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1.
Commun Biol ; 6(1): 118, 2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-36709236

RESUMO

Although Clostridium novyi-NT is an anti-cancer bacterial therapeutic which germinates within hypoxic tumors to kill cancer cells, the actual germination triggers for C. novyi-NT are still unknown. In this study, we screen candidate germinants using combinatorial experimental designs and discover by serendipity that D-valine is a potent germinant, inducing 50% spore germination at 4.2 mM concentration. Further investigation revealed that five D-valine analogs are also germinants and four of these analogs are enantiomeric pairs. This stereoflexible effect of L- and D-amino acids shows that spore germination is a complex process where enantiomeric interactions can be confounders. This study also identifies L-cysteine as a germinant, and hypoxanthine and inosine as co-germinants. Several other amino acids promote (L-valine, L-histidine, L-threonine and L-alanine) or inhibit (L-arginine, L-glycine, L-lysine, L-tryptophan) germination in an interaction-dependent manner. D-alanine inhibits all germination, even in complex growth media. This work lays the foundation for improving the germination efficacy of C. novyi-NT spores in tumors.


Assuntos
Esporos Bacterianos , Valina , Valina/metabolismo , Valina/farmacologia , Esporos Bacterianos/metabolismo , Aminoácidos/metabolismo , Alanina , Esporos/metabolismo
2.
Int J Nanomedicine ; 17: 6399-6412, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36545219

RESUMO

Introduction: To present a safer tumor therapy based on bacteria and identify in detail how the activation and infection behavior of spores can be controlled remotely by near-infrared light (NIR-irradiation) based on nanoheaters' modification. Methods: Spores bring a better tolerance to surface modification. Transitive gold-nanorods-allied-nanoclusters-modified spores (Spore@NRs/NCs) were constructed by covalent glutaraldehyde crosslink. The photothermal properties of nanoheaters before and after attachment to spores were studied by recording temperature-irradiation time curves. The controlled viability and infection behavior of Spore@NRs/NCs were investigated by NIR-irradiation. Results: In this work, a controllable sterilizing effect to activated vegetative bacteria was obtained obviously. When met with a suitable growth-environment, Spore@NRs/NCs could germinate, activate into vegetative bacteria and continue to reproduce. Without NIR-irradiation, nanoheaters could not affect the activity of both spores and vegetative bacterial cells. However, with NIR-irradiation after incubating in growth medium, nanoheaters on spores could control the spores' germination and affect the growth curve as well as the viability of the vegetative bacterial cells. For Spore@NRs/NCs (Spore:NCs:NRs=1:1:4, 67.5 µg mL-1), a ~98% killing rate of vegetative bacterial cells was obtained with NIR-irradiation (2.8 W cm-2, 20 min) after 2 h-incubation. In addition, these nanoheaters modified on spores could be taken not only to the vegetative bacteria cells, but also to the first-generation bacteria cells with their excellent photothermal and bactericidal performance, as well as synergetic anticancer effect. NIR-irradiation after 2 h-incubation could also trigger Spore@NRs/NCs (1:1:4, 6 µL) to synergistically reduce the viability of HCT116 cells to 15.63±2.90%. Conclusion: By using NIR-irradiation, the "transitive" nanoheaters can remotely control the activity of both bacteria (germinated from spore) and cancer cells. This discovery provides basis and a feasible plan for controllable safer treatment of bacteria therapy, especially anaerobes with spores in hypoxic areas of the malignant solid tumors.


Assuntos
Neoplasias , Esporos , Humanos , Bactérias , Temperatura , Esporos Bacterianos , Neoplasias/terapia
3.
Sci Rep ; 12(1): 21965, 2022 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-36536009

