ABSTRACT
Babesia ovis, transmitted by Rhipicephalus bursa ticks, is the causative agent of ovine babesiosis, a disease characterized by fever, anemia, hemoglobinuria, and high mortality in sheep. This study investigates whether sheep that survived babesiosis without treatment can serve as a source of infection for B. ovis-free host-seeking R. bursa larvae in a later season. Three donor sheep were experimentally infected with B. ovis, and after six months, persistence of B. ovis was assessed through blood and tick transmission experiments. Blood from donor sheep was intravenously injected into three recipient sheep, while donor sheep were also infested with B. ovis-free R. bursa larvae. Engorged nymphs molted to adults, and new recipient sheep were infested with these ticks. All recipient sheep were monitored for B. ovis for 100 days using microscopic, serological, and molecular approaches. The presence of B. ovis was confirmed in the recipient sheep that received blood, leading to clinical infection in two. However, no B. ovis was detected in recipient sheep infested with ticks. These results suggest that sheep recovering from B. ovis infection do not serve as a source of infection for R. bursa larvae in subsequent seasons.
Subject(s)
Babesia , Babesiosis , Larva , Rhipicephalus , Sheep Diseases , Animals , Sheep , Babesiosis/transmission , Babesiosis/parasitology , Rhipicephalus/parasitology , Sheep Diseases/parasitology , Sheep Diseases/transmission , Babesia/isolation & purification , Babesia/pathogenicity , Female , Chronic DiseaseABSTRACT
Introduction: Babesia bovis, a tick-borne apicomplexan parasite causing bovine babesiosis, remains a significant threat worldwide, and improved and practical vaccines are needed. Previous studies defined the members of the rhoptry associated protein-1 (RAP-1), and the neutralization-sensitive rhoptry associated protein-1 related antigen (RRA) superfamily in B. bovis, as strong candidates for the development of subunit vaccines. Both RAP-1 and RRA share conservation of a group of 4 cysteines and amino acids motifs at the amino terminal end (NT) of these proteins. Methods and results: Sequence comparisons among the RRA sequences of several B. bovis strains and other Babesia spp parasites indicate a high level of conservation of a 15-amino acid (15-mer) motif located at the NT of the protein. BlastP searches indicate that the 15-mer motif is also present in adenylate cyclase, dynein, and other ATP binding proteins. AlphaFold2 structure predictions suggest partial exposure of the 15-mer on the surface of RRA of three distinct Babesia species. Antibodies in protected cattle recognize a synthetic peptide representing the 15-mer motif sequence in iELISA, and rabbit antibodies against the 15-mer react with the surface of free merozoites in immunofluorescence. Discussion and conclusion: The presence of the 15-mer-like regions in dynein and ATP-binding proteins provides a rationale for investigating possible functional roles for RRA. The demonstrated presence of a surface exposed B-cell epitope in the 15-mer motif of the B. bovis RRA, which is recognized by sera from protected bovines, supports its inclusion in future subunit epitope-based vaccines against B. bovis.
Subject(s)
Antigens, Protozoan , Babesia bovis , Babesiosis , Protozoan Proteins , Animals , Cattle , Amino Acid Motifs , Amino Acid Sequence , Antibodies, Protozoan/immunology , Antigens, Protozoan/immunology , Babesia bovis/immunology , Babesiosis/immunology , Babesiosis/parasitology , Babesiosis/prevention & control , Cattle Diseases/immunology , Cattle Diseases/parasitology , Cattle Diseases/prevention & control , Conserved Sequence , Epitopes, B-Lymphocyte/immunology , Protozoan Proteins/immunology , Protozoan Vaccines/immunologyABSTRACT
Theileria equi (T. equi) is an apicomplexan parasite that causes severe hemolytic anemia in equids. Presently, there is inadequate knowledge of the immune responses induced by T. equi in equid hosts impeding understanding of the host parasite relationship and development of potent vaccines for control of T. equi infections. The objective of this study was to evaluate the host-parasite dynamics between T. equi merozoites and infected horses by assessing cytokine expression during primary and secondary parasite exposure, and to determine whether the pattern of expression correlated with clinical indicators of disease. Our findings showed that the expression of pro-inflammatory cytokines was very low and inconsistent during both primary and secondary infection. There was also no correlation between the symptoms observed during primary infection and expression of the cytokines. This suggests that the symptoms might have occurred primarily due to hemolysis and likely not the undesirable effects of pro-inflammatory responses. However, IL-10 and TGF-ß1 were highly expressed in both phases of infection, and their expression was linked to antibody production but not moderation of pro-inflammatory cytokine responses.
