Development Of Isothermal Microcalorimetric Method For Detecting Drug-resistance In Clostridium Perfringens And The Profiling Of Genes For Drug-Resistance Among The Strains Of Clostridium Perfringens From Broiler Chickens

Necrotic enteritis(NE)is a disease characterized by mucosal necrosis of the intestine mucosa,diarrhea,bloody diarrhea and the like caused by Clostridium perfringens type A or C.The disease often associated with coccidiosis,huge economic losses even death.In recent years,the incidence and prevalence of the disease have been on a global upward trend.C.perfringens is a Gram-positive anaerobic bacillus which is ubiquitous in nature.It is a normal inhabitant in the intestinal tract of animals and humans.When the growth environment is changed to cause its proliferation,the bacteria attach to the gut mucosa and produce large amounts of toxins and enzymes that cause intestinal mucosa damage,causing intestinal disease.The recent studies have indicated that C.perfringens virulence is typically linked to highly effecient of toxins,or plasmids carring antibiotic-resistance traits.Antibacterial plasmids that can bind to metastases are common in C.perfringens and become more and more complex with increasing use of feed antibiotic.In this study,Isothermal Microcalorimetry(IMC)technique was used to establish a rapid and accurate method for the determination of drug resistance and drug resistance of C.perfringens in poultry.Pan-genomic analysis was used to explore the distribution and population diversity of drug resistance genes in C.perfringens from poultry at pan-genome level.To provide experimental basis for studying the pathogenesis and prevention of C.perfringens.1.IMC method for detecting drug resistance of C.perfringens strains in poultry.In this study,we used C.perfringens ATCC3624 as a reference strain,at different concentrations of various antibacterial drugs and continuous monitoring of the curve of calorie in culture,real-time,visual changes reflect the growth of bacteria,established a rapid,real-time quantitative detection of C.perfringens resistance method.Comparison of the IMC versus MIC results shows that both MICs(Mini-inhibitory concentration)were identical,demonstrating that IMC is a useful in vitro tool for detecting bacterial growth and studying functional characteristics of different antibiotics;overcoming some of the limitations of the conventional methods.2.In order to understand the carrying and distribution of resistance genes of C.perfringens in some areas of our country,52 strains of C.perfringens sampled from different farms were sequenced,and the resistance genes among different strains were obtained of the carrier,as well as the resistance gene transfer.Solve the problem of C.perfringens plasmid extraction is not satisfactory and there is no repeatability.Currently found in China's poultry C.perfringens mostly are mult-antidrug,carrying drug-resistant plasmid tetracycline resistant gene,bacitracin resistant gene and macrolide resistant gene,laid the foundation for subsequent studies.