Walther Birgit, Friedrich Alexander W, Brunnberg Leo, Wieler Lothar H, Lübke-Becker Antina
Institut für Mikrobiologie und Tierseuchen, Fachbereich Veterinärmedizin, Freie Universität Berlin.
Berl Munch Tierarztl Wochenschr. 2006 May-Jun;119(5-6):222-32.
The problem of nosocomial infections is of increasing importance in veterinary medicine. As an example, this review summarizes current knowledge regarding methicillin-resistant Staphylococcus aureus (MRSA) as a typical example, as these pathogens are the most important agents of nosocomial infections in human medicine worldwide and are being increasingly reported in veterinary medicine. MRSA are classified by their ability to be resistant against oxacillin/methicillin, this feature being confered by mecA, a gene which was acquired by horizontal gene transfer of the staphylococcal gene cassette (SCCmec). It is this genetic information that enables MRSA to be resistant against all penicillins, cehalosporins and carbapenems. In addition, MRSA are often resistant against a variety of other antiinfectives, i.e. aminoglycosides, macrolides, lincosamide, streptomycins, tetracyclin, chloramphenicol, but also against fluorquinolones and rifampicin. Presumably, these highly adapted strains are particularly able to acquire resistance genes located on plasmids or transposons. They are also able to develop point mutations, further leading to resistant phenotypes. If these pathogens are leading to infectious diseases, veterinarians may be confronted with a worst-case scenario, being left without any antiinfective therapeutic. As Staphylococcus aureus is highly tenacid, professional hygiene management is of utmost importance. The increasing number of published sporadic MRSA infections, MRSA-infectious diseases as well as MRSA outbreaks in veterinary medicine justifies their recognition as a "New Emerging Pathogen". So far, horses and dogs are mostly affected by MRSA. Although transmission between humans and animals has been reported occasionally, the sources, routes of transmission or the epidemiological relevance of MRSA infections in animals are far from being understood. Therefore, epidemiological investigations utilizing molecular typing tools are mandatory. Typing tools like multilocus-sequence-typing (MLST), pulsefield-gelelectrophoresis (PFGE), sequence analysis of the gene encoding protein A (spa-typing) as well as SCCmec-typing are all at hand.
医院感染问题在兽医学中日益重要。例如，本综述总结了关于耐甲氧西林金黄色葡萄球菌（MRSA）的现有知识，以此作为典型例子，因为这些病原体是全球人类医学中医院感染的最重要病原体，并且在兽医学中报告的数量也日益增加。MRSA根据其对苯唑西林/甲氧西林的耐药能力进行分类，这一特性由mecA基因赋予，该基因通过葡萄球菌基因盒（SCCmec）的水平基因转移获得。正是这种遗传信息使MRSA对所有青霉素、头孢菌素和碳青霉烯类耐药。此外，MRSA通常还对多种其他抗感染药物耐药，即氨基糖苷类、大环内酯类、林可酰胺类、链霉素类、四环素类、氯霉素，也对氟喹诺酮类和利福平耐药。据推测，这些高度适应的菌株特别能够获得位于质粒或转座子上的耐药基因。它们还能够发生点突变，进一步导致耐药表型。如果这些病原体导致传染病，兽医可能会面临最坏的情况，即没有任何抗感染治疗手段。由于金黄色葡萄球菌具有高度耐受性，专业的卫生管理至关重要。兽医学中已发表的散发性MRSA感染、MRSA传染病以及MRSA暴发数量不断增加，这证明它们被认定为“新出现的病原体”是合理的。到目前为止，马和狗受MRSA影响最为严重。虽然偶尔有关于人与动物之间传播的报道，但动物中MRSA感染的来源、传播途径或流行病学相关性仍远未明确。因此，利用分子分型工具进行流行病学调查是必不可少的。诸如多位点序列分型（MLST）、脉冲场凝胶电泳（PFGE）、蛋白A编码基因的序列分析（spa分型）以及SCCmec分型等分型工具都已具备。
