Antimicrobial Resistance And PFGE Tying Of Campylobacter In Guangdong

Campylobacter,especially campylobacter jejuni(C.jejuni)and campylobacter coli(C.coli),often causing human's diarrhea,gastroenteritis and other diseases,is one of the important zoonotic pathogen that impact human and animal health.Campylobacter spread through animal,food,water and other approach,poultry is the important “reservoir” of Campylobacter.In the poultry industry and poultry food safety is of great significance.In this study,we detect the antimicrobial resistance,resistance genes and of C.jejuni and C.coli isolated from different sources in Guangdong Province,and type them with PFGE typing method.The aim of this study is to investigate the antimicrobial resistance,the main resistance mechanism and genotype analysis of Campylobacter from different origins in Guangdong,and aslo provide some important scientific basis for the monitor of antimicrobial resistance,and the research of antimicrobial resistance and molecular epidemiology.We use the agar dilution method to detect the antimicrobial resistance of 114 C.jejuni and 58 C.coli of Guangdong province to 12 commonly used antibiotics.The results showed a severe resistance of Campylobacter against to quinolones agent(nalidixic acid,ciprofloxacin,levofloxacin,enrofloxacin),the resistance rate from 86.21% to 100%.Tetracycline agent resistance rate is 79% or more.The antimicrobial resistance between C.jejuni and C.coli was different,C.jejuni showed a lower resistance of Macrolides(erythromycin and azithromycin),aminoglycosides(gentamicin and kanamycin)and clindamycin,resistance rates were below 10%,however,the C.coli resistant rate of erythromycin and azithromycin were 81.03%,gentamicin and clindamycin resistance were 79.31%,much higher than C.jejuni.To the Florfenicol,the resistance rates of C.jejuni and C.coli were approximately 29.82% and 29.31%,respectively.The main multiple antimicrobial resistance pattern of C.jejuni was Q-T-F(21.93%).Q-M-T-A-L(55.17%)was the predominant multiple antimicrobial resistance model of C.jejuni,and two strains of C.jejuni and 12 colon Bacteria to achieve Q-M-T-A-L-F mode of six drug resistance.On the basis of antimicrobials resistance detection,the main antimicrobial resistance genes of Campylobacter to quinolones,macrolides,aminoglycosides and tetracycline is performed by polymerase chain reaction(PCR)and Sequencing.The result showed the 169 quinolone resistant Campylobacter have a C257 T mutation of the quinolones resistance determining region(QRDR)of the gyr A gene,result in amino acid Thr-86-Ile mutation,mutation rate of 100%,it's the main mechanism leading to quinolone antimicrobial resistance.The QRDR of gyr B gene has many base mutations,but all are silent mutations,did not cause the amino acid mutations.The 23 S r RN A gene of 52 Campylobacter strians of macrolide resistant Campylobacter was mutated with A2075 G,and there were 1 strain of C.jejuni and 8 strains of C.coli,have the macrolide resistant methylationase erm B.In the 57 strains of aminoglycoside resistant Campylobacter,64.91% of the strains were infected with the aph(2 ")-If gene and 12.28% of the strains carrying the aac(6 ')-Ie / aph(2")-Ia gene,This is the main reason for mediating the antibiotic resistance of aminoglycoside.151 Campylobacter strains resistant to tetracycline or doxycycline,135 strains of Campylobacter carrying tetracycline resistance gene tet(O),the carrying rate was 89.40%.Pulsed field gel electrophoresis(PFGE)was used to analyze 43 C.jejuni and 39 C.coli isolate in 2016.PFGE results showed that C.jejuni can be divided into 27 PFGE type,including 5 PFGE cluster;C.coli can be divided into 32 PFGE type,including 6 PFGE cluster.The genotype of campylobacter was various characteristics,the C.coli was more various than the C.jejuni.The relationship between most PFGE type is for a single source of the strain,but the same source of the strain has several different PFGE types.The relationship between genotype and antimicrobial resistance of Campylobacter was not obvious.The same type of pathogen showed a certain difference in genotype.The same genotype of Campylobacter showed different resistance.