Subject(s)
Horse Diseases , Interleukin-10 , Theileria , Theileriasis , Transforming Growth Factor beta1 , Animals , Horses , Theileriasis/immunology , Theileriasis/parasitology , Interleukin-10/metabolism , Interleukin-10/immunology , Theileria/immunology , Transforming Growth Factor beta1/metabolism , Horse Diseases/immunology , Horse Diseases/parasitology , Merozoites/immunology , Antibodies, Protozoan/immunology , Antibody Formation/immunology , Cytokines/metabolism , Host-Parasite Interactions/immunologyABSTRACT
Introduction: B. bovis is an apicomplexan parasite responsible for bovine babesiosis, a tick-borne disease with a worldwide impact. The disease remains inefficiently controlled, and few effective drugs, including imidocarb dipropionate (ID), are currently available in endemic areas. The objective of this study was to evaluate whether buparvaquone (BPQ), a drug currently used to treat cattle infected with the Babesia-related Theileria spp. parasites, could be active against Babesia parasites. Herein, we compared the effect of ID and BPQ on B. bovis growth in vitro erythrocyte culture. Methods: We compared the effect of ID and BPQ on the culture-adapted Texas T2Bo strain of B. bovis. In vitro cultured parasites were incubated with ID and BPQ at two starting parasitemia levels (PPE), 0.2% and 1%. In vitro cultured parasites were treated with ID or BPQ at concentrations ranging from 10 to 300 nM, during 4 consecutive days. Parasitemia levels were daily evaluated using microscopic examination. Data was compared using the independent Student's t-test. Results and discussion: Both ID and BPQ significantly inhibited (p < 0.05) the growth of B. bovis, regardless of the initial parasitemia used. At 1% parasitemia, BPQ had lower calculated inhibitory concentration 50 (IC50: 50.01) values than ID (IC50: 117.3). No parasites were found in wells with 0.2% starting parasitemia, treated previously with 50 nM of BPQ or ID, after 2 days of culture without drugs. At 1% parasitemia, no parasite survival was detected at 150 nM of BPQ or 300 nM of ID, suggesting that both drugs acted as babesiacidals. Conclusion: Overall, the data suggests that BPQ is effective against B. bovis and shows a residual effect that seems superior to ID, which is currently the first-line drug for treating bovine babesiosis globally.
ABSTRACT
Ticks are obligatory voracious blood feeders infesting diverse vertebrate hosts, that have a crucial role in the transmission of diverse pathogens that threaten human and animal health. The continuous emergence of tick-borne diseases due to combined worldwide climatic changes, human activities, and acaricide-resistant tick strains, necessitates the development of novel ameliorative tick control strategies such as vaccines. The synchrotron-based Fourier transform infrared micro-spectroscopy (SR-FTIR) is a bioanalytical microprobe capable of exploring the molecular chemistry within microstructures at a cellular or subcellular level and is considered as a nondestructive analytical approach for biological specimens. In this study, SR-FTIR analysis was able to explore a qualitative and semi-quantitative biochemical composition of gut and salivary glands of Hyalomma dromedarii (H. dromedarii) tick detecting differences in the biochemical composition of both tissues. A notable observation regarding Amide I secondary structure protein profile was the higher ratio of aggregated strands in salivary gland and beta turns in gut tissues. Regarding the lipid profile, there was a higher intensity of lipid regions in gut tissue when compared to salivary glands. This detailed information on the biochemical compositions of tick tissues could assist in selecting vaccine and/or control candidates. Altogether, these findings confirmed SR-FTIR spectroscopy as a tool for detecting differences in the biochemical composition of H. dromedarii salivary glands and gut tissues. This approach could potentially be extended to the analysis of other ticks that are vectors of important diseases such as babesiosis and theileriosis.
Subject(s)
Acaricides , Ixodidae , Animals , Humans , Spectroscopy, Fourier Transform Infrared , Salivary Glands , Synapsins , LipidsABSTRACT
Apicomplexan protozoa are intracellular parasites of medical and economic importance. These parasites contain specialized apical complex organelles, including rhoptries, that participate in the process of host cell invasion. Conserved antigens expressed in the rhoptries are rational vaccine targets, but whether conservation of protein structure is a functional requirement for invasion remains unknown. Novel protein structural modeling enables identification of structurally conserved protein families that are not evident by sequence analysis alone. Here we show by AlphaFold2 structural modeling that the rhoptry-associated protein 1 superfamily of the Piroplasmida hemoparasites Babesia and Theileria (pRAP-1) is structurally conserved, with the core conserved region being composed of a globin-like and a 4-helix bundle subdomain. Search for structurally related members of this protein family in other apicomplexan parasites revealed structural homologues of pRAP-1 in several species of Plasmodium, Toxoplasma gondii and other members of the Sarcocystidae family. Based on these structural findings, pRAP-1 is a conserved apical complex protein, but whether these proteins share functional features in different species remains unknown. Identification of widely conserved elements involved in infection in these parasites will enhance our knowledge of invasion mechanisms, and facilitate the design of methods for controlling diseases that affect humans and animals globally.
