Distinct mutations emerge in the genome of serotype O foot-and-mouth disease virus during persistence in cattle

• DOI: 10.1128/jvi.01422-24
• Publication Date: 2025-02-07T14:01:37Z
• Authors: Benedikt Litz; Leonie F. Forth; Florian Pfaff; Martin Beer; Michael Eschbaumer
• Keywords: Aphthovirus

ABSTRACT Like other RNA viruses, foot-and-mouth disease virus (FMDV) has a high mutation rate. After the acute phase of infection, about half infected cattle develop persistent FMDV infection that can last for weeks or months. During this phase, continues to replicate, resulting in emergence genomic heterogeneity. We have documented pattern mutations by obtaining consensus-level sequences directly from oropharyngeal fluid (OPF) without prior isolation culture. OPF samples were repeatedly collected 22 experimentally cattle, 20 which positive on day 21 after later. observed during amount non-synonymous causing an amino acid change increased over time. Two changes showed striking increase VP3 A75T and VP2 Y79H, present neither inoculum nor phase. Another VP3, R56C, was previously implicated pathogenicity, already dominated toward end trial most samples. Several occurred, particularly surface around residue 79. By functional analysis, we show isolates evolve distinctly compared with cell culture adaptation but do not signs antigenic escape neutralizing antibodies. In agreement previous observations, conclude these are indeed associated serotype O. IMPORTANCE Our research article describes genetic occur infection. This is particular interest understand viral dynamics within population new strains could emerge. Especially FMDV, its diversity very limited cross-reactivity between serotypes, demonstrated past variants quickly emerge evade vaccine responses. our study, dynamic evolution Persistently animals, clinically indistinguishable healthy also pose reservoir recombination. A better understanding essential improved vaccines prevent variants.