Study of Candida Species in Stool of Children with Autism Spectrum Disorders in Alexandria, Egypt

Background and Aims: The pathogenesis of Autism spectrum disorders (ASDs) is still controversial. The aim of the present study was to investigate the presence and to identify the species and the antimicrobial sensitivity of Candida present in stool of autistic children.

Subjects and Methods: A total of 50 children with ASD, 36 siblings controls (brother or sister) and 50 healthy controls were enrolled in the study. Stool samples were subjected to examination and culture on Sabouraud dextrose (SDA) and Brilliance Candida selective agars (BCA) (Oxoid, UK) followed by complete identification and antifungal susceptibility disc diffusion testing. DNA extraction was performed for all stool samples and then subjected to multiplex PCR for identification of Candida species.

Results: Out of the 50 ASD stool samples, 23 (46%) were culture positive and 33 (66%) were PCR positive. Of which, 51 different Candida species were isolated. C. glabrata (43.1%) was the most commonly isolated, followed by C. parapsilosis (19.6%), C. tropicalis (17.7%), then C. albicans (9.8%), and C. krusei (9.8%). All C. albicans isolates were sensitive to nystatin, fluconazole and voriconazole. When controls (siblings and healthy) were compared with ASD patients, the rate of Candida isolation was found significantly lower in controls (p value = .019 & p value = .046 respectively). No significant difference was found between Candida positive and negative ASD groups regarding the severity of autism and GIT manifestations.

Conclusion: The present work found that the colonization with Candida spp. did not affect the severity of symptoms in ASD children. However, Future studies should verify whether Candida elimination therapy is useful to manage ASDs symptoms.