According to Reuters Health news, Japanese scientists recently announced that they have sequenced the genome of Clostridium perfringens. The anaerobic (active in the absence of oxygen) pathogen is widely recognized as being a causal organism of gas gangrene in Word War I. However, the organism also can cause diarrhea, scours, and other intestinal problems in horses. Clostridia are normally found in various environments, including soil.

Stephen M. Reed, DVM, Dipl. ACVIM, and Warwick M. Bayly, BVSc, MS, PhD, Dipl. ACVIM, authors of Equine Internal Medicine, wrote that C. perfringens releases a number of toxins and enzymes, some of which have “necrotizing and lethal properties” and cause clinical signs from diarrhea to hemorrhagic necrotizing enterocolitis (bloody, inflammatory disease of the large and small intestine). Signs of this disorder include colic, diarrhea, dehydration, depression, and weakness.

The researchers, led by Tohru Shimizu of the University of Tsukuba, noted that C. perfringens has more than 2,600 genes on its single chromosome, including 20 that are believed to be virulence factors. Five hyaluronidase genes were also recognized, which seem to help the bacteria destroy tissues. Understanding the organism’s genome opens the door for more genetic studies that could find ways to fight gangrene and other infections caused by clostridia.

“No equine vaccine for this bacteria is available,” said Roberta Dwyer, DVM, MS, Dipl. ACVPM, of the University of Kentucky’s Gluck Equine Research Center. “Any new understanding of clostridial organisms is good news for the horse, since they are susceptible to often deadly infections from enterocolitis