Study of Antibiotic Resistance in ESKAPE Bacteria Using β-lactamase and ESBL Genes

Abstract

Background: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species, collectively known as ESKAPE bacteria, pose a significant threat in healthcare settings due to their increasing antibiotic resistance. Understanding the mechanisms underlying their resistance is crucial for developing effective therapeutic strategies. Methods: This study aimed to investigate the phenotypic and genotypic properties of β-lactamase enzymes in ESKAPE bacteria isolated from ulcer infections. Clinical specimens were collected from patients with various ulcer diseases, and bacterial isolates were identified using standard bacteriological methods and the Vitek-2 automated system. DNA extraction, polymerase chain reaction (PCR), and antibiotic susceptibility testing using the Kirby-Bauer disk diffusion method were performed. The presence of specific β-lactamase genes (blaKPC, blaTEM, blaCTX-M, and blaAMPC) was examined through molecular techniques. Results: Among the 104 clinical specimens collected, 88% yielded positive cultures, with Gram-negative bacteria predominating. Antibiotic susceptibility testing revealed high resistance rates, particularly to β-lactam antibiotics, among ESKAPE isolates. Molecular analysis identified the presence of extended-spectrum β-lactamases (ESBLs) in all isolates, with blaKPC and blaTEM being the most prevalent β-lactamase genes. Notably, blaKPC was detected in 72% of E. cloacae, 13.3% of S. aureus, 33.33% of Klebsiella pneumoniae, 50% of Pseudomonas aeruginosa, 0% of E. faecium, and 100% of A. baumannii isolates. Similarly, blaCTX-M and blaAMPC genes showed distinct distribution patterns across the different species. Conclusion: The study highlights the widespread presence of ESBL-producing ESKAPE bacteria in ulcer infections and underscores the importance of molecular techniques for accurate detection of β-lactamase production.