THE MOLECULAR CHARACTERISTICS AND ANTIMICROBIAL RESISTANCE OF ACINETOBACTER BAUMANNII ISOLATES FROM HOSPITAL-ACQUIRED INFECTIONS IN INTENSIVE CARE UNIT
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Abstract
Background: Acinetobacter baumannii is a major cause of hospital-acquired infections in intensive care units (ICUs), notable for its multidrug resistance and biofilm-forming ability, which complicate treatment and infection control.
Aims: This study aimed to determine the antimicrobial resistance patterns, biofilm formation, and molecular characteristics, including carbapenemase and metallo-β-lactamase (MBL) genes, of ICU-associated A. baumannii isolates.
Materials and Methods: A cross-sectional observational study was conducted over 18 months including 6 months data analysis in ICU patients with infections >48 hours after admission. Clinical specimens (blood, urine, respiratory samples, pus) were processed for culture and identification. Phenotypic identification included Gram staining, biochemical tests, and PCR targeting blaOXA-51. Antibiotic susceptibility was determined by Kirby–Bauer disk diffusion and MIC testing. Molecular characterization involved real-time PCR for blaOXA-51 and MBL genes (blaNDM, blaVIM, blaIMP). Biofilm formation was assessed qualitatively (tube method) and quantitatively (microtiter plate assay).
Results: All 126 isolates (100%) were confirmed as A. baumannii via blaOXA-51 PCR. Biofilm production was observed in 63% of isolates, with 18.3% strong, 26.9% moderate, and 17.5% weak producers. Multidrug resistance was detected in 73% of isolates, while 38.1% were extensively drug-resistant; only 3% were pandrug-resistant. MBL genes were identified in 6.3% of isolates (blaNDM-1: 2.4%, blaVIM: 2.4%, blaIMP: 1.6%).
Conclusion: ICU-associated A. baumannii exhibits high multidrug drug resistance and substantial biofilm-forming capacity, with low prevalence of MBL genes. Continuous antimicrobial surveillance, molecular characterization, and biofilm-targeted strategies are crucial for infection control and optimizing patient outcomes.
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Hemant Kumar
PhD Scholar, Department of Microbiology, Index Medical College, Hospital & Research Centre, Indore, (M.P) India (Malwanchal University) Email – [email protected]
Dr. Harshada Shah
Research supervisor, Department of Microbiology, Index Medical College, Hospital & Research Centre, Indore (M.P)India. (Malwanchal University) [email protected]
Neha Rani
PhD Scholar, Department of Microbiology, Index Medical College, Hospital & Research Centre, Indore, India. (Malwanchal University) Email- [email protected]
