Choudhury Ankan, Ortiz Patrick S, Young Mikaeel, Mahmud Md Toslim, Stoffel Ryan T, Greathouse K Leigh, Kearney Christopher M
Department of Biology, Baylor University , Waco, Texas, USA.
Baylor Sciences Building Vivarium, Baylor University , Waco, Texas, USA.
Microbiol Spectr. 2023 Sep 15;11(5):e0201423. doi: 10.1128/spectrum.02014-23.
is the primary cause of 78% of gastric cancer cases, providing an opportunity to prevent cancer by controlling a single bacterial pathogen within the complex gastric microbiota. We developed highly selective antimicrobial agents against by fusing an -binding guide peptide (MM1) to broad-spectrum antimicrobial peptides. The common dairy probiotic was then engineered to secrete these guided antimicrobial peptides (gAMPs). When co-cultured with , the gAMP probiotics lost no toxicity compared to unguided AMP probiotics against the target, , while losing >90% of their toxicity against two tested off-target bacteria. To test binding to , the MM1 guide was fused to green fluorescent protein (GFP), resulting in enhanced binding compared to unguided GFP as measured by flow cytometry. In contrast, MM1-GFP showed no increased binding over GFP against five different off-target bacteria. These highly selective gAMP probiotics were then tested by oral gavage in mice infected with . As a therapy, the probiotics outperformed antibiotic treatment, effectively eliminating in just 5 days, and also protected mice from challenge infection as a prophylactic. As expected, the gAMP probiotics were as toxic against as the unguided AMP probiotics. However, a strong rebound in gastric species diversity was found with both the selective gAMP probiotics and the non-selective AMP probiotics. Eliminating the extreme microbial dysbiosis caused by appeared to be the major factor in diversity recovery. IMPORTANCE Alternatives to antibiotics in the control of and the prevention of gastric cancer are needed. The high prevalence of in the human population, the induction of microbial dysbiosis by antibiotics, and increasing antibiotic resistance call for a more sustainable approach. By selectively eliminating the pathogen and retaining the commensal community, control may be achieved without adverse health outcomes. Antibiotics are typically used as a therapeutic post-infection, but a more targeted, less disruptive approach could be used as a long-term prophylactic against or, by extension, against other gastrointestinal pathogens. Furthermore, the modular nature of the guided antimicrobial peptide (gAMP) technology allows for the substitution of different guides for different pathogens and the use of a cocktail of gAMPs to avoid the development of pathogen resistance.
是78%胃癌病例的主要病因，这为通过控制复杂胃微生物群中的单一细菌病原体来预防癌症提供了契机。我们通过将一种结合幽门螺杆菌的导向肽（MM1）与广谱抗菌肽融合，开发出了针对幽门螺杆菌的高选择性抗菌剂。然后对常见的乳制品益生菌进行基因工程改造，使其分泌这些导向抗菌肽（gAMP）。当与幽门螺杆菌共培养时，与未导向的AMP益生菌相比，gAMP益生菌对目标菌幽门螺杆菌的毒性没有降低，而对两种测试的非目标细菌的毒性降低了90%以上。为了测试与幽门螺杆菌的结合，将MM1导向肽与绿色荧光蛋白（GFP）融合，通过流式细胞术检测，结果显示与未导向的GFP相比，结合能力增强。相比之下，MM1-GFP对五种不同的非目标细菌的结合能力与GFP相比没有增加。然后通过对感染幽门螺杆菌的小鼠进行口服灌胃来测试这些高选择性的gAMP益生菌。作为一种治疗方法，这些益生菌的效果优于抗生素治疗，仅在5天内就有效清除了幽门螺杆菌，并且作为预防性措施还能保护小鼠免受感染挑战。正如预期的那样，gAMP益生菌对幽门螺杆菌的毒性与未导向的AMP益生菌相同。然而，发现选择性gAMP益生菌和非选择性AMP益生菌都导致胃物种多样性出现强烈反弹。消除由幽门螺杆菌引起的极端微生物失调似乎是多样性恢复的主要因素。重要性在控制幽门螺杆菌和预防胃癌方面需要抗生素的替代方法。幽门螺杆菌在人群中的高流行率、抗生素对微生物失调的诱导以及抗生素耐药性的增加，都需要一种更可持续的方法。通过选择性地消除病原体并保留共生菌群，可以在不产生不良健康后果的情况下实现对幽门螺杆菌的控制。抗生素通常在感染后用作治疗手段，但一种更具针对性、破坏性更小的方法可以用作针对幽门螺杆菌的长期预防性措施，或者进而针对其他胃肠道病原体。此外，导向抗菌肽（gAMP）技术的模块化性质允许用不同的导向肽替代不同的病原体，并使用gAMP混合物来避免病原体耐药性的产生。
