Comparative molecular-genetic typing of Brucella strains isolated in Mongolia from different animal species as well as from humans.
Twenty-one strains of Brucella isolated from different hosts in 7 provinces of Mongolia were typed. Conventional phenotypic methods, genotyping by PCR with primers for genus- and species-specific differentiating targets of Brucella genes as well as multiple locus variable number tandem repeats analysis (MLVA) with 12 pairs of primers bounding locus variable tandem repeats of different length (from 134 bp to 8 bp).
Phenotypic identification and genotyping by PCR using primers for differentiating DNA markers allowed to attribute 14 isolates to B. melitensis biovar 2, and 7 - to B. abortus biovar 3. By using the MLVA method, connection of MLVA genotypes of 9 Brucella isolates with their reservoir hosts (sheep, cows) was shown providing their circulation in Khentii, Bulqan, and Khubsgul provinces bordering with Russia. Nine isolates from different hosts (camel, yaks, goats, sheep) isolated in Ovorkhangai, Dundgovi, and Dornogovi provinces, which have not border with Russia, had closely related MLVA genotypes indicating an opportunity of migration of pathogenic Brucella species to not-typical hosts.
Molecular-genetic typing of Brucella isolated in Mongolia was done for the first time; levels of their genetic relation and diversity were demonstrated. Circulation of Brucella isolated with specific MLVA genotypes was connected to territories of specific Mongolian provinces. The study proved migration of Brucella to not-typical hosts. Comparative study of isolates circulating in frontier with Mongolia areas of Russia (Irkutsk region, Tyva and Buryat Republics) are necessary to perform.
The northern fur seal (Callorhinus ursinus) is an important cultural and nutritional resource for the Aleut community on St. Paul Island Alaska. In recent years, an increasing number of zoonotic pathogens have been identified in the population, but the public health significance of these findings is unknown. To determine the prevalence of Coxiella burnetii and Brucella spp. in northern fur seal tissues, eight tissue types from 50 subsistence-harvested fur seals were tested for bacterial DNA by real-time polymerase chain reaction.
Of the 400 samples tested, only a single splenic sample was positive for Brucella spp. and the cycle threshold (ct) value was extremely high suggesting a low concentration of DNA within the tissue. C. burnetii DNA was not detected.
Findings suggest that the risk of humans contracting brucellosis or Q fever from the consumption of harvested northern fur seals is low.