Gram negative organisms mostly produce extended spectrum beta-lactamases (ESBLs) which is an important beta-lactamases enzymes known to confer resistance to an important group of antibiotics referred as beta-lactams. Antibiotics resistance has become a global problem and a threat for optimal patients’ care in healthcare institutions. To phenotypically and genotypically determine the presence and prevalence of ESBL- producing A. baumannii, a total of 385 clinical samples were obtained from catheter urine, wound drain, wound sores, respiratory fluids, skin swab and bed rail swabs of critically ill patients admitted in orthopaedic wards, surgical wards, intensive care unit and medical wards of Alex Ekwueme Federal University Teaching Hospital, Abakaliki. All the samples were subjected to cultural, microscopic and biochemical tests. While the isolated A. baumannii was confirmed using 16S rRNA PCR. Antimicrobial susceptibility studies of all the bacterial isolates were determined using Kirby-Bauer disc diffusion method. While double discs synergy testing method (DDST) was used to determine the production of ESBLs among these organisms. PCR techniques were used to identify the isolates harboring blaTEM, blaSHV and blaOXA genes. The results showed that of the 385 clinical samples collected, 23(6%) A. baumannii isolates were recovered. There was high-level of antibiotic resistance observed as the isolates were found to show resistance to two or more classes of antibiotics signifying multidrug resistance (MDR) strains. The percentage of ESBL-producing A. baumannii was 43.5% using phenotypic methods. PCR techniques as used to detect ESBL production showed that the isolated A. baumannii harbored ESBL genes of 9(90%), 3(30%) and none (0) for blaTEM, blaOXA and blaSHV genes respectively. Conclusively, the isolated A. baumannii were found to produce ESBLs as it is observed that most of the isolates harbored blaTEM and blaOXA genes. Importantly, this is the first report of ESBL-producing A. baumannii in Ebonyi, Nigeria.

Keywords: ESBL, MDR, antibiotic resistant, A. baumannii