Basic Characterization of Natural Transformation in a Highly Transformable Haemophilus parasuis Strain SC1401

Frontiers in Cellular and Infection Microbiology

Han, Xinfeng¹  Cao, Sanjie¹  Wen, Xintian¹  He, Lvqin¹  Wu, Rui¹  Zhao, Qin²  Chang, Yung-Fu³  Yan, Qigui³  Wen, Yiping³  Huang, Xiaobo³  Ma, Xiaoping³  Dai, Ke³  Huang, Yong⁴ 

[1] College of Veterinary Medicine, Sichuan Agricultural University, China;Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, United States;Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, China;Sichuan Science-Observation Experimental Station of Veterinary Drugs and Veterinary Diagnostic Technology, Ministry of Agriculture, China

关键词: Haemophilus parasuis;    crp;    uptake signal sequence;    Natural competence;    transformation;   

DOI  :  10.3389/fcimb.2018.00032

学科分类：生物科学（综合）

来源: Frontiers

【 摘 要 】

Haemophilus parasuis causes Glässer’s disease and pneumonia, incurring serious economic losses in the porcine industry. In this study, natural competence was investigated in H. parasuis. We found competence genes in H. parasuis homologous to ones in H. influenzae and a high consensus battery of Sxy-dependent cyclic AMP (cAMP) receptor protein (CRP-S) regulons using bioinformatics. High rates of natural competence were found from the onset of stationary-phase growth condition to mid-stationary phase (OD600 from 0.29 to 1.735); this rapidly dropped off as cells reached mid-stationary phase (OD600 from 1.735 to 1.625). As a whole, bacteria cultured in liquid media were observed to have lower competence levels than those grown on solid media plates. We also revealed that natural transformation in this species is stable after 200 passages and is largely dependent on DNA concentration. Transformation competition experiments showed that heterogeneous DNA cannot outcompete intraspecific natural transformation, suggesting an endogenous uptake sequence or other molecular markers may be important in differentiating heterogeneous DNA. We performed qRT-PCR targeting multiple putative competence genes in an effort to compare bacteria pre-cultured in TSB++ vs. TSA++ and SC1401 vs. SH0165 to determine expression profiles of the homologues of competence-genes in H. influenzae. Taken together, this study is the first to investigate natural transformation in H. parasuis based on a highly naturally transformable strain SC1401.

【 授权许可】

CC BY