ABSTRACT
Novel species of fungi described in this study include those from various countries as follows: Argentina, Neocamarosporium halophilum in leaf spots of Atriplex undulata. Australia, Aschersonia merianiae on scale insect (Coccoidea), Curvularia huamulaniae isolated from air, Hevansia mainiae on dead spider, Ophiocordyceps poecilometigena on Poecilometis sp. Bolivia, Lecanora menthoides on sandstone, in open semi-desert montane areas, Sticta monlueckiorum corticolous in a forest, Trichonectria epimegalosporae on apothecia of corticolous Megalospora sulphurata var. sulphurata, Trichonectria puncteliae on the thallus of Punctelia borreri. Brazil, Catenomargarita pseudocercosporicola (incl. Catenomargarita gen. nov.) hyperparasitic on Pseudocercospora fijiensis on leaves of Musa acuminata, Tulasnella restingae on protocorms and roots of Epidendrum fulgens. Bulgaria, Anthracoidea umbrosae on Carex spp. Croatia, Hymenoscyphus radicis from surface-sterilised, asymptomatic roots of Microthlaspi erraticum, Orbilia multiserpentina on wood of decorticated branches of Quercus pubescens. France, Calosporella punctatispora on dead corticated twigs of Aceropalus. French West Indies (Martinique), Eutypella lechatii on dead corticated palm stem. Germany, Arrhenia alcalinophila on loamy soil. Iceland, Cistella blauvikensis on dead grass (Poaceae). India, Fulvifomes maritimus on living Peltophorum pterocarpum, Fulvifomes natarajanii on dead wood of Prosopis juliflora, Fulvifomes subazonatus on trunk of Azadirachta indica, Macrolepiota bharadwajii on moist soil near the forest, Narcissea delicata on decaying elephant dung, Paramyrothecium indicum on living leaves of Hibiscus hispidissimus, Trichoglossum syamviswanathii on moist soil near the base of a bamboo plantation. Iran, Vacuiphoma astragalicola from stem canker of Astragalus sarcocolla. Malaysia, Neoeriomycopsis fissistigmae (incl. Neoeriomycopsidaceae fam. nov.) on leaf spots on flower Fissistigma sp. Namibia, Exophiala lichenicola lichenicolous on Acarospora cf. luederitzensis. Netherlands, Entoloma occultatum on soil, Extremus caricis on dead leaves of Carex sp., Inocybe pseudomytiliodora on loamy soil. Norway, Inocybe guldeniae on calcareous soil, Inocybe rupestroides on gravelly soil. Pakistan, Hymenagaricus brunneodiscus on soil. Philippines, Ophiocordyceps philippinensis parasitic on Asilus sp. Poland, Hawksworthiomyces ciconiae isolated from Ciconia ciconia nest, Plectosphaerella vigrensis from leaf spots on Impatiens noli-tangere, Xenoramularia epitaxicola from sooty mould community on Taxus baccata. Portugal, Inocybe dagamae on clay soil. Saudi Arabia, Diaporthe jazanensis on branches of Coffea arabica. South Africa, Alternaria moraeae on dead leaves of Moraea sp., Bonitomyces buffels-kloofinus (incl. Bonitomyces gen. nov.) on dead twigs of unknown tree, Constrictochalara koukolii on living leaves of Itea rhamnoides colonised by a Meliola sp., Cylindromonium lichenophilum on Parmelina tiliacea, Gamszarella buffelskloofina (incl. Gamszarella gen. nov.) on dead insect, Isthmosporiella africana (incl. Isthmosporiella gen. nov.) on dead twigs of unknown tree, Nothoeucasphaeria buffelskloofina (incl. Nothoeucasphaeria gen. nov.), on dead twigs of unknown tree, Nothomicrothyrium beaucarneae (incl. Nothomicrothyrium gen. nov.) on dead leaves of Beaucarnea stricta, Paramycosphaerella proteae on living leaves of Protea caffra, Querciphoma foliicola on leaf litter, Rachicladosporium conostomii on dead twigs of Conostomium natalense var. glabrum, Rhamphoriopsis synnematosa on dead twig of unknown tree, Waltergamsia mpumalanga on dead leaves of unknown tree. Spain, Amanita fulvogrisea on limestone soil, in mixed forest, Amanita herculis in open Quercus forest, Vuilleminia beltraniae on Cistus symphytifolius. Sweden, Pachyella pulchella on decaying wood on sand-silt riverbank. Thailand, Deniquelata cassiae on dead stem of Cassia fistula, Stomiopeltis thailandica on dead twigs of Magnolia champaca. Ukraine, Circinaria podoliana on natural limestone outcrops, Neonematogonum carpinicola (incl. Neonematogonum gen. nov.) on dead branches of Carpinus betulus. USA, Exophiala wilsonii water from cooling tower, Hygrophorus aesculeticola on soil in mixed forest, and Neocelosporium aereum from air in a house attic. Morphological and culture characteristics are supported by DNA barcodes. Citation: Crous PW, Costa MM, Kandemir H, et al. 2023. Fungal Planet description sheets: 1550-1613. Persoonia 51: 280-417. doi: 10.3767/persoonia.2023.51.08.