RESUMO

The study's goal was to develop a spore-based paper strip biosensor for detecting ß-lactam antibiotics in milk using the enzyme induction principle. A new spore-based paper strip biosensor has been developed after important operating parameters such as spore volume, substrate volume, exposure time and temperature, and incubation time and temperature were optimised. The limit of detection for various ß-lactam antibiotics, including amoxicillin, penicillin, ampicillin, carbenicillin, cloxacillin, nafcillin, oxacillin, cephalothin, cefalexin, cefoxitin, cefazolin, and cefuroxime, was determined in milk with detection sensitivity of 1 ppb, 2 ppb, 2 ppb, 10 ppb, 10 ppb, 10 ppb, 20 ppb, 10 ppb 1000 ppb, 10 ppb 300 ppb and 100 ppb, respectively. It was also tested with other contaminants such non-ß-lactam antibiotics, pesticides, aflatoxin, heavy metals, and other chemical contaminants, and no interference was found, indicating that the created biosensor had a low rate of false positive and negative results. In comparison to the AOAC-approved CHARM-ROSA ß-lactam strip test, which identified 7 raw milk and zero pasteurised milk samples positive for ß-lactam antibiotics, the sensor was further analysed and verified using 200 raw milk and 105 pasteurised milk samples. This indicates a perfect match between our biosensor and the AOAC-approved CHARM-ROSA ß-lactam strip test. The developed spore-based paper strip biosensors are expected to be useful in the rapid and cost-effective detection of ß-lactam antibiotic residues in milk samples at the dairy farm, reception dock, and production units, respectively.


Assuntos
Lactamas , beta-Lactamas , Animais , Leite/química , Antibacterianos/análise , Monobactamas , Esporos/química
4.
Med Mycol ; 61(1)2022 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-36565722

RESUMO

The molecular composition and structural organization of the cell wall of filamentous fungi underlie the ability of the host to identify them as pathogens. Although the organization of the fungal cell wall, composed of 90% polysaccharides, is similar from one fungus to another, small variations condition their ability to trigger pattern recognition receptors. Because the incidence of mucormycosis, an emerging life-threatening infection caused by the species of the order Mucorales is increasing worldwide, the precise composition of the cell wall of two strains of Lichtheimia corymbifera was investigated in the early growth stages of germination (spores and germ-tubes) using trimethylsilylation and confocal microscopy. This study also characterizes the response of THP-1 cells to Mucorales. The study identified the presence of uncommon monosaccharides (fucose, galactose, and glucuronic acid) whose respective proportions vary according to the germination stage, revealing early parietal reorganization. Immunofluorescence studies confirmed the exposure of ß-glucan on the surface of swollen spores and germ-tubes. Both spores and germ-tubes of L. corymbifera promoted an early and strong pro-inflammatory response, through TLR-2. Our results show the singularity of the cell wall of the order Mucorales, opening perspectives for the development of specific diagnostic biomarkers.


Lichtheimia corymbifera is a causative agent of mucormycosis, an emerging invasive fungal infection. Deciphering cell wall composition can lead to the identification of a polysaccharide epitope, which could be used as a biomarker, useful for the diagnosis of mucormycosis.


Assuntos
Mucorales , Mucormicose , Animais , Mucorales/fisiologia , Mucormicose/diagnóstico , Mucormicose/veterinária , Esporos , Interações Hospedeiro-Patógeno
5.
Nat Commun ; 13(1): 6962, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36379934

RESUMO

Proteasomes play an essential role in the life cycle of intracellular pathogens with extracellular stages by ensuring proteostasis in environments with limited resources. In microsporidia, divergent parasites with extraordinarily streamlined genomes, the proteasome complexity and structure are unknown, which limits our understanding of how these unique pathogens adapt and compact essential eukaryotic complexes. We present cryo-electron microscopy structures of the microsporidian 20S and 26S proteasome isolated from dormant or germinated Vairimorpha necatrix spores. The discovery of PI31-like peptides, known to inhibit proteasome activity, bound simultaneously to all six active sites within the central cavity of the dormant spore proteasome, suggests reduced activity in the environmental stage. In contrast, the absence of the PI31-like peptides and the existence of 26S particles post-germination in the presence of ATP indicates that proteasomes are reactivated in nutrient-rich conditions. Structural and phylogenetic analyses reveal that microsporidian proteasomes have undergone extensive reductive evolution, lost at least two regulatory proteins, and compacted nearly every subunit. The highly derived structure of the microsporidian proteasome, and the minimized version of PI31 presented here, reinforce the feasibility of the development of specific inhibitors and provide insight into the unique evolution and biology of these medically and economically important pathogens.


