| Enterococcus faecalis is widely distributed in the natural environment and the digestive tract of human and animals.As an opportunistic pathogen,it could lead to multiple organ infections of human and animals.It is an important zoonotic pathogen.In chickens,E.faecalis is usually associated with sepsis,endocarditis,salpingitis and amyloid arthritis.Since the 1980 s,the incidence and mortality of severe infection of E.faecalis have increased significantly.Due to the inherent and acquired resistance of E.faecalis,many commonly used antibiotics fail in the treatment of its infection,which brings serious economic losses to the breeding industry.In this study,61 strains of E.faecalis were identified by Moldi Biotyer Microbial Rapid Identification Mass Spectrometer from chicken.Their drug resistance to11 kinds of antibiotics was determined by MICROSCAN walkaway-96 and drug sensitivity analyzer 27 kinds of virulence genes and drug resistance genes of E.faecalis were detected by PCR;These strains of E.faecalis were sequenced by MLST method,and the phylogenetic relationship of drug-resistant strains was analyzed.The results are as follows:The results of drug resistance spectrum analysis showed that the drug resistance rates of the 61 clinical isolates to 11 kinds of antibiotics were as follows: E(96.72%),TE(96.72%),S(72.13%),CN(67.21%),CIP(54.10%),LEV(37.70%),P(24.59%),LZD(18.03%),DAP(14.75%),AMP(14.75%)and VA(8.20%).The results showed that the detection rate of multi drug resistant strains was 72.13%,and the dominant drug resistance spectrum was E-TE-S-CN(19.68%).The detection rates of 12 virulence genes were ace(57.38%),asal(78.69%),agg(75.41%),cob(78.69%),ccf(80.33%),cpd(77.05%),cyl A(16.39%),cyl B(16.39%),cyl M(16.39%),esp(11.48%),hyl(6.56%),mef A(8.20%);The detection rates of 15 drug resistance genes were:aac(6')/aph(2'')(67.21%),ant(6)-I(0.00%),aph(3')-III(65.57%),cat(26.23%),erm B(95.08%),gel E(59.02%),gyr A(14.75%),par C(60.66%),tet K(0.00%),tet L(90.16%),tet M(91.80%),tet S(1.64%),van A(1.64%),van B(0.00%),Intl 1(77.05%).The most virulence genes detected were ccf(80.33%),asal(78.69%)and cob(78.69%).The resistance genes were erm B(95.08%)and tet M(91.80%).According to MLST,61 strains showed 34 sequence types.The 34 sequences formed 5clone complexes and 20 independent sequences.The proportion of each sequence type was:ST631,11.5%(7 strains);ST634,8.2%(5 strains);ST4,ST480 and ST758,6.6%(4 strains each);ST10,ST32,ST195,ST257,ST314,ST363 and ST968,3.3%(2 strains each)ST16,ST33,ST38,ST49,ST59,ST69,ST80,ST143,ST169,ST198,ST251,ST256,ST262,ST265,ST452,ST476,ST479,ST650,ST689,ST736,ST862 and ST991,1.6% respectively,and the dominant sequence types were ST631,ST634.In conclusion,dozens of E.faecalis were isolated from chickens in Tai'an area.The drug resistance and their relevant genes were analyzed.Our results provided the epidemiological data for risk analysis of foodborne bacteria and antimicrobial resistance in poultry farms in Shandong province. |
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