UBE3A and bacterial infectious disease: Environmental toxins like lead, mercury, formaldehyde, pesticides and asbestos [80,78], food containing propionic acid, sodium benzoate and benzoic acid ([67,91]), genes like MAPK3 (mitogen-activated protein kinase 3) and UBE3A (ubiquitin-protein ligase E3A) [66], bacterial infection like R. Torques, and virus in the family Herpesviridae are the major etiological factors behind autism [83,48].