Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
Environ Res. 2017 May;155:359-364. doi: 10.1016/j.envres.2017.03.002. Epub 2017 Mar 20.
Livestock can carry extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, with bla being most prevalent. ESBL carriage in farmers is associated with ESBL carriage in animals, with direct animal-human contact considered as the dominant route of transmission. However, inhalation of stable air might represent another route of transmission. We, therefore, quantified presence of bla group 1 genes (CTX-M-gr1) in dust and the association with CTX-M-gr1 carriage in pig farmers, family members and employees. We included 131 people living and/or working on 32 conventional Dutch pig production farms (farmers, family members and employees) during two sampling moments over a 12-month interval. Human stool samples, rectal swabs from 60 pigs per farm, and 2-5 dust samples collected using an electrostatic dust collector (EDC) (as a proxy for presence of viable CTX-M-gr1 carrying bacteria in air) were obtained per farm. Presence of ESBL-producing Escherichia Coli (E. coli) in stool samples and rectal swabs was determined by selective plating and CTX-M-gr1 was identified by PCR. Dust samples were analyzed directly by PCR for presence of CTX-M-gr1. Questionnaires were used to collect information on nature, intensity and duration of animal contact. Overall human prevalence of CTX-M-gr1 carriage was 3.6%. CTX-M-gr1 was detected in dust on 26% of the farms and in pigs on 35% of the farms, on at least one sampling moment. Human CTX-M-gr1 carriage and presence of CTX-M-gr1 in dust were associated univariately (OR=12.4, 95% CI=2.7-57.1). In multivariate analysis human CTX-M-gr1 carriage was associated with the number of working hours per week (OR=1.03, 95% CI=1.00-1.06), presence of CTX-M-gr1 carrying pigs on the farm (OR=7.4, 95% CI=1.1-49.7) and presence of CTX-M-gr1 in dust (OR=3.5, 95% CI=0.6-20.9). These results leave open the possibility of airborne CTX-M-gr1 transmission from animals to humans next to direct contact.
家畜可能携带产extended-spectrum beta-lactamase (ESBL)的肠杆菌科细菌，其中 bla 最为普遍。农民携带 ESBL 与动物携带 ESBL 有关，直接的动物-人类接触被认为是主要的传播途径。然而，吸入稳定的空气可能代表另一种传播途径。因此，我们定量了尘埃中 bla 组 1 基因（CTX-M-gr1）的存在，并研究了其与猪农、家庭成员和员工携带 CTX-M-gr1 的关系。我们在 12 个月的时间内，分两个采样时段，共纳入了 32 个传统荷兰养猪场（农民、家庭成员和员工）的 131 人。每个农场都获得了人粪便样本、每个农场 60 头猪的直肠拭子，以及使用静电除尘器（EDC）采集的 2-5 个灰尘样本（作为空气中存在携带 CTX-M-gr1 活菌的细菌的代表）。通过选择性平板培养确定粪便样本和直肠拭子中是否存在产 ESBL 的大肠埃希菌（E. coli），并通过 PCR 鉴定 CTX-M-gr1。通过 PCR 直接分析灰尘样本中 CTX-M-gr1 的存在情况。问卷调查收集了有关动物接触的性质、强度和持续时间的信息。总体而言，CTX-M-gr1 携带率为人 3.6%。CTX-M-gr1 在 26%的农场的尘埃中、在 35%的农场的猪中，在至少一个采样时刻被检测到。人类 CTX-M-gr1 携带和尘埃中 CTX-M-gr1 的存在，单变量分析（OR=12.4，95%CI=2.7-57.1）呈正相关。多变量分析表明，人类 CTX-M-gr1 携带与每周工作小时数（OR=1.03，95%CI=1.00-1.06）、农场中存在携带 CTX-M-gr1 的猪（OR=7.4，95%CI=1.1-49.7）和尘埃中存在 CTX-M-gr1（OR=3.5，95%CI=0.6-20.9）相关。这些结果表明，除了直接接触之外，空气中 CTX-M-gr1 从动物向人类传播的可能性仍然存在。