Assuntos
Microsporídios , Complexo de Endopeptidases do Proteassoma , Complexo de Endopeptidases do Proteassoma/genética , Microscopia Crioeletrônica , Filogenia , Peptídeos , Esporos
6.
Mar Pollut Bull ; 185(Pt B): 114336, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36372050

RESUMO

Kelp habitats contribute to marine productivity and diversity, making understanding the constraints on their distribution important. In the Gulf of St. Lawrence, Alaria esculenta occupies a subset of Saccharina latissima's range. Since tolerance to sedimentation by early life stages was suggested to cause this contrasting distribution, we tested the influence of sediment levels on spore attachment and development. For both species, the proportion of attached spores that developed decreased with increasing sediment. However, spore attachment and gametophyte density increased with sediment concentration but only for Saccharina. At the maximum sediment level examined, spore attachment and gametophyte densities of the two species were similar, contrary to the idea that sediment effects on early life stages explain differences in adult distribution. Further investigation, particularly with higher sediment loads, is required to confirm this conclusion. As turbidity is increasing globally, understanding the mechanisms underpinning changes in seaweed distribution will facilitate appropriate local-scale management.


Assuntos
Kelp , Feófitas , Alga Marinha , Esporos , Ecossistema
7.
An Acad Bras Cienc ; 94(suppl 3): e20211145, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36417605

RESUMO

The spore morphology and wall ultrastructure of 12 species of Ctenitis from Southern Cone of America were studied using light microscope, scanning and transmission electron microscope. The study was carried out with herbarium material from Argentine and Brazilian institutions. Equatorial diameters, polar diameters and laesura length were measured. The spores are monolete with echinate or folded ornamentation. In the echinate type, the spines are conical, with broad base and attenuate apex. In the rugate type, the folds are inflated, linear, sinuous, subglobose or handle-shape. The perispore surface is scabrate, rugulate, microverrucose or psilate. Stratification and ultrastructure in the species analyzed are very similar. The exospore is smooth and two-layered in section. Simple and branched channels are observed mainly in the outer exospore. The perispore is composed of two layers, the inner one forms the ornamentation and the outer covers all the outer and inner surfaces. Immature spores were found in all samples of C. fenestralis. The characteristics of the studied spores like macro-ornamentation, color and fold length provide relevant information to differentiate some species or groups of species within the genus.


Assuntos
Dryopteridaceae , Esporos/ultraestrutura , Microscopia , Brasil
8.
Microbiologyopen ; 11(5): e1327, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36314748

RESUMO

Spores are an infectious form of the zoonotic bacterial pathogen, Bacillus anthracis. The outermost spore layer is the exosporium, comprised of a basal layer and an external glycoprotein nap layer. The major structural proteins of the inner basal layer are CotY (at the mother cell central pole or bottlecap) and ExsY around the rest of the spore. The basis for the cap or noncap specificity of the CotY and ExsY proteins is currently unknown. We investigated the role of sequence differences between these proteins in localization during exosporium assembly. We found that sequence differences were less important than the timing of expression of the respective genes in the positioning of these inner basal layer structural proteins. Fusion constructs with the fluorescent protein fused at the N-terminus resulted in poor incorporation whereas fusions at the carboxy terminus of CotY or ExsY resulted in good incorporation. However, complementation studies revealed that fusion constructs, although accurate indicators of protein localization, were not fully functional. A model is presented that explains the localization patterns observed. Bacterial two-hybrid studies in Escherichia coli hosts were used to examine protein-protein interactions with full-length and truncated proteins. The N-terminus amino acid sequences of ExsY and CotY appear to be recognized by spore proteins located in the spore interspace, consistent with interactions seen with ExsY and CotY with the interspace proteins CotE and CotO, known to be involved with exosporium attachment.


