Influence of temperature and pH on induction of Shiga toxin Stx1a in Escherichia coli
Shiga toxin-producing strains represent pathogenic group that is of concern in food production. The present study evaluated forty-eight E. coli isolates (11 with intact stx gene, while remaining isolates presented only stx-fragments) for Shiga toxin production. The four most expressive stx-producers...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-07-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmicb.2023.1181027/full |
| _version_ | 1827906482083987456 |
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| author | Vinicius Silva Castro Skyler Ngo Kim Stanford |
| author_facet | Vinicius Silva Castro Skyler Ngo Kim Stanford |
| author_sort | Vinicius Silva Castro |
| collection | DOAJ |
| description | Shiga toxin-producing strains represent pathogenic group that is of concern in food production. The present study evaluated forty-eight E. coli isolates (11 with intact stx gene, while remaining isolates presented only stx-fragments) for Shiga toxin production. The four most expressive stx-producers (O26, O103, O145, and O157) were selected to evaluate effects of pH (3.5, 4.5, and 7) and temperature (35, 40, and 50°C). After determining acid stress effects in media on Stx-induction, we mimicked “in natura” conditions using milk, apple, and orange juices. Only isolates that showed the presence of intact stx gene (11/48) produced Shiga toxin. In addition, acid pH had a role in down-regulating the production of Shiga toxin, in both lactic acid and juices. In contrast, non-lethal heating (40°C), when in neutral pH and milk was a favorable environment to induce Shiga toxin. Lastly, two isolates (O26 and O103) showed a higher capacity to produce Shiga toxin and were included in a genomic cluster with other E. coli involved in worldwide foodborne outbreaks. The induction of this toxin when subjected to 40°C may represent a potential risk to the consumer, since the pathogenic effect of oral ingestion of Shiga toxin has already been proved in an animal model. |
| first_indexed | 2024-03-13T00:57:09Z |
| format | Article |
| id | doaj.art-754fe596671a4006afc745c7f1c84f31 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-03-13T00:57:09Z |
| publishDate | 2023-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-754fe596671a4006afc745c7f1c84f312023-07-06T16:45:57ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2023-07-011410.3389/fmicb.2023.11810271181027Influence of temperature and pH on induction of Shiga toxin Stx1a in Escherichia coliVinicius Silva CastroSkyler NgoKim StanfordShiga toxin-producing strains represent pathogenic group that is of concern in food production. The present study evaluated forty-eight E. coli isolates (11 with intact stx gene, while remaining isolates presented only stx-fragments) for Shiga toxin production. The four most expressive stx-producers (O26, O103, O145, and O157) were selected to evaluate effects of pH (3.5, 4.5, and 7) and temperature (35, 40, and 50°C). After determining acid stress effects in media on Stx-induction, we mimicked “in natura” conditions using milk, apple, and orange juices. Only isolates that showed the presence of intact stx gene (11/48) produced Shiga toxin. In addition, acid pH had a role in down-regulating the production of Shiga toxin, in both lactic acid and juices. In contrast, non-lethal heating (40°C), when in neutral pH and milk was a favorable environment to induce Shiga toxin. Lastly, two isolates (O26 and O103) showed a higher capacity to produce Shiga toxin and were included in a genomic cluster with other E. coli involved in worldwide foodborne outbreaks. The induction of this toxin when subjected to 40°C may represent a potential risk to the consumer, since the pathogenic effect of oral ingestion of Shiga toxin has already been proved in an animal model.https://www.frontiersin.org/articles/10.3389/fmicb.2023.1181027/fullShiga-toxigenic Escherichia colienterohemorrhagic Escherichia coliprophageshydrogen-ion concentrationShiga toxins |
| spellingShingle | Vinicius Silva Castro Skyler Ngo Kim Stanford Influence of temperature and pH on induction of Shiga toxin Stx1a in Escherichia coli Frontiers in Microbiology Shiga-toxigenic Escherichia coli enterohemorrhagic Escherichia coli prophages hydrogen-ion concentration Shiga toxins |
| title | Influence of temperature and pH on induction of Shiga toxin Stx1a in Escherichia coli |
| title_full | Influence of temperature and pH on induction of Shiga toxin Stx1a in Escherichia coli |
| title_fullStr | Influence of temperature and pH on induction of Shiga toxin Stx1a in Escherichia coli |
| title_full_unstemmed | Influence of temperature and pH on induction of Shiga toxin Stx1a in Escherichia coli |
| title_short | Influence of temperature and pH on induction of Shiga toxin Stx1a in Escherichia coli |
| title_sort | influence of temperature and ph on induction of shiga toxin stx1a in escherichia coli |
| topic | Shiga-toxigenic Escherichia coli enterohemorrhagic Escherichia coli prophages hydrogen-ion concentration Shiga toxins |
| url | https://www.frontiersin.org/articles/10.3389/fmicb.2023.1181027/full |
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