Quantitative Veterinary Epidemiology Group, Wageningen Institute of Animal Sciences, Wageningen University, PO Box 338, 6700 AH Wageningen, The Netherlands.
Vet Microbiol. 2012 Mar 23;155(2-4):381-8. doi: 10.1016/j.vetmic.2011.09.010. Epub 2011 Sep 16.
Antimicrobial resistance in pigs becomes a public health issue when resistant organisms transfer from pigs to humans. Pigs are a large reservoir for livestock-associated (LA-)MRSA and people in contact with pigs are at risk for infection with LA-MRSA. Transmission and persistence of LA-MRSA within a pig population contributes to the maintenance of this zoonotic reservoir. Current knowledge on colonization and transmission of LA-MRSA in pigs is limited and mainly based on observational field surveys. Two experiments were performed to colonize pigs and quantify transmission of LA-MRSA between pigs. In the first experiment, colonization of six-week old piglets failed after intranasal inoculation, confirming the complexity of MRSA-colonization. In the second experiment, naive pigs got colonized after exposure to orally inoculated pigs. Subsequently, these contact-infected pigs transmitted MRSA to a new group of naive pigs. The reproduction ratio, R(0), was estimated with a SIS-model to quantify transmission between the first and second contact pigs as this resembles more the natural transmission. Two scenarios were evaluated, with different assumptions regarding infection status of individual pigs. R(0) varied between 3.7 and 4.3 and was significantly above 1, indicating a high probability of persistence of LA-MRSA, even without antimicrobial use.
当耐药菌从猪转移到人身上时，猪的抗生素耐药性就成为了一个公共卫生问题。猪是与牲畜相关的耐甲氧西林金黄色葡萄球菌（LA-MRSA）的重要宿主，与猪接触的人有感染 LA-MRSA 的风险。LA-MRSA 在猪群中的传播和持续存在有助于维持这种人畜共患病的储存库。目前关于猪体内 LA-MRSA 的定植和传播的知识有限，主要基于观察性的现场调查。进行了两项实验来定植猪并量化猪之间 LA-MRSA 的传播。在第一项实验中，鼻腔接种六周大的仔猪后定植失败，证实了 MRSA 定植的复杂性。在第二项实验中，接触经口接种的猪后，未感染的猪被定植。随后，这些接触感染的猪将 MRSA 传播给了一组新的未感染的猪。繁殖率 R(0) 用 SIS 模型进行估计，以量化第一和第二接触猪之间的传播，因为这更类似于自然传播。评估了两种情况，对个体猪的感染状况有不同的假设。R(0) 介于 3.7 和 4.3 之间，明显大于 1，表明即使没有使用抗生素，LA-MRSA 也很可能持续存在。
