Reference | Braykov_2016_mSph (10369) (Excluded)

The study was conducted between August 2010 and July 2013 in a rural region of Esmeraldas Province, in northern coastal Ecuador. The present study was conducted in a subset of 17 villages where we were able to collect environmental and animal samples. In villages with production poultry farming, teams visited (i) all households with active poultry coops and (ii) an equivalent number of nonfarming households that were located far from coops. If villages had no poultry farming at the time of the visit, 3 to 10 nonfarming households were chosen at random, depending on the size of the village. The communities were visited 1 to 4 times between August 2010 and November 2013 to sample “production birds” and “household birds.” Production birds included breeds of laying hens raised for egg production or broiler chickens that are raised in coops for 6 to 7 weeks before slaughter. These birds eat formulated feed containing antibiotics and are also commonly given antibiotics as prophylaxis via water. Capacities of coops ranged from ~50 to ~100 birds of a single age for a typical single household coop to ~1,000 birds of multiple ages for the group facility. Thirteen households in seven villages were engaged in rearing production birds. In each coop, we sampled five production birds of each age group (categorized in weeks of age). Household birds included varietals not intended for commercial sale that are not held in coops, that eat scraps and ground maize rather than formula feed, and that do not receive antibiotics. We sampled 5 to 10 household birds from each village, regardless of whether the villagers were actively engaged in production poultry farming. Samples from household drinking water, soil from house surroundings, and kitchen surfaces were collected from households associated with production or household birds. In addition, soil and surface samples were collected from coops. Household birds (n = 360) were sampled in all 17 villages, and production birds (n = 262) were actively being raised in 10 villages at the time of sampling. Environmental samples were collected from all 17 villages.

For all birds, we collected cloacal samples using sterile swabs that were placed in Cary Blair transport medium (Becton, Dickinson, Franklin Lakes, NJ) and streaked directly on MacConkey lactose (MKL) agar for isolation. During the first half of the study period, between August 2010 and January 2012, we collected 50-ml water samples from two different household storage containers in Whirl-Pak bags (Nasco Corp., Fort Atkinson, WI) in the same manner that water was dispensed for drinking. If there was only one drinking water container available, then the second sample was taken from water used to wash dishes or bathe. For the remainder of the study period, only one sample per household was obtained from drinking containers. Samples were processed using membrane filtration for isolation of E. coli. During the first half of the study period, we collected two samples of approximately 15 cm^3 from around the house and from around the poultry coop, if one was present. Soil from just below the surface was placed into a conical tube using a sterile plastic spoon that was discarded after use. Samples were stored on ice until processing in the laboratory was performed (within 4 to 6 h). For the second part of the study period, only a single sample was obtained from the household yard. During the first half of the study period, we collected household surface samples from two locations, namely, where food was prepared (e.g., a cutting board) and where food was eaten (e.g., a table). A 28-by-30-cm plastic stencil was used to define a consistent sampling area. Two surface samples from the inside or outside the coop, which was usually constructed from cement or wood, were also taken using the same procedures. Surface samples were plated directly onto Chromocult agar and streaked for isolation. For the second part of the study period, surface samples were not collected due to the low rate of isolate recovery. We selected up to four E. coli colonies from soil and fecal samples and two from water and surface samples to test for AR.

AST Method: Disk Diffusion

Reference explicitly reports AST breakpoints: True

Reference reports using a MIC table: Uncertain