High genetic diversity of Mycobacterium tuberculosis concurrent with low genetic diversity among Mycobacterium bovis reveals their distribution patterns in northeast of Iran using ۲۴ loci MIRU-VNTR for the first time

Background and Aim : For the first time in Iran, Mycobacterium tuberculosis complex isolated from human and livestock populations, in the province of Khorasan Razavi, were simultaneously investigated using the standard ۲۴ loci MIRU-VNTR. The aim of this study was to evaluate the genetic diversity of Mycobacterium tuberculosis complex (Tuberculosis and Bovis).Methods : One hundred and twenty Mycobacterium tuberculosis were collected a year period. A total of ۱۲۳ samples from lymph nodes and tissues of reactor cattles were collected. All samples were then cultured in pyruvate and glycerol enriched Lowenstein Jensen media. To extract the DNA, boiling method was used. The ۲۴-loci MIRU-VNTR was performed for all Mycobacterium tuberculosis and bovis.Results : Among ۱۲۰ investigated isolates, detected patterns included genotypes NEW-۱ (۵۳.۳%), CAS/ Delhi (۲۴.۱%), Haarlem (۵%), Beijing (۴.۱۶%), Uganda I (۴.۱۶%), S (۳.۳%), Ural (۰.۸۳%), TUR (۰.۸۳%), Uganda II (۰.۸۳%), Lam (۰.۸۳%) and Cameroon (۰.۸۳%). The HDGI rate was ۰.۹۹۸۱ and the rate of clustering was ۱۰.۸۳%. In addition, recent TB transmission rate was ۶.۶۶%. The allele diversity was high in ۶ loci, moderate in ۱۰ loci and the rest of the loci showed a low allele diversity. QUB۲۶ had the highest allele diversity (h: ۰.۷۶) and the loci Mtub۲۹ and MIRU۲۴ had the lowest (h: ۰). Among ۱۲۳ collected tissue samples, ۲۱ (۱۷%) grew on the culture media. The HGDI rate was ۰.۷۱ and the rate of clustering was ۸۵.۷%. Also, recent bovine tuberculosis transmission rate was estimated to be ۷۱.۴%. Two loci had moderate allele diversity and other loci had low allele diversity. The locus ETRC had the highest allele diversity (h: ۰.۴۵). Conclusion : Since results suggest a high diversity in circulating Mycobacterium tuberculosis in human population, latent infections are reactivated. Thus, screening and treating individuals with latent tuberculosis is important in decreasing tuberculosis outbreaks. Moreover, the highest number of tuberculosis cases in livestock population are caused as a result of recent transmission, which makes it advisable for cattle farms to be under the supervision of veterinary organization for performing periodic tuberculin tests and eliminating reactor cattle to prevent the spread of the disease.

کلیدواژه ها:

Tuberculosis ، Mycobacterium tuberculosis ، Mycobacterium bovis ، MIRU-VNTR