Studies on the Use of the Microbilogical Methods in Screening for Mental Retardation

The study of mental retardation is undoubtedly, one . of the modern pediatrician s- priorities. At one time the mentally retarded child was hidden by his family away from the public gaze and even from the medical profession, but at present he receives more care and attention,Ninty two subjects, clinically suspected of .suffer¬ing from mental retardation and aged 6 months to 37 years, were examined for metabolic disorders of the following amino acids.-phenyl alanine, lysine, histidine, tyrosine , methionine, and cystine. The blood and urine of each sub¬ject were examined for the, presence of excess any of thelast mentioned amino acids using three methods Bacterial inhibition assay Auxotrophic assay and paper chromatography.Bacterial inhibition as, say method is an agar diffu¬sion, method based upon prevention of the inhibition of growth of B. subtilus (wild type) by a specific antagonist for the amino acid in question in a. minimal culture medium due to the specific amino acid in blood or urine of a patient. Auxotrophic assay method depends upon initiation of growth of the. specific auxotrophic mutants of B. subtilus by the presence of the elevated specific amino acid.