Fletcher H M, Macrina F L
Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond 23298-0678.
Antimicrob Agents Chemother. 1991 Nov;35(11):2415-8. doi: 10.1128/AAC.35.11.2415.
We have examined 13 clinical isolates of the intestinal Bacteroides group using DNA probes representing Bacteroides macrolide-lincosamide-streptogramin B (MLS) (ermF) and tetracycline resistance (tetQ) determinants as well as an insertion sequence (IS4351) previously seen in association with erm genes. tetQ-hybridizing sequences were detected in 11 of 13 tetracycline-resistant clinical isolates. On the other hand, ermF-like sequences were detected in only three of eight clindamycin-resistant strains. One isolate displayed low-level, inducible resistance to clindamycin and was sensitive to erythromycin. This same isolate had IS4351-like sequences but was missing ermF-like sequences, in contrast to previous reports which demonstrated the common association of IS4351 and erm genes. Our results suggest the occurrence of unclassified MLS genes in the Bacteroides group and furthermore suggest that IS4351-like sequences are not always linked to Bacteroides ermF-like sequences. Finally, 4 of 13 isolates conjugally transferred tetracycline resistance or linked tetracycline-clindamycin (MLS) resistances, but this process did not involve plasmids.
我们使用代表拟杆菌属大环内酯 - 林可酰胺 - 链阳菌素B（MLS）（ermF）和四环素抗性（tetQ）决定簇的DNA探针以及先前发现与erm基因相关的插入序列（IS4351），对13株肠道拟杆菌属临床分离株进行了检测。在13株四环素抗性临床分离株中，有11株检测到tetQ杂交序列。另一方面，在8株克林霉素抗性菌株中，只有3株检测到ermF样序列。一株分离株对克林霉素表现出低水平的诱导抗性，对红霉素敏感。与先前报道显示IS4351和erm基因常见关联相反，该分离株具有IS4351样序列，但缺少ermF样序列。我们的结果表明拟杆菌属中存在未分类的MLS基因，并且进一步表明IS4351样序列并不总是与拟杆菌属ermF样序列相连。最后，13株分离株中有4株通过接合转移了四环素抗性或连锁的四环素 - 克林霉素（MLS）抗性，但这一过程不涉及质粒。
