Isolation and molecular identification of Mycobacterium from commercially available pasteurized milk and raw milk samples collected from two infected cattle farms in Alborz Province, Iran

Publication date: Available online 27 October 2016 Source:International Journal of Mycobacteriology Author(s): M . Eftekhari, N. Mosavari Mycobacterium avium subsb. paratuberculosis (MAP) is an etiological agent of Johne’s disease in ruminant animals, including cattle, sheep, and goats. This disease is considered an economically important disease in cattle. Animals with paratuberculosis shed viable MAP, particularly in their milk and feces. MAP may be involved in the development of Crohn’s disease in humans through the consumption of contaminated milk and dairy products. Common methods of milk pasteurization are not enough to kill all MAP present in the milk, and the bacterium has been isolated from raw milk, pasteurized milk, and cheese samples. The purpose of this study was to evaluate two different methods for detecting MAP in milk and milk products. We analyzed the commonly used methods, culture and molecular biology methods, for the identification of MAP. For this study, 50 milk samples from cows with suspected Johne’s disease located in two dairy farms and 10 commercially available pasteurized milk and cheese samples from the market in Karaj city, Iran were selected. Following Ziehl–Neelsen staining of milk samples, direct microscopic detection of MAP was performed. All milk samples were centrifuged, and the concentrated samples were decontaminated using hexadecyl pyridinium chloride. The decontaminated milk suspensions were washed three times by centrifugin...
Source: International Journal of Mycobacteriology - Category: Infectious Diseases Source Type: research