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.     

Genetic identity and differential gene expression between Trichomonas vaginalis and Trichomonas tenax

Background  

Trichomonas vaginalis is a human urogenital pathogen responsible for trichomonosis, the number-one, non-viral sexually transmitted disease (STD) worldwide, while T. tenax is a commensal of the human oral cavity, found particularly in patients with poor oral hygiene and advanced periodontal disease. The extent of genetic identity between T. vaginalis and its oral commensal counterpart is unknown.     

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.