1. orf20 in prophage phiv142-3 contributes to the adhesion and colonization ability of avian pathogenic Escherichia coli strain DE142 by affecting the formation of flagella and I fimbriae
- Author
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Jianluan Ren, Dezhi Li, Jianhe Sun, Jianjun Dai, Yan Chen, Fang Tang, Yun Liu, Xinjie Qian, and Feng Xue
- Subjects
Virulence Factors ,Prophages ,Fimbria ,Mutant ,Flagellum ,Biology ,medicine.disease_cause ,Cell morphology ,Microbiology ,Bacterial Adhesion ,03 medical and health sciences ,Escherichia coli ,medicine ,Animals ,Adhesins, Bacterial ,Prophage ,030304 developmental biology ,0303 health sciences ,General Veterinary ,030306 microbiology ,Escherichia coli Proteins ,Wild type ,Membrane Proteins ,General Medicine ,Bacterial Load ,Bacterial adhesin ,Flagella ,Fimbriae, Bacterial ,Mutation ,Fimbriae Proteins ,Chickens - Abstract
We have previously demonstrated that prophage phiv142-3 enhances the colonization ability of avian pathogenic Escherichia coli (APEC) strain DE142. However, the mechanism of this action remains unknown. In this study, we demonstrate that deletion of phiv142-3 orf20 leads to a decrease in the survival ability in chicken serum, adhesion, and ability to invade DF-1 cells of mutant strain DE142Δorf20 compared with that of wild type (WT). Avian infection assays showed that bacterial loads in lungs and hearts of chickens challenged with the mutant are decreased to 7% and 8.3% compared with those challenged with the WT. The number of flagella and I fimbriae of the mutant are decreased and the mutant exhibits filamentation. However, protein ORF20 shows no adhesion ability to DF-1 cells in adherence inhibition experiments, indicating that it does not directly participate in adhesion. qRT-PCR revealed that the deletion of orf20 leads to reduction in the expression of nine genes related to the exportation of flagellar protein and two I-fimbriae-related genes (fimA and fimH), but does not affect genes related to the synthesis of flagella and other adhesins. Compared with the WT, the transcription level of the cell-division-associated genes minC and minD was increased 1.4-fold and 2.5-fold in mutant DE142Δorf20, respectively, indicating that orf20 affects the morphology of DE142 by regulating expression of minC and minD. Thus, our study revealed that orf20 in prophage phiv142-3 played a role in flagellar exportation, cell morphology, and I fimbriae synthesis.
- Published
- 2019