AOAC SPADA Meeting

Blindly trusting the information provided by the donor of a strain • BACI224 • PAK-1: supposed to be wild type Ba with both plasmids. Customer (assay developer) spent a bit of time trying to figure out the reason for PCR failure against one of the plasmids. Turned out, the stock had either lost one of the plasmids or a mixed population. Had been stored in BSL3 • YERS003 • CO92: Based on a PCR result, deemed to have a missing plasmid and was stored in BSL2. Other PCRs showed weak positive for the target plasmid. Sequencing could unequivocally resolve it. Again a problem of mixed population of both genotypes? Growth conditions (media and temperature can make a big difference)

2018_10_17_SPADA_Brief

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Strains with the same designations from different labs are not the same (phenotypically and genotypically) • Bacillus anthracis Sterne (different SNPs in WG sequences) • Phage gamma sensitivity is different for different Sterne strains and growth conditions • Bacillus globigii

2018_10_17_SPADA_Brief

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