title: CodY Promotes Sporulation and Enterotoxin Production by Clostridium perfringens Type A Strain SM101.
abstract: Clostridium perfringenstype D strains cause enterotoxemia and enteritis in livestock via epsilon toxin production. In type D strain CN3718, CodY was previously shown to increase the level of epsilon toxin production and repress sporulation.C. perfringenstype A strains producingC. perfringensenterotoxin (CPE) cause human food poisoning and antibiotic-associated diarrhea. Sporulation is critical forC. perfringenstype A food poisoning since spores contribute to transmission and resistance in the harsh food environment and sporulation is essential for CPE production. Therefore, the current study asked whether CodY also regulates sporulation and CPE production in SM101, a derivative ofC. perfringenstype A food-poisoning strain NCTC8798. An isogeniccodY-null mutant of SM101 showed decreased levels of spore formation, along with lower levels of CPE production. A complemented strain recovered wild-type levels of both sporulation and CPE production. When this result was coupled with the earlier results obtained with CN3718, it became apparent that CodY regulation of sporulation varies among differentC. perfringensstrains. Results from quantitative reverse transcriptase PCR analysis clearly demonstrated that, during sporulation,codYtranscript levels remained high in SM101 but rapidly declined in CN3718. In addition,abrBgene expression patterns varied significantly betweencodY-null mutants of SM101 and CN3718. Compared to the levels in their wild-type parents, the level ofabrBgene expression decreased in the CN3718codY-null mutant strain but significantly increased in the SM101codY-null mutant strain, demonstrating CodY-dependent regulation differences inabrBexpression between these two strains. This difference appears to be important since overexpression of theabrBgene in SM101 reduced the levels of sporulation and enterotoxin production, supporting the involvement of AbrB repression in regulatingC. perfringenssporulation.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
authors.forename: Jihong
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Freedman
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Evans
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA bamcc@pitt.edu.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: McClane
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003015:Clostridium Infections / Q000382:microbiology; D003016:Clostridium perfringens / Q000502:physiology*; D004768:Enterotoxins / Q000096:biosynthesis*; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D009154:Mutation; D013171:Spores, Bacterial / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004768:Enterotoxins; D014157:Transcription Factors
keywords: Clostridium perfringens; CodY; enterotoxin; food poisoning; gene regulation; sporulation