Kawanishi M, Kojima A, Ishihara K, Esaki H, Kijima M, Takahashi T, Suzuki S, Tamura Y
National Veterinary Assay Laboratory, Ministry of Agriculture, Forestry and Fisheries, Tokyo, Japan.
Lett Appl Microbiol. 2005;40(5):322-8. doi: 10.1111/j.1472-765X.2005.01690.x.
To investigate the existing antimicrobial susceptibility and genetic characteristics of Lactococcus garvieae isolates from cultured Seriola in Japan.
Minimum inhibitory concentrations (MICs) of 14 antimicrobial agents for 170 isolates were determined using the agar dilution method. Seventy-five isolates (44.1%) were simultaneously resistant to erythromycin (EM) (MIC>or=2 microg ml-1), lincomycin (LCM) (MIC>or=128 microg ml-1) and oxytetracycline (OTC) (MIC>or=4 microg ml-1). Resistance to EM was grouped as intermediate- and high-level resistant by MIC values. All resistant isolates possessed ermB and tet(S) genes. The number of different bands between pulsed-field gel electrophoresis patterns of 25 isolates and two ATCC strains (isolated in 1974), determined using two enzymes (ApaI and SmaI), did not exceed 3.
The present resistance pattern observed with ermB and tet(S) is similar to that observed in previous reports. Moreover, the genetic characteristics of L. garvieae isolates from a wide area in Japan in 2002 and ATCC strains were closely related.
This study suggests that EM-, LCM- and OTC-resistant isolates have been present for 15 years and that L. garvieae strains with same origin have spread among Seriola spp. in Japan since 1974.
调查从日本养殖的黄条鰤中分离出的格氏乳球菌的现有抗菌药敏性和遗传特征。
采用琼脂稀释法测定了14种抗菌药物对170株分离菌的最低抑菌浓度（MIC）。75株分离菌（44.1%）同时对红霉素（EM）（MIC≥2μg/ml）、林可霉素（LCM）（MIC≥128μg/ml）和土霉素（OTC）（MIC≥4μg/ml）耐药。根据MIC值将对EM的耐药分为中度和高度耐药。所有耐药分离菌均携带ermB和tet(S)基因。使用两种酶（ApaI和SmaI）对25株分离菌和两株ATCC菌株（1974年分离）的脉冲场凝胶电泳图谱之间不同条带的数量不超过3条。
目前观察到的ermB和tet(S)耐药模式与以往报道相似。此外，2002年从日本广大地区分离的格氏乳球菌分离菌与ATCC菌株的遗传特征密切相关。
本研究表明，对EM、LCM和OTC耐药的分离菌已经存在15年，并且自1974年以来，同源的格氏乳球菌菌株已在日本的黄条鰤属中传播。
