The continued search for intermediate hosts and potential reservoirs for SARS-CoV2 makes it clear that animal surveillance is critical in outbreak response and prevention. Real-time RT-PCR assays for SARS-CoV2 detection can easily be adapted to different host species. U.S. veterinary diagnostic laboratories have used the CDC assays or other national reference laboratory methods to test animal samples. However, these methods have only been evaluated using internal validation protocols. To help the laboratories evaluate their SARS-CoV2 test methods, an interlaboratory comparison (ILC) was performed in collaboration with multiple organizations. Forty-four sets of 19 blind-coded RNA samples in Tris-EDTA (TE) buffer or PrimeStore transport medium were shipped to 42 laboratories. Results were analyzed according to the principles of the International Organization for Standardization (ISO) 16140-2:2016 standard. Qualitative assessment of PrimeStore samples revealed that, in approximately two-thirds of the laboratories, the limit of detection with a probability of 0.95 (LOD95) for detecting the RNA was ≤20 copies per PCR reaction, close to the theoretical LOD of 3 copies per reaction. This level of sensitivity is not expected in clinical samples because of additional factors, such as sample collection, transport, and extraction of RNA from the clinical matrix. Quantitative assessment of Ct values indicated that reproducibility standard deviations for testing the RNA with assays reported as N1 were slightly lower than those for N2, and they were higher for the RNA in PrimeStore medium than those in TE buffer. Analyst experience and the use of either a singleplex or multiplex PCR also affected the quantitative ILC test results.

The current U.S. Food and Drug Administration (FDA) methodology for detection of Campylobacter, a leading source for foodborne illness, is outdated. The purpose of this study, therefore, was to improve and update the cultural and identification methods found in the FDA/Bacteriological Analytical Manual (BAM). Raw silo milk samples containing typical and atypical strains of Campylobacter jejuni and Campylobacter coli at different levels (5 CFU/25 g, 50 CFU/25 g, and 125 CFU/25 g) were analyzed. Valid results were obtained from 240 test portions. Six inoculated (at the levels described above) and two uninoculated samples were sent to a participating laboratory to mimic a "real-world" scenario. These combined data indicated that the use of sheep blood in combination with enrichment is not necessary. R & F Campylobacter jejuni/Campylobacter coli Chromogenic Plating Medium is significantly (P < 0.05) more sensitive for detection of C. jejuni or C. coli at low inoculation levels than the modified Cefoperazone Charcoal Deoxycholate Agar used in the BAM. The quantitative PCR method described demonstrated rapid confirmation and identification of C. jejuni or C. coli. It reduced the time to isolate C. jejuni or C. coli, and increased the sensitivity compared to the current BAM protocol.

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