ABSTRACT
Seven Fusarium species complexes are treated, namely F. aywerte species complex (FASC) (two species), F. buharicum species complex (FBSC) (five species), F. burgessii species complex (FBURSC) (three species), F. camptoceras species complex (FCAMSC) (three species), F. chlamydosporum species complex (FCSC) (eight species), F. citricola species complex (FCCSC) (five species) and the F. concolor species complex (FCOSC) (four species). New species include Fusicolla elongata from soil (Zimbabwe), and Neocosmospora geoasparagicola from soil associated with Asparagus officinalis (Netherlands). New combinations include Neocosmospora akasia, N. awan, N. drepaniformis, N. duplosperma, N. geoasparagicola, N. mekan, N. papillata, N. variasi and N. warna. Newly validated taxa include Longinectria gen. nov., L. lagenoides, L. verticilliforme, Fusicolla gigas and Fusicolla guangxiensis. Furthermore, Fusarium rosicola is reduced to synonymy under N. brevis. Finally, the genome assemblies of Fusarium secorum (CBS 175.32), Microcera coccophila (CBS 310.34), Rectifusarium robinianum (CBS 430.91), Rugonectria rugulosa (CBS 126565), and Thelonectria blattea (CBS 952.68) are also announced here. Citation: Crous PW, Sandoval-Denis M, Costa MM, Groenewald JZ, van Iperen AL, Starink-Willemse M, Hernández-Restrepo M, Kandemir H, Ulaszewski B, de Boer W, Abdel-Azeem AM, Abdollahzadeh J, Akulov A, Bakhshi M, Bezerra JDP, Bhunjun CS, Câmara MPS, Chaverri P, Vieira WAS, Decock CA, Gaya E, Gené J, Guarro J, Gramaje D, Grube M, Gupta VK, Guarnaccia V, Hill R, Hirooka Y, Hyde KD, Jayawardena RS, Jeewon R, Jurjevic Z, Korsten L, Lamprecht SC, Lombard L, Maharachchikumbura SSN, Polizzi G, Rajeshkumar KC, Salgado-Salazar C, Shang Q-J, Shivas RG, Summerbell RC, Sun GY, Swart WJ, Tan YP, Vizzini A, Xia JW, Zare R, González CD, Iturriaga T, Savary O, Coton M, Coton E, Jany J-L, Liu C, Zeng Z-Q, Zhuang W-Y, Yu Z-H, Thines M (2022). Fusarium and allied fusarioid taxa (FUSA). 1. Fungal Systematics and Evolution 9: 161-200. doi: 10.3114/fuse.2022.09.08.
