Comparison of transport media for the isolation and detection of Brachyspira hyodysenteriae

Brachyspira (B.) hyodysenteriae is a causative agent of swine dysentery that is responsible for death and economic losses in the pig industry. It is imperative that clinical samples be delivered fresh for accurate diagnosis. The viability and DNA detection of B. hyodysenteriae using lab-made (phosphate buffered saline and modified tryptic soy broth) or commercial transport media (C, D, and E) were compared by culturing and real-time PCR at 4°C or room temperature (RT), respectively. B. hyodysenteriae grown in D (Anaerobe Systems, USA) and E (Starplex Scientific, Canada) media was viable for 4 days at 4°C and RT. However, B. hyodysenteriae in A, B, and C (culture swab; BD Biosciences, USA) media were not recovered after 2 days at RT. Ct values for real-time PCR at 4°C and RT ranged from 27.2 ± 2.1 (C) to 29.6 ± 0.5 (B), and 28.0 ± 0.9 (E) to 30.2 ± 1.5 (B), respectively. Considering the field conditions, it is important that transport media is used for specimen isolation and PCR to obtain an accurate diagnosis of swine dysentery.