PHENOTYPIC CHARACTERIZATION OF UROPATHOGENIC ISOLATES FROM CONTAMINATED URINARY CATHETERS

CASTAGNARO, EMILIA; VILLEGAS, JOSEFINA MARÍA; RAPISARDA, VIVIANA ANDREA; FARIZANO, JUAN VICENTE; GRILLO PUERTAS, MARIANA

Congreso; LVII SAIB Meeting - XVI SAMIGE Meeting; 2021

SAIB-SAMIGE

The ability of pathogens to adhere and form biofilms in medical devices is a relevant issue. Urology is one of the main fields in which biofilm can become a serious problem, specifically in catheter-associated urinary tract infections (CAUTI). Often the main strategy against CAUTI is catheter removal and replacement. However, this could lead to additional complications such as the detachment of the biofilm from the device that would cause the spread of uropathogens (UP) to non-colonized sites. The biofilm formation ability varies in every single UP isolates. Therefore, it is important to extend the study of UP of medical devices in order to understand their behavior and design new detection protocols, appropriate antibiotic treatments and consequently avoid the severity, persistence and spread of infections. The aim of this study was to perform the phenotypic characterization of UP isolates obtained from catheters removed of patients without primary symptoms of urinary tract infection. A total of 26 UP isolates were collected from 9 catheters. Following their isolation and identification; biofilm formation patterns (BFP), colony morphology, motility, hemolytic capacity, and antibiotic susceptibility was analyzed in all the isolates. 20 out of 26 UP isolates (76.9%) were able to form biofilm either in M63 or McConkey medium; among them, 2 isolates showed a robust BFP, 7 isolates a strong BFP, 4 isolates a moderate BFP, and 7 isolates a weak BFP. Kinetic of biofilm formation showed that most of biofilm forming isolates increased their BFP from 24 to 96 h in both media. The expression of curli fimbriae and cellulose was observed in approximately 70% of the isolates, denoted by the rdar, pdar, ras, bdar and bas morphotypes. Among antibiotics tested, Imipenem and Amikacin were the most effective ones, being 90% and 72% of the isolates sensitive, respectively. The less effective antibiotics were ciprofloxacin and nalidixic acid. Approximately 30% of the isolates showed multi-resistance. Interestingly, a correlation between a high biofilm formation capacity and antibiotic resistance was observed. In addition, 61% of the isolates presented hemolysis capacity. This preliminary description of theisolates is relevant as an insight in the CAUTI field that would constitute progress in the knowledge of clinical isolates, their physiology and interaction in clinical settings. Data would contribute to the understanding of biofilm formation in medical devices.