ABSTRACT
In this study, Selective Laser Melting (SLM) was used to produce mono-material Ti64Al4V- and NiTi-cubic cellular structures with an open-cell size and wall thickness of 500⯵m and 100⯵m, respectively. Bioactive beta-tricalcium phosphate (ßTCP) and polymer poly-ether-ether ketone (PEEK) were used to fill the produced structures open-cells, thus creating multi-material components. These structures were characterized in vitro in terms of cell viability, adhesion, differentiation and mineralization. Also, bio-tribological experiments were performed against bovine plate to mimic the moment of implant insertion. Results revealed that metabolic activity and mineralization were improved on SLM mono-material groups, when compared to the control group. All cell metrics were improved with the addition of PEEK, conversely to ßTCP where no significant differences were found. These results suggest that the proposed solutions can be used to improve implants performance.
Subject(s)
Alloys , Prostheses and Implants , Animals , Cattle , Ethers , Ketones/chemistry , Ketones/pharmacology , Materials Testing , Polyethylene Glycols/chemistry , Polymers/pharmacology , Titanium/chemistry , Titanium/pharmacologyABSTRACT
Prototheca spp. cause numerous infections in a wide variety of species, including treatment-unresponsive mastitis. Thus, the search for an effective therapy is essential. Silver nanoparticles are compounds with high therapeutic potential. This study aimed to evaluate the susceptibility profile and morphological changes in Prototheca spp. treated with biogenic silver nanoparticles (Bio-AgNP). The algaecide activity was evaluated in microplates by microdilution method, resulting in a MIC50 of 30 µg ml-1 and a MIC90 of 60 µg ml-1 . Scanning electron microscopy demonstrated changes in the surface of Prototheca bovis cells following treatment. The algaecide activity of Bio-AgNP suggests a therapeutic potential as a novel approach for the control of Prototheca spp. in bovine mastitis.
Subject(s)
Herbicides , Mastitis, Bovine , Metal Nanoparticles , Prototheca , Animals , Cattle , Female , Mastitis, Bovine/drug therapy , Silver/pharmacologyABSTRACT
Circinotrichum, Gyrothrix and Vermiculariopsiella represent a complex of dematiaceous, setose, saprobic hyphomycetes that are commonly collected on plant litters in tropical, subtropical to temperate climates. Multi-locus analysis (ITS, LSU, rpb2) and morphological studies revealed that Gyrothrix and Circinotrichum are polyphyletic and species belong to 10 genera grouping in three different clades within Xylariales, named Coniocessiaceae (Circinotrichum and Pirozynskiomyces gen. nov.), Microdochiaceae (Selenodriella and the resurrected genus Peglionia) and the new family Gyrothricaceae (Gyrothrix, Xenoanthostomella, Neogyrothrix gen. nov., Pseudocircinotrichum gen. nov., and Pseudoceratocladium gen. nov.). Vermiculariopsiella (Vermiculariopsiellales, Vermiculariopsiellaceae) is emended for species with setose sporodochia with simple setae (V. dichapetali, V. eucalypticola, V. immersa, V. pini, V. spiralis, V. australiensis sp. nov.) while Vermiculariopsis is resurrected and includes setose fungi with branched setae (Vs. dunni, Vs. eucalypti, Vs. eucalyptigena, Vs. lauracearum, Vs. microsperma, Vs. pediculata and Vs. castanedae sp. nov.). Citation: Hernández-Restrepo M, Decock CA, Costa MM, et al. 2022. Phylogeny and taxonomy of Circinotrichum, Gyrothrix, Vermiculariopsiella and other setose hyphomycetes. Persoonia 49: 99-135. https://doi.org/10.3767/persoonia.2022.49.03.
ABSTRACT
This study describes changes in haematological parameters, cytokine profile, histopathology and cortisol levels in Swiss mice experimentally infected with Angiostrongylus costaricensis. Twenty-eight Swiss mice were divided into two groups (G1 and G2) of 14 animals each. In each group, eight animals were infected orally with ten third-stage larvae of A. costaricensis and six were used as a control group. The mice of groups G1 and G2 were sacrificed 14 and 24 days after infection, respectively. Samples were collected for histopathological and haematological analyses and determination of the cytokine profile and cortisol levels. Granulomatous reaction, eosinophilic infiltrate and vasculitis in the intestinal tract, pancreas, liver and spleen were observed with varying intensity in infected animals. Our results showed that the mice developed normocytic and hypochromic anaemia, and that the histopathological lesions caused by the experimental infection influenced increases in cortisol, neutrophil and monocyte levels. In addition to this, we detected increased interleukin-6 and tumour necrosis factor alpha levels in the infected animals.
