title: Mutations in rrs, rpsL and gidB in streptomycin-resistant Mycobacterium tuberculosis isolates from Thailand.
abstract: The objectives of this study were to characterise mutations in rrs, rpsL and gidB genes in Mycobacterium tuberculosis isolates from Thailand and to examine possible associations between mutations and strain genotypes. In total, 110 streptomycin (STR)-resistant M. tuberculosis isolates and 51 STR-susceptible isolates obtained from a sample collection in Thailand during 1999-2011 were sequenced for mutation analysis in rrs, rpsL and gidB. Genotypes of the isolates were identified using spoligotyping and large sequence polymorphisms. Mutations at codons 43 and 88 in rpsL represented 63.6% of the STR-resistant isolates and were mostly associated with Beijing strains. Mutations in rrs existed in 17.3% of the STR-resistant isolates; only 8.2% harboured resistance-associated mutations. Twenty-five different mutations were found in gidB, twelve of which are new. Eight gidB mutations were likely to contribute to STR resistance in ca. 14% of the resistant isolates; about one-half of the isolates also had a mutation in rrs or rpsL. Nearly all of the double mutants belonged to Beijing strains, whereas isolates carrying only STR-associated gidB mutation were non-Beijing strains. Three different alleles in gidB were also found, each specific to Beijing, East-African Indian and Euro-American lineages, respectively. Most of the STR-resistant isolates (80.9%) carried putative resistance-associated mutations in the analysed genes. Beijing strains were related not only to single resistance-associated mutations in rpsL or rrs but usually harboured a second mutation in gidB. Strains harbouring resistance-associated gidB mutations without rrs or rpsL mutations were more associated with non-Beijing isolates. Certain gidB mutations were also potential lineage markers.
authors.affiliation: Tuberculosis Research Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand. Electronic address: nat.smi@biotec.or.th.
authors.forename: Nat
authors.initials: N
authors.lastname: Smittipat
authors.affiliation: Tuberculosis Research Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand.
authors.forename: Tada
authors.initials: T
authors.lastname: Juthayothin
authors.affiliation: Tuberculosis Research Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand.
authors.forename: Pamaree
authors.initials: P
authors.lastname: Billamas
authors.affiliation: Tuberculosis Research Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand.
authors.forename: Sarinya
authors.initials: S
authors.lastname: Jaitrong
authors.affiliation: Mahidol University Amnat Charoen Campus, Amnat Charoen, Thailand.
authors.forename: Kamolchanok
authors.initials: K
authors.lastname: Rukseree
authors.affiliation: Tuberculosis Research Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand.
authors.forename: Kanchana
authors.initials: K
authors.lastname: Dokladda
authors.affiliation: TB/HIV Research Project, Research Institute of Tuberculosis, Chiang Rai, Thailand.
authors.forename: Boonchai
authors.initials: B
authors.lastname: Chaiyasirinroje
authors.affiliation: Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Areeya
authors.initials: A
authors.lastname: Disratthakit
authors.affiliation: Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Angkana
authors.initials: A
authors.lastname: Chaiprasert
authors.affiliation: Medical Genetics Section, Department of Medical Science, National Institute of Health, Ministry of Public Health, Nonthaburi, Thailand.
authors.forename: Surakameth
authors.initials: S
authors.lastname: Mahasirimongkol
authors.affiliation: Fukujuji Hospital, Japan Anti-tuberculosis Association, Kiyose, Tokyo, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Yanai
authors.affiliation: TB/HIV Research Project, Research Institute of Tuberculosis, Chiang Rai, Thailand; Research Institute of Tuberculosis, Japan Anti-tuberculosis Association, Tokyo, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Yamada
authors.affiliation: Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Katsushi
authors.initials: K
authors.lastname: Tokunaga
authors.affiliation: Tuberculosis Research Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand; Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Prasit
authors.initials: P
authors.lastname: Palittapongarnpim
mesh_terms: D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D005838:Genotype; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D013307:Streptomycin / Q000494:pharmacology*; D013785:Thailand
chemical_list: D013307:Streptomycin
keywords: Chromosomal mutations; Mycobacterium tuberculosis; Streptomycin resistance; gidB; rpsL; rrs