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Mycoplasma mobile is a fish pathogen that glides on solid surfaces by means of a unique mechanism. The gliding machinery of M. mobile is composed of internal and surface structures. In the present study, we focused on the function and structure of Gli123, a surface protein that is essential for the localization of other surface proteins. The amino acid sequence of Gli123, which is 1128 amino acids long, contains lipoprotein-specific repeats. We isolated the native Gli123 protein from M. mobile cells and a recombinant protein, rGli123, from Escherichia coli. The isolated rGli123 complemented a non-binding and non-gliding mutant of M. mobile that lacked Gli123. Circular dichroism and rotary-shadowing electron microscopy (EM) showed that rGli123 has a structure that is not significantly different from that of the native protein. Rotary-shadowing EM suggested that the molecules changed their shape between globular and rod-like structures, depending on the ionic strength of the solution. Negative-staining EM coupled with single-particle analysis revealed that Gli123 forms a globular structure featuring a small protrusion with dimensions of 20.0, 14.5, and 16.0 nm. Small-angle X-ray scattering analyses indicated a rod-like structure composed of several tandem globular domains with total dimensions of approximately 34 nm length and 4 nm width. Both molecular structures were suggested to be dimers based on the predicted molecular size and structure. Gli123 may have evolved by multiplication of repeating lipoprotein units and acquired clumping role of surface proteins.IMPORTANCEMycoplasmas are pathogenic bacteria that are widespread in animals. They are characterized by small cell and genome sizes but are equipped with unique abilities to escape host immunity, such as surface variation and gliding. Here, we focused on a surface-localizing protein that is essential for Mycoplasma mobile gliding. The findings of this study suggested that the protein undergoes drastic conformational changes between its rod-like and globular structures. These changes may be caused by a repetitive structure common in the surface proteins that is responsible for the modulation of the cell surface structure and related to the assembly process for the surface gliding machinery. An evolutionary process for this unique mycoplasma gliding mechanism has also been suggested in the present study.

Objective To examine the effect of Ureaplasma parvum (U. parvum) infection on mouse sperm motility, structure, and fertilizing ability and on embryo development. Design In vitro model of the effects of U. parvum serovar 3 infection on mouse sperm. Setting Basic research laboratory. Intervention(s) None. Animals Mice. Main Outcome Measure(s) Mouse sperm motility was examined using the swim-up method, and their motility parameters were analyzed using the sperm motility analysis system. Localization and invasion of U. parvum were observed with fluorescence, confocal, and scanning electron microscopy. After in vitro fertilization with U. parvum–infected sperm, the quality of the fertilized egg and embryo development were assessed. Result(s) U. parvum was attached and internalized into mouse sperms and localized mainly at the sperm head and midpiece. U. parvum–infected mouse sperms exhibited decreased motility in a dose- and duration-dependent manner. Electron micrographs revealed that U. parvum infection induced the aggregation and morphological destruction of mouse sperm. Infected mouse sperm transported U. parvum into the fertilized egg with reduced fertilization rates, and infected embryo development was impaired. Conclusion(s) U. parvum infection caused deterioration of the mouse sperm quality and its functions, which affected the fertilization rate and embryo development.

Previously, we found that Ureaplasma parvum internalised into HeLa cells and cytosolic accumulation of galectin-3. U. parvum induced the host cellular membrane damage and survived there. Here, we conducted vesicular trafficking inhibitory screening in yeast to identify U. parvum vacuolating factor (UpVF). U. parvum triggered endoplasmic reticulum (ER) stress and upregulated the unfolded protein response-related factors, including BiP, P-eIF2 and IRE1 in the host cells, but it blocked the induction of the downstream apoptotic factors. MicroRNA library screening of U. parvum-infected cells and UpVF-transfected cells identified miR-211 and miR-214 as the negative regulators of the apoptotic cascade under ER stress. Transient expression of UpVF induced HeLa cell death with intracellular vacuolization; however, some stable UpVF transformant survived. U. parvum-infected cervical cell lines showed resistance to actinomycin D, and UpVF stable transformant cell lines exhibited resistance to X-ray irradiation, as well as cisplatin and paclitaxel. UpVF expressing cervical cancer xenografts in nude mice also acquired resistance to cisplatin and paclitaxel. A mycoplasma expression vector based on Mycoplasma mycoides, Syn-MBA (multiple banded antigen)-UpVF, reduced HeLa cell survival compared with that of Syn-MBA after 72 hr of infection. These findings together suggest novel mechanisms for Ureaplasma infection and the possible implications for cervical cancer malignancy. TAKE AWAYS: • Ureaplasmal novel virulence factor, UpVF, was identified. • UpVF triggered ER stress but suppressed apoptotic cascade via miR-211 and -214. • UpVF conferred resistance to anticancer treatments both in vivo and in vitro. • Dual expression of MBA and UpVF in JCVI-syn3B showed host cell damage.

Background Bioactive lipid mediators play a crucial role during infection. Previously, we showed the expression level of FAAH mRNA in septic patients was lower than in healthy controls. Case Presentation Four patients with a Sequential Organ Failure Assessment (SOFA) score of

Here, we present the complete genome sequence of Ureaplasma parvum serovar 3, clinical strain SV3F4, isolated from a Japanese patient with a history of an infectious abortion.

Mycoplasma mobile, a pathogen of freshwater fish, glides easily across surfaces, colonizes on the fish gill, and causes necrosis. The cell surface is differentiated into three parts: the head, neck, and body. Mobile variable surface proteins (Mvsps) localizing at each of these parts may be involved in surface variation including phase variation and antigenic variation, although no proof exists. In this study, we examined this possibility by focusing on MvspI, the largest Mvsp. Immunofluorescence microscopy showed that MvspI is expressed on the surfaces of all cells. When anti-MvspI antibody was added at concentrations over 0.8 nM, MvspI was observed to decrease over time. After 72 h of cultivation with the antibody, the fluorescence intensity and amount of MvspI decreased up to 13 and 39%, respectively, compared to those of cells grown without antibody. These changes were reversed by the removal of the antibody. Such effects were not observed when another antibody targeting other Mvsps was used, suggesting that the decrease is specific to the relationship between MvspI and the antibody. Cell growth was also inhibited by the antibody, but the decrease in MvspI could not be explained by the selective growth of MvspI-negative variants or by the inhibition of growth with other conditions. The decrease in MvspI caused by the antibody binding may suggest a novel type of surface variation, designated here as “mycoplasmal antigen modulation.”