U.S. Department of Agriculture, Agricultural Research Service, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebraska 68933.
https://orcid.org/0000-0003-0494-2436 [J.W.S.].
J Food Prot. 2021 May 1;84(5):827-842. doi: 10.4315/JFP-20-376.
Antibiotics used during food animal production account for approximately 77% of U.S. antimicrobial consumption by mass. Ground beef products labeled as raised without antibiotics (RWA) are perceived to harbor lower levels of antimicrobial-resistant bacteria than conventional (CONV) products with no label claims regarding antimicrobial use. Retail ground beef samples were obtained from six U.S. cities. Samples with an RWA or U.S. Department of Agriculture Organic claim (n = 299) were assigned to the RWA production system. Samples lacking these claims (n = 300) were assigned to the CONV production system. Each sample was cultured for the detection of five antimicrobial-resistant bacteria. Genomic DNA was isolated from each sample, and a quantitative PCR assay was used to determine the abundance of 10 antimicrobial resistance (AMR) genes. Prevalence of tetracycline-resistant Escherichia coli (CONV, 46.3%; RWA, 34.4%; P < 0.01) and erythromycin-resistant Enterococcus (CONV, 48.0%; RWA, 37.5%; P = 0.01) was higher in CONV ground beef. Salmonella was detected in 1.2% of samples. The AMR gene blaCTX-M (CONV, 4.1 log-normalized abundance; RWA, 3.8 log-normalized abundance; P < 0.01) was more abundant in CONV ground beef. The AMR genes mecA (CONV, 4.4 log-normalized abundance; RWA, 4.9 log-normalized abundance; P = 0.05), tet(A) (CONV, 3.9 log-normalized abundance; RWA, 4.5 log-normalized abundance; P < 0.01), tet(B) (CONV, 3.9 log-normalized abundance; RWA, 4.5 log-normalized abundance; P < 0.01), and tet(M) (CONV, 5.4 log-normalized abundance; RWA, 5.8 log-normalized abundance; P < 0.01) were more abundant in RWA ground beef. Although these results suggest that antimicrobial use during U.S. cattle production does not increase human exposure to antimicrobial-resistant bacteria via ground beef, quantitative microbiological risk assessments are required for authoritative determination of the human health impacts of the use of antimicrobial agents during beef production.
在食用动物生产过程中使用的抗生素约占美国按质量计算的抗生素消费的 77%。贴有“无抗生素饲养（RWA）”标签的碎牛肉产品被认为比没有使用抗生素标签声明的传统（CONV）产品含有更低水平的抗药性细菌。从美国六个城市采集零售碎牛肉样本。有 RWA 或美国农业部有机标签声明的样本（n=299）被归入 RWA 生产系统。缺乏这些声明的样本（n=300）被归入 CONV 生产系统。对每个样本进行了五种抗药性细菌的检测。从每个样本中提取基因组 DNA，并使用定量 PCR 检测来确定 10 个抗生素抗性（AMR）基因的丰度。四环素抗性大肠杆菌（CONV，46.3%；RWA，34.4%；P<0.01）和红霉素抗性肠球菌（CONV，48.0%；RWA，37.5%；P=0.01）在 CONV 碎牛肉中的检出率更高。沙门氏菌在 1.2%的样本中被检出。AMR 基因 blaCTX-M（CONV，4.1 对数正态化丰度；RWA，3.8 对数正态化丰度；P<0.01）在 CONV 碎牛肉中更为丰富。AMR 基因 mecA（CONV，4.4 对数正态化丰度；RWA，4.9 对数正态化丰度；P=0.05）、tet(A)（CONV，3.9 对数正态化丰度；RWA，4.5 对数正态化丰度；P<0.01）、tet(B)（CONV，3.9 对数正态化丰度；RWA，4.5 对数正态化丰度；P<0.01）和 tet(M)（CONV，5.4 对数正态化丰度；RWA，5.8 对数正态化丰度；P<0.01）在 RWA 碎牛肉中更为丰富。尽管这些结果表明，美国牛肉生产过程中使用抗生素并不会通过碎牛肉增加人类接触抗药性细菌的风险，但需要进行定量微生物风险评估，以权威确定在牛肉生产过程中使用抗生素对人类健康的影响。
