van Duijkeren E, Hengeveld P D, Albers M, Pluister G, Jacobs P, Heres L, van de Giessen A W
Centre for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
Centre for Infectious Disease Control Netherlands (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
Vet Microbiol. 2014 Jul 16;171(3-4):364-7. doi: 10.1016/j.vetmic.2013.12.024. Epub 2014 Jan 15.
In the Netherlands, livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has been found in pigs, veal calves, horses and poultry. However, little is known about its prevalence in healthy dairy cattle. Recently, a new mec gene, called mecC, has been found in methicillin-resistant S. aureus (MRSA) isolates from humans and animals in several countries. The objective of our pilot study was to investigate the prevalence of MRSA (mecA and mecC) in dairy cows at a large slaughterhouse. Samples from the skin between the udder and hind leg were taken from 411 cows. The samples were incubated in Mueller-Hinton enrichment broth with 6.5% NaCl, followed by selective enrichment and plated onto Columbia agar with 5% sheep blood, Brilliance MRSA 2 agar and Baird-Parker agar. Suspected colonies were tested by PCR for a S. aureus specific DNA fragment, the mecA and mecC genes and the Panton-Valentine leucotoxin (PVL) genes. All MRSA isolates and methicillin-susceptible S. aureus (MSSA) isolates were typed by spa typing and MLVA typing. Sixteen of 411 (3.9%) cows, all originating from different farms, were found to be MRSA positive and this prevalence is lower than in Dutch pigs, veal calves and broilers. All MRSA isolates belonging to livestock-associated MLVA complex 398, were PVL-negative and spa type t011 predominated. MSSA isolates (n=39) were of many different MLVA types and spa type t543 was found most often. Four MSSA isolates belonging to MLVA clonal complex 398 and spa types t011 (n=2), t108 and t034 were isolated from different MRSA-negative animals. In conclusion, the prevalence of MRSA in dairy cows was low and isolates carrying the mecC gene were not found, indicating that it is absent or has a low prevalence (<0.73%) in Dutch dairy cows.
在荷兰，已在猪、犊牛、马和家禽中发现与家畜相关的耐甲氧西林金黄色葡萄球菌（LA-MRSA）。然而，对于其在健康奶牛中的流行情况知之甚少。最近，在几个国家从人和动物中分离出的耐甲氧西林金黄色葡萄球菌（MRSA）菌株中发现了一种名为mecC的新mec基因。我们的初步研究目的是调查一家大型屠宰场中奶牛的MRSA（mecA和mecC）流行情况。从411头奶牛的乳房和后腿之间的皮肤采集样本。将样本在含6.5%氯化钠的穆勒-欣顿增菌肉汤中培养，随后进行选择性增菌，并接种到含5%羊血的哥伦比亚琼脂、Brilliance MRSA 2琼脂和贝尔德-帕克琼脂上。通过PCR检测疑似菌落是否含有金黄色葡萄球菌特异性DNA片段、mecA和mecC基因以及杀白细胞素（PVL）基因。所有MRSA分离株和甲氧西林敏感金黄色葡萄球菌（MSSA）分离株均通过spa分型和多位点可变数目串联重复序列分析（MLVA）分型。411头奶牛中有16头（3.9%）被发现MRSA呈阳性，所有这些奶牛均来自不同农场，这一流行率低于荷兰猪、犊牛和肉鸡中的流行率。所有属于家畜相关MLVA复合体398的MRSA分离株均为PVL阴性，且spa型t011占主导。MSSA分离株（n = 39）有许多不同的MLVA类型，其中spa型t543最为常见。从不同的MRSA阴性动物中分离出4株属于MLVA克隆复合体398且spa型分别为t011（n = 2）、t108和t034的MSSA分离株。总之，奶牛中MRSA的流行率较低，且未发现携带mecC基因的分离株，这表明荷兰奶牛中不存在该基因或其流行率较低（<0.73%）。
