Genotyping Trichomonas vaginalis

A genotyping method has been developed to distinguish each Trichomonas vaginalis isolate and has provided the first genome mapping studies of this protist with an estimated 180Mb genome. The technique was developed using high molecular weight DNA prepared from five laboratory isolates from Australia and USA and 20 clinical isolates from South Africa. Inhibition of the notorious T. vaginalis endogenous nucleases by addition of potent inhibitors was essential to the success of this study. Chromosomal DNA larger than 2.2Mb was macrorestricted to a minimum segment size of approximately 50kb, separated by pulsed field gel electrophoresis and hybridised with a variety of gene probes. Each isolate generated a unique pattern that was distinguished by each of the probes. Four single copy gene probes (fd, hmp35, ibp39 and pfoD) were identified but probes which identified several bands (pfoB and alpha-scs) per isolate were most informative for genotyping. The pyruvate:ferredoxin oxidoreductase B gene probe identified two to seven copies of pfoB (or its closely related homologue pfoA) per genome in different isolates and is an obvious candidate probe to identify epidemiological linkage between infections by this genotyping method. Cleavage of the genomes into smaller fragments failed to distinguish isolates from diverse locations indicating the proximal regions of genes are conserved.     

Purification and characterization of pyruvate: ferredoxin oxidoreductase from the anaerobic protozoon Trichomonas vaginalis.

The pyruvate: ferredoxin oxidoreductase from the anaerobic protozoon Trichomonas vaginalis is an extrinsic protein bound to the hydrogenosomal membrane. It has been solubilized and purified to homogeneity, principally by salting-out chromatography on Sepharose 4B. Low recoveries of active enzyme were caused by inactivation by O2 and the irreversible loss of thiamin pyrophosphate. It is a dimeric enzyme of overall Mr 240,000 and subunit Mr 120,000. The enzyme contains, per mol of dimer, 7.3 +/- 0.3 mol of iron and 5.9 +/- 0.9 mol of acid-labile sulphur, suggesting the presence of two [4Fe-4S] centres, and 0.47 mol of thiamin pyrophosphate. The absorption spectrum of the enzyme is characteristic of a non-haem iron protein. The pyruvate: ferredoxin oxidoreductase from T. vaginalis is therefore broadly similar to the 2-oxo acid: ferredoxin (flavodoxin) oxidoreductases purified from bacterial sources, except that it is membrane-bound.     

Purification and specificity of two alpha-glucosidase isoforms of the parasitic protist Trichomonas vaginalis

Two isoforms of alpha-glucosidase were purified from the parasitic protist Trichomonas vaginalis. Both consisted of 103 kDa subunits, but differed in pH optimum and substrate specificity. Isoform 1 had a pH optimum around 4.5 and negligible activity on glucose oligomers other than maltose, while isoform 2 with a pH optimum of 5.5 hydrolyzed also such substrates at considerable rates. Neither had activity on glycogen or starch. Isoform 1 had a specific activity for hydrolysis of maltose of 30 U/mg protein and isoform 2 101 U/mg protein. The Km values were 0.4 mM and 2.0 mM, respectively. Isoform 2 probably corresponds to the activity detected on the cell surface.     

Freeze-fracture study of Trichomonas vaginalis

The freeze-fracture technique was used to analyse the organization of the plasma membrane, as well as membranes of cytoplasmic organelles, of the pathogenic protozoan Trichomonas vaginalis. Rosettes formed by 4 to 14 intramembranous particles were seen on the fracture faces of the membrane lining the anterior flagella as well as in fracture faces of the plasma membrane enclosing the anterior region of the protozoan and in cytoplasmic organelles. Special organization of the membrane particles were also seen in the region of association of the recurrent flagellum to the cell body.     

Acquisition of hydrogenosomal presequences: examples from Trichomonas vaginalis

Presequences play an important role in protein import into mitochondria-like organelles. Acquisition pathways have been revealed for some mitochondrial presequences, but little is known about hydrogenosomal presequences. Here we investigated the hydrogenosomal proteins of Trichomonas vaginalis and suggest that several hydrogenosomal presequences probably evolved from pre-existing sequences that were thereafter modified.     

On Glycolysis in Trichomonas vaginalis

SYNOPSIS. The mechanism of carbohydrate dissimilation was studied in cell-free extracts prepared from mass cultures of the trichomonads. Evidence for the presence of all the enzymes associated with the Embden-Meyerhof glycolytic scheme was obtained. Several enzyme systems directly associated with the glycolytic pathway were examined. Two of these, alcohol dehydrogenase and phosphorylase, were not demonstrated in the T. vaginalis extract. The absence of phosphorylase in the presence of a very high glycogen concentration in the cell (20.8%) suggests the possibility of an alternate route. A very active TPN-linked "malic enzyme" was also demonstrated, although no functional citric acid cycle is known for this trichomonad. Based on the experimental evidence and collateral data, a functional Embden-Meyerhof system was suggested for T. vaginalis.     

阴道毛滴虫染色体组型观察

采用火焰干燥法制备阴道毛滴虫染色体标本,按 Levan等方法,进行核型分析。阴道毛滴虫的染色体数目为n＝10,2n ＝20,染色体的组型为3m、3sm、1st和3T。 Abstract：　The chromosomes ofTrichomonas vaginaliswere prepared by flame-drying method. Data of chromosome were measured and calculated. According to Levan's method, analysis of karyotype was described. The results showed that the chromosome number ofT. vaginalisconsisted of twenty pairs(2n=20) and chromosome type was 3m, 3sm, 1st and 3T.     

阴道毛滴虫染色体组型观察

采用火焰干燥法制备阴道毛滴虫染色体标本,按 Levan等方法,进行核型分析。阴道毛滴虫的染色体数目为n＝10,2n ＝20,染色体的组型为3m、3sm、1st和3T。 Abstract：　The chromosomes ofTrichomonas vaginaliswere prepared by flame-drying method. Data of chromosome were measured and calculated. According to Levan's method, analysis of karyotype was described. The results showed that the chromosome number ofT. vaginalisconsisted of twenty pairs(2n=20) and chromosome type was 3m, 3sm, 1st and 3T.     

Physicochemical and biological properties of an allergen from Trichomonas vaginalis

The chemical and biological characterization of the preparation, found to be strictly specific, is presented. The allergen is nontoxic and has sensitizing properties. The active principle of the preparation is protein.     

Eicosapentaenoic Acid Modulates Trichomonas vaginalis Activity

Trichomonas vaginalis is a sexually transmitted parasite and, while it is often asymptomatic in males, the parasite is associated with disease in both sexes. Metronidazole is an effective treatment for trichomoniasis, but resistant strains have evolved and, thus, it has become necessary to investigate other possible therapies. In this study, we examined the effects of native and oxidized forms of the sodium salts of eicosapentaenoic, docosahexaenoic, and arachidonic acids on T. vaginalis activity. Eicosapentaenoic acid was the most toxic with 190 and 380 μM causing approximately 90% cell death in Casu2 and ATCC 50142 strains, respectively. In contrast, oxidized eicosapentaenoic acid was the least toxic, requiring > 3 mM to inhibit activity, while low levels (10 μM) were associated with increased parasite density. Mass spectrometric analysis of oxidized eicosapentaenoic acid revealed C20 products containing one to six additional oxygen atoms and various degrees of bond saturation. These results indicate that eicosapentaenoic acid has different effects on T. vaginalis survival, depending on whether it is present in the native or oxidized form. A better understanding of lipid metabolism in T. vaginalis may facilitate the design of synthetic fatty acids that are effective for the treatment of metronidazole‐resistant T. vaginalis.