Glycoconjugates have been shown to play important roles in Leishmania development. However, the ability to study these molecules and other processes would benefit greatly from improved methods for genetic manipulation and analysis of the amastigote stage. This is especially challenging for L. donovani, the agent of the most severe form of leishmaniasis, which can rapidly lose virulence during i...

Glass wool, hydrophilic cotton wool, non-electrically charged BIO-GEL P2 and common tissue paper columns were used to purify trypomastigotes from a mixed Trypanosoma cruzi population grown in axenic culture medium. With all these columns, highly purified (up to 98%) trypomastigote preparations were obtained. Trypomastigote yields from cotton wool, BIO-GEL P2 and common tissue paper columns were...

The frequent re-isolation of known compounds is one of the major challenges in drug discovery. Many biosynthetic genes are not expressed under standard culture conditions, thus limiting the chemical diversity of microbial compounds that can be obtained through fermentation. On the other hand, the competition during co-cultivation of two or more different microorganisms in most cases leads to an...

Mutants that have been selected for defects in phagocytic recognition, adhesion, and vegetative cell-cell cohesion were found to be larger and more highly multinucleate than their parent strain. This defect is associated with the complex mutant phenotype of these mutants since revertants of the mutants coordinately acquire the wild-type phenotype for all of the defects. The larger size and mult...

Amastigogenesis occurs first when metacyclic trypomastigotes from triatomine urine differentiate into amastigotes inside mammalian host cells and a secondary process when tissue-derived trypomastigotes invade new cells and differentiate newly to amastigotes. Using scanning electron microscopy, we compared the morphological patterns manifested by trypomastigotes and metacyclic forms of Trypanoso...

In vitro cultured monolayers of normal human vaginal epithelial cells were incubated with axenic cultures of Trichomonas vaginalis. Two strains freshly isolated from patients with trichomoniasis and one strain that had been maintained in axenic culture for several years were studied. Freshly isolated trichomonads showed amoeboid movements, adherence to epithelial cell surfaces, and were cytotox...

A strategy to obtain axenic cultures of the cyanobacterium Arthrospira sp. ('platensis') Lefevre 1963/M-132-1 strain, consisting of a series of physical and chemical procedures, and the application of an optimized pool of antibiotics, is described in this paper. This strategy, which is an inexpensive and fast way to obtain axenic cultures, can be applied to Arthrospira spp. from culture collect...

Biofilm communities in the euphotic zone of aquatic habitats comprise photoautotrophic microorganisms, such as diatoms, green algae and cyanobacteria, which produce the organic carbon that fuels the life of a heterotrophic contingent of microorganisms, mostly bacteria. Such photoautotrophic-heterotrophic mixed-species biofilms have received little attention in biofilm research due to a lack of ...

The formal description of Prochlorococcus marinus Chisholm et al. 1992, 299 was based on the non-axenic nomenclatural type, strain CCMP 1375T. The purification and properties of the axenic strain PCC 9511, derived from the same primary culture (SARG) as the type species, are reported here. Prochlorococcus PCC 9511 differs from the latter in possessing horseshoe-shaped thylakoids, exhibiting a l...