Phenotypic and Molecular Characterization of Acinetobacter Baumannii and its Ability to Produce Beta-Lactamase Isolated from Different Clinical Samples in Diwaniyah Governorate

Acinetobacter baumannii is an opportunistic bacterial pathogen responsible for a significant proportion of nosocomial infections, particularly in intensive care units. The bacterium’s multidrug resistance and ability to survive in hospital environments contribute to its persistence and pathogenicity. In Diwaniyah Governorate, limited studies have explored the phenotypic and molecular characteristics of A. baumannii, particularly its beta-lactamase production and antibiotic resistance. Identifying genetic markers associated with drug resistance is crucial for developing targeted antimicrobial strategies. Although previous research has investigated A. baumannii in different hospital settings, data on its molecular characterization and resistance profile in this region remain scarce. Understanding the prevalence of resistance genes, such as TEM-2 and blaOXA-51, can provide valuable insights into infection control measures. This study aimed to isolate and identify A. baumannii from clinical samples, determine its antibiotic resistance profile, and analyze the presence of beta-lactamase-producing genes using molecular techniques. Results: Of the 60 clinical samples, 20 (33%) were confirmed as A. baumannii. The highest isolation rate was from sputum (55%), followed by burns (45%) and wounds (15%). The rapid iodine test and Vitek 2 system confirmed that 85% of isolates produced beta-lactamase, exhibiting resistance to most antibiotics except Tigecycline. PCR analysis revealed that all isolates carried the 16S rRNA gene, 85% harbored the TEM-2 gene, and 50% contained the blaOXA-51 gene. This study is among the first to document the molecular profile of A. baumannii in Diwaniyah Governorate, highlighting its high resistance levels and genetic determinants of beta-lactamase production. Implications: The findings underscore the urgent need for continuous surveillance, stringent infection control protocols, and antimicrobial stewardship programs to combat the spread of drug-resistant A. baumannii in healthcare settings.