University of Prince Edward Island, Charlottetown, PE, Canada.
University of Calgary, Calgary, AB, Canada; Provincial Laboratory for Public Health, Calgary, AB, Canada.
Int J Food Microbiol. 2018 May 2;272:41-48. doi: 10.1016/j.ijfoodmicro.2018.02.022. Epub 2018 Feb 27.
Emergence and dissemination of antimicrobial resistance (AMR) in food-borne bacteria is a public health issue. Retail meat is considered an important carrier for antimicrobial-resistant Escherichia coli. Currently, resistance of E. coli strains to third generation cephalosporins are of particular concern, with significant potential animal and public health consequences. Resistance to tetracyclines is also a concern, due to high prevalence of this resistance and important co-resistance patterns. However, the actual likelihood of exposure to antimicrobial-resistant bacteria via the consumption of retail meats, beyond the simple frequencies of resistance found in samples of meat at the grocery store, in Canada remains to be investigated. This study was conducted to estimate the potential human exposure to ceftriaxone- and tetracycline-resistant E.coli (CREC and TREC; the hazards of interest) through the consumption of ground beef in Western Canada. Our exposure assessment simulation model included five modules: 1) estimation of prevalence and concentration of the hazards of interest in retail ground beef samples collected by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS), 2011-2014; 2) potential growth of the hazards during transportation from retail to home; 3) potential growth or reduction of the hazards during home storage; 4) thermal inactivation of the hazards due to cooking; and 5) consumption. The outputs of the model were presented as the probability of consumers' exposure to various threshold levels of the hazards [10 to 10 colony forming units (CFU)] in one serving of cooked ground beef. Overall, the probabilities of exposure to high threshold levels of the hazards (>4 log CFU/serving) were estimated to be lower than 0.12% in the study population (2011-2014). The mean probabilities of exposure to at least 1 log CFU CREC and TREC in a single meal containing cooked ground beef were 0.067% (SD: 0.001%) and 1.20% (SD: 0.02%), respectively. This probability substantially decreased as the threshold level of exposure increased to ≥6 log CFU. The probability of exposure to TREC was consistently greater than that for CREC. Cooking led to a prominent drop in the mean concentration of the hazards (4.7 log CFU/g). The findings from this research could inform the policy-making process and provide suggestions for adjustments in future retail surveillance plans. In addition, important knowledge gaps in this area have been highlighted.
食源性细菌中抗菌药物耐药性（AMR）的出现和传播是一个公共卫生问题。零售肉被认为是携带抗菌抗性大肠杆菌的重要载体。目前，大肠杆菌菌株对第三代头孢菌素的耐药性尤其令人关注，因为这具有重大的潜在动物和公共卫生影响。由于这种耐药性的高流行率以及重要的共同耐药模式，对抗生素四环素的耐药性也令人担忧。然而，在加拿大，通过食用零售肉类而接触抗菌抗性细菌的实际可能性（除了在杂货店的肉类样本中发现的简单耐药频率之外）仍有待调查。本研究旨在通过食用加拿大西部的碎牛肉来估计人类接触头孢曲松和四环素耐药大肠杆菌（CREC 和 TREC；感兴趣的危害）的潜在风险。我们的暴露评估模拟模型包括五个模块：1）估计 2011-2014 年加拿大抗菌药物耐药性综合监测计划（CIPARS）收集的零售碎牛肉样本中感兴趣的危害的流行率和浓度；2）从零售到家庭运输过程中危害的潜在生长；3）家庭储存过程中危害的潜在生长或减少；4）由于烹饪而导致的危害的热失活；5）消费。模型的输出以消费者在一份煮熟的碎牛肉中接触各种危害阈值水平（10 到 10 个菌落形成单位（CFU））的概率呈现。总体而言，在研究人群（2011-2014 年）中，估计接触高危害阈值水平（>4 log CFU/份）的概率低于 0.12%。在含有煮熟的碎牛肉的一顿饭中，接触至少 1 个 CFU CREC 和 TREC 的平均概率分别为 0.067%（SD：0.001%）和 1.20%（SD：0.02%）。随着接触阈值水平增加到≥6 log CFU，接触的概率显著降低。接触 TREC 的概率始终大于接触 CREC 的概率。烹饪导致危害的平均浓度显著下降（4.7 log CFU/g）。本研究的结果可以为决策过程提供信息，并为未来零售监测计划的调整提供建议。此外，该领域的重要知识空白已被突出强调。
