Kim Young-Hwa, Jun Lyu Jin, Park Shin-Hoo, Yoon So Hye, Chung Joon Ki, Kim Jae Cherl, Jeong Hyun Do
Department of Aquatic Life Medicine, Pukyong National University, 599-1 Dae Yeon Dong, Nam Ku, Busan 608-737, South Korea.
Dis Aquat Organ. 2007 May 9;75(3):209-16. doi: 10.3354/dao075209.
Of 24 tetracycline(Tc)-resistant Vibrio spp. isolated from different marine sources in Korea between 1993 and 2003, 23 were identified as carrying both tet(B) and tet(M), while 1 strain carried tet(B) only. In conjugation experiments, 3 strains appeared to be able to transfer both tet(B) and tet(M) to the recipient. Both discriminatory PCR and sequence analysis showed that tet(M) genes of Vibrio spp. appear to be a single allele containing a specific region of tet(M) in Tn1545. However, erm(B) and aphA3, known to be linked to Tn1545-like genes, were not detected in Tc-resistant Vibrio spp., even in 9 strains resistant to erythromycin. In analysis to examine the relative position of tet(B) and tet(M), it was shown that tet(M) was present at the 3'-end of the insertion sequence IS10 of Tn10 carrying tet(B). At the junctional region between Tn10 and tet(M), we found a 14 bp sequence of unknown function and the deletion of regulatory sequences reported to be needed for tet(M) expression in conjugative transposons. This is the first report of the simultaneous presence of tet(B) and tet(M), and of the tet(M) gene being linked to the 3'-end of Tn10 in Tc-resistant Vibrio spp. in Korea.
1993年至2003年期间，从韩国不同海洋来源分离出24株四环素（Tc）抗性弧菌属菌株，其中23株被鉴定为同时携带tet（B）和tet（M），而1株仅携带tet（B）。在接合实验中，3株菌株似乎能够将tet（B）和tet（M）都转移给受体。鉴别性PCR和序列分析均表明，弧菌属菌株的tet（M）基因似乎是一个单一等位基因，包含Tn1545中tet（M）的一个特定区域。然而，即使在9株对红霉素耐药的Tc抗性弧菌属菌株中，也未检测到已知与Tn1545样基因相关的erm（B）和aphA3。在检查tet（B）和tet（M）相对位置的分析中，结果表明tet（M）存在于携带tet（B）的Tn10插入序列IS10的3'端。在Tn10和tet（M）的连接区域，我们发现了一个14 bp的功能未知序列，并且缺失了据报道在接合转座子中tet（M）表达所需的调控序列。这是韩国关于Tc抗性弧菌属菌株中tet（B）和tet（M）同时存在以及tet（M）基因与Tn10的3'端相连的首次报道。