Assuntos
Bacillus anthracis , Bacillus anthracis/genética , Bacillus anthracis/química , Bacillus anthracis/metabolismo , Esporos Bacterianos/genética , Esporos Bacterianos/química , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , Esporos
9.
Microbiol Spectr ; 10(5): e0024822, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36214685

RESUMO

The interest and exploration of biodiversity in subsurface ecosystems have increased significantly during the last 2 decades. The aim of this study was to investigate the in vitro probiotic properties of spore-forming bacteria isolated from deep caves. Two hundred fifty spore-forming microbes were enriched from sediment samples from 10 different pristine caves in Algeria at different depths. Isolates showing nonpathogenic profiles were screened for their potential to produce digestive enzymes (gliadinase and beta-galactosidase) in solid and liquid media, respectively. Different probiotic potentialities were studied, including (i) growth at 37°C, (ii) survival in simulated gastric juice, (iii) survival in simulated intestinal fluid, and (iv) antibiotic sensitivity and cell surface properties. The results showed that out of 250 isolates, 13 isolates demonstrated nonpathogenic character, probiotic potentialities, and ability to hydrolyze gliadin and lactose in solution. These findings suggest that a selection of cave microbes might serve as a source of interesting candidates for probiotics. IMPORTANCE Previous microbial studies of subsurface ecosystems like caves focused mainly on the natural biodiversity in these systems. So far, only a few studies focused on the biotechnological potential of microbes in these systems, focusing in particular on their antibacterial potential, antibiotic production, and, to some extent, enzymatic potential. This study explores whether subsurface ecosystems can serve as an alternative source for microbes relevant to probiotics. The research focused on the ability of cave microbes to degrade two substrates (lactose and gliadin) that cause common digestive disorders. Since these enzymes may prove to be useful in food processing and in reducing the effect of lactose and gliadin digestion within intolerant patients, isolation of microbes such as in this study may expand the possibilities of developing alternative strategies to deal with these intolerances.


Assuntos
Gliadina , Probióticos , Humanos , Argélia , Lactose , Ecossistema , Bactérias , Esporos , Antibacterianos/farmacologia , beta-Galactosidase
10.
FEMS Microbiol Ecol ; 98(12)2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36302145

RESUMO

Microbial diversity can restrict the invasion and impact of alien microbes into soils via resource competition. However, this theory has not been tested on various microbial invaders with different ecological traits, particularly spore-forming bacteria. Here we investigated the survival capacity of two introduced spore-forming bacteria, Bacillus mycoides (BM) and B. pumillus (BP) and their impact on the soil microbiome niches with low and high diversity. We hypothesized that higher soil bacterial diversity would better restrict Bacillus survival via resource competition, and the invasion would alter the resident bacterial communities' niches only if inoculants do not escape competition with the soil community (e.g. through sporulation). Our findings showed that BP could not survive as viable propagules and transiently impacted the bacterial communities' niche structure. This may be linked to its poor resource usage and low growth rate. Having better resource use capacities, BM better survived in soil, though its survival was weakly related to the remaining resources left for them by the soil community. BM strongly affected the community niche structure, ultimately in less diverse communities. These findings show that the inverse diversity-invasibility relationship can be valid for some spore-forming bacteria, but only when they have sufficient resource use capacity.


Assuntos
Inoculantes Agrícolas , Bacillus , Solo , Microbiologia do Solo , Bactérias , Esporos
11.
Int J Biol Macromol ; 222(Pt B): 2957-2965, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36244536

RESUMO

The objective of this review article is to present the utility of Sporopollenin, a natural biopolymer, for a wide range of applications. Sporopollenin is a ubiquitous natural polymer and chief ingredient of plant pollen grains, spores and it is chemically inert. Sporopollenin has a beautifully sculpted, decorated, and nano porous surface that is species unique. In both organic and aqueous solutions, it is stable. Purified sporopollenin keeps its spore or pollen particle shape, size, and surface properties while remaining an empty shell (sporopollenin microcapsules). Sporopollenin microcapsules and Sporopollenin Exine Shells (SEC) from pollen grains of plants (Angiosperms), spores of Bryophytes, Pteridophytes Gymnosperms and fungi have been developed as new biomaterials for drug/vaccine delivery, catalyst support, and heavy metal removal, among other sustainable applications. This review paper could pave the way for further research into sporopollenin production and the development of novel biomimetic polymers with desirable inert characteristics. The authors anticipate that this unique renewable polymer, which is abundant in nature and can be made from a variety of plants and fungal sources, will have biomedical applications contributing to sustainability in the future.