Subject(s)
Angiostrongylus , Strongylida Infections , Animals , Hydrocortisone , Intestines , Larva , MiceABSTRACT
Ti6Al4V sub-millimetric cellular structures arise as promising solutions concerning the progress of conventional orthopedic implants due to its ability to address a combination of mechanical, physical and topological properties. Such ability can improve the interaction between implant materials and surrounding bone leading to long-term successful orthopedic implants. Selective Laser Melting (SLM) capability to produce high quality Ti6Al4V porous implants is in great demand towards orthopedic biomaterials. In this study, Ti6Al4V cellular structures were designed, modeled, SLM produced and characterized targeting orthopedic implants. For that purpose, a set of tools is proposed to overcome SLM limited accuracy to produce porous biomaterials with desired dimensions and mechanical properties. Morphological analyses were performed to evaluate the dimensional deviations noticed between the model CAD and the SLM produced structures. Tensile tests were carried out to estimate the elastic modulus of the Ti6Al4V cellular structures. The present work proposes a design methodology showing the linear correlations found for the dimensions, the porosity and the elastic modulus when comparing the model CAD designs with Ti6Al4V structures by SLM.
Subject(s)
Lasers , Titanium , Alloys , Biocompatible Materials , Materials Testing , PorositySubject(s)
Betacoronavirus , Coronavirus Infections/epidemiology , Pneumonia, Viral/epidemiology , Tuberculosis/diagnosis , Tuberculosis/epidemiology , Brazil/epidemiology , COVID-19 , Coronavirus Infections/diagnosis , Coronavirus Infections/therapy , Humans , Pandemics , Pneumonia, Viral/diagnosis , Pneumonia, Viral/therapy , SARS-CoV-2 , Tuberculosis/therapyABSTRACT
Nickel-titanium (NiTi) cellular structures are a very promising solution to some issues related to orthopaedic implant failure. These structures can be designed and fabricated to simultaneously address a combination of mechanical and physical properties, such as elastic modulus, porosity, wear and corrosion resistance, biocompatibility and appropriate biological environment. This ability can enhance the modest interaction currently existing between metallic dense implants and surrounding bone tissue, allowing long-term successful orthopaedic implants. For that purpose, NiTi cellular structures with different levels of porosity intended to reduce the elastic modulus were designed, modelled, selective laser melting (SLM) fabricated and characterized. Significant differences were found between the CAD design and the SLM-produced NiTi structures by performing systematic image analysis. This work proposes designing guidelines to anticipate and correct the systematic differences between CAD and produced structures. Compressive tests were carried out to estimate the elastic modulus of the produced structures and finite element analyses were performed, for comparison purposes. Linear correlations were found for the dimensions, porosity, and elastic modulus when comparing the CAD design with the SLM structures. The produced NiTi structures exhibit elastic moduli that match that of bone tissue, which is a good indication of the potential of these structures in orthopaedic implants.
Subject(s)
Nickel , Titanium , Biocompatible Materials , Elastic Modulus , Lasers , Materials Testing , PorosityABSTRACT
Primary bilateral adrenal macronodular hyperplasia is characterized by functioning adrenal macronodules and variable cortisol secretion. Familial clustering suggests a genetic cause that has been confirmed with the identification of some genetic mutations, including inactivating germline mutations, in armadillo repeat containing 5 (ARMC5) gene. The identification of the pathogenic variant enables the physician to identify and treat these patients earlier and more effectively. It has also been noticed that patients with germline causative variants show a different clinical spectrum, presenting specific clinical characteristics, as the association with the presence of meningiomas.
