ABSTRACT
Objective To analyze the etiological characteristics of human Brucella strains isolated, and to improve the precision in control and prevention of brucellosis. Methods In 2016, blood samples were collected from patients in Jingyuan County Gansu Province, and tested via the Rose-Bengal Plate Agglutination Test (RBPT) and the tube agglutination test methods,and serological positive blood samples were inoculated to bidirectional blood culture bottle for culturing, and further identified by traditional biological classification method and the Brucella abortus, Brucella melitensis, Brucella ovis, and Brucella suis species-specific PCR (AMOS-PCR). Multiple-locus variable number tandem repeat sequence analysis (MLVA) -16 was used to detect molecular typing and do cluster analysis. Results The isolated strain was identified by the traditional biological classification method, bacteria could grow in thionine and reddened dye, A and M factors agglutination tests were positive, Bk2phage treatment of bacterial strain cracking, but Tb, Wb phages were not cracked. AMOS-PCR amplification result showed a 731 bp band, which was a strain of Brucella melitensis. The results of MLVA-16 showed that there was a difference in the number of repeats on some Variaable Number of Tandem Repeat(VNTR)sites of the isolated strain. Clustering analysis showed that, the isolated strain was clusted into the same clade with the clustering of Brucella melitensis type 3 from GS-201605 in Gansu. And the clustering was similar compared with that of Zhejiang, Guangdong, Fujian and Yunnan. Conclusion Human brucellosis is a inputting transmission in Gansu Province, there is a genetic variation of genotype 3 sheep Brucella between Gansu Province and other domestic provinces.
ABSTRACT
Objective To identify the Brucella strains isolated from sheep blood in Jingyuan County Gansu Province,and to provide scientific basis for Brucellosis control and prevention.Methods In 2016,blood samples from suspected cases of sheep were collected in the home of Brucellosis patient of Jingyuan County,and cultured with vaccination double blood bottles via the enrichment method,and the Brucella strains isolated from sheep were identified by traditional bio-typing,genus specific Brucella surface protein 31 PCR (BSCP31-PCR) and Brucella abortus,Brucella melitensis,Brucella ovis,Brucella suis species-specific PCR (AMOS-PCR),respectively.Results The isolated strain was identified using the traditional biological classification method,bacteria could grow in thionine and fuchsin dyes,A and M factors serum agglutination tests were positive,Bk2 phage lysis test was positive,but Tb and Wb phage lysis tests were negative;and the results of BSCP31-PCR of tested strain was 223 bp band same to Brucella;the results of AMOS-PCR was 731 bp band same to Brucella melitensis.Conclusion Conventional bio-typing test assisted with molecular techniques has confirmed that the isolated Brucella strain from sheep blood is Brucella melitensis type 3 in Jingyuan County Gansu Province.
ABSTRACT
Objective To investigate influencing factors of brucellosis infection in occupational population in Gansu Province.Methods In Jingyuan County of Gansu Province,using the case-control method,the cases were collected through "National Disease Surveillance Information Reporting Management System",the case group was confirmed as brucellosis professionals after laboratory tests were positive in 2013-2015 (203 cases),and the control group was confmmed as occupations without brucellosis (809 cases) in the same periods.Information on general sociological characteristics and occupational exposure characteristic was collected,non-conditional Logistic regression analysis was used for analyzing influence factors of brucellosis.Results A total of 1 012 questionnaires were collected,among them,203 were case group and 809 were control group.Logistic regression analysis showed that,captive (OR =1.971,95％CI:1.193-3.256),type of water source (lage,OR =1.610,95％CI:1.392-1.950),often stripping the dead lamb (OR =2.027,95 ％ CI:1.272-3.231),processing abortion material (throwing away,feeding the dog,stripping;OR =2.120,1.176,2.160;95％CI:1.274-3.731,1.148-2.134,1.548-4.671),often eating dead meat (OR =2.497,95％CI:1.438-4.339),Hui nationality (OR =1.202,95％CI:1.061-1.995),household income less than 10 000 yuan (OR =3.857,95％CI:1.593-9.336),work experience 1-4 years (OR =2.892,95％CI:1.838-4.552) were major risk factors for occupational persons suffering from brucellosis.Livestock was sheep or sheep and goats (OR =0.412,0.277,95％CI:0.217-0.782,0.107-0.720),married(OR =0.124,95％CI:0.016-0.979),wearing gloves and mask when exposed to livestock or livestock lambing (OR =0.455,95％CI:0.230-0.899),and livestock vaccination (OR =0.283,95％CI:0.107-0.747) were protective factors for occupational infection of brucellosis.Conclusions The poor living habits and behaviors of professional people in Jingyuan County of Gansu Province are the main causes of the disease.Among them,captive,often stripping the dead lamb,processing abortion material,eating dead meat are the risk factors for brucella infection.Wearing masks and gloves when livestock lambing,and livestock vaccination are important means in avoiding brucellosis infection.