The Antimicrobial Susceptibility Of Clostridium Perfringens Isolated From Broiler Chickens And The Detection Of Inhibitory Characteristics Of Antimicrobial Peptides

As one of the most important zoonotic pathogens, Clostridium perfringens cancause infections and food poisoning in human beings and animals. Type A or type CClostridium perfringens can make chickens get necrotic enteritis which characterizedby the bacterial acute infectious disease that cause intestinal mucosal bleeding andnecrosis. Antimicrobials are used to control and treat this disease and sometimesclinical outbreaks do not respond well to certain treatments. With the extensive use ofantibiotics by a large number of farms, the seriousness of Clostridium perfringens’multi-drug resistance has become the focus of attention in public health and safety.Inorder to comprehend drug resistance of Clostridium perfringens isolated fromarge-scale broiler chickens nationally, this study uses resistance experiment to detectClostridium perfringens isolated from different parts of the country and test theresistance difference of Clostridium perfringens from different regions, so as toprovide important conditions and a reliable basis for the diagnosis and treatment ofNecrotic enteritis in chickens. At the same time, with the cooperation of a corporation,this study tests the bacteriostatic and bactericidal characteristic of Antimicrobialpeptides on Clostridium perfringens, and provide important data for drugdevelopment.The drug sensitivity of the40positive strains isolated from different parts of thecountry was tested by using16kinds of drugs which were usually used in farmsaccording to Kirby-Bauer disk diffusion of NCCLS. The results revealed that2(5%,2/40) strains were resistant to penicillin G,24(60%,24/40) strains were resistant totetracycline; among the macrolide, there are2(5%,2/40) strains were resistant totilmicosin,5(12.5%,5/40) strains were resistant to erythromycin,14(35%,14/40)strains were resistant to tylosin. There are23resistant strains to lincomycin. However,the majority of strains were sensitive to phenicol, which only5strains are sensitive tochloramphenicol moderate. All the strains had not been sensitive to Sulfa drugs,24(24/40) strains were resistant to methicillin-pyrimidine, and38(95%，38/40) strains tocotrimoxazole. All the strains were sensitive to phosphonomycin. Accordingly, Clostridium perfringens has been resistant to.tetracyclines and macrolides widely.Simultaneously, most Clostridium perfringens were resistant to several kinds of drugrespectively, which5(12.5%,5/40) of the strains were resistant to2kinds of drugs,20(50%,20/40) strains were resistant to3kinds of drugs,9(22.5%,9/40) strainswere resistant to4kinds of drugs,4(10%,4/40) strains were resistant to5kinds ofdrugs,1(2.5%,1/40) strains were resistant to6kinds of drugs. In themulti-resistances, the resistant strains to3kinds of drugs were the most.In general, widespread chickens were infected by Clostridium perfringens widely.The drug sensitive test revealed that some Clostridium perfringens were no longersensitive; many strains were resistant to different kinds of drugs, may because thatsome of which were resistant to the drugs in the long-term clinical application, such asPenicillin G and Lincomycin.To analyses and comprehend the minimal inhibitory and bactericidalconcentration of Antimicrobial peptides, this study uses Fine purification, Crudepurification and Extraction dope to detect Clostridium perfringens. At last, theminimal inhibitory concentration of the three production is1850μg/ml,3000μg/ml,800μg/ml respectively, and the bactericidal concentration is2000μg/ml,8500μg/ml,1600μg/ml respectively.