Isolation and identification of two Trueperella pyogenes strains from different hosts and bioinformatics analysis of the plo gene

Abstract:

[Background] Trueperella pyogenes is an opportunistic pathogen causing infections in humans and diverse animal species, particularly non-specific purulent infections in animals. [Objective] To characterize the suspected T. pyogenes strains from different hosts. [Methods] Strains were isolated from the subcutaneous abscess of forest musk deer and duck tarsal joint abscess and identified based on Gram staining and bacterial 16S rRNA gene analysis. The biological properties of the two strains were characterized through the analysis of the growth curves, drug sensitivity test, and detection of virulence genes. Then we analyzed the sequence and predicted the structure of the pyolysin gene plo. [Results] The strains isolated from forest musk deer and duck were named FTP-1 and DTP-1, respectively. According to the growth curves, the growth rates of the two were quite different. Drug sensitivity test showed that the two strains were resistant to β-lactams, sulfonamides, and rifamycins and sensitive to aminoglycosides and quinolones. Both strains carried plo, nanH, nanP, fimA, and fimE genes, and DTP-1 also harbored fimC gene. There were host-specific differences in the nucleotide sequence of plo gene between the two strains, but the amino acid sequences of encoded proteins were the same. The pyolysin (PLO) of T. pyogenes was highly similar to other members of the cholesterol-dependent cytolysin family. [Conclusion] One strain of T. pyogenes was respectively isolated from forest musk deer and duck in Yiliang of Yunnan Province, and the plo gene of two strains had close genetic relationship. The biological characteristics can serve as a reference for further research on and prevention and control of the pathogen.