ABSTRACT
Blastocystis sp. has been described as the most common intestinal parasite in humans and has an increased impact in public health. To improve our understanding of the molecular epidemiology of this human-emerging parasite, we determined the Blastocystis subtypes (STs) and their relative frequency in Egyptian patients living in or in the vicinity of Cairo and presenting gastrointestinal symptoms. We obtained a total of 20 stool samples identified as positive for Blastocystis by microscopic examination of smears. Genotyping using partial small subunit ribosomal RNA gene analysis identified a total of 21 Blastocystis isolates corresponding to 19 single infections and one mixed infection (ST1 and ST3). Three STs were identified: ST3 was the most common ST in the present Egyptian population (61.90%) followed by ST1 (19.05%) and ST2 (19.05%). Together with previous studies carried out in different areas in Egypt, a total of five STs (ST1, ST2, ST3, ST4, and ST6) have been found in symptomatic patients. These data were compared to those available in the literature, and we underlined variations observed in the number and relative proportions of STs between and within countries. On the whole, it seemed that Blastocystis infection is likely not associated with specific STs even if some STs are predominant in the epidemiologic studies, but rather with a conjunction of factors in the course of infection including environmental risk and parasite and host factors.
Subject(s)
Blastocystis Infections/epidemiology , Blastocystis Infections/parasitology , Blastocystis/classification , Blastocystis/genetics , Adolescent , Adult , Blastocystis/isolation & purification , Child , Cluster Analysis , DNA, Protozoan/chemistry , DNA, Protozoan/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Egypt/epidemiology , Feces/parasitology , Female , Gastroenteritis/epidemiology , Gastroenteritis/parasitology , Genes, rRNA , Humans , Male , Middle Aged , Molecular Epidemiology , Molecular Sequence Data , Phylogeny , RNA, Protozoan/genetics , RNA, Ribosomal, 18S/genetics , Sequence Analysis, DNA , Young AdultABSTRACT
A new Tetratrichomonas species was identified by molecular and phylogenetic approaches in the pleural fluid from a patient with encysted empyema leading to dyspnea. This observation raised the questions of the real prevalence of pulmonary trichomonosis in humans, the zoonotic potential of trichomonads, and the existence of human-host-adapted strains.
Subject(s)
Empyema, Pleural/parasitology , Protozoan Infections/diagnosis , Protozoan Infections/parasitology , Trichomonadida/classification , Trichomonadida/isolation & purification , Adult , Animals , Cluster Analysis , DNA, Protozoan/chemistry , DNA, Protozoan/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Female , Genes, rRNA , Humans , Molecular Sequence Data , Phylogeny , RNA, Protozoan/genetics , RNA, Ribosomal, 5.8S/genetics , Radiography, Thoracic , Sequence Analysis, DNA , Trichomonadida/geneticsABSTRACT
Blastocystis sp. is the most common eukaryotic parasite in the intestinal tract of humans. Due to its strong impact in public health, in this study, we determined the frequency of different Blastocystis subtypes in patients in France. We hypothesized on the mode of transmission and tested a possible relationship between the subtype and symptomatic status. We obtained a total of 40 stool samples identified as positive for Blastocystis by microscopic examination of smears. Participants consisted of 25 symptomatic and 15 asymptomatic patients, for whom clinical and parasitological data were collected. For nested-polymerase chain reaction and genotyping, DNA was extracted directly from fecal samples or from fecal cultures. Morphological forms observed in fecal cultures were uncorrelated with symptomatic status. Genotyping using partial small subunit rRNA gene analysis identified a total of 43 Blastocystis isolates corresponding to 37 single infections and three mixed infections by two different subtypes. These 43 isolates belonged to five subtypes (1, 2, 3, 4, and 7) with predominance of subtype 3 (53.5%). Patient symptomatic status was uncorrelated with Blastocystis subtype.
