title: Cereulide-producing strains of Bacillus cereus show diversity.
abstract: Producers of cereulide, the emetic toxin of Bacillus cereus, are known to constitute a specific subset within this species. We investigated physiological and genetic properties of 24 strains of B. cereus including two high cereulide producers (600-1,800 ng cereulide mg(-1) wet weight biomass), seven average producers (180-600 ng cereulide mg(-1) wet weight biomass), four low cereulide producers (20-160 ng cereulide mg(-1) wet weight biomass) and 11 non-producers representing isolates from food, food poisoning, human gut and environment. The 13 cereulide producers possessed 16S rRNA gene sequences identical to each other and identical to that of B. anthracis strains Ames, Sterne from GenBank and strain NC 08234-02, but showed diversity in the adk gene (two sequence types), in ribopatterns obtained with EcoRI and PvuII (three types of patterns), in tyrosin decomposition, haemolysis and lecithin hydrolysis (two phenotypes). The cereulide-producing isolates from the human gut represented two ribopatterns of which one was novel to cereulide-producing B. cereus and two phenotypes. We conclude that the cereulide-producing B. cereus are genetically and biochemically more diverse than hitherto thought.
authors.affiliation: Department of Applied Chemistry and Microbiology, University of Helsinki, P.O. Box 56, Viikinkaari 9, 00014 Helsinki, Finland.
authors.forename: Camelia
authors.initials: C
authors.lastname: Apetroaie
authors.forename: Maria A
authors.initials: MA
authors.lastname: Andersson
authors.forename: Cathrin
authors.initials: C
authors.lastname: Spröer
authors.forename: Irina
authors.initials: I
authors.lastname: Tsitko
authors.forename: Ranad
authors.initials: R
authors.lastname: Shaheen
authors.forename: Elina L
authors.initials: EL
authors.lastname: Jääskeläinen
authors.forename: Luc M
authors.initials: LM
authors.lastname: Wijnands
authors.forename: Ritva
authors.initials: R
authors.lastname: Heikkilä
authors.forename: Mirja S
authors.initials: MS
authors.lastname: Salkinoja-Salonen
mesh_terms: D000262:Adenylyl Cyclases / Q000235:genetics; D001408:Bacillus anthracis / Q000235:genetics; D001409:Bacillus cereus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D015246:Deoxyribonuclease EcoRI / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D047630:Depsipeptides / Q000096:biosynthesis*; D004783:Environmental Microbiology; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000382:microbiology; D041981:Gastrointestinal Tract / Q000382:microbiology; D014644:Genetic Variation; D006461:Hemolysis; D008969:Molecular Sequence Data; D010713:Phosphatidylcholines / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D021521:Ribotyping; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014443:Tyrosine / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D047630:Depsipeptides; D010713:Phosphatidylcholines; D012336:RNA, Ribosomal, 16S; C089294:cereulide; D014443:Tyrosine; D015246:Deoxyribonuclease EcoRI; C025630:CAGCTG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific; D000262:Adenylyl Cyclases