Yazdankhah Siamak P, Asli Anette W, Sørum Henning, Oppegaard Hanne, Sunde Marianne
Department of Food Safety and Infection Biology, The Norwegian School of Veterinary Science, Oslo, Norway.
J Antimicrob Chemother. 2006 Dec;58(6):1254-6. doi: 10.1093/jac/dkl418. Epub 2006 Oct 23.
The aim of this study was to determine the occurrence of fusidic acid resistance, mediated by the fusB gene, among coagulase-negative staphylococci (CoNS) isolated from bovine mastitis.
A total of 113 CoNS isolates were screened for susceptibility to fusidic acid by using a disc diffusion method. The fusB gene was detected by using PCR and subsequent DNA sequencing. The localization of fusB was determined by hybridization.
The fusB gene was detected in 3 of 11 fusidic acid-resistant bovine CoNS isolates. The organization of the fusB downstream region on a 40 kb plasmid in a Staphylococcus haemolyticus isolate (288/96) was highly similar to the previously reported organization of fusB on plasmid pUB101 from a Staphylococcus aureus isolate of human origin. The fusB gene was chromosomally located in the remaining two isolates.
Fusidic acid resistance mediated by fusB is not the dominant resistance mechanism in fusidic acid-resistant CoNS studied in this work. The similarity between the organization of the fusB downstream region in S. haemolyticus (isolate 288/96) and on plasmid pUB101 from an S. aureus isolate of human origin indicates a common ancestral origin of these genes.
本研究旨在确定从牛乳腺炎分离出的凝固酶阴性葡萄球菌（CoNS）中由fusB基因介导的夫西地酸耐药性的发生率。
采用纸片扩散法对113株CoNS分离株进行夫西地酸敏感性筛选。通过PCR及后续DNA测序检测fusB基因。通过杂交确定fusB的定位。
在11株对夫西地酸耐药的牛CoNS分离株中，有3株检测到fusB基因。溶血葡萄球菌分离株（288/96）中40 kb质粒上fusB下游区域的结构与先前报道的来自人源金黄色葡萄球菌分离株质粒pUB101上fusB的结构高度相似。在其余两株分离株中，fusB基因位于染色体上。
在本研究中，fusB介导的夫西地酸耐药性并非夫西地酸耐药CoNS的主要耐药机制。溶血葡萄球菌（分离株288/96）中fusB下游区域的结构与来自人源金黄色葡萄球菌分离株的质粒pUB101上fusB的结构相似，表明这些基因有共同的祖先起源。
