Prevalent toxin types of Clostridium botulinum in South Korean cattle farms

Clostridium botulinum produces neurotoxic substrates that can cause fatal flaccid paralysis called botulism. These neurotoxins are classified into types A–G. Several botulism cases were recorded in 2012–2013 in the Gyeonggi province, South Korea. We assessed the distribution of C. botulinum types B, C, and D in several South Korean farms. A total of 184 samples collected in 2012–2013, including feces (n = 72), hay and silage (n = 50), soil (n = 26), water trough (n = 21), and stomach contents (n = 15), were subjected to multiplex polymerase chain reaction (PCR) to screen for types B, C, and D. Twenty-four samples tested PCR-positive as follows: type B (n = 11), type C/D (n = 4), and type D (n = 18). Eight of the 11 type B samples were detected in hay and silage. Sixteen of the 18 type D samples were detected in fecal and stomach content samples. PCR-positivity was observed in fecal (n = 9, 12.5%), hay and silage (n = 10, 20.0%), water trough (n = 2, 9.5%), and stomach content (n = 12, 80.0%) samples. Fourteen (42.4%) C. botulinum-positive samples were isolated from the PCR-positive samples (type B [n = 8], type C/D [n = 1], and type D [n = 5]). Our findings demonstrate that C. botulinum types B, C/D, and D were prevalent in South Korean cattle farms between 2012 and 2013.