Reference | Hering2014 (10208)

The aim of the present study was to estimate the prevalence of cefotaxime resistant (ESBL suspicious) E. coli on commercial pig farms in Germany and to identify potential risk factors for the number (risk) of positive samples per sampling group on a farm. For this cross-sectional study four sampling regions in Germany were chosen according to the principle management characteristics of livestock breeding. The information material provided the inclusion criteria, which were keeping of fattening pigs and commercial animal production. All farmers who volunteered for the study were included. The sample size was estimated prior to data collection. Based on the approximate two-sided 95%-confidence interval for one proportion, approx. 50 farms are necessary to estimate a prevalence of 10–20% with an error of ±10%. In total 48 farms with fattening pigs were enrolled in the study. On each farm two sampling groups of different ages were investigated. Sampling groups on one farm were defined as animals that were kept in different compartments with separate ventilation and with no contact to each other. A questionnaire to assess potential risk factors on farm level as well as on sampling group level was developed and pre-tested by different veterinarians and farmers. On the farms a printed version of the questionnaire was filled in by the study epidemiologist.

The farms were visited between May 2011 and October 2012. In each of the two sampling groups per farm, three mixed faecal samples from the floor of three pens were transferred to a sterile 50 ml centrifuge tube. Additionally, one sample was taken with a pair of autoclaved boot swabs from the corridor inside the compartment. The boot swabs were packed in a sterile sample bag. To screen the distribution of cefotaxime resistant E. coli on the farm, one pooled dust sample per group from the windowsill, pen separation or automatic feeder within each sampled compartment was also transferred to a 50 ml centrifuge tube. The samples were cooled down in a cold box to about 4 ◦C before being sentto the laboratory in a Süsse Post Box Maxi on the day of sampling and analysed within 24 h after sampling.

AST Method: Agar Dilution

Reference explicitly reports AST breakpoints: True

Reference reports using a MIC table: False