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.