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Volume 28, Number 9—September 2022

Laboratory Misidentifications Resulting from Taxonomic Changes to Bacillus cereus Group Species, 2018–2022

Laura M. CarrollComments to Author , Itumeleng Matle, Jasna Kovac, Rachel A. Cheng, and Martin Wiedmann
Author affiliations: EMBL, Heidelberg, Germany (L.M. Carroll); Onderstepoort Veterinary Research, Pretoria, South Africa (I. Matle); The Pennsylvania State University, University Park, Pennsylvania, USA (J. Kovac); Cornell University, Ithaca, New York, USA (R.A. Cheng, M. Wiedmann)

Main Article

Table 1

Summary of cases of laboratory misidentifications caused by taxonomic changes to Bacillus cereus group species, 2018–2022*

Case Date Location Inquiring party WGS-assigned species of inquiry Case summary†
November 2018
Industrial laboratory
B. anthracis
Two B. cereus strains isolated from a food processing facility were assigned to the B. anthracis species but were not closely related to the B. anthracis lineage most commonly responsible for anthrax illness and did not possess anthrax encoding genes or represent an anthrax threat. They would historically be referred to as B. cereus or group III B. cereus.
October 2021
North America (USA)
Government laboratory
B. paranthracis
A B. cereus strain isolated from a food product responsible for a foodborne outbreak was assigned to the B. paranthracis species using WGS-based methods. B. paranthracis was historically referred to as B. cereus or group III B. cereus and encompasses B. cereus group strains capable of causing emetic and/or diarrheal foodborne illness.
3 January 2022 Africa (South Africa) Government laboratory B. anthracis Two B. cereus strains isolated during routine surveillance of meat products were classified using multiple WGS-based methods; they were assigned to the B. anthracis species but did not represent an anthrax threat. They would historically be referred to as B. cereus or group III B. cereus.

*WGS, whole genome sequencing; ANI, average nucleotide identity; MLST, multilocus sequence typing; ST, sequence type; Group III, panC phylogenetic Group III; PubMLST,; GTDB, Genome Taxonomy Database Releases R95 and R202, †B. cereus refers to the historical and/or colloquial species definition assigned using traditional microbiological methods, as outlined in the US Food and Drug Administration’s Bacteriological Analytical Manual (FDA BAM) (5).

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Page created: July 31, 2022
Page updated: August 19, 2022
Page reviewed: August 19, 2022
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.