Determination of the expression of three fimbrial subunit proteins in cultured Trueperella pyogenes

作者:Liu, Mengcheng; Wang, Bing; Liang, Hongmin; Ma, Bo; Wang, Junwei; Zhang, Wenlong*
来源:Acta Veterinaria Scandinavica, 2018, 60(1): 53.
DOI:10.1186/s13028-018-0407-3

摘要

Background: Trueperella pyogenes is a commensal and a significant opportunistic pathogen in animals. A variety of identified or putative virulence factors are considered to significantly contribute to the occurrence of T. pyogenes infection in different species. However, these virulence factors are not fully understood. @@@ Results: In the current study, the genes encoding putative fimbrial proteins, i.e. Fim A, Fim C, and Fim E, were cloned. Recombinant Fim A (rFim A), Fim C (rFim C), and Fim E (rFim E) were prepared and used to generate rabbit anti-rFim A, anti-rFim C, and anti-rFim E serum, respectively. Using these sera, we found that only Fim E was constitutively expressed in T. pyogenes. The expression level of Fim E in T. pyogenes peaked within 6-10 h of culture period in pH 7.5. Fim E protein expression was unaffected by anaerobic condition, but was inhibited by the microaerophilic condition. Tube agglutination tests indicated that Fim E was exhibited on the surface of T. pyogenes cells because anti-rFim E serum caused strong agglutination. Additionally, the blots for Fim A detection showed nonspecific reactions. Furthermore, the tube agglutination tests showed that anti-Fim A serum failed to cause agglutination of T. pyogenes cells, which indicated that Fim A was not, or poorly, expressed in cultured T. pyogenes. Anti-rFim C serum caused strong agglutination. However, the blots for Fim C detection showed a strong nonspecific reaction. Thus, the expression of Fim C was difficult to be determined using the current method. @@@ Conclusions: Fim E was expressed in cultured T. pyogenes. However, Fim A was either not or poorly expressed in cultured T. pyogenes. Moreover, Fim C expression was not determined using the current strategy.