Lunha Kamonwan, Leangapichart Thongpan, Jiwakanon Jatesada, Angkititrakul Sunpetch, Sunde Marianne, Järhult Josef D, Ström Hallenberg Gunilla, Hickman Rachel A, Van Boeckel Thomas, Magnusson Ulf
Department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
Section for Food Safety and AMR, Norwegian Veterinary Institute, N-0106 Oslo, Norway.
Antibiotics (Basel). 2020 Sep 30;9(10):662. doi: 10.3390/antibiotics9100662.
The overall aim of the current study was to test the hypotheses that (i) antibiotic resistance in bacteria were more frequent in clinically health pigs in intensified company owned, medium-scale farms (MSFs) (100-500 sows) than in pigs in family-owned, small-scale farms (SSFs) (1-50 sows) and (ii) that farmers working at the MSFs were more prone to attain antibiotic resistant bacteria than farmers working at SSFs. The study was conducted in North-Eastern Thailand, comprising fecal isolates from pigs, farmers working with the pigs (contact humans) and persons living in the same household as the farmer (non-contact humans) at 51 MSFs and 113 SSFs. Samples from all farms were also screened for methicillin-resistant staphylococcus aureus (MRSA), which was not detected in pig samples, but was found in one human sample. Susceptibility was tested by disc-diffusion for seven antibiotics commonly used in the study area. Resistance in pig isolates from MSFs were more frequent for chloramphenicol which ( < 0.001), trimethoprim/sulfamethoxazole ( < 0.001) and gentamicin ( < 0.05) compared with isolates from SSFs, whereas the opposite was true for tetracycline ( < 0.01). Resistance in the human isolates was lower than those in the isolates from pigs for tetracycline, trimethoprim/sulfamethoxazole and chloramphenicol ( < 0.001). The frequency of resistance in the contact human samples from SSFs and MSFs did not differ. There was no difference between isolates from contact and non-contact humans for any of the tested antibiotics. Multidrug resistance in isolates from pigs was 26%, significantly higher ( < 0.01) than the 13% from humans. The data indicate that (i) resistance to antibiotics, including those critical and highly important for human medicine, were more common in fecal from pigs at the MSFs than at the SSFs, whereas (ii) the resistance in fecal from pig farmers seemed not to be influenced by the level of intensification of the farm they were working at.
（i）在集约化公司所有的中型农场（MSF，100 - 500头母猪）中，临床健康猪的细菌抗生素耐药性比家庭所有的小型农场（SSF，1 - 50头母猪）中的猪更常见；（ii）在MSF工作的农民比在SSF工作的农民更容易获得抗生素耐药菌。该研究在泰国东北部进行，包括从51个MSF和113个SSF的猪粪便分离物、与猪接触的农民（接触人群）以及与农民同住在一个家庭的人（非接触人群）中采集样本。所有农场的样本还进行了耐甲氧西林金黄色葡萄球菌（MRSA）筛查，在猪样本中未检测到，但在一份人类样本中发现。通过纸片扩散法对研究区域常用的七种抗生素进行药敏试验。与SSF的分离株相比，MSF猪分离株对氯霉素（<0.001）、甲氧苄啶/磺胺甲恶唑（<0.001）和庆大霉素（<0.05）的耐药性更常见，而四环素则相反（<0.01）。四环素、甲氧苄啶/磺胺甲恶唑和氯霉素的人类分离株耐药性低于猪分离株（<0.001）。SSF和MSF接触人群样本中的耐药频率没有差异。对于任何测试抗生素，接触人群和非接触人群的分离株之间没有差异。猪分离株中的多重耐药率为26%，显著高于人类的13%（<0.01）。数据表明：（i）对包括对人类医学至关重要和非常重要的抗生素在内的耐药性，在MSF猪的粪便中比在SSF中更常见；（ii）猪农粪便中的耐药性似乎不受他们工作的农场集约化程度的影响。
