Arbitrarily primed polymerase chain reaction for fingerprinting the genotype identification of mutans streptococci in children with Down syndrome

This study investigated the possible intrafamilial similarity of mutans streptococcal strains in some families with a child with Down syndrome using chromosomal DNA fingerprinting. The isolates were genotyped using arbitrarily primed polymerase chain reaction with the OPA 02 and OPA 03 primers. The results showed that five children with Down syndrome harbored mutans strep-tococol genotypes different from those of their mothers. A matching of genotypes was observed within the control pair (mother/child without Down syndrome). After six months, new samples were collected from all participants. Analysis showed that samples from children with Down syndrome ware colonized by a new strain of Streptococcus mutate, that did not match the previously collected one. The results suggest the S. means Indigenous bacteria change more then once In children with Down syndrome.