An outbreak of staphylococcal food poisoning caused by enterotoxin H in mashed potato made with raw milk

Abstract

Mashed potato made with raw bovine milk was suspected to have been the source of a food poisoning outbreak. Almost 8 x 10(8)Staphylococcus aureus CFU g(-1) were detected in the mashed potato. S. aureus was also found in bulk milk from the farm that had supplied milk for the mashed potato. Isolates from mashed potato and bulk milk were positive for the gene encoding staphylococcal enterotoxin H (seh), and the corresponding protein toxin, SEH, was detected by ELISA in the mashed potato. Production of SEH by S. aureus isolates from mashed potato (n = 4) and bulk milk (n = 4) was also demonstrated by ELISA. Sequencing of seh from one mashed potato isolate and one bulk milk isolate confirmed that the gene was a variant seh, and that the genes in both isolates were identical. Macrorestriction of chromosomal DNA with Sma1 followed by pulsed-field gel electrophoresis of seh-positive S. aureus from mashed potato and bulk milk revealed indistinguishable banding patterns between isolates from both sources. It seems likely that raw bovine milk used in the preparation of mashed potato contained S. aureus that subsequently produced sufficient SEH in the mashed potato to cause food poisoning.

Enterotoxigenic potential of Staphylococcus aureus isolated from Artisan Minas cheese from the Serra da Canastra - MG, Brazil

“…Counts from all samples were higher than 2.0 log cfu.g -1 , which is the maximum limit allowed by the Brazilian legislation. Approximately one third of the Canastra cheese samples were within the ranges indicated in the literature (>5 log cfu.g -1 ) as those likely to produce enterotoxins (IKEDA et al, 2005;JØRGENSEN et al, 2005;ZWEIFEL et al, 2006).…”

“…The lack of correlation between the results from biochemical and molecular assays have already been observed in the literature (McLAUCHLIN et al, 2000;ROSEC;GIGAUD, 2002;JØRGENSEN et al, 2005). Jørgensen et al (2005) and Kérouanton et al (2007) suggested the possibility of variations in the sequences of the analyzed genes, which could hinder the proper annealing of the primers in the PCR reaction.…”

“…Jørgensen et al (2005) and Kérouanton et al (2007) suggested the possibility of variations in the sequences of the analyzed genes, which could hinder the proper annealing of the primers in the PCR reaction. Analysis of DNA sequences could be a solution to reveal…”

Combined application of origanum vulgare l. essential oil and acetic acid for controlling the growth of staphylococcus aureus in foods

“…Twenty different types of SEs, i.e., SEA-SEE, SEG-SER, and SEU have already been discovered, however SEA-SEE are the most common enterotoxins involved in staphylococcal food poisoning (20). These toxins are heat stable, resistant to gut proteases, and stable over a wide range of pH (pH 4-10) (37).…”

Production of staphylococcal enterotoxins in food

“…Trzy lata później w Norwegii stwierdzono szereg przypadków zatruć pokarmowych związanych ze spożyciem mleka. W zanieczyszczonym mleku nie wykryto enterotoksyn SEA-SEE, a jedynie SEH w stężeniu 56 ng/g (19).…”