| Salmonella and Campylobacter are both of the most important zoonotic pathogens,causing great harm to human health worldwide,which widely spread in humans,pets,livestock,poultry and so on.Poultry is the most common host of Salmonella and Campylobacter,intimate contact with pets has been considered to be an important source of human infections with Salmonella and Campylobacter.Therefore,strengthening the control of Campylobacter and Salmonella in pets is significantly for the prevention of human campylobacteriosis and salmonellosis.The main objectives of this study were followed:(1)investigating the distributions and epidemiological characteristics of Campylobacter and Salmonella in pets,human beings and poultry in Yangzhou,tracing back to the pet family and exploring the role of pets played in human infection.(2)MLST typing the isolates isolated from different sources,in order to elucidate the intrinsic relationship of Campylobacter and Salmonella between pets and other sources,and then based on the international strains data in PubMLST database,analyzing the clonal population of Campylobacter at home and abroad.1.Epidemiological researches on Campylobacter and Salmonella from pets and other sources in YangzhouFrom July 2015 to September 2016,we collected 607 rectal cotton swabs of pet and 97 liver and intestine samples of sick poultry in Animal Hospital of Yangzhou University randomly,204 fecal samples of diarrhea people in hospital A in Yangzhou,and a total of 354 samples from the live-poultry market and three Agricultural Market.Besides,we have also collected 333 samples from the pet-keeping families.According to the national standard method,Campylobacter and Salmonella were isolated and identified.Results of Campylobacter prevalence were:25 strains of Campylobacter jejuni and 8 strains of Campylobacter coli were isolated in pet samples collected from animal hospital,with the positive rates were 4.1%and 1.3%,respectively(P<0.05).The detection rate of Campylobacter was higher in juvenile pet(1 year old)than in adult pet(P<0.05).The results showed that the positive rate of Campylobacter was significantly higher than that of adult pet(P<0.05).No significant difference was founded in the detection rate of Campylobacter between different sexes(P>0.05).There were 11(5.4%)strains of Campylobacter jejuni isolated from the diarrhea people in hospital A,while the positive rate of Campylobacter coli was 2.5%with 5 strains.16 strains of Campylobacter jejuni and 29 strains of Campylobacter coli were isolated from poultry samples,which positive rates were 16.5%and 29.9%,respectively.10 samples were co-infected by Campylobacter jejuni and Campylobacter coli,and the rate of mixed infection was 10.3%.15.6%of the samples collected in live-poultry market were Campylobacter jejuni,while 8.8%of which were Campylobacter coli.37 cases of Campylobacter jejuni and 48 cases of Campylobacter coli were isolated in broiler carcass surface wipe samples,and the positive rates were 34.6%and 44.8%,among which 21 samples were Campylobacter jejuni and Campylobacter coli mixed infection,the positive rate was 19.6%.The results of Salmonella detection showed that 5 strains of Salmonella were isolated in pet samples from animal hospital,the positive rate was 2.5%.Among them,13 Salmonella strains were isolated out of 503 dogs,the positive rate was 2.6%,2 Salmonella strains were isolated out of 104 cats,the positive rate was 1.9%.A total of 11 strains of Salmonella were isolated from the samples of hospital diarrhea people,the positive rate was 5.4%.Results of classification statistics showed that the positive rate of Salmonella in women was higher than that in men,but the difference was not significant(P>0.05).The average positive rate of Salmonella was significantly higher in people under 14 years old than in people over 14 years old(P<0.05).A total of 31 isolates of Salmonella were detected in 451 poultry samples.The average positive rate was 6.9%.The results of Salmonella serotype identification showed that the distribution of serotypes of Salmonella isolates was more dispersed,including common serotypes such as S.Typhimurium,S.Enteritidis,S.Derby and S.London;rare domestic serotypes such as S.Fillmore,S.Dabou and other serotypes.The dominant serotype in different sources of isolates is varied while some serotypes were cross-distribution.Living with pets is at risk of the infection with Campylobacter and Salmonella,but there