1.Whole genome sequencing of Streptococcus suis revealed potential drug resistance and zoonotic transmission in companion cat
Lee, C.Y. ; Selvarajah, G.T. ; Zakaria, Z. ; Mustaffa-Kamal, F. ; Gan, H.M. ; Voon, K.G.L. ; Fong, M.W.C ; Ooi, P.T.
Tropical Biomedicine 2024;41(No.1):97-108
Streptococcus suis is a bacterium of clinical importance in diverse animal hosts including companion
animals and humans. Companion animals are closely associated in the living environment of humans
and are potential reservoirs for zoonotic pathogens. Given the zoonotic potential of S. suis, it is crucial
to determine whether this bacterium is present among the companion animal population. This study
aimed to detect Streptococcus suis in companion animals namely cats and dogs of the central west
coast of Peninsular Malaysia and further characterize the positive isolates via molecular and genomic
approach. The detection of S. suis was done via bacterial isolation and polymerase chain reaction assay
of gdh and recN gene from oral swabs. Characterization was done by multiplex PCR serotyping, as well
as muti-locus sequence typing, AMR gene prediction, MGE identification and phylogenomic analysis
on whole genome sequence acquired from Illumina and Oxford Nanopore sequencing. Among the 115
samples, PCR assay detected 2/59 of the cats were positive for S. suis serotype 8 while all screened
dog samples were negative. This study further described the first complete whole genome of S. suis
strain SS/UPM/MY/F001 isolated from the oral cavity of a companion cat. Genomic analysis revealed a
novel strain of S. suis having a unique MLST profile and antimicrobial resistance genes of mefA, msrD,
patA, patB and vanY. Mobile genetic elements were described, and pathogenic determinants matched
to human and swine strains were identified. Phylogenetic tree analysis on the core genome alignment
revealed strain SS/UPM/MY/F001 was distinct from other S. suis strains. This study provided insight
into the detection and genomic features of the S. suis isolate of a companion cat and highlighted its
potential for antimicrobial resistance and pathogenicity.