Detection of viable Mycobacterium avium subspecies paratuberculosis in powdered infant formula by phage-PCR and confirmed by culture

作者：Botsaris George^*; Swift Benjamin M C; Slana Iva; Liapi Maria; Christodoulou Maritsa; Hatzitofi Maria; Christodoulou Vasiliki; Rees Catherine E D

来源：International Journal of Food Microbiology, 2016, 216: 91-94.

DOI：10.1016/j.ijfoodmicro.2015.09.011

• Paratuberculosis
• Phage
• PCR
• Rapid methods
• Pasteurised milk
• Powdered infant formula

Surveys from different parts of the world have reported that viable Mycobacterium avium subsp. paratuberculosis (MAP) can be cultured from approximately 2% of samples of retail pasteurised milk samples. Pasteurised milk is used for the production of powdered infant formula (PIF) and therefore there is a concern that MAP may also be present in these products. Several studies have previously reported the detection of MAP in PIF using PCR-based assays. However, culture-based surveys of PIF have not detected viable MAP. Here we describe a phage amplification assay coupled with PCR (page-PCR) that can rapidly detect viable MAP in PIF. The results of a small survey showed that the phage-PCR assay detected viable MAP in 13% (4/32) of PIF samples. Culture detected viable MAP in 9% (3/32) PIF samples, all of which were also phage-PCR positive. Direct IS900 PCR detected MAP DNA in 22% (7/32) of PIF samples. The presence of viable MAP in PIF indicates that MAP either survived PIP manufacturing or that post-production contamination occurred. Irrespective of the route of MAP contamination, the presence of viable MAP in PIF is a potential public health concern.

• 出版日期2016-1-4