Molecular identification of TEM-116 beta-lactamase gene in isolates of pathogenic Pseudomonas aeruginosa: A first report from Pakistan

Abstract

Purpose: Purpose: To determine TEM-116 beta-lactamase gene prevalence in drug-resistant Pseudomonas aeruginosa isolates from Pakistan. Methods: Sequence analysis of TEM beta-lactamase isolates and their antibiotic susceptibility patterns were carried out. Quantitative bacteriostatic concentrations for commonly used antibiotics were measured against TEM-116 beta-lactamase isolates. Results: Among the 102 isolates of P. aeruginosa, 23 (22.5%) were TEM beta-lactamase producers. Sequence analysis of TEM gene from selected isolates showed homology with TEM-116. Two mutations at positions 84 (p.Val84Ile) and 184 (p.Ala184Val) were documented. The TEM-116 isolates exhibited 100% resistance to sulphamethoxazole/trimethoprim, amoxycillin/clavulanic acid and doxycycline, but showed sensitivity to levofloxacin, norfloxacin and amikacin. One TEM-116 P. aeruginosa (PA11) isolate was resistant to all available antibiotics. Conclusion: These results reveal increased antibiotic resistance in the TEM-116 P. aeruginosa isolates studied, a phenomenon which will be helpful in understanding the molecular mechanisms of antibiotic resistance in P. aeruginosa.