Prevalence of blaIMP-1 among P. aeruginosa isolated from patients with burn infections

Abstract

Carbapenems are often used as antibiotics for treating infections by multidrug-resistant Gram-negative bacteria. Pseudomonas aeruginosa is considered a major cause of health care issues associated with higher mortality and morbidity rates worldwide. This study aimed to detect the prevalence of carbapenemase gene blaIMP-1 that is produced by carbapenem-resistant P. aeruginosa isolated from burn infection patients. A total of 137 burn swabs were collected from burn patients in different hospitals in Babylon province from December 2021 to April 2022. All of the swabs were streaked on selective media cetrimide agar. Antibiotic susceptibility was performed for Imipenem and meropenem and polymerase chain reaction for species specific 16S rDNA gene and blaIMP-1 gene was done for all isolates. 50 isolates were confirmed by amplicon of species-specific 16S rDNA for P. aeruginosa. Results of antibiotic susceptibility for imipenem and meropenem revealed that 5/50 (10%) and 13/50(26%) of P. aeruginosa isolates were resistant to imipenem and meropenem, respectively. Co-susceptibility (co-resistance or co-sensitive) for both imipenem and meropenem results showed 5/50 (10%) display resistance for both imipenem and meropenem, 8/50(16%) display resistance for only meropenem while 37/50(74%) sensitive for both and none was resistant to imipenem and sensitive for meropenem. Phenotypic detection of Metallo-β-lactamase gave inverse result while the Mean±SD of inhibition zone (mm) for imipenem disc (10μg) =29.34±7.11 and for imipenem+EDTA (10 μg+750 μg) =21.8±4.98. Investigation of blaIMP-1 gene revealed that 23/50 (46%) have blaIMP-1 while 18/50 (36%) were sensitive for imipenem and meropenem but have blaIMP-1. The current study concludes the possibility of the presence of resistance gene among phenotypically sensitive isolates pushing great threat of antibiotic misuse and leaving the infection untreated.