Establishment of urinary catheter materials antibacterial efficacy evaluation platform in pigs
Authors: Yu-Hsing Lin  , Yan-Zhong Wu  , Ya-Ling Cyue  , Pi-Hsin Chen  , Ya-Peng Wang  , Yu-Ying Fang  , Tsung-Han Wu  , Shih-Yi Guo  , Keng-Chia Hsu  , Chia-Ying Lin  , Shao-Qun Lai  , Shao-Wen Hung  
Published: June 2024

Urinary catheters are one of the common invasive medical catheters, mostly composed of high-polymer materials such as polyurethanes. During clinical use, the high friction between the catheter material surface and tissues can lead to tissue damage, patient discomfort, and pain during insertion or removal. Moreover, due to the hydrophobic nature of the polymer material surface, there is a risk of urinary tract infections (CTIs) caused by problems such as protein adsorption and bacterial infection upon insertion into the body. Prolonged indwelling time of urinary catheters in the body increases the probability of other complications, potentially leading to life-threatening consequences and imposing medical burdens. Therefore, the purpose of this study was focused on the insertion of the Escherichia coli (E. coli, 1 × 105 CFU/mL)-coated urinary catheter to implant into a female pig’s urethra for establishing the urinary catheter materials antibacterial efficacy evaluation platform in pigs. Results were shown that during the experimental period, the week 1 and week 2 average pig’ body temperature were 39.4 ± 0.6°C and 39.1 ± 0.2°C, respectively. The average pig’s body temperature was normal and there was no significant differences in body temperature at week 1 and week 2 urinary catheter implanted-experiment period. Moreover, the clinical observation of the pigs showed that their vitality, appetite, and excretion were all normal, and they survived until the end of the experiment without presenting any abnormal clinical symptoms. In addition, E. coli in urine culture respectively showed 0.95 ± 0.03 × 105 CFU/mL, 1.23 ± 0.03 × 105 CFU/mL, 1.43 ± 0.04 × 105 CFU/mL, 1.75 ± 0.08 × 105 CFU/mL, and 1.91 ± 0.09 × 105 CFU/mL on day 0, 3, 7, 10, and 14 of urinary catheter implantation. As time progressed after urinary catheter implantation, there was an increasing trend in E. coli counts. Staining with crystal violet for urinary catheter showed that the urinary catheter wall was positive for crystal violet staining. E. coli isolation and counts from biofilm on inside and outside of urinary catheter respectively showed 5.10 ± 0.10 × 105 CFU/mL and 7.50 ± 1.08 × 105 CFU/mL on day 14 of urinary catheter implantation. As time progressed after urinary catheter implantation, there was an increasing trend in E. coli counts. Finally, the pathological interpretation of the urinary tract indicates that in the tissue morphology of the bladder, there is observed a localized mild shedding of superficial and intermediate layer cells in the transitional epithelium of the ureteral stent group, with only basal cells remaining connected to its submucosa. There are no significant pathological changes observed in the tissue morphology of the urethra and kidneys. According to the results of this study, a urinary catheter materials antibacterial efficacy evaluation platform in pigs has successfully established, which can be provided for R&D of urinary catheter antibacterial materials.