Molecular Analysis of Catheter-Associated Proteus mirabilis Isolates: Insights into Adhesion and Antibiotic Resistance

BACKGROUND AND OBJECTIVESProteus mirabilis is a prominent uropathogens responsible for catheter-associated urinary tract infections (CAUTIs). It colonizes the urinary tract and forms biofilms that confer protection against antibiotics. This study aimed to investigate the presence and expression of specific genes associated with adhesion and antibiotic resistance in catheter isolates, particularly focusing on mrpA and pmfA as adhesion genes.MATERIALS AND METHODSA total of ۳۸۵ non-duplicate catheters were collected from intensive care unit (ICU) patients across multiple hospitals in Isfahan. The catheter solutions were cultured on blood and MacConkey agar, followed by conventional biochemical tests. Additionally, PCR and multiplex PCR techniques were employed to identify resistance genes in the isolates. Real-time PCR was performed to analyze the expression levels of the two adhesion genes.RESULTS AND DISCUSSIONAmong the isolated P. mirabilis bacteria, ۳۵% (۱۴/۴۰) harbored the K۲ capsular gene, while none exhibited the K۱ gene. The blaNDM gene was not detected; however, ۶۰% of the isolates tested positive for the acc gene. The frequencies of blaOXA۲۳, blaOXA۲۴, and blaOXA۵۸ were ۱۰%, ۲.۵%, and ۲.۵%, respectively, with one isolate displaying positivity for all three genes. No instances of blaSIM-۱ and blaVIM۱ were observed in the isolates. Furthermore, no significant correlation was found between capsular genes and biofilm formation. Real-time PCR analysis revealed elevated expression levels of mrpA and pmfA genes in clinical isolates compared to the control strain obtained from urine.CONCLUSIONThe presence of carbapenems genes (OXA-۲۳, OXA-۲۴, and OXA-۵۸) in P. mirabilis isolates underscores the dissemination of resistance genes among different bacterial species and emphasizes the significance of infection control measures in healthcare settings. Moreover, the involvement of acetyl-CoA biotin decarboxylase (ACD) in metabolism, indole production, and biofilm formation highlights the intricate nature of P. mirabilis pathogenesis. Enhanced comprehension of the molecular mechanisms underlying these processes could pave the way for novel strategies aimed at prevention and treatment of P. mirabilis infections.

کلیدواژه ها:

Proteus mirabilis ، catheter-associated urinary tract infections ، Real-time PCR