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Comparison of two sampling and culture systems for detection of S almonella enterica in the environment of a large animal hospital
Author(s) -
RupleCzerniak A.,
Bolte D. S.,
Burgess B. A.,
Morley P. S.
Publication year - 2014
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/evj.12193
Subject(s) - salmonella enterica , agar , veterinary medicine , outbreak , tetrathionate , sampling time , sampling (signal processing) , agar plate , contamination , microbiological culture , animal health , microbiology and biotechnology , biology , medicine , salmonella , virology , bacteria , mathematics , ecology , statistics , genetics , filter (signal processing) , computer science , computer vision
Summary Reasons for performing study Nosocomial salmonellosis is an important problem in veterinary hospitals that treat horses and other large animals. Detection and mitigation of outbreaks and prevention of healthcare‐associated infections often require detection of S almonella enterica in the hospital environment. Objectives To compare 2 previously published methods for detecting environmental contamination with S . enterica in a large animal veterinary teaching hospital. Study design Hospital‐based comparison of environmental sampling techniques. Methods A total of 100 pairs of environmental samples were collected from stalls used to house large animal cases (horses, cows or New World camelids) that were confirmed to be shedding S . enterica by faecal culture. Stalls were cleaned and disinfected prior to sampling, and the same areas within each stall were sampled for the paired samples. One method of detection used sterile, premoistened sponges that were cultured using thioglycolate enrichment before plating on XLT ‐4 agar. The other method used electrostatic wipes that were cultured using buffered peptone water, tetrathionate and R appaport‐ V assiliadis R10 broths before plating on XLT ‐4 agar. Results S almonella enterica was recovered from 14% of samples processed using the electrostatic wipe sampling and culture procedure, whereas S . enterica was recovered from only 4% of samples processed using the sponge sampling and culture procedure. There was test agreement for 85 pairs of culture‐negative samples and 3 pairs of culture‐positive samples. However, the remaining 12 pairs of samples with discordant results created significant disagreement between the 2 detection methods (P<0.01). Conclusions Persistence of S almonella in the environment of veterinary hospitals can occur even with rigorous cleaning and disinfection. Use of sensitive methods for detection of environmental contamination is critical when detecting and mitigating this problem in veterinary hospitals. These results suggest that the electrostatic wipe sampling and culture method was more sensitive than the sponge sampling and culture method.