ABSTRACT
Objective@#To investigate whether plague phages were present in the indicator animals of plague foci in Yunnan Province, and to explore their epidemiological significance.@*Methods@#Anus swabs were collected from indicator animals (dogs or cats) of the 41 plague affected villages in 26 towns of 10 cities (counties, districts) of Yunnan plague foci from November of 2015 to March of 2018. The Yersinia pestis phages were isolated by plague vaccine strain EV76. The isolation of plague phages from different plague foci, the isolation of plague phages from different canine species (cats), the polymorphism of plaque and the host spectrum of phages were analyzed.@*Results@#A total of 1 014 indicator animals (1 003 dogs and 11 cats) were studied, and 102 of plague phages were isolated. In the 10 cities (counties, districts), plague phages were only not isolated from Lancang County, and the plague phages were isolated from the other 9 cities (counties, districts). The separation rates from high to low were as follows: Yiliang County (21.00%, 21/100), Menghai County (19.23%, 25/130), Yuanjiang County (11.63%, 10/86), Midu County (11.50%, 13/113), Wenshan County (10.10%, 10/99), Mile Country (7.07%, 7/99), Lianghe County (6.67%, 7/105), Baoshan Longyang District (4.90%, 5/102) and Gengma County (3.81%, 4/105). Of the 102 plague phages, 75 were isolated from the native dogs (Chinese pastoral dogs, 9.32%, 75/805), 20 from the pug dogs (13.70%, 20/146), 5 from the wolf dogs (17.24%, 5/29), 1 from Samoye (1/4) and 1 from Alaska dog (1/2). The plaque of the phage was divided by five appearance of complete lysis (the plate was clear), large (2.5-4.0 mm), big (1.5-< 2.5 mm), middle (0.5-< 1.5 mm) and small (< 0.5 mm). The representative phages were all of the Myoviridae family. Most of the phages could lysis the strains of Yersinia pestis, and some phages could lysis Shigella and type 5 Yersinia pseudotuberculosis (PST5).@*Conclusion@#The plague phages are present in the plague foci of Yunnan, and the phages are polymorphic.
ABSTRACT
Objective To investigate whether plague phages were present in the indicator animals of plague foci in Yunnan Province,and to explore their epidemiological significance.Methods Anus swabs were collected from indicator animals (dogs or cats) of the 41 plague affected villages in 26 towns of 10 cities (counties,districts) of Yunnan plague foci from November of 2015 to March of 2018.The Yersinia pestis phages were isolated by plague vaccine strain EV76.The isolation of plague phages from different plague foci,the isolation of plague phages from different canine species (cats),the polymorphism of plaque and the host spectrum of phages were analyzed.Results A total of 1 014 indicator animals (1 003 dogs and 11 cats) were studied,and 102 of plague phages were isolated.In the 10 cities (counties,districts),plague phages were only not isolated from Lancang County,and the plague phages were isolated from the other 9 cities (counties,districts).The separation rates from high to low were as follows:Yiliang County (21.00％,21/100),Menghai County (19.23％,25/130),Yuanjiang County (11.63％,10/86),Midu County (11.50％,13/113),Wenshan County (10.10％,10/99),Mile Country (7.07％,7/99),Lianghe County (6.67％,7/105),Baoshan Longyang District (4.90％,5/102) and Gengma County (3.81％,4/105).Of the 102 plague phages,75 were isolated from the native dogs (Chinese pastoral dogs,9.32％,75/805),20 from the pug dogs (13.70％,20/146),5 from the wolf dogs (17.24％,5/29),1 from Samoye (1/4) and 1 from Alaska dog (1/2).The plaque of the phage was divided by five appearance of complete lysis (the plate was clear),large (2.5-4.0 mm),big (1.5-＜ 2.5 mm),middle (0.5-＜ 1.5 mm) and small (＜ 0.5 mm).The representative phages were all of the Myoviridae family.Most of the phages could lysis the strains of Yersinia pestis,and some phages could lysis Shigella and type 5 Yersinia pseudotuberculosis (PST5).Conclusion The plague phages are present in the plague foci of Yunnan,and the phages are polymorphic.
ABSTRACT
Objective To establish a real-time quantitative PCR (RT-PCR) preliminary screening method for rapid detection of Brucella.Methods Based on the nucleotide sequence encoding Brucella's outer membrane proteins omp10 and omp31,four primers and probes of omp10,omp10-1,omp31 and omp31-1 were designed.The primers and probes were used to detect 19 strains of 6 categories of Brucella DNA of known organisms,10 strains of Brucella DNA that were isolated from Yuxi of Yunnan.And 224 negative Brucella DNA,including 35 strains of Bartonella DNA,103 strains of the Lord Komori enterocolitis DNA (including 4 parts of O ∶ 3 and 9 parts of O ∶ 9) and 86 samples of hybrids bacteria DNA.Then the specificity of primers and probes were evaluated based on the test results.Results The DNA of 19 standard Brucella strains could be amplified by omp10 and omp10-1,and the peak time and amplification curve of omp10 is better than omp10-1,and the DNA of negative control strains could not be amplified by omp10.The DNA of 16 standard Brucella strains could be amplified by omp31-1.The DNA of standard Brucella strains could not be amplified by omp31.The average Ct values of 10 strains of Brucella DNA which were isolated from Yuxi of Yunnan that were detected by omp10,omp10-1 and omp31-1 respectively were 19.87,19.14 and 17.52.Conclusion Omp10 has strong specificity and only specific for Brucella,so it can be used for rapid detection of Brucella.