Prevalence of beta 2-toxigenic Clostridium perfringens in horses with intestinal disorders

The incidence of a new, yet unassigned toxin type of Clostridium perfringen s containing the genes for the alpha-toxin and the recently described beta 2-toxin in horses with intestinal disorders is reported. The study included 18 horses suffering from typical typhlocolitis, 7 horses with atypical typ hlocolitis, 16 horses with other intestinal disorders, and 58 horses withou t intestinal disease. In total, 20 samples of ingesta of the small and larg e intestines, five biopsy specimens of the intestinal wall, and 74 fecal sa mples were analyzed bacteriologically, C. perfringens isolates were typed f or the presenceof the alpha-, beta-, beta 2-, and epsilon-toxin and enterot oxin genes by PCR, including a newly developed PCR for the detection of the beta 2-toxin gene cpb2, beta 2-Toxigenic C. perfringens was detected in sa mples from 13 of 25 (52%) horses with typical or atypical typhlocolitis, wi th a particularly high incidence in specimens of ingesta and biopsy specime ns (75%), whereas only 6 of 16 specimens from horses with other intestinal diseases yielded PZ-toxigenic C. perfringens. No beta 2-toxigenic C, perfri ngens was found in the samples from the 58 control horses, of which only on e fecal sample contained C, perfringens type A. Among the samples from the 15 horses with fatal cases of typical and atypical typhlocolitis 9 (60%) we re positive for beta 2-toxigenic C. perfringens, whereas samples from only 4 of the 10 (40%) animals with nonfatal cases of infection were positive. W e found an interesting correlation between the antibiotic-treated horses wh ich were positive for beta 2-toxigenic C. perfringens and lethal progressio n of the disease. No C, perfringens strains isolated in this study containe d genes for the beta- and epsilon-toxins and enterotoxin. The high incidenc e of beta 2-toxigenic C. perfringens in samples of ingesta, biopsy specimen s of the intestinal wall, and feces from horses suffering or dying from typ hlocolitis together with the absence of this organism in healthy horses pro vides strong evidence that beta 2-toxigenic C. perfringens play an importan t role in the pathogenesis of typhlocolitis.