title: Screening for streptomycin resistance conferring mutations in Mycobacterium tuberculosis isolates from Iran.
abstract: Point mutations in the rpsL and rrs genes can lead to development of streptomycin (STR) resistance in Mycobacterium tuberculosis. The aims of this study were to determine the frequency of mutations in STR resistant M. tuberculosis isolates in Iran and to analyze the possible relationship between bacterial genotype and STR resistance. Twenty-three M. tuberculosis samples comprising 9 multidrug-resistant (MDR) and 14 non-MDR isolates, recovered from TB patients in four regions: Tehran (n = 14), Isfahan (n = 2), Zahedan (n = 2), and Khorasan (n = 5), were analysed. Mutational profiling was performed by sequencing of the rrs and rpsL genes and spoligotyping method was used for genotyping. Nineteen isolates were resistant to STR, among them 7 exhibited mutations in the rpsL gene and 7 had mutations in the rrs gene. The remaining 5 STR resistant as well as all susceptible isolates lacked any mutation in both genes. Beijing genotype was associated with both MDR and STR resistance in which all mutations occurred at codon 43 of the rpsL gene. There was an association between mutations in the rpsL and rrs genes and STR resistance. We also found a correlation between Beijing genotype and STR resistance.
authors.affiliation: a Department of Microbiology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Faranak
authors.initials: F
authors.lastname: Rezaei
authors.affiliation: b Department of Biology, Faculty of Natural Sciences , University of Tabriz , Tabriz , Iran.
authors.forename: Mehri
authors.initials: M
authors.lastname: Haeili
authors.affiliation: c Applied Microbiology Research Center , Baqiyatallah University of Medical Sciences , Tehran , Iran.
authors.forename: Abbasali
authors.initials: A
authors.lastname: Imani Fooladi
authors.affiliation: d Department of Microbiology and Virology , Mashhad University of Medical Science , Mashhad , Iran.
authors.forename: Gholam Ali
authors.initials: GA
authors.lastname: Azari Garmjan
authors.affiliation: a Department of Microbiology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Mohammad Mehdi
authors.initials: MM
authors.lastname: Feizabadi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004252:DNA Mutational Analysis; D024881:Drug Resistance, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D005838:Genotype; D006801:Humans; D007492:Iran; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D013307:Streptomycin / Q000494:pharmacology; D014376:Tuberculosis / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D013307:Streptomycin
keywords: Mycobacterium tuberculosis; Spoligotyping; Streptomycin; rpsL; rrs