Genome characterization of the novel lytic phage vB_AbaAut_ChT04 and the antimicrobial activity of its lysin peptide against Acinetobacter baumannii isolates from different time periods

In this study, we isolated and determined the biological features of a lyticA. baumannii phage called vB_AbaAut_ChT04 (vChT04). The vChT04 phage was classified as a member of the familyAutographiviridae of the classCaudoviricetes. It showed a short latent period (10 min) and a large burst size (280 PFU cell−1), and it was able to infect 52 out of 150 clinical MDR-AB strains tested (34.67%). Most of the phage-sensitive strains wereA. baumannii strains that had been isolated during the same year that the phage was isolated. The phage showed activity across a broad pH (pH 5.0 –8.0) and temperature (4–37°C) range. Whole-genome analysis revealed that the vChT04 genome comprises 41,158 bp with a 39.3% GC content and contains 48 open reading frames (ORFs), 28 of which were assigned putative functions based on homology to previously identified phage genes. Comparative ge nomic analysis demonstrated that vChT04 had the highest similarity to phage vB_AbaP_WU2001, which was isolated in the southern part of Thailand. An endolysin gene found in the vChT04 genome was used to synthesize an antimicrobial peptide (designated as PLysChT04) and its antimicrobial activity was e valuated using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. The MIC and MBC values of peptide PLysChT04 against MDR-AB and XDR-AB were 312.5–625 µg/mL, and it was able to inhibit both phage-susceptible and phage-resistant isolates collected over diff erent time peri...
Source: Archives of Virology - Category: Virology Source Type: research