Ohta T, Dairi T, Hasegawa M
Tokyo Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., Tokyo, Japan.
J Gen Microbiol. 1993 Mar;139(3):591-9. doi: 10.1099/00221287-139-3-591.
Fortimicin-A (FTM-A; astromicin)-resistance genes (fmr genes) isolated from six producers of the FTM-group of antibiotics were analysed. These genes could be classified into two types by the resistance profiles to aminoglycoside antibiotics and by their DNA homologies. Three genes, fmrT from the istamycin producer Streptomyces tenjimariensis ATCC 31603, fmrS from the sannamycin producer Streptomyces sannanensis IFO 14239 and fmrH from the sporaricin producer Saccharopolyspora hirsuta ATCC 20501, conferred resistance to FTM-A, kanamycin (Km) and neomycin B (Nm-B), but not to gentamicin (Gm). The other three genes, fmrO from the FTM-A producer Micromonospora olivasterospora ATCC 21819, fmrM from the antibiotic SF-2052 producer Micromonospora sp. SF-2098 (ATCC 31580) and fmrD from the dactimicin producer Dactylosporangium matsuzakiense ATCC 31570, conferred resistance to FTM-A, Km and Gm, but not to Nm-B. No DNA homology was detected between the two types of the resistance genes in Southern-blot analysis. The present results revealed that, in spite of the similarity of their biosynthesis genes, there are at least two different types of resistance genes among the FTM-group antibiotic producers.
对从六种福提霉素类抗生素产生菌中分离得到的福提霉素A（FTM-A；阿司米星）抗性基因（fmr基因）进行了分析。根据对氨基糖苷类抗生素的抗性谱及其DNA同源性，这些基因可分为两种类型。来自异他霉素产生菌天城链霉菌ATCC 31603的fmrT、来自三amycin产生菌三南链霉菌IFO 14239的fmrS以及来自sporaricin产生菌赫氏糖多孢菌ATCC 20501的fmrH这三个基因赋予对FTM-A、卡那霉素（Km）和新霉素B（Nm-B）的抗性，但对庆大霉素（Gm）无抗性。另外三个基因，来自FTM-A产生菌橄榄色小单孢菌ATCC 21819的fmrO、来自抗生素SF-2052产生菌小单孢菌属SF-2098（ATCC 31580）的fmrM以及来自达克替米星产生菌松崎指孢囊菌ATCC 31570的fmrD，赋予对FTM-A、Km和Gm的抗性，但对Nm-B无抗性。在Southern杂交分析中，两种类型的抗性基因之间未检测到DNA同源性。目前的结果表明，尽管福提霉素类抗生素产生菌的生物合成基因相似，但在这些产生菌中至少存在两种不同类型的抗性基因。
