title: New amino acid germinants for spores of the enterotoxigenic Clostridium perfringens type A isolates.
abstract: Clostridium perfringens spore germination plays a critical role in the pathogenesis of C. perfringens-associated food poisoning (FP) and non-food-borne (NFB) gastrointestinal diseases. Germination is initiated when bacterial spores sense specific nutrient germinants (such as amino acids) through germinant receptors (GRs). In this study, we aimed to identify and characterize amino acid germinants for spores of enterotoxigenic C. perfringens type A. The polar, uncharged amino acids at pH 6.0 efficiently induced germination of C. perfringens spores; L-asparagine, L-cysteine, L-serine, and L-threonine triggered germination of spores of most FP and NFB isolates; whereas, L-glutamine was a unique germinant for FP spores. For cysteine- or glutamine-induced germination, gerKC spores (spores of a gerKC mutant derivative of FP strain SM101) germinated to a significantly lower extent and released less DPA than wild type spores; however, a less defective germination phenotype was observed in gerAA or gerKB spores. The germination defects in gerKC spores were partially restored by complementing the gerKC mutant with a recombinant plasmid carrying wild-type gerKA-KC, indicating that GerKC is an essential GR protein. The gerKA, gerKC, and gerKB spores germinated significantly slower with L-serine and L-threonine than their parental strain, suggesting the requirement for these GR proteins for normal germination of C. perfringens spores. In summary, these results indicate that the polar, uncharged amino acids at pH 6.0 are effective germinants for spores of C. perfringens type A and that GerKC is the main GR protein for germination of spores of FP strain SM101 with L-cysteine, L-glutamine, and L-asparagine.
authors.affiliation: Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA; Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA; Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok, Thailand.
authors.forename: Pathima
authors.initials: P
authors.lastname: Udompijitkul
authors.affiliation: Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Maryam
authors.initials: M
authors.lastname: Alnoman
authors.affiliation: Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA; Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA; Medical Laboratories Department, College of Science Al-Zulfi, Majmaah University, Saudi Arabia.
authors.forename: Saeed
authors.initials: S
authors.lastname: Banawas
authors.affiliation: Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA; Laboratorio de Mecanismos de Patogénesis Bacteriana, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago, Chile.
authors.forename: Daniel
authors.initials: D
authors.lastname: Paredes-Sabja
authors.affiliation: Department of Biomedical Sciences, Oregon State University, Corvallis, OR 97331, USA; Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA. Electronic address: sarkerm@oregonstate.edu.
authors.forename: Mahfuzur R
authors.initials: MR
authors.lastname: Sarker
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003015:Clostridium Infections / Q000382:microbiology; D003016:Clostridium perfringens / Q000254:growth & development / Q000378:metabolism*; D006801:Humans; D013171:Spores, Bacterial / Q000254:growth & development* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins
keywords: Amino acids; Clostridium perfringens; Germinant receptors; Germinants; Spores