Figure 1.
PCR-RFLP analysis of Giardia isolates.
Panel A: Gelred (Biotium) stained 3.5% MetaPhor agarose gel (Cambrex) showing electrophoretic separation of nested β-giardin PCR products (511 bp) after digestion with HaeIII: lane 1, assemblage A (novel pattern Sweh166, 173, 178); lane 2, assemblage A (ordinary pattern); lane 3, assemblage B (ordinary pattern), lane 4, assemblage B (novel pattern Sweh198); lane 5, assemblage B (mixed pattern). Panel B: Electrophoretic separation of nested tpi PCR products (530 bp) after digestion with DdeI: lane 1, assemblage A; lane 2, assemblage B (ordinary pattern); lane 3, assemblage B (novel pattern Sweh121), lane 4, assemblage B (novel pattern Sweh154); lanes 5, 6 and 7, assemblage B (mixed patterns). Panel C: Electrophoretic separation of semi-nested gdh PCR products (432 bp) after digestion with NlaIV: lane 1, assemblage AII; lane 2, assemblage AI; lanes 3 and 4, assemblage B; lanes 5 and 6, assemblage B (mixed patterns). Molecular size markers (M) are 50-bp ladders (Invitrogen).
Table 1.
Distribution of assemblages among 207 isolates determined by PCR-RFLP and assemblage A- and B-specific PCR.
Table 2.
Molecular characterization of isolates from patients presenting with mixed assemblage A and B infections.
Table 3.
Characterization of 67 assemblage A isolates* based on sequencing data and assemblage-specific PCR.
Figure 2.
Nucleotide maximum likelihood trees based on concatenated datasets for ß-giardin, gdh, and tpi gene sequences.
MLGs with unambiguous sequences identified in this study (Table 3 and 4) are combined with reference isolates and isolates from our previous MLG study of animals in Sweden [20] (Supplementary Table S1). (A) Phylogenetic tree based on 1884 aligned positions of assemblage A isolates. Isolates identified in the present study are indicated in red. (B) Phylogenetic tree based on 1358 aligned positions of 17 assemblage B MLGs identified in our present and our previous study [20]. BIII (red) and BIV (blue) isolates are assigned according to their clustering with reference isolates in phylogenetic trees of the individual genes (Fig. S1). Only bootstrap support values >50% are shown.
Table 4.
Characterization of 31 assemblage B isolates based on the ß-giardin, gdh, and tpi gene sequences*.
Table 5.
Probable area of origin of infection in 214 giardiasis patients presented in relation to assemblages.
Table 6.
Symptoms of 145 giardiasis patients in relation to assemblage (mixed infections with other enteropathogens excluded).*