Identification and functional characterization of a novel Acinetobacter pittii bacteriophage-encoded depolymerase

作者：Na Zhang, Wei Li, Xue Du, Danish Daniyal, Meng-ai Feng, Xu Jing, Ziqin Yang, Hailin Jiang, Muhammad Sheraz, Honglan Huang, Santasree Banerjee, Hongyan Shi · 发表于：Frontiers in Cellular and Infection Microbiology · 年份：2025 · DOI：10.3389/fcimb.2025.1608526 · 被引用次数：2 · 研究领域：Bacteriophages and microbial interactions、Bacterial biofilms and quorum sensing、Cancer Research and Treatments

Introduction Acinetobacter pittii is increasingly recognized as a significant cause of nosocomial infections. Bacteriophage-encoded depolymerases that degrade capsular polysaccharides (CPS)—a major virulence factor of A. pittii —represent promising therapeutic tools. Methods This study identified and characterized a novel depolymerase, designated 31TSP, derived from the A. pittii bacteriophage 31Y. Its functional stability across various pH levels (5–11) and temperatures (4 °C to 121 °C) was assessed. The inhibitory effect of 31TSP on biofilm formation and its disruptive activity against preformed biofilms were evaluated using crystal violet staining, viable cell counts and scanning electron microscopy. Combinatorial treatments with 31TSP and ampicillin were conducted. Furthermore, the enzyme's stability under different ion concentrations (NaCl) and its ability to enhance serum bactericidal activity were tested under experimental conditions. Results Characterization demonstrated that 31TSP exhibits a broad host range against A. pittii , A. baumannii , and A. nosocomialis . The enzyme degraded the CPS of host bacteria and displayed inhibition effects on sensitive hosts. 31TSP retained functional stability across a wide pH range (5–11) and temperatures from 4 °C to 121 °C. Its inhibitory effect on biofilm formation and disruptive activity against preformed biofilms were confirmed. Notably, combinatorial treatment with 31TSP and ampicillin significantly enhanced biofilm inhibiti...