Detection And Drug Resistance Of Campylobacter From Poultry In Zhejiang Province

Campylobacter is not only a foodborne pathogen causing human gastroenteritis,but also a zoonosis pathogen.Human and animal infected Campylobacter can develop diarrhea,vomiting,blood stool,abortion and other clinical symptoms.Campylobacter widely exists in soil,water and other natural environment and in animal breeding,slaughtering,food processing and marketing.Food animals,especially poultry,are the main hosts of Campylobacter.Nowadays,the outbreak of campylobacteriosis is gradually increasing,which has become a common problem all over the world,which is a serious threat to human life and health.At present,food poisoning caused by infecting Campylobacter occurs frequently in China,and there are few studies on the prevalence of Campylobacter in poultry.Therefore,it is of great significance to strengthen the study on the prevalence of Campylobacter fowl in China to prevent the infection of Campylobacter fowl.In the process of clinical treatment and animal breeding,the abuse and misuse of antibiotics lead to and accelerate the occurrence of drug resistance.Quinolones and macrocyclic lipid antibiotics are the first choice for clinical treatment of campylobacteriosis.There are also many quinolones and macrocyclic lipid resistant Campylobacter.Therefore,the detection of drug resistance of Campylobacter can be used to understand which antibiotics should be limited in animal husbandry,which plays a very important role in guiding the rational use of antibiotics in animal husbandry.Based on Zhejiang Province,this study collected 725 samples of poultry feces,cecum and swabs from farms and slaughterhouses in Hangzhou,Shaoxing,Jiaxing and Jiande,as well as poultry products from supermarkets in Hangzhou and Shaoxing.The Campylobacter was isolated by national standard method(GB4789.9-2014),and then the Campylobacter strains were identified by MALDI-TOF MS mass spectrometry and multiplex PCR.Secondly,110 strains of Campylobacter were detected by microbroth dilution method and the whole genome of 3 strains of multi-drug-resistant strains were sequenced.In addition,the isolated C.jejuni was typed by multilocus sequencing typing.The main results are as follows:(1)A total of 110 strains of Campylobacter were isolated and the isolation rate was15.2%.Among them,100 strains(13.8%)were C.jejuni and 10 strains(1.4%)were C.coli.The separation rates of farms and slaughterhouses were 18.3% and 12.5%,respectively,which were higher than that of supermarkets(10.9%).The isolation rate in Jiaxing(28.8%)was significantly higher than that in Shaoxing(16.1%)and Hangzhou(8.5%).There was no significant difference between Hangzhou and Jiande(17.5%).(2)The results of drug resistance test of Campylobacter strains showed that Campylobacter showed high resistance to ciprofloxacin,nalidic acid,with resistance rates of89.1%,89.1%,respectively,followed by tetracycline.The drug resistance rate was 82.7%,followed by gentamicin and florfenicol.The drug resistance rates were 39.1% and 33.6%,respectively,and the drug resistance rates of telithromycin,erythromycin,azithromycin and clindamycin were 10%,8.2%,8.2% and 6.4%,respectively.There were some differences in drug resistance of Campylobacter from different regions and different sources.Among them,the drug resistance of C.coli was higher than that of C.jejuni,110 strains of Campylobacter were 16 kinds of drug resistance spectrum,more than 80% of Campylobacter were multi-drug resistant,and 2 strains of C.jejuni were resistant to 9 kinds of antibiotics.(3)The whole genome sequencing results showed that the predicted drug resistance genes were basically consistent with the drug resistance phenotype,and some drug resistance phenotypes had high drug resistance due to chromosome mutation.In this study,it was found that the mutation of Thr-86-Ile site in the gyr A gene of strain COZHT006 resulted in a high level of resistance to quinolones.The mutation at 2074 and 2075 in the 23 s r RNA gene of the isolated strain ZJBT004 resulted in the resistance of Campylobacter to macrolide antibiotics.(4)The results of multilocus sequencing typing showed that there were 53 sequence types of C.jejuni,including 21 known sequence types and 32 unknown sequence types.ST113,ST305 and ST464 were the most frequent sequence types,all from farms.The proportion of unknown sequence type is high,indicating that C.jejuni in Zhejiang Province has high genetic diversity and strong ability of variation.