 3 bands. Conclusion: The role of adeJ and OprD in resistance to A. baumannii, via decreased accumulation of drugs and increased expulsion and modification of Omp33-36 in all isolates indicates the contribution of this gene to membrane permeability and Antibiotics resistance. The RT-PCR ERIC signifies that for variation in the Banding patterns of the different isolates; these may be differential expression profiles of the strains.