ABSTRACT
Abdominal angiostrongyliasis is caused by Angiostrongylus costaricensis, the definitive and intermediate hosts of which are wild rodents and terrestrial molluscs, respectively. Humans are accidental hosts and can be infected by ingesting the third-stage (infective) larvae (L3). It remains unclear whether the number of L3 inoculated is related to lesion severity. Our aim was to analyse histopathological alterations in Swiss mice infected with different doses of A. costaricensis. Thirty-two mice were randomly divided into four groups (n = 8/group): uninfected, control mice; mice infected with a low dose (five L3); mice infected with an intermediate dose (15 L3); and mice infected with a high dose (30 L3). The frequency of intestinal thrombi, splenitis, eggs/larvae, hepatic infarction and acute pancreatitis differed among the groups, the last being considered a significant finding. We conclude that different infective doses alter the histopathological aspects of the infection in Swiss mice, those aspects being more pronounced at medium and high doses, with no effect on the development of the disease. This experimental model shows that the parasite life cycle can be maintained in Swiss mice through the inoculation of a low dose (five L3).
Subject(s)
Gastrointestinal Tract/pathology , Gastrointestinal Tract/parasitology , Host-Parasite Interactions , Parasite Load , Strongylida Infections/parasitology , Acute Disease , Angiostrongylus/pathogenicity , Animals , Larva/pathogenicity , Male , Mice , Pancreatitis/parasitologyABSTRACT
The aim of the present study was to evaluate the antibacterial behavior of polypyrrole nanoparticles (PPy-NPs) in water against biofilm producer or not S. aureus isolated from cows and goats with mastitis. One hundred and thirty-eight isolates of S. aureus were initially evaluated for bioï¬lm formation by spectrophotometry in microplates. In addition, the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) of PPy-NPs in water for planktonic S. aureus were determined. From the bovine samples analyzed, 5 (4.46%) S. aureus isolates showed a strong biofilm production, 17 (15.18%) moderate production, 36 (32.14%) with weak production and 54 (48.21%) did not produce biofilms. Strains from goats (26) showed no bioï¬lm production in 18 (69.23%) strains and weak bioï¬lm production in 8 (30.76%) strains. The MIC and MBC of S. aureus to PPy-NPs were found in the same concentration (125µÉ¡/mL) in all strains tested, regardless of biofilm production or not. This ï¬nding provides a new insight into the interaction between PPy-NPs and S. aureus, and will offer potential beneï¬ts for the control of mastitis.(AU)
Subject(s)
Animals , Female , Cattle , Pyrroles/administration & dosage , Staphylococcus aureus/drug effects , Goats/microbiology , Mastitis/veterinary , Biofilms , Anti-Bacterial Agents/therapeutic useABSTRACT
BACKGROUND: Quality improvement (QI) methods are recommended to address healthcare-associated infections (HCAIs) in hospitals, but whereas internal initiatives have been widely studied, there is little evidence on the application and effect of a QI approach from an external system-wide perspective. AIM: To analyse the effect of a national system-wide QI initiative aimed at promoting HCAI prevention via regulatory interventions in Brazil. METHODS: A QI cycle approach designed and assessed with a before-and-after quasi-experimental design was implemented by the Brazilian Health Regulatory Agency (ANVISA), targeting 1869 hospitals. Eleven evidence-based quality indicators related to HCAI prevention and a composite measure were assembled, shared, and assessed; the intervention to improve was then based on participatory multifaceted regulatory actions. Absolute and relative improvements were estimated after the intervention. FINDINGS: In all, 563 hospitals (30.1% response) totalling 86,837 beds participated in the baseline assessment, and 681 hospitals (36.4% response) totalling 101,231 beds in the second. Ten of the 11 criteria improved (P < 0.05), as well as the composite indicator (P = 0.001) in all the regions of the country, particularly in the group of hospitals participating at baseline. 'Hand hygiene (HH) infrastructure' reached 100% (baseline: 97.9; P = 0.001), 'HH protocol' 96.9% (baseline: 92.9; P = 0.001), 'HH monitoring' 70% (baseline: 60.7; P < 0.001) and 'existence of antimicrobial prescription protocol' 80.7% (baseline: 73.2; P < 0.001), among others. The HCAI rates of the participating hospitals decreased after the intervention (P < 0.05). CONCLUSION: The QI cycle approach was useful in guiding system-wide interventions for patient safety. External regulation was feasible and effective in promoting internal HCAI prevention nationwide.