Assuntos
Carotenoides , Pólen , Cápsulas/análise , Biopolímeros/química , Carotenoides/química , Pólen/química , Esporos , Plantas
12.
Front Endocrinol (Lausanne) ; 13: 942549, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36120443

RESUMO

Persistent chronic oxidative stress is a primary pathogenic characteristics of diabetic foot ulcers. Puffball spores are a traditional Chinese medicine used to treat diabetic foot ulcers infections and bedsores. However, their effects against diabetic wounds and the mechanism underlying these effects remain largely unknown. The present study explored the effectiveness of puffball spores in diabetic wound treatment and the mechanisms underlying their effects. Sprague-Dawley rats with streptozotocin (STZ)-induced diabetes were treated with puffball spores to ascertain whether they accelerated wound healing.Real-time quantitative PCR, western blotting, hematoxylin-eosin and Masson's trichrome staining, immunohistochemistry analysis, and immunofluorescence assays were performed. As indicated by wound and serum histology and biochemical analyses, the puffball spores accelerated wound healing by activating Akt/Nrf2 signaling and promoting the expression of its downstream antioxidant genes, markedly stimulating antioxidant activity and enhanceing angiogenesis and collagen deposition. Our findings showed that puffball spores could accelerate diabetic wound healing, enhance antioxidant ability, promote the expression of vascular markers, and suppress inflammation, thus providing a theoretical basis for the treatment of diabetic and refractory wounds.


Assuntos
Diabetes Mellitus Experimental , Pé Diabético , Animais , Antioxidantes/farmacologia , Colágeno/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/terapia , Amarelo de Eosina-(YS)/farmacologia , Hematoxilina/farmacologia , Fator 2 Relacionado a NF-E2 , Proteínas Proto-Oncogênicas c-akt , Ratos , Ratos Sprague-Dawley , Esporos/metabolismo , Estreptozocina , Cicatrização
13.
World J Microbiol Biotechnol ; 38(12): 225, 2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36121519

RESUMO

Global warming has a significant impact on different viticultural parameters, including grape maturation. An increment of photosynthetic activity generates a rapid accumulation of sugars in the berry, followed by a dehydration process which leads to a higher concentration of soluble solids. This effect is exacerbated by current viticultural practices which favor the harvest of very mature grapes to obtain wines with sweet tannins. Considering the initial hyperosmotic stress conditions and the high ethanol concentration of the produced wine, fermentation of grape musts with high sugar content could be problematic for yeast starters. In the present study, we were able to obtain by classical hybridization and spore dissection methods one hybrid and one monosporic wine yeast strain with a combined ethanol and osmotolerant phenotype. The improved yeasts were tested in vinification trials with high sugar concentration and displayed excellent fermentation performance. Importantly, the obtained wines also showed good organoleptic properties during sensory analysis. Based on our results, we believed our improved hybrid and monosporic strains can be considered good alternatives to be used as yeast starters for fermentations with high sugar content.


Assuntos
Vitis , Vinho , Carboidratos/análise , Etanol/análise , Saccharomyces cerevisiae/genética , Esporos/química , Açúcares/análise , Taninos , Vinho/análise
14.
Science ; 377(6613): 1369-1370, 2022 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-36137030
15.
Food Res Int ; 160: 111652, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36076441

RESUMO

A novel continuous thin-film (1.59 mm) serpentine path coiled tube (SPCT) UV system operating at 254 nm wavelength was designed and compared with flow field distribution of whole milk with helical path coiled tube (HPCT) UV system using computational fluid dynamics. The results revealed efficient velocity magnitude distribution at serpentine bend geometric locations of the SPCT UV system. Further in this study, we evaluatedBacillus cereusSpores inactivation in whole milk (WM) and almond milk (AM) using the developed SPCT UV system. Experimental data showed that > 4 log reduction of spores was achieved after six and ten passes of WM and AM at a flow rate of 70 and 162 mL/min, respectively. The bio-dosimetry method was used to verify the delivered reduction equivalent fluence (REF) and reported as 33 ± 0.73 and 36.5 ± 1.9 mJ/cm2. We noticed no significant effect on lipid oxidation and volatiles profile (p > 0.05) up to delivered REF of 60 mJ/cm2. This study demonstrated that high levels of inactivation ofB. cereusspores could be feasible with minimal impact on product quality by UV-C processing of dairy and non-dairy opaque scattering fluids.


