Molecular Detection of Selected Adhesion-Related Genes (fnbA and papC) in Proteus Species Isolated from Clinical Specimens at Federal Medical Centre, Yenagoa, Bayelsa State, Nigeria: A Preliminary Study

Abstract

Background: Proteus species are opportunistic Gram-negative bacilli frequently implicated in urinary and genital tract infections. Adhesion-related genes contribute to colonisation and persistence; however, the relevance of genes such as fnbA and papC (classically described in other genera) in clinical Proteus isolates from Nigeria remains poorly documented. Objective: To determine the distribution of Proteus species among clinical specimens at Federal Medical Centre (FMC) Yenagoa and to perform a preliminary molecular screen for the presence of fnbA and papC sequences in a subset of isolates. Methods: A total of 196 clinical specimens (urine and high vaginal swabs) were processed using standard bacteriological methods. Isolates were identified by colonial morphology, Gram staining and biochemical tests. Eight Proteus isolates were selected for DNA extraction (boiling method) and conventional PCR targeting fnbA and papC. Amplicons were visualised by agarose gel electrophoresis. Associations between isolate distribution and specimen source were examined by chi-square test (α = 0.05). Results: Twenty-five Proteus isolates (12.8%) were recovered. Other isolates included Escherichia coli (23.0%), Staphylococcus aureus (23.0%), Pseudomonas aeruginosa (21.4%) and Klebsiella pneumoniae (19.9%). Proteus was recovered more frequently from female patients (64%) and from the 21–30-year age group. Of the eight isolates tested by PCR, all (100%) yielded an amplicon consistent with the expected size for fnbA, while four (50%) yielded an amplicon consistent with papC. No statistically significant association was observed between bacterial species and specimen source (p = 0.456). Conclusions: Proteus species constitute an important proportion of isolates from urine and high vaginal swabs at FMC Yenagoa, with higher recovery among young adult females. The preliminary molecular findings require cautious interpretation: fnbA and papC are not established virulence markers of Proteus, the number of isolates tested was small, and amplicons were not sequenced. Future work should target Proteus-specific adhesin genes (e.g., mrpA, ucaA, pmfA) and include species-level identification and sequence confirmation.