A urinary tract infection (UTI) is a multi-factorial disease including cystitis, pyelonephritis, and pyelitis. After Escherichia coli, Proteus mirabilis is the most common UTI-associated opportunistic pathogen. Antibiotic resistance of bacteria and infection recurrence can be connected to biofilm formation by P. mirabilis. In this study, human and sheep isolates of P. mirabilis were investigated for antibiotic sensitivity using an antibiotic disk test. Co-aggregation of the tested potential probiotic bacilli, Bacillus amyloliquefaciens B-1895 and Bacillus subtilis KATMIRA1933, with the isolated pathogen was also evaluated. Then, the anti-biofilm activity of naturally derived metabolites, such as subtilin and subtilosin, in the bacilli-free supernatants was assessed against biofilms of P. mirabilis isolates. The isolated pathogens were sensitive to 30 μg of amikacin and 5 μg of ciprofloxacin but resistant to other tested antibiotics. After 24 h, auto-aggregation of B. amyloliquefaciens B-1895 was at 89.5% and higher than auto-aggregation of B. subtilis KATMIRA1933 (59.5%). B. amyloliquefaciens B-1895 strongly co-aggregated with P. mirabilis isolates from human UTIs. Cell-free supernatants of B. amyloliquefaciens B-1895 and B. subtilis KATMIRA1933 showed higher antimicrobial activity against biofilms of P. mirabilis isolated from humans as compared with biofilms of sheep isolates. According to our knowledge, this is the first report evaluating the anti-biofilm activity of probiotic spore-forming bacilli against clinical and animal UTI isolates of P. mirabilis. Further studies are recommended to investigate the anti-biofilm activity and the mode of action for the antimicrobial substances produced by these bacilli, subtilosin and subtilin.

尿路感染（UTI）是一种多因素疾病，包括膀胱炎，肾盂肾炎和肾盂炎。之后大肠杆菌，变形杆菌是最常见的泌尿道感染相关的条件致病菌。细菌的抗药性和感染的复发可能与奇异假单胞菌的生物膜形成有关。在这项研究中，使用抗生素盘试验研究了人和绵羊分离的狂犬疟原虫的抗生素敏感性。被测试的潜在益生菌，解淀粉芽孢杆菌B-1895和枯草芽孢杆菌的共聚集还评估了带有分离的病原体的KATMIRA1933。然后，天然衍生的代谢物，如枯草菌素和枯草溶菌素，在自由杆菌上清液的抗生物膜活性进行了评估针对生物膜奇异变形杆菌分离株。分离出的病原体对30μg阿米卡星和5μg环丙沙星敏感，但对其他测试的抗生素有抗性。24小时后，解淀粉芽孢杆菌B-1895的自动聚集为89.5％，高于枯草芽孢杆菌KATMIRA1933的自动聚集（59.5％）。淀粉芽孢杆菌B-1895与来自人UTI的奇异假单胞菌分离物强烈共聚集。的无细胞上清液解淀粉芽孢杆菌B-1895和与绵羊分离物的生物膜相比，枯草芽孢杆菌KATMIRA1933对分离自人的奇异假单胞菌的生物膜表现出更高的抗菌活性。据我们所知，这是第一次的评估报告对临床和动物UTI株益生菌孢子形成杆菌的抗生物活性奇异变形杆菌。建议进一步研究以调查这些细菌，枯草杆菌蛋白酶和枯草杆菌蛋白酶产生的抗菌物质的抗生物膜活性和作用方式。