Release the iron: does the infection of magnetotactic bacteria by phages play a role in making iron available in aquatic environments?

Magnetotactic bacteria(MTB)are ubiquitous prokaryotes that orient along magnetic field lines due to magnetosomes’biomineralization within the cell.These structures are ferrimagnetic organelles that impart a magnetic moment to the cell.To succeed in producing magnetosomes,MTB accumulate iron in(i)cytoplasm;(ⅱ)magnetosomes;and(ⅲ)nearby the organelle.It has already been estimated that a single MTB has an iron content of 10 to 100-fold higher than Escherichia coli.Phages are the most abundant entity in oceans and are known for controlling nutrient flow such as carbon and nitrogen by viral shunt and pump.The current work addresses the putative role of phages that infect MTB on the iron biogeochemical cycle.Can phage infection in MTB hosts cause a biogenic iron fertilization-like event in localized microenvironments?Are phages critical players in driving magnetosome biomineralization genes(BGs)horizontal transfer?Further investigation of those events,including frequency of occurrence,is necessary to fully comprehend MTB’s effect on iron cycling in aqueous environments.

Ultrastructural and enzymatic alterations in the ovary of Rhodnius prolixus infected with Trypanosoma rangeli

Objective:To investigate the morphological structure of ovarian follicular cells and biochemical parameters of both ovaries and fat bodies(sites of vitellogenesis)from Rhodnius(R.)prolixus infected with Trypanosoma(T.)rangeli.Methods:Adult virgin females of R.prolixus were fed upon a membrane apparatus containing heat-inactivated citrated rabbit blood and a suspension of T.rangeli epimastigotes(Macias strain).Females from the control group and all the males received parasite-free blood.Transmission electron microscopy was used to reveal the morphological aspects of ovarian follicle cells in both control and parasite-infected groups.Protein profile,proteolytic activities and Western blotting analyses were performed in either ovary or fat body samples of control and parasite-infected groups.Results:According to the ultrastructural data,T.rangeli infection elicited a degeneration process in the ovarian follicular cells of R.prolixus.Proteolytic assays indicated a reduction in the activity of aspartic peptidases in the ovary and fat body from parasite-infected group,while a significant increase in the cysteine peptidase activity was measured in both insect organs.Additionally,immunoblotting revealed that vitellogenin was overexpressed in the ovary of parasite-infected insects.Conclusions:T.rangeli infection seems to elicit an early programmed cell death in the ovarian follicle cells as well as induces the modulation on the activities of different peptidase classes in either ovaries or fat bodies and the overexpression of the vitellogenin in the ovary of R.prolixus.

Proposed nomenclature for Pseudallescheria,Scedosporium and related genera

As a result of fundamental changes in the International Code of Nomenclature on the use of separate names for sexual and asexual stages of fungi,generic names of many groups should be reconsidered.Members of the ECMM/ISHAM working group on Pseudallescheria/Scedosporium infections herein advocate a novel nomenclature for genera and species in Pseudallescheria,Scedosporium and allied taxa.The generic names Parascedosporium,Lomentospora,Petriella,Petriellopsis,and Scedosporium are proposed for a lineage within Microascaceae with mostly Scedosporium anamorphs producing slimy,annellidic conidia.Considering that Scedosporium has priority over Pseudallescheria and that Scedosporium prolificans is phylogenetically distinct from the other Scedosporium species,some name changes are proposed.Pseudallescheria minutispora and Petriellidium desertorum are renamed as Scedosporium minutisporum and S.desertorum,respectively.Scedosporium prolificans is renamed as Lomentospora prolificans.