Department of Microbiology and Molecular Genetics University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
Appl Environ Microbiol. 2024 Oct 23;90(10):e0091424. doi: 10.1128/aem.00914-24. Epub 2024 Sep 18.
type F isolates utilize enterotoxin (CPE) to cause food poisoning (FP) and nonfoodborne gastrointestinal diseases. The enterotoxin gene () can be located on either the chromosome or plasmids, but most FP isolates carry a chromosomal (c) gene. Our 2000 article in (66:3234-3240, 2000, https://doi.org/10.1128/aem.66.8.3234-3240.2000https://doi.org/10.1128/AEM.66.8.3234-3240.2000) determined that vegetative cells and spores of c- isolates are more heat resistant than those of plasmid (p-) isolates, which is favorable for their survival in improperly cooked or held food. However, that 2000 article was recently retracted (90:e00249-24, 2024, https://doi.org/10.1128/aem.00249-24). To our knowledge, the 2000 article remains the only study reporting that heat resistance differences are common between both vegetative cells and spores of type F c- isolates vs type F p- isolates. To confirm and preserve this information in the literature, the heat resistance portion of the 2000 study has been repeated. The 2024 results reproduced the 2000 results by indicating that, relative to the surveyed type F p- isolates, the vegetative cells of surveyed type F c- isolates are ~2-fold more heat resistant and the spores of most surveyed c- isolates are ~30-fold more heat resistant. However, consistent with several reports since our 2000 paper, one surveyed type F c- isolate (which did not appreciably sporulate in 2000 but sporulated in 2024) produced spores with intermediate heat sensitivity, confirming that spores of some type F c- isolates lack exceptional heat resistance.IMPORTANCE type F food poisoning (FP), which is the second most common bacterial cause of FP, involves the production of enterotoxin. While the enterotoxin gene () can be located on either the chromosome or plasmids in type F isolates, most FP cases are caused by chromosomal isolates. The current results support the conclusion that the vegetative cells and spores of type F chromosomal isolates are often more heat resistant than vegetative cells and spores of type F plasmid isolates. Greater heat resistance should favor the survival of the spores and vegetative cells of those chromosomal isolates in temperature-abused food, which may help explain the strong association of type F chromosomal strains with FP.
F 型菌株利用肠毒素（CPE）引起食物中毒（FP）和非食源性胃肠道疾病。肠毒素基因（）可以位于染色体或质粒上，但大多数 FP 分离株携带染色体（c）基因。我们 2000 年在（66:3234-3240, 2000, https://doi.org/10.1128/aem.66.8.3234-3240.2000https://doi.org/10.1128/AEM.66.8.3234-3240.2000）发表的文章确定，c-分离株的营养细胞和孢子比质粒（p-）分离株的更耐热，这有利于它们在未煮熟或保存不当的食物中存活。然而，该 2000 年的文章最近被撤回（90:e00249-24, 2024, https://doi.org/10.1128/aem.00249-24）。据我们所知，该 2000 年的文章仍然是唯一报道 F 型 c-分离株的营养细胞和孢子的耐热性差异普遍存在于 F 型 p-分离株的文章。为了在文献中确认和保存这一信息，重复了 2000 年研究的耐热性部分。2024 年的结果与 2000 年的结果一致，表明与调查的 F 型 p-分离株相比，调查的 F 型 c-分离株的营养细胞耐热性约高 2 倍，大多数调查的 c-分离株的孢子耐热性约高 30 倍。然而，与我们 2000 年论文之后的几项报告一致，一个调查的 F 型 c-分离株（2000 年时不明显产孢，但 2024 年时产孢）产生的孢子耐热性中等，证实了一些 F 型 c-分离株的孢子缺乏异常耐热性。
重要性 F 型食物中毒（FP）是第二常见的细菌性 FP 病因，涉及肠毒素的产生。虽然肠毒素基因（）可以位于 F 型分离株的染色体或质粒上，但大多数 FP 病例是由染色体（c）分离株引起的。目前的结果支持这样的结论，即 F 型染色体（c）分离株的营养细胞和孢子通常比 F 型质粒（p-）分离株的营养细胞和孢子更耐热。更高的耐热性应该有利于那些染色体（c）分离株的孢子和营养细胞在温度滥用食物中的存活，这可能有助于解释 F 型染色体（c）菌株与 FP 的强烈关联。
