PDF(Pubmed)
Abstract：
Traditional bacteriocin screening methods often face limitations due to diffusion-related challenges in agar matrices, which can prevent the peptides from reaching their target organism. Turbidimetric techniques offer a solution to these issues, eliminating diffusion-related problems and providing an initial quantification of bacteriocin efficacy in producer organisms. This study involved screening the cell-free supernatant (CFS) from eight uncharacterized asymptomatic bacteriuria (ABU) isolates and Escherichia coli 83972 for antimicrobial activity against clinical uropathogenic E. coli (UPEC) strains using turbidimetric growth methods. ABU isolates exhibiting activity against five or more UPEC strains were further characterized (PUTS 37, PUTS 58, PUTS 59, S-07-4, and SK-106-1). The inhibition of the CFS by proteinase K suggested that the antimicrobial activity was proteinaceous in nature, potentially bacteriocins. The activity of E. coli PUTS 58 and SK-106-1 was enhanced in an artificial urine medium, with both inhibiting all eight UPECs. A putative microcin H47 operon was identified in E. coli SK-106-1, along with a previously identified microcin V and colicin E7 in E. coli PUTS 37 and PUTS 58, respectively. These findings indicate that ABU bacteriocin-producers could serve as viable prophylactics and therapeutics in the face of increasing antibiotic resistance among uropathogens.
摘要：
由于琼脂基质中扩散相关的挑战，传统的细菌素筛选方法通常面临局限性。这可以防止肽到达它们的目标生物体。比浊技术为这些问题提供了解决方案，消除与扩散相关的问题，并提供生产者生物中细菌素功效的初步定量。这项研究涉及使用比浊法生长方法从八个未表征的无症状菌尿（ABU）分离株和大肠杆菌83972中筛选无细胞上清液（CFS），以对临床尿路致病性大肠杆菌（UPEC）菌株具有抗菌活性。进一步表征了对五种或更多种UPEC菌株表现出活性的ABU分离株(PUTS37、PUTS58、PUTS59、S-07-4和SK-106-1)。蛋白酶K对CFS的抑制作用表明抗菌活性本质上是蛋白质的，潜在的细菌素。大肠杆菌PUTS58和SK-106-1的活性在人工尿液培养基中增强，两者都抑制了所有八个UPEC。在大肠杆菌SK-106-1中鉴定了推定的microcinH47操纵子，以及先前分别在大肠杆菌PUTS37和PUTS58中鉴定的microcinV和大肠杆菌素E7。这些发现表明，面对尿路病原体中抗生素耐药性的增加，ABU细菌素生产者可以作为可行的预防和治疗方法。
