AUTHOR=Lahti Päivi , Jaakkola Kaisa , Hörman Ari , Heikinheimo Annamari , Sovijärvi Ava , Korkeala Hannu 

TITLE=Identification of a new Clostridium perfringens variant with a chromosomally encoded enterotoxin gene in a suspected persistent food poisoning outbreak in Eritrea

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1459840

DOI=10.3389/fmicb.2024.1459840

ISSN=1664-302X

ABSTRACT=<p><italic>Clostridium perfringens</italic> is a causative agent of various human and animal enteric diseases including food poisoning. In this study, we describe an interesting case of a persistent food poisoning outbreak among Finnish peacekeepers in Eritrea, possibly caused by <italic>Clostridium perfringens</italic> carrying a new variant of the chromosomally encoded enterotoxin gene. <italic>C. perfringens</italic> strains causing food poisoning carry the enterotoxin gene, <italic>cpe</italic>, in its chromosome (c-<italic>cpe</italic>) or on a plasmid (p-<italic>cpe</italic>). PCR assays are widely used for toxinotype <italic>C. perfringens</italic> strains. The integration sites for the <italic>cpe</italic> gene are highly conserved, and PCR assays targeting the <italic>cpe</italic> gene and the adjacent IS elements (the IS<italic>1470</italic> in c-<italic>cpe</italic> and the IS<italic>1470</italic>-like or IS<italic>1151</italic> in p-<italic>cpe</italic> strains) are used to further determine the genetic location of the <italic>cpe</italic> gene. We sequenced nine enteropathogenic <italic>C. perfringens</italic> strains related to a persistent food poisoning outbreak among Finnish peacekeepers in Eritrea. Six of these strains produced non-typeable <italic>cpe</italic> results in the standard PCR assay due to divergence in the enterotoxin integration site. The gene order of the new variant of the chromosomal <italic>cpe</italic> insertion site with an additional IS1470 element impairing genotyping PCR assay for the location of <italic>cpe</italic> is described. In addition, variant c-<italic>cpe</italic> strains carried 58–81 copies of IS1470 in their genomes, compared to 9–23 copies found in previously described c-<italic>cpe</italic> strains. Thus, the present study represents an untraditional type of <italic>C. perfringens</italic> food poisoning caused by variant c-<italic>cpe</italic> strains, and the sequenced strains bring geographic variation to the existing strain collection of sequenced <italic>C. perfringens.</italic></p>