Isolation and characterization of a psychrotolerant toxin producer, Bacillus weihenstephanensis, in liquid egg products.
A psychrotolerant bacteria of the Bacillus cereus group was found responsible for the spoilage of whole liquid egg products. By sequencing a 16S rRNA region and performing a PCR amplification of specific 16S rRNA and cspA signatures, a Bacillus weihenstephanensis was identified. Characterization of this strain shows its ability to grow in defined medium as well as in whole liquid egg at refrigerated temperatures. The strain isolated possesses genes encoding for hemolysin BL, nonhemolytic enterotoxin, and B. cereus enterotoxins and produces enterotoxins with cytotoxic activity in whole liquid egg, even at refrigerated temperatures. The isolate exhibits a clear ability to stick and form biofilms on stainless steel, the most common material used in egg breaking factories, as well as on model hydrophilic (glass) and hydrophobic (polytetrafluoroethylene) materials. These findings show the necessity to monitor for Bacillus contamination in egg products that are often used in the composition of particularly susceptible finished products such as cream, dessert, dairy, meat, and seafood.
Baron
Florence
F
Unit Mixte de Recherche Science et Technologie du Lait et de l'Oeuf equipe de Microbiologie, Agrocampus Rennes-INRA, 65 rue de Saint Brieuc, 35042 Rennes, France. florence.baron@agrocampus-rennes.fr
Cochet
Marie-Françoise
MF
Grosset
Noël
N
Madec
Marie-Noëlle
MN
Briandet
Romain
R
Dessaigne
Sabine
S
Chevalier
Séverine
S
Gautier
Michel
M
Jan
Sophie
S
D000818:Animals; D001407:Bacillus / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004531:Eggs / Q000382:microbiology*; D004768:Enterotoxins / Q000096:biosynthesis; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D005784:Gene Amplification; D006801:Humans; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013696:Temperature
D004269:DNA, Bacterial; D004768:Enterotoxins; D012336:RNA, Ribosomal, 16S