Clostridium Perfringens: Bacillus Welchii

Clostridium perfringens, formally known as C. welchii or Bacillus welchii, is a gram-positive, rod-shaped, anaerobic, spore forming bacterium. The first association C. perfringens had with gastrointestinal disease was in the 1920s (Songer, 1996). The next case was post-World War 1, in Germany, in the 1940s, when it caused gangrene of the bowel, enteritis necroticans. Since then, C. perfringens has been the most commonly associated with gas gangrene (Lawrence et al., 1997). In 1950, there was a confirmed food poisoning case that linked back to C. perfringens (McDonel, 1986). It was not until the late 1970s that there was a relationship made between equine enteric disease and C. perfringens. However, it was not extensively studied until 1977,

perfringens type A in the feces of racehorses suffering from colitis in comparison to the lower levels detected in healthy horses (Borriello, 1995). Currently, C. perfringens is associated with causing severe colitis in horses, yet can sometimes be ingested without causing any harm. Therefore, it is vital to understand what type of strain and toxins are causing gastrointestinal diseases and how to control and prevent them.

C. perfringens, Bacteria (Domain), Firmicutes (Phylum), Clostridia (Class), Clostridiales (Order), Clostridiaceae (Family), Clostridium (Genus), C. perfringens (Species), is found in the intestinal tract as well as decaying vegetation, marine sediment, and soil (Herholz et al., 1999). This bacterium is a mesophile with optimum growing temperatures at 37° C. It is non-motile, but has the ability to

perfringens is the most common cause of foodborne illness in the United States, with a million cases each year (CDC, 2014). C. perfringens is able to produce up to 15 different toxins, making it versatile. These toxins are used to isolate the five different types of C. perfringes: type A, B, C, D, and E. The four toxins that are primarily used to isolate the different types include alpha, beta, epsilon, and iota-toxins. Type A is the most common and most variable, and subdivided into entertoxigenic and non-enterotoxigenic strains (Herholz et al., 1999). Enterotoxigenic type A and C are associated with equine enterocolitis, gas gangrene, infections, avian and canine necrotic enteritis, colitis in horses, and diarrhea in pigs (Divers and Ball, 1996). Types B, C, D, and E can cause severe enteritis, dysentery, toxemia, and high mortality rates in young lambs, calves, pigs, and foals. Types B, C, D, and E have been intermittently associated with foal enterocolitis, and equine antibiotic associated diarrhea (Divers and Ball, 1996). Even though the alpha toxin is noted to be relatively nonpathogenic, the beta2 toxin plays a significant role in digestive disease, specifically, enterocolitis in equine (Herholz et al., 1999). This is mainly due to the C. perfringens entertoxin (CPE), the main virulence factor that initiates many critical gastrointestinal diseases across species (Herholz et al. 1999). CPE works in a four-step mechanism against membrane action (CDC, 2014). First,