Open AccessIdentification of genes required for the fitness of Streptococcus equi subsp. equi in whole equine blood and hydrogen peroxide
Author(s) -
Amelia R. L. Charbonneau,
Emma Taylor,
Catriona Mitchell,
Carl Robinson,
Amy K. Cain,
James A. Leigh,
Duncan J. Maskell,
Andrew S. Waller
Publication year - 2020
Publication title -
microbial genomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.476
H-Index - 28
ISSN - 2057-5858
DOI - 10.1099/mgen.0.000362
Subject(s) - streptococcus equi , biology , gene , whole blood , genetics , microbiology and biotechnology , immunology , bacteria
The availability of next-generation sequencing techniques provides an unprecedented opportunity for the assignment of gene function.Streptococcus equisubspeciesequiis the causative agent of strangles in horses, one of the most prevalent and important diseases of equids worldwide. However, the live attenuated vaccines that are utilized to control this disease cause adverse reactions in some animals. Here, we employ transposon-directed insertion-site sequencing (TraDIS) to identify genes that are required for the fitness ofS. equiin whole equine blood or in the presence of H 2 O 2 to model selective pressures exerted by the equine immune response during infection. We report the fitness values of 1503 and 1471 genes, representing 94.5 and 92.5 % of non-essential genes inS. equi , following incubation in whole blood and in the presence of H 2 O 2 , respectively. Of these genes, 36 and 15 were identified as being important to the fitness ofS. equiin whole blood or H 2 O 2 , respectively, with 14 genes being important in both conditions. Allelic replacement mutants were generated to validate the fitness results. Our data identify genes that are important forS. equito resist aspects of the immune response in vitro , which can be exploited for the development of safer live attenuated vaccines to prevent strangles.