Department of Food Science and Agricultural Chemistry, Faculty of Agricultural and Environmental Sciences, McGill University, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC, H9X 3V9, Canada.
Microb Ecol. 2012 Jan;63(1):41-50. doi: 10.1007/s00248-011-9954-0. Epub 2011 Oct 14.
The addition of antibiotics to livestock feed has contributed to the selection of antibiotic-resistant bacteria in concentrated animal feeding operations and agricultural ecosystems. The objective of this study was to assess the occurrence of resistance to chlortetracycline and tylosin among bacterial populations at the Swine Complex of McGill University (Province of Quebec, Canada) in the absence of antibiotic administration to pigs for 2.5 years prior to the beginning of this study. Feces from ten pigs born from the same sow and provided feed without antibiotic were sampled during suckling (n = 6 for enumerations, n = 10 for PCR), weanling (n = 10 both for PCR and enumerations), growing (n = 10 both for PCR and enumerations), and finishing (n = 10 both for PCR and enumerations). The percentage of chlortetracycline-resistant anaerobic bacterial populations (Tet(R)) was higher than that of tylosin-resistant anaerobic bacterial populations (Tyl(R)) at weanling, growing, and finishing. Prior to the transportation of animals to the slaughterhouse, resistant populations varied between 6.5 and 9.4 Log colony-forming units g humid feces(-1). In all pigs, tet(L), tet(O), and erm(B) were detected at suckling and weanling, whereas only tet(O) was detected at growing and finishing. The abundance of tet(O) was similar between males and females at weanling and growing and reached 5.1 × 10(5) and 5.6 × 10(5) copies of tet(O)/ng of total DNA in males and females, respectively, at finishing. Results showed high abundances and proportions of Tet(R) and Tyl(R) anaerobic bacterial populations, as well as the occurrence of tet and erm resistance genes within these populations despite the absence of antibiotic administration to pigs at this swine production facility since January 2007, i.e., 2.5 years prior to the beginning of this study. This work showed that the occurrence of bacterial resistance to chlortetracycline and tylosin is high at the Swine Complex of McGill University.
在集约化动物养殖场和农业生态系统中，将抗生素添加到牲畜饲料中导致了抗生素耐药菌的选择。本研究的目的是评估在开始本研究之前的 2.5 年内，没有向猪使用抗生素的情况下，麦吉尔大学（魁北克省，加拿大）养猪场的细菌种群对金霉素和泰乐菌素的耐药性的发生情况。从同一头母猪所生的 10 头仔猪在哺乳期（n = 6 用于计数，n = 10 用于 PCR）、断奶期（n = 10 用于 PCR 和计数）、生长期（n = 10 用于 PCR 和计数）和育肥期（n = 10 用于 PCR 和计数）采集粪便样本。在断奶期、生长期和育肥期，金霉素耐药厌氧细菌种群（Tet(R)）的百分比高于泰乐菌素耐药厌氧细菌种群（Tyl(R)）。在运往屠宰场之前，耐药种群在 6.5 到 9.4 个对数菌落形成单位 g 潮湿粪便(-1)之间变化。在所有仔猪中，在哺乳期和断奶期检测到 tet(L)、tet(O)和 erm(B)，而在生长期和育肥期仅检测到 tet(O)。在断奶期和生长期，雄性和雌性猪的 tet(O)丰度相似，分别达到雄性和雌性的 5.1×10(5)和 5.6×10(5)拷贝 tet(O)/ng 总 DNA。结果表明，尽管自 2007 年 1 月以来，该养猪场没有向猪使用抗生素，即开始本研究之前的 2.5 年内，仍存在大量 Tet(R)和 Tyl(R)厌氧细菌种群，以及这些种群中 tet 和 erm 耐药基因的存在。这项工作表明，在麦吉尔大学养猪场，金霉素和泰乐菌素对细菌的耐药性发生率很高。
