A novel small acid soluble protein variant is important for spore resistance of most Clostridium perfringens food poisoning isolates.
A novel small acid soluble protein variant is important for spore resistance of most Clostridium perfringens food poisoning isolates.
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DOI：
10.1371/journal.ppat.1000056
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发表时间：
2008-05-02
期刊：
影响因子：
6.7
通讯作者：
McClane BA
中科院分区：
文献类型：
--
作者：
Li J;McClane BA
产气荚膜梭菌是发达国家食物中毒（FP）的主要原因。产气荚膜梭菌分离株通常通过产生由染色体 (cpe) 基因编码的肠毒素来诱发该 FP 的胃肠道症状。这些典型的 FP 菌株还产生对食品保存方法（例如加热和化学防腐剂）具有极强抵抗力的孢子。这种抵抗力有利于它们在未正确烹调、准备或储存的食物中生存和随后发芽。目前的研究鉴定了一种新的α/β型小酸可溶性蛋白，现在命名为Ssp4，并表明产生抗性孢子的FP分离株的孢子培养物始终表达在残基36处具有Asp取代的变体Ssp4。相比之下，在产生敏感孢子的产气荚膜梭菌菌株中，在Ssp4残基36处检测到Gly。对同基因突变体和互补菌株的研究证明了 Asp 36 Ssp4 变体对于大多数携带染色体 cpe 基因的 FP 菌株产生的孢子具有出色的耐热性和亚硝酸钠性的重要性。电泳迁移率变动分析和 DNA 结合研究表明，在残基 36 处具有天冬氨酸的 Ssp4 变体比在残基 36 处具有甘氨酸的 Ssp4 变体与 DNA 的结合更有效、更紧密。除了对大多数携带染色体 cpe 基因的 FP 菌株的高抗性孢子表型提出一种可能的机制解释外，这些发现可能有助于最终开发有针对性的策略，以增加对食品中抗性孢子的杀灭。他们还首次表明，SASP 变异可能是细菌孢子抗性表型的种内（或许还有种间）变异的重要贡献者。最后，Ssp4 可能有助于整个梭菌属的孢子抗性特性，因为 ssp4 基因也存在于其他梭菌物种的基因组中。由致病性芽孢杆菌和梭菌属产生的孢子。助长疾病传播。产气荚膜梭菌食物中毒 (FP) 分离株通常会产生对热和亚硝酸钠具有出色抵抗力的孢子。这种孢子抗性可能有利于 FP 菌株在烹调/保存不当的食品中存活，从而导致产气荚膜梭菌 FP 爆发，这是发达国家最常见的食源性疾病之一。目前，FP菌株抗性孢子表型的机制基础尚不清楚。在这里，我们报告了一种新的小酸可溶性蛋白，称为Ssp4的鉴定，并表明产生抗性孢子的FP菌株的孢子培养物表达在残基36处具有天冬氨酸的Ssp4变体，而产生敏感孢子的产气荚膜梭菌菌株的孢子培养物在残基36处表达具有甘氨酸的Ssp4。我们现在证明i) Ssp4 Asp变体是FP菌株的极端孢子抗性所必需的，ii)该蛋白可能通过比 Ssp4 Gly 变体更紧密的 DNA 结合来帮助保护 FP 菌株。我们的研究为常见 FP 病原体的传播提供了重要见解，并可能提出干扰 FP 菌株耐药孢子的策略。这些发现也可能与其他致病性梭状芽胞杆菌属相关。携带ssp4基因。
Clostridium perfringens is a major cause of food poisoning (FP) in developed countries. C. perfringens isolates usually induce the gastrointestinal symptoms of this FP by producing an enterotoxin that is encoded by a chromosomal (cpe) gene. Those typical FP strains also produce spores that are extremely resistant to food preservation approaches such as heating and chemical preservatives. This resistance favors their survival and subsequent germination in improperly cooked, prepared, or stored foods. The current study identified a novel α/β-type small acid soluble protein, now named Ssp4, and showed that sporulating cultures of FP isolates producing resistant spores consistently express a variant Ssp4 with an Asp substitution at residue 36. In contrast, Gly was detected at Ssp4 residue 36 in C. perfringens strains producing sensitive spores. Studies with isogenic mutants and complementing strains demonstrated the importance of the Asp 36 Ssp4 variant for the exceptional heat and sodium nitrite resistance of spores made by most FP strains carrying a chromosomal cpe gene. Electrophoretic mobility shift assays and DNA binding studies showed that Ssp4 variants with an Asp at residue 36 bind more efficiently and tightly to DNA than do Ssp4 variants with Gly at residue 36. Besides suggesting one possible mechanistic explanation for the highly resistant spore phenotype of most FP strains carrying a chromosomal cpe gene, these findings may facilitate eventual development of targeted strategies to increase killing of the resistant spores in foods. They also provide the first indication that SASP variants can be important contributors to intra-species (and perhaps inter-species) variations in bacterial spore resistance phenotypes. Finally, Ssp4 may contribute to spore resistance properties throughout the genus Clostridium since ssp4 genes also exist in the genomes of other clostridial species. Spores made by pathogenic Bacillus and Clostridium spp. contribute to disease transmission. Clostridium perfringens food poisoning (FP) isolates typically produce spores with exceptional resistance to heat and sodium nitrite. This spore resistance probably facilitates FP strain survival in improperly cooked/held foods, contributing to C. perfringens FP outbreaks, which rank among the most common food-borne diseases in developed countries. Currently, the mechanistic basis of the resistant spore phenotype of FP strains is unknown. Here, we report the identification of a novel small acid soluble protein, named Ssp4, and show that sporulating cultures of FP strains producing resistant spores express an Ssp4 variant with Asp at residue 36, while sporulating cultures of C. perfringens strains producing sensitive spores express an Ssp4 with Gly at residue 36. We now demonstrate that i) the Ssp4 Asp variant is required for extreme spore resistance of FP strains and ii) this protein may help protect FP strains via tighter DNA binding than the Ssp4 Gly variant. Our study provides important insights into the transmission of a common FP agent and may suggest strategies to interfere with resistant spores of FP strains. These findings may also have relevance for other pathogenic Clostridium spp. carrying an ssp4 gene.
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研究小酸溶性孢子蛋白（SASP）在裂孔孢子孢子对热的耐药性中的作用。
影响因子：
4.2
作者：
Raju, Deepa;Waters, Michael;Setlow, Peter;Sarker, Mahfuzur R.
通讯作者：
Sarker, Mahfuzur R.
影响因子：
4.4
作者：
Chen, Y;McClane, BA;Gupta, P
通讯作者：
Gupta, P
影响因子：
4
作者：
Tennen, R;Setlow, B;Setlow, P
通讯作者：
Setlow, P
影响因子：
4.4
作者：
Raju, D;Sarker, MR
通讯作者：
Sarker, MR
影响因子：
3.6
作者：
Sayeed, Sameera;Uzal, Francisco A.;McClane, Bruce A.
通讯作者：
McClane, Bruce A.