Genetic diversity based on ۲۴-locus MIRU-VNTR typing method among first and second line drugs-resistant Mycobacterium tuberculosis isolates in Isfahan, Iran

Background and Aim : We aimed to determine the genetic diversity of first and second-line drugs resistant Mycobacterium tuberculosis isolates based on ۲۴-locus MIRU-VNTR genotyping method in Isfahan, Iran.Methods : A set of ۴۸۲ patients with tuberculosis among referrals of Mollahadi Sabzevari Tuberculosis Center, Isfahan, Iran, from ۲۰۱۴ to ۲۰۱۷ were studied. Drug susceptibility testing was done for the first-line drugs (Isoniazid, Rifampin, and Ethambutol) on all culture-positive specimens and second-line drugs (Ofloxacin, Amikacin, Kanamycin, and Capreomycin) only on the multi-drug resistant (MDR) and rifampin-resistant (RR) isolates using the proportion method on the Lowen-stein Jensen medium according to the ۲۰۱۴ WHO guideline. We also did a similarity search and phylogenetic tree analysis based on the (http://www.miru-vntrplus.org) website.Results : Of ۴۸۲, ۳۲ (۶.۶۳%) isolates were resistant to the first-line drugs and ۱۳ (۲.۶%) MDR/RR isolates were also resistant to second-line drugs. Two lineages (Lineages ۳ and ۴) of seven global lineages was observed. Lineage ۳ including Delhi/CAS sub-lineage (n=۱۷; ۵۳.۱%), and lineage ۴ including NEW-۱ (n=۱۱; ۳۴.۳%), H۳۷Rv-like (n=۲; ۶.۲%), LAM (n=۱; ۳.۱%) and URAL (n=۱; ۳.۱%) sub-lineages identified among first-line drugs-resistant isolates and NEW-۱ (n=۶; ۴۶.۱%), Delhi/CAS (n=۵; ۳۸.۴%) and H۳۷Rv-like (n=۲; ۱۵.۳%) sub-lineages identified among second line drugs resistant isolates.Conclusion : We did not detect any XDR isolates; however, MDR and pre-XDR isolates were observed and can be alarming. Delhi/CAS and NEW-۱ genotypes were the most prevalent among first and second-line drugs resistant M. tuberculosis isolates, respectively. Also, the frequency of isoniazid-resistant isolates was significantly higher in Delhi/CAS genotype.

کلیدواژه ها:

Tuberculosis ، Drug resistance ، Iran ، Mycobacterium tuberculosis ، MIRU-VNTR