Isolation And Identification Of Trueperella Pyogenes Isolated From Pigs And Transcription Profile Analyses Of Resistance Strain To Aminoglycosides

Trueperella pyogenes is an important opportunistic pathogen and a causative agent of various pyogenic diseases in sheep,cattle,swine and other species.Infection leads to serious economic losses in animal husbandry due to misdiagnoses and a lack of preventive measures.Drug resistance rates are rising because of misuse of antimicrobial agents.However,about resistance mechanisms of Trueperella pyogenes has not been studied in China.The present study aims to determine the resistance mechanisms and main virulence genes of Trueperella pyogenes isolated from swine in the Jilin province of China.We collected 8 Trueperella pyogenes specimens using pcr amplification of 16 S rRNA gene.The drug sensitivity results indicated that most of the isolated strains were resistance to aminoglycosides.Therefore,we investigated genes involved in target alteration,integron and drug resistance as potential mechanisms of resistance to aminoglycosides in Trueperella pyogenes.Transcriptome analyses were carried out on resistance strain and sensitive strain,analyses of resistance mechanisms from mRNA level.This study may provide data support for control technique,research and development of new drug or drug resistance inhibitor.1.Isolation and identification of Trueperella pyogenes and detection of virulence factorsIn order to investigate the major virulence genes of Trueperella pyogenes isolated from swine in Jilin Province.8 isolate strains identified as Trueperella pyogenes by morphological observation,biochemical tests and bacteria 16 S rRNA gene sequencing.The genes encoding major virulence factors were detected by PCR.The nanH and nanP genes was a slight different from different regions,all isolated carry plo gene,and all isolated lacks of cbpA gene.2.Preliminary study on the aminoglycoside resistance mechanisms of Trueperella pyogenesThe minimal inhibition concentration(MIC)of 8 strains for 5 aminoglycoside antibiotics was determined via an agar dilution method,total of 6 resistance strains and 2 sensitive strains.In order to investigate the resistance mechanism to aminoglycosides of Trueperella pyogenes,target alteration,integron and drug resistance were detected.Test results were negative for drug resistance gene,two 16 s ribosomal RNA sequencing result of Trueperella pyogenes compare with reference strain,result show that 16 s ribosomal RNA of resistance strains and sensitive strains without mutation.But class 1 integrons were highly prevalent among T.pyogenes and all carry gene cassettes,including aadA1,aadA2,aadA5,aacA4 and aac(6')-Ib 5 kinds of drug resistance gene that induce drug resistance to aminoglycosides.3.Transcription profile analyses of sensitive strain and resistance strain to aminoglycosidesBased on the transcriptome sequencing technology,for further research resistance mechanisms to aminoglycosides of Trueperella pyogenes,Transcriptome analyses were carried out on Trueperella pyogenes which resistance to aminoglycosides.The results of the present study demonstrated that the resistance strain compare with sensitive strain exists 245 differentially expressed genes.The rbsB which involved biofilm formation has a significant increase in bacterial chemotaxis,it may be important factor to resistance mechanism of Trueperella pyogenes.