A novel β-1,2-mannosidase GH130-BG31 from glycoside hydrolase family 130 targets healthcare-associated bacterial biofilms and potentiates antibiotic activity.

Hospital-acquired infections (HAIs) pose a major global health challenge, largely due to persistent biofilms formed by multidrug-resistant pathogens. In this study, we investigate GH130-BG31, a β-1,2-mannosidase from the GH130 glycoside hydrolase family, and demonstrate for the first time that it exhibits strong activity against mannose-rich biofilms associated with HAIs. By targeting β-1,2-mannosidic linkages in exopolysaccharides, GH130-BG31 inhibits 80% of biofilm formation in Escherichia coli and Staphylococcus epidermidis at 10 μg/mL, and in Klebsiella pneumoniae at 100 μg/mL. At 100 μg/mL, it also reduces early adhesion of Pseudomonas aeruginosa by 30% and Acinetobacter baumannii by 50%. The enzyme partially degrades preformed K. pneumoniae and S. epidermidis biofilms and significantly enhances the efficacy of various antibiotics. In the catheter-associated K. pneumoniae model, the combination of GH130-BG31 (100 μg/mL) with colistin (4 μg/mL) reduces biofilm formation by up to 8 logs, and with 8 μg/mL colistin, it disrupts mature biofilms by 4 logs. The enzyme functions optimally at 37 °C and neutral to slightly acidic pH, and remains stable at temperatures up to 37 °C and within a pH range of 4-7. It also shows no cytotoxicity in human cell lines or in Caenorhabditis elegans. Overall, GH130-BG31 emerges as a promising enzyme for preventing and controlling clinically relevant HAI-associated biofilms and as a potential adjuvant to antibiotic therapy.