Assuntos
Prunus dulcis , Animais , Peroxidação de Lipídeos , Leite , Esporos , Esporos Bacterianos
16.
Dis Aquat Organ ; 151: 75-84, 2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36173118

RESUMO

In this study, we examined myxozoan infections of Labeobarbus batesii sampled from the Makombè River in Cameroon. Fish were infected with Myxobolus makombensis n. sp. in the gill filament and M. dibombensis in the fins. Mature myxospores of M. makombensis n. sp. are pyriform in frontal view and biconvex in lateral view, with a truncated and slightly narrow anterior end. Spore dimensions (mean ± SD, with range in parentheses) are 17.5 ± 0.22 (16.2-18.9) µm length, 13.4 ± 0.25 (12-14.9) µm width, and 7 ± 0.21 (6.7-7.5) µm thickness, and spores exhibit a conspicuous anterior intercapsular appendix of 4.4 ± 0.18 (3.9-5.5) µm length. Myxospores have 2 pyriform polar capsules of unequal size; the larger one is 9.8 ± 0. 22 (8.2-10.9) µm long × 4.7 ± 0.15 (3.5-5.2) µm wide, and the smaller one is 8.8 ± 0.22 (7-10) µm long × 4.3 ± 0.12 (3.5-5.2) µm wide. Polar filaments possess 10 to 11 coils in the large polar capsule and 8 to 10 coils in the small polar capsule. Phylogenetic analysis of SSU rDNA sequences showed clustering of M. makombensis n. sp. close to M. dibombensis recently reported from the fins of the same host within a clade composed exclusively of parasites infecting cyprinid fishes.


Assuntos
Carpas , Cyprinidae , Doenças dos Peixes , Myxobolus , Doenças Parasitárias em Animais , Animais , Camarões/epidemiologia , Cápsulas , DNA Ribossômico/genética , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Myxobolus/genética , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/parasitologia , Filogenia , Rios/parasitologia , Esporos
17.
Dis Aquat Organ ; 151: 85-96, 2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36173119

RESUMO

In the present study, 2 species of myxozoan parasites, the novel Ceratomyxa scophthalmi sp. nov. and Myxidium finnmarchicum, were documented from the gallbladder of Scophthalmus maeoticus inhabiting the Turkish Black Sea coast at Sinop. C. scophthalmi sp. nov. had mostly spherical, clavate, and fine-grained polymorphic plasmodia that ranged in diameter from 16.0 to 29.0 µm. Spores were arcuate with a convex anterior margin and concave posterior. Valves of spores were highly elongated and unequal in thickness with one valve 1.1-1.3 times thicker than the other. Valves narrowed gradually toward slightly truncated ends. The mean (range) dimensions of spores were 9.4 (8.5-10.0) µm in length and 49.6 (44.5-55.0) µm in thickness, with polar capsules that were 3.1 (2.7-3.5) µm in length and 3.2 (2.7-3.5) µm in width. Polar filaments were coiled with 4-5 turns. Large numbers of immature forms of C. scophthalmi sp. nov., which were often 'crumpled', and mature forms were found together in the gallbladder bile. Along with morphological differences, phylogenetic analysis based on 18S rDNA, including pairwise nucleotide similarities with other related Ceratomyxa species, suggests C. scophthalmi as a novel species. Moreover, this report provides the first morphological and molecular descriptions of M. finnmarchicum outside of its original geographical location and type host species.


