| a three nucleotide signature sequence in small subunit rrna divides human giardia in two different genotypes. | the nucleotide sequence of the 16s rrna gene and the space dna region was determined for giardia duodenalis, obtained from humans in the netherlands (amc-4) and washington state (cm). these rdna sequences differ from other g. duodenalis isolates (portland-1 and bris/83/hepu/ 106) both of which have virtually identical rdna sequences. the most characteristic feature was found close to the 5' end of the 16s rrna. the portland-1 -bris/83/hepu/ 106 type has gcg in position 22-24, while amc-4 and cm ... | 1995 | 7620463 |