Combined effect of SAR-endolysin LysKpV475 with polymyxin B and Salmonella bacteriophage phSE-5

• DOI: 10.1099/mic.0.001462
• Publication Date: 2024-05-13T15:17:07Z
• Authors: Marco Gontijo; Mateus Pereira Teles; Hugo Martins Correia; Genesy Pérez Jorge; Isabella Carolina...; Anthony Jhoao Fas...; Márcia Braz; Lucas de Moraes C...; Priscila Zonzini ...; Ivan Rosa e Silva; Pedro Marcus Pere...; Jörg Kobarg; Rafael Miguez Cou...; Cristina Elisa Al...; Carla Pereira; Carmen S. R. Freire; Adelaide Almeida; Marcelo Brocchi
• Keywords: Lysin; Polymyxin B; Salmonella enterica

Endolysins are bacteriophage (or phage)-encoded enzymes that catalyse the peptidoglycan breakdown in bacterial cell wall. The exogenous action of recombinant phage endolysins against Gram-positive organisms has been extensively studied. However, outer membrane acts as a physical barrier when considering use to combat Gram-negative bacteria. This study aimed evaluate antimicrobial activity SAR-endolysin LysKpV475 bacteria single or combined therapies, using an permeabilizer (polymyxin B) and phage, free immobilized pullulan matrix. In first step, endolysin solution, alone with polymyxin B, was tested vitro vivo ten bacteria, including highly virulent strains multidrug-resistant isolates. second lyophilized phSE-5 investigated, matrix, Salmonella enterica subsp. serovar Typhimurium ATCC 13311. bacteriostatic purified varied between 8.125 μg ml −1 Pseudomonas aeruginosa 27853, 16.25 S . 13311, 32.50 Klebsiella pneumoniae BAA-2146 Enterobacter cloacae P2224. showed bactericidal only for P. 27853 (32.50 ) P2307 (65.00 at concentrations. effect B increased K. [fractional inhibitory concentration index (FICI) 0.34; value lower than 1.0 indicates additive/combined effect] 13311 (FICI 0.93). A synergistic also observed ⅔ MIC (m.o.i. 100). matrix maintained significant almonella reduction 2 logs after 6 h treatment. These results demonstrate potential SAR-endolysins, combination other treatments, form solid matrices, which paves way their application different areas, such biocontrol food processing stage, biosanitation contact surfaces biopreservation processed active packing.