Five subgroups of Blastocystis hominis isolates from symptomatic and asymptomatic patients revealed by restriction site analysis of PCR‐amplified 16S‐like rDNA

Abstract

SummaryDNA polymorphism of Blastocystis hominis isolates was examined by the amplification of a gene fragment coding for the 16S-like rRNA. Using identical primers, fragments of approximately 850 bp were amplified from 110 B. hominis isolates and fragments of 1.1kbp were amplified from 48 isolates. Digestion of the amplification products with the restriction enzymes HinfI, RsaI, and AluI revealed different profiles for each fragment length. Subgroup I and II, resulting from digestion of the smaller 850 bp fragment, have identical HinfI and AluI restriction bands, subgroup III and IV have identical RsaI fragments after digestion of the 1.1kbp DNA. Subgroup V resembles subgroup III in a few bands after the RsaI and AluI restriction, respectively. Ninety (54%) of the isolates studied were assigned to subgroup I, 20 (12%) to subgroup II, 35 (21%) to subgroup III, 12 (7%) to subgroup IV, and 1 (1%) to subgroup V. Five (3%) of the examined people were coinfected with B. hominis of subgroup I and III, 3 (2%) carried B. hominis of subgroup I and II. These results show that there are 5 B. hominis subgroups none of which was found to be significantly correlated with the reported disease.keywords Blastocystis hominis, 16S-like rDNA, PCR, restriction analysis correspondence Dr. Brigitte Böhm-Gloning,

Comparison of Microscopy, Culture, and Conventional Polymerase Chain Reaction for Detection of Blastocystis sp. in Clinical Stool Samples

“…The following reaction was used: 35 cycles with denaturation at 94°C for 1 minute, annealing at 60°C for 1 minute, and extension at 72°C for 1 min. PCR 2 used primers F1 (5′GGA GGT AGT GAC AAT AAA TC-3′) 22 and BHCRseq3 (5′-TAA GAC TAC GAG GGT ATC TA-3′), 12 which are also specific for the SSU rDNA of Blastocystis. The PCR involved denaturation at 95°C for 7 minutes, 35 cycles at 94°C for 60 seconds, 56°C for 45 seconds, followed by a final extension step at 72°C for 7 minutes.…”

Recent Developments in Blastocystis Research

“…The SSU-rDNA from Blastocystis in humans is genetically extremely diverse; 2. SSU-rDNA from Blastocystis in other hosts can be indistinguishable from that in humans (Böhm-Gloning et al, 1997;Clark, 1997). This meant that host origin was not a reliable indicator of organism identity and that some other means of identifying types of Blastocystis would be necessary.…”

Direct characterization of Blastocystis from faeces by PCR and evidence of zoonotic potential

“…The primary PCR utilized previously published forward and reverse primers (RD3, 5k-GGG ATC CTG ATC CTT CCG CAG GTT CAC CTA C-3k ; RD5, 5k-GGA AGC TTA TCT GGT TGA TCC TGC CAG TA-3k) for PCR amplification under the conditions described by Clark (1997). The secondary PCR utilized previously published forward and reverse primers (forward, 5k-GGA GGT AGT GAC AAT AAA TC-3k ; reverse, 5k-CGT TCA TGA TGA ACA ATT AC-3k) under the conditions described by Bohm-Gloning et al (1997). The PCR was carried out in 0 .…”