Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Nov 7;66(4):605-611.
doi: 10.2478/jvetres-2022-0060. eCollection 2022 Dec.

Potential Risk of Botulinum Neurotoxin -producing Clostridia Occurrence in Canned Fish

Aleksandra Jarosz  1 , Tomasz Grenda  1 , Magdalena Goldsztejn  1 , Beata Kozak  1 , Krzysztof Kwiatek  1
Affiliations

Potential Risk of Botulinum Neurotoxin -producing Clostridia Occurrence in Canned Fish

Aleksandra Jarosz et al. J Vet Res. .

Abstract

Introduction: Heat treatment is indispensable in fish canning to provide an acceptable shelf life. Its optimisation reduces the risk of the presence of Clostridium botulinum spores, which could potentially cause botulism cases. This study evaluated canned fish samples for botulism neurotoxin (BoNT)-producing clostridia contamination and can bulging through microbiological contaminant growth. A new analytical approach was developed for detection of such clostridia and phenotypically similar species.

Material and methods: A total of 70 canned fish samples suspected of exhibiting bulging features were analysed. Culture methods were used to detect clostridia. The isolates obtained were evaluated on the basis of the exhibited phenotypic characteristics. Also, PCRs were used for the detection of genes determining BoNT production (non-toxic non-haemagglutinin (ntnh) genes) and the amplification of conservative 16S rDNA genes, which were Sanger sequenced. The obtained sequences were analysed using the Basic Local Alignment Search Tool.

Results: Clostridium genus species were isolated from 17 (24%) bulging and organoleptically changed samples. No ntnh genes were present in these isolates; however, sequencing confirmed the presence of C. sporogenes, a species with close affinity to C. botulinum.

Conclusion: To eliminate the threat of foodborne botulism, laboratory diagnostic techniques must detect species of the Clostridium genus and elucidate their ability to produce BoNTs. Although Clostridium botulinum is the most common cause of botulism, the possibility may not be ignored that non-pathogenic Clostridium species may acquire botulinum toxigenicity. The similarity between the isolated strains of C. sporogenes and C. botulinum should be incorporated in the optimisation of heat treatment to guarantee a sterilised, microbiologically safe product.

Keywords: Clostridium botulinum; Clostridium sporogenes; canned fish; microbiological contamination.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest Conflict of Interests Statement: The authors declare that there is no conflict of interests regarding the publication of this article.

Figures

Fig. 1
Fig. 1
Canned fish by batch exhibiting bulging and organoleptic changes
Fig. 2
Fig. 2
Canned fish samples by batch in which the presence of anaerobes was revealed
Fig. 3
Fig. 3
Isolated Gram-positive Clostridium bacteria with subterminal spores
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Al-Baali A.A.G., Farid M.M. Sterilization of Food in Retort Pouches, Food Engineering Series. Springer Science+Business Media; New York, NY: 2006. Chapter 5, Thermal Sterilization of Food in Cans; pp. 45–62. - DOI
    1. Banga J.R., Balsa-Canto E., Moles C.G., Alonso A.A.. Improving food processing using modern optimization methods. Trends Food Sci Technol. 2003;14:131–144. doi: 10.1016/S0924-2244(03)00048-7. - DOI
    1. Barra–Carrasco J., Olguín–Araneda V., Plaza–Garrido A., Miranda–Cárdenas C., Cofré–Araneda G., Pizarro–Guajardo M., Sarker M.R., Paredes–Sabja D.. The Clostridium difficile exosporium cysteine (CdeC)-rich protein is required for exosporium morphogenesis and coat assembly. J Bacteriol. 2013;195:3863–3875. doi: 10.1128/JB.00369-13. - DOI - PMC - PubMed
    1. Benoit R.M.. Botulinum neurotoxin diversity from a genecentered view. Toxins. 2018;10:310. doi: 10.3390/toxins10080310. - DOI - PMC - PubMed
    1. Brown J.L., Tran-Dinh N., Chapman B.. Clostridium sporogenes PA 3679 and its uses in the derivation of thermal processing schedules for low-acid shelf-stable foods and as a research model for proteolytic Clostridium botulinum. J Food Prot. 2012;75:779–792. doi: 10.4315/0362-028X.JFP-11-391. - DOI - PubMed

LinkOut - more resources