Bradshawlove9641
The invasive ascomycete Hymenoscyphus fraxineus has been threatening Fraxinus excelsior populations throughout Europe for over two decades. Since the infection and first colonization by the pathogen occurs in leaves, leaf-colonizing microorganisms have been discussed as a barrier and as possible biocontrol agents against the disease. To identify fungal groups with health-supporting potential, we compared the fungal microbiota of compound leaves from susceptible and tolerant ash trees in four ash stands with high H. fraxineus exposure. The fungal communities were analyzed both culture-independently by ITS2 amplicon sequencing and by the taxonomic classification of 1,704 isolates using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) or sequencing of the entire ITS region. The fungal community structure did not show significant differences depending on the health status. However, for several OTUs and a MALDI group, a significantly higher abundance was found in toleranteus strains with a rate of 72-100%, and five further isolates inhibited only one H. fraxineus strain significantly. The most effective isolates were members of the genus Cladosporium. During the next step, in planta tests will be necessary to verify the efficacy of the antagonistic isolates and to assess their suitability as biocontrol agents.[This corrects the article DOI 10.3389/fmicb.2020.00254.].Autophagy is an important homeostatic mechanism, in which lysosomes degrade and recycle cytosolic components. As a key defense mechanism against infections, autophagy is involved in the capture and elimination of intracellular parasites. However, intracellular parasites, such as Toxoplasma gondii, have developed several evasion mechanisms to manipulate the host cell autophagy for their growth and establish a chronic infection. This review provides an insight into the autophagy mechanism used by the host cells in the control of T. gondii and the host exploitation by the parasite. First, we summarize the mechanism of autophagy, xenophagy, and LC3-associated phagocytosis. Then, we illustrate the process of autophagy proteins-mediated T. gondii clearance. S-Adenosyl-L-homocysteine purchase Furthermore, we discuss how the parasite blocks and exploits this process for its survival.
In view of increasing resistance against antibiotics and antiseptics, antimicrobial photodynamic therapy (aPDT) may be a promising approach for use in dentistry. The aim of this study was to investigate the mechanism of action of aPDT with the phenalene-1-one derivatives SAPYR and SA-PN-05 as photosensitizers by evaluating bacterial ability to replicate, membrane integrity, metabolic activity, and formation of reactive oxygen species (ROS) in biofilms of
,
, and
.
Single-species biofilms (
,
, and
) were cultured under aerobic conditions for 48 h followed by treatment with the photosensitizers SAPYR and SA-PN-05 at various concentrations (0, 50, 100, 500 μM) and different incubation periods of 5, 10, 20, and 30 min and subsequent irradiation for 10 min (Waldmann PIB 3000; λ
= 360-600 nm; 50 mW/cm
; 30 J/cm
). Control samples were treated with dH
O and kept in dark for the same periods. Bacterial ability to replicate was evaluated by colony forming unit (CFU) assay. The cytoplasmic membraneth SAPYR in single-species biofilms may be due to an increase in formation of intracellular ROS upon photodynamic treatment.
The observed loss in ability to replicate upon aPDT with SAPYR in single-species biofilms may be due to an increase in formation of intracellular ROS upon photodynamic treatment.Spiroplasmas are cell-wall-deficient helical bacteria belonging to the class Mollicutes. Their ability to maintain a helical shape in the absence of cell wall and their motility in the absence of external appendages have attracted attention from the scientific community for a long time. In this review we compare and contrast motility, shape determination and cytokinesis mechanisms of Spiroplasma with those of other Mollicutes and cell-walled bacteria. The current models for rod-shape determination and cytokinesis in cell-walled bacteria propose a prominent role for the cell wall synthesis machinery. These models also involve the cooperation of the actin-like protein MreB and FtsZ, the bacterial homolog of tubulin. However the exact role of the cytoskeletal proteins is still under much debate. Spiroplasma possess MreBs, exhibit a rod-shape dependent helical morphology, and divide by an FtsZ-dependent mechanism. Hence, spiroplasmas represent model organisms for deciphering the roles of MreBs and FtsZ in fundamental mechanisms of non-spherical shape determination and cytokinesis in bacteria, in the absence of a cell wall. Identification of components implicated in these processes and deciphering their functions would require genetic experiments. Challenges in genetic manipulations in spiroplasmas are a major bottleneck in understanding their biology. We discuss advancements in genome sequencing, gene editing technologies, super-resolution microscopy and electron cryomicroscopy and tomography, which can be employed for addressing long-standing questions related to Spiroplasma biology.[This corrects the article DOI 10.3389/fmicb.2020.01776.].The family Nosodendridae is a small group of tree sap beetles with only 91 described species representing three genera from the world. In 1930s, bacteria-harboring symbiotic organs, called bacteriomes, were briefly described in a European species Nosodendron fasciculare. Since then, however, no studies have been conducted on the nosodendrid endosymbiosis for decades. Here we investigated the bacteriomes and the endosymbiotic bacteria of Nosodendron coenosum and Nosodendron asiaticum using molecular phylogenetic and histological approaches. In adults and larvae, a pair of slender bacteriomes were found along both sides of the midgut. The bacteriomes consisted of large bacteriocytes at the center and flat sheath cells on the surface. Fluorescence in situ hybridization detected preferential localization of the endosymbiotic bacteria in the cytoplasm of the bacteriocytes. In reproductive adult females, the endosymbiotic bacteria were also detected at the infection zone in the ovarioles and on the surface of growing oocytes, indicating vertical symbiont transmission via ovarial passage.