Antimicrobial Susceptibility Pattern and Molecular Identification of Acinetobacter baumannii in Alex Ekwueme-Federal University Teaching Hospital Abakaliki, Nigeria

Background and Objectives: Acinetobacter baumannii, a notorious opportunistic pathogen known to seriously affect debilitated individuals especially intensive care unit (ICU) patients and others with underlying illness, have consistently jeopardized many antibiotics. This study was therefore aimed to ascertain the antimicrobial susceptibility profile and molecularly identify A. baumannii pathogens in Alex Ekwueme-Federal University Teaching Hospital, Abakaliki, Nigeria.

Methodology: A total of 385 clinical samples were collected aseptically from debilitated patients and analyzed following standard microbiological procedures. Acinetobacter species was confirmed by Gram staining reaction and biochemical tests. All bacterial isolates were phenotypically screened for multidrug resistance using the Kirby–Bauer disc diffusion technique and results interpreted as per CLSI criteria. A. baumannii isolates were finally confirmed using 16S rRNA sequencing.

Results: A total of 23(6%) A. baumannii isolates were recovered from 385 clinical samples collected from 87 patients comprising 48 males and 39 females admitted in various hospital wards of AE-FETHA. The age of the patients varied from 20–79 years. The commonest sites for isolation of A. baumannii pathogen were catheter urine (8/8%) and wound sores (7/8%). The highest percentage resistance was observed with cefuroxime (96%), tetracycline (96%), sulfamethoxazole/trimethoprim (96 %), and ofloxacin (91%) while meropenem (91%) and imipenem (78%) were the most effective antibiotics against A. baumannii. The isolated A. baumannii was re-confirmed genotypically by 16S rRNA gene amplification. Variations were observed in the gene sequence of all the isolated A. baumannii.

Conclusion: Catheter urine, wound sores, and respiratory fluids were the more easily colonized samples. Also, high frequency of multidrug resistance observed in this study further established A. baumannii as a notorious opportunistic pathogen.