An automated method for the detection of staphylococcal heat stable deoxyribonuclease in dairy products

Abstract

1999. An automated sandwich immunoassay with specific polyclonal antibodies for the detection of Staphylococcus aureus thermostable nuclease (DNase) is described. To evaluate this assay, different quantities of purified S. aureus nuclease were added to dairy products. Additionally, staphylococcal counts and nuclease activity of milk samples inoculated with S. aureus were determined. Different extraction procedures were performed and compared. The results indicated that the automated test was a reliable method for detecting DNase activity in milk products. The procedure was completed in 2 h and detected 1 ng of DNase ml −1 . Detection of the DNase was especially useful in cheeses and could be used to confirm positive enterotoxin results.

Facing Antibiotic Resistance: Staphylococcus aureus Phages as a Medical Tool

“…This makes it possible for S. aureus to be found in cheeses made from either raw or pasteurized milk [22]. Furthermore, an initial population of 10 3 cfu mL −1 of S. aureus in milk may be sufficient for the production of enterotoxin A in cheese at detectable levels [21,23]. Therefore, all new strategies to prevent growth of this bacterium are desirable in the food industry.…”

Occurrence and characterization of Staphylococcus aureus isolated from raw milk for cheesemaking

“…2003). As DNase is synthesized under the same conditions as those described for staphylococcal enterotoxins, and it exhibits the same stability in foods under all conditions of processing or storage (Tatini 1981), DNase activity detection has been suggested to confirm positive enterotoxin results by Meyrand et al. (1999), who found an excellent correlation between the presence of DNase and enterotoxin production.…”

Quantification of Staphylococcus aureus in white cheese by the improved DNA extraction strategy combined with TaqMan and LNA probe-based qPCR

“…The target gene, the thermostable nuclease enzyme that is encoded by the nuc gene, is expressed under similar conditions and shows comparable stability properties with staphylococcal enterotoxins (Brakstad et al, 1992;Meyrand et al, 1999;Tang et al, 2008). Therefore, the laborious and expensive methods used for detection of enterotoxins in routine analysis of food products can be replaced by the detection of the nuc gene (Szabo, 2001).…”