Assuntos
Doenças dos Peixes , Linguado , Myxozoa , Doenças Parasitárias em Animais , Animais , Mar Negro , Cápsulas , DNA Ribossômico/genética , Doenças dos Peixes/parasitologia , Nucleotídeos , Doenças Parasitárias em Animais/parasitologia , Filogenia , Esporos
18.
J Contam Hydrol ; 251: 104080, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36179584

RESUMO

To guarantee proper protection from fecally transmitted pathogen infections, drinking water wells should have a sufficiently large setback distance from potential sources of contamination, e.g. a nearby river. The aim of this study was to provide insight in regards to microbial contamination of groundwater under different flow velocities, which can vary over time due to changes in river stage, season or pumping rate. The effects of these changes, and how they affect removal parameters, are not completely understood. In this study, field tracer tests were carried out in a sandy gravel aquifer near Vienna, Austria to evaluate the ability of subsurface media to attenuate Bacillus subtilis spores, used as a surrogate for Cryptosporidium and Campylobacter. The hydraulic gradient between injection and extraction was controlled by changing the pumping rate (1, 10 l/s) of a pumping well at the test site, building upon previously published work in which tracer tests with a 5 l/s pumping rate were carried out. Attachment and detachment rate coefficients were determined using a HYDRUS-3D model and ranged from 0.12 to 0.76 and 0-0.0013 h-1, respectively. Setback distances were calculated based on the 60-day travel time, as well as a quantitative microbial risk assessment (QMRA) approach, which showed similar results at this site; around 700 m at the highest pumping rate. Removal rates (λ) in the field tests ranged from 0.2 to 0.3 log/m, with lower pumping rates leading to higher removal. It was shown that scale must be taken into consideration when determining λ for the calculation of safe setback distances.


Assuntos
Criptosporidiose , Cryptosporidium , Água Subterrânea , Humanos , Bacillus subtilis , Esporos , Movimentos da Água
19.
Small ; 18(38): e2204011, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35996807

RESUMO

Vaccines have been one of the most powerful weapons to defend against infectious diseases for a long time now. Subunit vaccines are of increasing importance because of their safety and effectiveness. In this work, a Bacillus amyloliquefaciens spore@zeolitic imidazolate framework-8 (ZIF-8) vaccine platform is constructed. The ovalbumin (OVA) is encapsulated in the ZIF-8 shells as a model antigen to form a spore@OVA@ZIF-8 (SOZ) composite. The assembly of ZIF-8 improves the loading content of OVA on the spores and provides OVA with long-term protection. The SOZ composite enhances the immunization efficacy in multiple ways, such as facilitation of antigen uptake and lysosome escape, stimulation of dendritic cells to mature and secrete cytokines, boosting of antibody production and formation of an antigen depot. This platform shows several advantages including easy preparation, cost-effectiveness, long life, convenience of transportation and storage, and no need for the cold chain. These findings may have promising implications for the rational design of safe and effective spore-based composite vaccine platforms.


Assuntos
Vacinas , Zeolitas , Antígenos , Biomimética , Citocinas , Microesferas , Ovalbumina , Esporos , Vacinação
20.
Lett Appl Microbiol ; 75(6): 1449-1459, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35981120

RESUMO

Clostridioides difficile spores were previously demonstrated to survive industrial laundering. Understanding interactions between heat, disinfectants and soiling (e.g. bodily fluids) affecting C. difficile spore survival could inform the optimization of healthcare laundry processes. Reducing spore attachment to linen could also enhance laundering efficacy. This study aimed to compare the sensitivity of C. difficile spores to heat and detergent, with and without soiling and to investigate adherence to cotton. Survival of C. difficile spores exposed to industrial laundering temperatures (71-90°C), reference detergent and industrial detergent was quantified with and without soiling. The adherence to cotton after 0 and 24 h air drying was determined with the exosporium of C. difficile spores partially or fully removed. Clostridioides difficile spores were stable at 71°C for 20 min (≤0·37 log10 reduction) while 90°C was sporicidal (3 log10 reduction); soiling exerted a protective effect. Industrial detergent was more effective at 71°C compared to 25°C (2·81 vs 0·84 log10 reductions), however, specifications for sporicidal activity (>3 log10 reduction) were not met. Clostridioides difficile spores increasingly adhered to cotton over time, with 49% adherence after 24 h. Removal of the exosporium increased adherence by 19-23% compared to untreated spores. Further understanding of the role of the exosporium in attachment to cotton could enhance spore removal and aid decontamination of linen.


Assuntos
Clostridioides difficile , Lavanderia , Esporos Bacterianos , Clostridioides , Detergentes/farmacologia , Esporos , Gossypium
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