1 Department of Veterinary Public Health & Epidemiology, College of Veterinary and Animal Sciences, Govind Ballabh Pant University of Agriculture & Technology , Pantnagar, Uttarakhand, India .
2 Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University , Raleigh, North Carolina.
Foodborne Pathog Dis. 2018 Apr;15(4):210-217. doi: 10.1089/fpd.2017.2354. Epub 2017 Dec 21.
The deposition of manure originating from food animal farms in the environment can lead to the dissemination of antimicrobial-resistant (AMR) bacterial foodborne pathogens, thereby potentially impacting human health. The objective of our study was to determine the dissemination of multidrug methicillin-resistant Staphylococcus sciuri (MDR-MRSS) in the environment after land application of manure on commercial swine farms. A total of 400 environmental samples (40 manure and 360 soil) were collected after repeated sampling from four commercial swine farms located in North Carolina (n = 1) and Iowa (n = 3) in the United States. At each farm, we collected 10 manure and 40 soil samples (20 samples before and after 2 h of manure application) from four plots (five soil samples/plot) on day 0. Subsequently, 20 soil samples were collected on day 7, 14, and 21 from the same plots. A total of 67 (16.75%) MRSS were isolated from the 400 samples. The prevalence in soil and manure was 13.33% (48/360) and 47.5% (19/40), respectively. Prevalence was highest in the soil samples collected after 2 h of manure application on day 0 and decreased subsequently on 7, 14, and 21 days. Antimicrobial susceptibility testing was done against a panel of 12 antibiotics. A majority of S. sciuri isolates exhibited resistance against ampicillin (AMP; 95.5%), penicillin (PEN; 95.5%), clindamycin (CLI; 95.5%), cefoxitin (FOX; 92.5%), ceftiofur (XNL; 92.5%), tetracycline (TET; 86.56%), and erythromycin (ERY; 50.74%). The MDR pattern AMP FOX CLI PEN TET XNL (n = 24; 35.8%) was the most commonly observed. We detected multiple AMR genes, including mecA, aac(6'), Ie-aph(2″)Ia, tetM, tetK, mphC, ermA, ermB, and ermC. Pulsed-field gel electrophoresis clustered isolates from different sample collection days from the same farm into one group. Overall, our study identifies swine manure as an important reservoir of MDR-MRSS and highlights its dissemination in the environment upon spreading of manure.
动物农场的粪便沉积在环境中会导致抗微生物药物耐药（AMR）的食源性致病菌传播，从而可能影响人类健康。我们的研究目的是确定在北卡罗来纳州（n = 1）和爱荷华州（n = 3）的四个商业养猪场进行粪便土地应用后，环境中多药耐甲氧西林表皮葡萄球菌（MDR-MRSS）的传播情况。我们在美国从四个商业养猪场重复取样后收集了 400 个环境样本（40 个粪便和 360 个土壤）。在每个农场，我们从四个地块（每个地块 5 个土壤样本）收集了 10 个粪便和 40 个土壤样本（粪便应用后 2 小时前和后各 20 个样本）。随后，在第 0 天、第 7 天、第 14 天和第 21 天从相同的地块收集了 20 个土壤样本。从 400 个样本中总共分离出 67 株（16.75%）MRSS。土壤和粪便中的流行率分别为 13.33%（48/360）和 47.5%（19/40）。第 0 天粪便应用后 2 小时收集的土壤样本中的流行率最高，随后在第 7、14 和 21 天下降。对抗生素药敏试验进行了 12 种抗生素的测试。大多数表皮葡萄球菌分离株对氨苄青霉素（AMP；95.5%）、青霉素（PEN；95.5%）、克林霉素（CLI；95.5%）、头孢西丁（FOX；92.5%）、头孢噻呋（XNL；92.5%）、四环素（TET；86.56%）和红霉素（ERY；50.74%）表现出耐药性。最常见的多药耐药模式为 AMP FOX CLI PEN TET XNL（n = 24；35.8%）。我们检测到多种 AMR 基因，包括 mecA、aac(6')、Ie-aph(2″)Ia、tetM、tetK、mphC、ermA、ermB 和 ermC。脉冲场凝胶电泳将来自同一农场不同样本采集日的分离株聚类到一个组中。总体而言，我们的研究表明，猪粪是 MDR-MRSS 的重要储存库，并强调了其在粪便传播时在环境中的传播。
