Optimization of methods for culturing Mycobacterium avium subsp. paratuberculosis from bovine milk and colostrum and application to samples collected from naturally infected dairy cows

摘要: Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne’s disease (JD), a chronic granulomatous enteritis small intestine ruminants, taking many years for clinical symptoms to develop. Though primarily transmitted through ingestion contaminated feces, MAP also can be milk and colostrum. Unfortunately, other microorganisms are present in along with MAP. Therefore, decontamination protocol must applied before culture. The objective this research was optimize culture recovery from milk. optimal then colostrum samples obtained naturally infected dairy cows over complete 305-day lactation cycles evaluate whether correlation exists between stage JD progression or point concentration shed into Studies found most efficacious consisted exposing solution N-acetyl-Lcysteine-1.5% sodium hydroxide 15 min followed by inoculation BACTEC 12B medium. When collected various stages JD, it that more advanced had higher likelihood shedding likely isolated taken within early (0-60 days milk). This study demonstrated viable route transmission calves, especially when calves susceptible infection JD. Dairy producers should use valuable information change their calf-rearing practices decrease chances disseminating herds.