are few studies on the transmission of Campylobacter and Salmonella in pet-keeping families currently.In this study,the prevalence of Campylobacter and Salmonella in 25 pet-keeping families was investigated,and Campylobacter and Salmonella were detected from three families respectively.It is noteworthy that,in a family where a dog was infected by Campylobacter coli,and the bacteria was also detected out from a soil sample.Besides,one healthy pet owner was found to be mixed infected with Campylobacter jejuni and Salmonella Typhimurium,neither of Campylobacter or Salmonella were detected in the pet and family environment samples.Among the 1595 samples collected in this study,5 samples were Salmonella and Campylobacter mixed infection,the proportion of mixed infection was 0.31%.The results showed that there were co-infection with Campylobacter and Salmonella,but the co-infection rate was not high.2.Analysis on the epidemiological characteristics of Campylobacter and Salmonella isolates by MLSTIn order to clarify the intrinsic relationship of Campylobacter and Salmonella isolates between pet and other sources,and to understand the further possible pathways of Campylobacter and Salmonella in a pet family,we choose seven housekeeper gene(aspA,glnA,gltA,glyA,pgm,tkt and UncA)to typing the Campylobacter and Salmonella isolates from pet,human and poultry,which contains 195 strains of Campylobacter and 67 strains of Salmonella,The results of MLST typing showed that 195 isolates of Campylobacter were divided into 21 colonal complexes and unique ones,which contained 107 STs.There were 16 new sequence types,including 9 strains of Campylobacter jejuni and 9 strains of Campylobacter coli.The genetic relationship between the strains belonged to the same colonal complex is relatively close.In this study,bacteria with colonal complex accounted for 85.6%,bacteria belonging to the unique type accounted for 14.4%.The predominant colonal complex of Campylobacter jejuni is ST-353,the predominant ST of Campylobacter jejuni is ST-5;the predominant ST of Campylobacter coli is ST-830,and the isolates belonging to ST-828 clonal complex accounts for 92.6%of all.A total of 46 isolates from pets were typed to 28 STs,belonging to 11 clonal complexes and unique ones.The results of MLST typing of Campylobacter jejuni in this study were compared with the results of 130 strains of Campylobacter jejuni in the PubMLST database.The results showed that the clonal complex in this study is similar to the common clonal complexes in database,but only four sequence types are identical to that of the selected international strain,namely ST-22,ST-45,ST-48 and ST-13,and the remaining sequences were different,indicating that the distribution of Campylobacter jejuni was also has a regional characteristic.The distribution of STs in different strains of different years was also analyzed.It was found that the dominant ST type was different in the isolates of different years.The farther the year was,the less the same ST type isolates were.Results showed that there were 11 clonal complexes contained two or more strains,among which 10 strains were from pet.These isolates were similar to those in other clonal isolates,and were partially cross-linked,indicating that Campylobacter isolated from pet was closely related to other sources.Pet and poultry meat are the main sources of Campylobacter infection.Results of MLST typing of Campylobacter isolates showed that the isolates from pet dogs and grassland were both belonged to ST-830,indicating that the isolates from dog were closely related to the environmental samples.The results showed that in a family,when a dog infected with Campylobacter,bacteria can be discharged into environment through feces,which could probably result into human infection.Salmonella MLST results showed that 64 strains were divided into 21 different STs,The predominant ST is ST 314,accounting for 28.1%of the total,ST 292(12.5%),ST 34(12.5%)and ST 155(6.3%)were followed.Other STs distributions were scattered and sporadic.Partial ST cross-distributions were founded in three sources,such as ST14,ST34,and ST155.There was a close relationship between ST and serotype of Salmonella from different sources,and most of the serotypes had a corresponding relationship with STs.The results show that Salmonella is widespread in nature and can be transmitted in pets,humans and poultry. |
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