title: Molecular mechanisms of high level tetracycline-resistance in group A streptococcal isolates, T serotypes 4 and 11.
abstract: The molecular mechanism of high level tetracycline resistance in T serotypes 4 and 11 group A streptococcal (GAS) isolates was examined in 61 tetracycline-resistant isolates in Japan. PCR and sequencing analyses revealed that the T serotype/emm genotype, T4/4 isolates carried tet(O) genes, which were genetically homogenous. The T11/11 and T11/89 isolates carried different subtypes of tet(M) genes, which were present on transposons Tn916 and Tn1545, respectively. In addition, these T11 isolates may have obtained the tet(M) gene after the 1990s, because resistance to tetracycline in T11 isolates was rarely found before then. These results strongly suggested that the T4 and T11 GAS isolates acquired tetracycline-resistance via different molecular mechanisms.
authors.affiliation: Department of Microbiology, Aichi Prefectural Institute of Public Health, Nagoya 462-8576, Japan. eiseiken@pref.aichi.lg.jp
authors.forename: Masakado
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Sakae
authors.forename: Michio
authors.initials: M
authors.lastname: Ohta
authors.forename: Miyoko
authors.initials: M
authors.lastname: Endo
authors.forename: Rumi
authors.initials: R
authors.lastname: Okuno
authors.forename: Shoko
authors.initials: S
authors.lastname: Murayama
authors.forename: Kyoko
authors.initials: K
authors.lastname: Hirasawa
authors.forename: Rieko
authors.initials: R
authors.lastname: Suzuki
authors.forename: Junko
authors.initials: J
authors.lastname: Isobe
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tanaka
authors.forename: Chihiro
authors.initials: C
authors.lastname: Katsukawa
authors.forename: Aki
authors.initials: A
authors.lastname: Tamaru
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tomita
authors.forename: Kikuyo
authors.initials: K
authors.lastname: Ogata
authors.forename: Tomihisa
authors.initials: T
authors.lastname: Yasuoka
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Ikebe
authors.forename: Haruo
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D004251:DNA Transposable Elements; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013297:Streptococcus pyogenes / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D013753:Tetracycline Resistance / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D004251:DNA Transposable Elements; C083138:Tet M resistance protein, Bacteria; C083139:Tet O resistance protein, Bacteria