Reference | Hille2017 (10212)

The primary objective of this study was to determine the prevalence of cefotaxime resistance in commensal E. coli from dairy and beef cattle at the farm level throughout Germany. Secondarily, the association between management factors and the presence of cefotaxime resistance was investigated. Two project partners collected samples and data via questionnaire on cattle farms in different regions of Germany. Study protocols were harmonised during the planning phases of both studies. In Study 1, 45 cattle farms were visited: 25 farms keeping beef and dairy cattle, 15 farms keeping only beef cattle and 5 farms keeping dairy cattle and veal calves. Overall, in the south of Germany, dairy and beef cattle were present on 30 and 40 investigated farms, respectively. In Study 2, cattle farms located in the remaining agricultural regions of Germany were sampled. In this parallel study, 35 cattle farms were visited: 7 farms keeping beef and dairy cattle, 13 farms keeping only beef cattle and 15 farms keeping only dairy cattle. Overall, dairy and beef cattle were present on 22 and 20 investigated farms, respectively. Within the present publication, the data sets from both studies were aggregated. It was decided to exclude calves from the joint analyses. The two production types, beef or dairy cattle, were analysed separately, irrespective of whether cattle from the other production type were also kept on the same farm. Farms were visited between May 2011 and October 2012. During the planning phase of the studies, the sample size was estimated with an assumed farm prevalence of 10–20% with an error of ±10% and the approximate two-sided 95%-confidence interval for one proportion. Based on these presuppositions, approximately 50 farms are necessary to estimate the farm prevalence. Studies 1 and 2 used the same questionnaires, which were developed for the project.

One or two animal groups that had no direct contact with each other were sampled per production unit. Overall, in the 60 beef cattle production units, 93 animal groups were sampled, while in the 52 dairy cattle production units, 65 animal groups were sampled. When possible, five samples per animal group were taken as follows: three collective faecal samples from the stable floor, a pooled dust sample from the pen separators or window sills and one pair of boot swabs from the feed alley. Collective faecal samples represent the animals from one pen. Depending on the amount of dust present, up to 50 ml were collected.

AST Method: Agar Dilution

Reference explicitly reports AST breakpoints: True

Reference reports using a MIC table: False