Subject(s)
Cross Infection/prevention & control , Health Plan Implementation , Hospitals/statistics & numerical data , Infection Control/methods , Brazil , Humans , Infection Control/organization & administration , National Health Programs , Patient Safety , Quality ImprovementABSTRACT
INTRODUCTION: Several reports highlight bariatric surgery as an efficient and long-lasting strategy for weight loss. Herein, we aimed to evaluate the impact of bariatric surgery on 10-year cardiovascular disease (CVD) risk and to compare the effectiveness of different surgical procedures, employing the Framingham Risk Score (FRS). METHODS: Retrospective longitudinal observational study of patients undergoing bariatric surgery. Data was assessed preoperatively and during a 4-year follow-up period. RESULTS: We evaluated 1449 individuals, 85.2% female, age of 42.4 ± 10.6 years, and preoperative BMI of 44.3 ± 5.8 kg/m2; 58.0% underwent Roux-en-Y gastric bypass (RYGB), 23.4% sleeve gastrectomy (SG), and 18.6% adjustable gastric band (AGB). The 10-year CVD risk decreased 43.6% in the first postoperative year. The decrease in FRS was more pronounced in the RYGB group (50.5% in the first postoperative year) (p < 0.001). Although there was a subsequent slight increase in FRS during the follow-up period, the cardiovascular benefits were maintained when compared with baseline. For all surgical procedures, CVD risk showed a quadratic trend with a J-shaped curve. A negative interaction between the RYGB group CVD risk and time was observed (ß = - 0.072 (95% CI, - 0.109; - 0.035)). In the RYGB group, FRS decreased more when compared with the SG and AGB groups and, from the second postoperative year onwards, increased more slowly, regardless of gender. The SG group showed similar trend as that of the AGB (ß = - 0.002 (95% CI, - 0.049; 0.053)). CONCLUSION: Our study showed a significant reduction of 10-year CVD risk after bariatric surgery. This decrease was more pronounced in the first postoperative year, and RYGB was the procedure with the greatest decrease of the 10-year CVD risk.
Subject(s)
Bariatric Surgery , Heart Disease Risk Factors , Obesity, Morbid/surgery , Adult , Bariatric Surgery/adverse effects , Bariatric Surgery/methods , Bariatric Surgery/statistics & numerical data , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/etiology , Cardiovascular Diseases/prevention & control , Female , Follow-Up Studies , Gastrectomy/adverse effects , Gastrectomy/methods , Gastrectomy/statistics & numerical data , Gastric Bypass/adverse effects , Gastric Bypass/methods , Gastric Bypass/statistics & numerical data , Humans , Longitudinal Studies , Male , Middle Aged , Obesity, Morbid/complications , Obesity, Morbid/epidemiology , Portugal/epidemiology , Postoperative Period , Retrospective Studies , Risk Factors , Treatment Outcome , Weight Loss/physiologyABSTRACT
Load-bearing implants success is strongly dependent on several physical and chemical properties that are known to drive cellular response. In this work, multi-material ß-TCP-Ti6Al4V cellular structures were designed to combine Ti6Al4V mechanical properties and ß-Tricalcium Phosphate bioactivity, in order to promote bone ingrowth as the bioactive material is being absorbed and replaced by newly formed bone. In this sense, the produced structures were characterized regarding roughness, wettability, ß-TCP quantity and quality inside the structures after fabrication and the pH measured during cell culture (as consequence of ß-TCP dissolution) and those aspects were correlated with cellular viability, distribution, morphology and proliferation. These structures displayed a hydrophilic behavior and results showed that the addition of ß-TCP to these cellular structures led to an alkalization of the medium, aspect that significantly influences the cellular response. Higher impregnation ratios were found more adequate for lowering the media pH and toxicity, and thus enhance cell adhesion and proliferation.
