Detection of Mycobacterium avium subspecies paratuberculosis genetic components in retail cheese curds purchased in Wisconsin and Minnesota by PCR.
Research has been focused on the detection of Mycobacterium avium subspecies paratuberculosis (MAP) in pasteurized milk; however, pasteurized milk is a key ingredient in a variety of food products. Therefore, MAP contamination in milk-derived products must be investigated. We undertook a six-month study to investigate the presence of viable MAP and MAP genetic components in cheese curds purchased from retail outlets in the northern and southern regions of Wisconsin and Minnesota. A total of 98 retail cheese curd samples were tested for MAP by PCR prescreen, culture on Herrold's egg yolk agar slants with mycobactin J and amphoteracin B, naladixic acid, and vancomycin, and slant rinse PCR using IS900 and hspX primer sets. Although no viable MAP were able to be cultured, 5% of the samples were PCR positive with both the IS900 and hspX primer sets (MAP-specific DNA) when prescreened and 1% of the samples were PCR positive with both the IS900 and hspX primer sets when culture slants were rinsed and tested.
Marshfield Clinic Laboratories-Food Safety Services, Marshfield Clinic, 1000 North Oak Avenue, WI 54449, USA.
Dorn L
DL
Clark
Jennifer L
JL
Anderson
Jeff J
JJ
Koziczkowski
Jay L E
JL
Ellingson
D000818:Animals; D002417:Cattle; D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D008910:Minnesota; D016927:Mycobacterium avium subsp. paratuberculosis / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods*; D013242:Sterilization; D014922:Wisconsin
D017931:DNA Primers; D004269:DNA, Bacterial