Occurrence of and Genes and Biofilm-Forming Ability Among Clinical Isolates of and in Yaoundé, Cameroon

Background: (PSA) and (ACB) are non-fermentative bacteria mostly associated with nosocomial infections in humans.

Objective: This study aimed to determine the antimicrobial resistance profiles and virulence gene of PSA and ACB previously isolated from humans in selected health facilities in Yaoundé, Cameroon.

Methods: A total of 77 and 27 presumptive PSA and ACB isolates, respectively, were collected from the Yaoundé teaching hospital. These isolates were previously isolated from various samples including pus, blood and broncho-alveolar lavage. The identities of the isolates were determined through polymerase chain reaction (PCR) amplification of PSA and ACB specific sequences. Antimicrobial susceptibility testing (AST) was performed using the Kirby-Bauer disc diffusion method. Phenotypical expression of AmpC β-lactamases (C), extended spectrum β-lactamases (ESBLs) and metallo β-Lactamases (MBLs) were determined using the combined disc method. Bacterial genomes were screened for the presence of β-lactamases and genes using specific PCR. The pathogenicity of PSA and ACB was assessed through amplification of the and as well as and virulence genes, respectively.

Results: Of the 77 presumptive PSA isolates, a large proportion (75 to 97.4%) were positively identified. All (100%) of the presumptive 27 ACB harbored the ACB-specific gene fragment by PCR. Twenty five percent of the PSA isolates produced ESBLs phenotypically while more than 90% of these isolates were positive for the and genes. A large proportion (88%) of the ACB isolates harboured the and genes. and were detected in 17 and 4% of PSA, respectively, while a much higher proportion (70 and 29%) of the ACB isolates possessed these resistance determinants respectively.

Conclusion: Our findings reveal the occurrence of both virulence and drug-resistant determinants in clinical PSA and ACB isolates from patients in health care settings in Yaoundé, Cameroon, thus suggesting their role in the pathological conditions in patients.