Toxin profile of fecal Clostridium perfringens strains isolated from children with autism spectrum disorders.

Infectious factors are taken into consideration in pathophysiology of autism spectrum disorders (ASD). ASD patients often suffer from gastrointestinal disorders. The intestinal microbiota of autistic patients significantly differs from that in healthy individuals. The aim of the study was to compare the profile of toxins produced by C. perfringens strains isolated from feces of children with ASD, with healthy individuals and obese subjects. This study included 111 strains of C. perfringens: 49 isolates from 29 children with ASD, 30 - from 17 healthy individuals and 32 - from 24 young obese subjects. Alpha, beta, beta2, epsilon, iota and enterotoxin genes were detected using appropriate PCRs. The alpha toxin gene (cpa) was present in all 111 examined strains (100%). The beta2 gene (cpb2) was detected in 45/49 strains (91.8%) isolated from children with ASD, 17/30 (56.7%) isolates from healthy subjects, and 12 of 32 (37.5%) isolates from obese subjects. C. perfringens strains with cpb2 gene were detected in 27/29 ASD patients (93.1%), 10/17 healthy subjects (58.8%) and 11/24 (45.8%) obese subjects. Beta2 toxin encoding cpb2 gene was significantly more common in strains isolated from ASD patients, with no significant difference between control subjects regardless of diet. Further research to explain observed phenomena and pathomechanism of beta2 toxin is required.