Subject(s)
Biocompatible Materials/chemistry , Calcium Phosphates/chemistry , Alloys , Animals , Cell Line , Materials Testing , Rats , Titanium/chemistryABSTRACT
The following study proposes a multi-material solution in which Ti6Al4V cellular structures produced by Selective Laser Melting are impregnated with bioactive materials (hydroxyapatite or ß-tricalcium phosphate) using press and sintering technique. To assess the tribological response of these structures, an alumina plate was used as a counterpart in a flat-on-flat reciprocating sliding test. Ti6Al4V cellular structures impregnated with bioactive materials displayed the highest wear resistance when compared with the unreinforced structures. Among the bioactive structures, Ti6Al4V cellular structures impregnated with ßTCP were the ones with higher wear resistance, having the lowest weight loss. Hence, these structures are promising multifunctional solutions for load-bearing applications by gathering suitable mechanical properties (strength and stiffness); bioactive properties and in addition an improved wear performance.
Subject(s)
Biocompatible Materials/chemistry , Orthopedic Procedures , Alloys , Aluminum Oxide/chemistry , Calcium Phosphates/chemistry , Durapatite/chemistry , Titanium/chemistryABSTRACT
AIMS: This study aimed to verify the formation of biofilms by Moraxella bovis, Moraxella ovis and Moraxella bovoculi isolates from ruminants. In addition, the lysozyme activity against the isolates of M. bovis, M. ovis and M. bovoculi in free form and in biofilms was determined. METHODS AND RESULTS: In this study, 54 isolates of Moraxella sp. obtained from bovine and ovine clinical samples were evaluated in vitro for capacity of biofilm formation and lysozyme susceptibility in planktonic and sessile cells. In addition, biofilms produced by four Moraxella sp. isolates were visualized under scanning electron microscope (SEM). It was possible to demonstrate, for the first time, the ability to form biofilms by M. ovis and M. bovoculi. The isolates of Moraxella sp. have the capacity to form biofilms in different intensities, varying among weak, moderate and strong. It was verified that the lysozyme shows activity on Moraxella sp. in planktonic form. However, on biofilms there was a reduction in the production, but without impairing its formation, and on consolidated biofilms the lysozyme did not have the capacity to eradicate the preformed biofilms. CONCLUSIONS: This work shows the capacity of biofilm formation by Moraxella sp. of veterinary importance. The lysozyme susceptibility of Moraxella sp. in planktonic form shows that this enzyme has bacteriostatic activity on this micro-organism and it reduced the production of biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: Based on the results, it is possible to infer that the biofilm formation capacity by Moraxella sp. and the resistance to lysozyme concentrations equal to or greater than the physiological levels of the ruminant tear may be linked not only to the capacity to colonize the conjunctiva, but also to remain in this place even after healing of the lesions, being a reservoir of Moraxella sp. in a herd.
Subject(s)
Biofilms , Moraxella bovis/physiology , Moraxella/physiology , Muramidase/metabolism , Animals , Cattle , Cattle Diseases , Keratoconjunctivitis, Infectious , Moraxella/isolation & purification , Moraxellaceae Infections , Sheep/microbiologyABSTRACT
Ti6Al4V-alloy is commonly used in dental and orthopedic applications where tribochemical reactions occur at material/bone interface. These reactions are one of the main concerns regarding Ti6Al4V implants due to the generation of wear particles, linked to the release of metallic ions in toxic concentration which occurs when TiO2 passive film is destroyed by means of wear and corrosion simultaneously. In the present study, a multi-material Ti6Al4V-PEEK cellular structure is proposed. Selective Laser Melting technique was used to produce Ti6Al4V dense and cellular structured specimens, whilst Hot-Pressing technique was employed to obtain multi-material Ti6Al4V-PEEK structures. This study investigates the tribocorrosion behavior of these materials under reciprocating sliding, comparing them with commercial forged Ti6Al4V. Open-circuit-potential was measured before, during and after sliding while dynamic coefficient of friction was assessed during sliding. The results showed an improved wear resistance and a lower tendency to corrosion for the multi-material Ti6Al4V-PEEK specimens when compared to dense and cellular structures mono-material specimens. This multi-material solution gathering Ti6Al4V and PEEK, besides being able to withstand the loads occurring after implantation on dental and orthopedic applications, is a promising alternative to fully dense metals once it enhances the tribocorrosion performance.