Subject(s)
Babesia , Parasites , Plasmodium , Toxoplasma , Humans , Animals , Host-Parasite Interactions , Protozoan Proteins/metabolism , Parasites/metabolism , Plasmodium/genetics , Plasmodium/metabolism , Toxoplasma/genetics , Toxoplasma/metabolism , Babesia/metabolism , Organelles/metabolismABSTRACT
Babesiosis is an acute and persistent tick-borne disease caused by protozoan parasites of the genus Babesia. These hemoparasites affect vertebrates globally, resulting in symptoms such as high fever, anemia, jaundice, and even death. Advancements in molecular parasitology revealed new Babesia species/genotypes affecting sheep and goats, including Babesia aktasi n. sp., which is highly prevalent in goats from Turkiye's Mediterranean region. The objective of this study was to investigate the pathogenesis of B. aktasi infection in immunosuppressed (n=7) and non-immunosuppressed (n=6) goats. These animals were experimentally infected with fresh B. aktasi infected blood, and their clinical signs, hematological and serum biochemical parameters were monitored throughout the infection. The presence of parasites in the blood of immunosuppressed goats was detected by microscopic examination between 4 and 6 days after infection, accompanied by fever and increasing parasitemia. Goats that succumbed acute disease exhibited severe clinical signs, such as anemia, hemoglobinuria, and loss of appetite. However, the goats that survived showed milder clinical signs. In the non-immunosuppressed group, piroplasm forms of B. aktasi were observed in the blood within 2-5 days after inoculation, but with low (0.01-0.2%) parasitemia. Although these goats showed loss of appetite, typical signs of babesiosis were absent except for increased body temperature. Hematological analysis revealed significant decreases in the levels of red blood cells, leukocytes and platelet values post-infection in immunosuppressed goats, while no significant hematological changes were observed in non-immunosuppressed goats. In addition, serum biochemical analysis showed elevated transaminase liver enzymes levels, decreased glucose, and lower total protein values in the immunosuppressed group post-infection. Babesia aktasi, caused mild disease with minor clinical symptoms in non-immunosuppressed goats. However, in immunosuppressed goats, it exhibited remarkable pathogenicity, leading to severe clinical infections and death. In conclusion, this study provides valuable insights into the pathogenicity of the parasite and will serve as a foundation for future research aimed at developing effective prevention and control strategies against babesiosis in small ruminants. Further research is required to investigate the pathogenicity of B. aktasi in various goat breeds, other potential hosts, the vector ticks involved, and its presence in natural reservoirs.
Subject(s)
Anemia , Babesia , Babesiosis , Sheep Diseases , Animals , Sheep , Babesia/genetics , Babesiosis/parasitology , Goats , Parasitemia/veterinary , Sheep Diseases/parasitology , Anemia/veterinaryABSTRACT
Piroplasmosis is a global tick-borne disease caused by hemoprotozoan parasites, which causes high morbidity and substantial economic losses in farm animals. Equine and camel piroplasmosis causes significant losses worldwide and in Egypt. The multifactorial effects and overall impact of equine and camel piroplasmosis in Egypt remain poorly characterized. However, several Babesia and Theileria spp. as well as potential tick vectors affecting these two species have been identified in the country. Equine and camel piroplasmosis has been reported by all governates in the country. Thus, in this work, we intend to provide a broad depiction of the current approaches used for diagnosis and control and the impact of piroplasmosis on the equine and camel industries in Egypt. We also identified current gaps in knowledge that might help develop future research efforts towards improved intervention and control of equine and camel piroplasmosis. It is important to develop specific diagnostic tools suitable for the early and chronic diagnosis of this disease. Altogether, the current situation warrants the development of large-scale epidemiological studies in order to obtain an accurate estimate for equine and camel piroplasmosis to secure the highly needed food resources in the country.
ABSTRACT
The radiological protection has the purpose of safeguarding the physical well-being of the user, preventing exposure to detrimental levels of ionizing radiation. This study introduces a novel, cost-effective category of lead-free elastomeric material designed for radiation shielding. The filler compounds utilized are notably lighter than conventional lead-based materials, enhancing user ergonomics during application. They comprise of a blend of barium sulfate combined or not with magnesium oxide with addition-cure liquid silicone rubber. To ensure the effectiveness of the radiation shielding, X-ray transmission measurements were performed for the different thicknesses of the materials and the results compared with Monte Carlo simulations. Additionally, the physical properties of the new materials, such as density, homogeneity, tensile strength, viscosity, and wettability, were also evaluated. The findings indicate that both materials fulfill the requirement for application in radiation protection garments.
ABSTRACT
The apicomplexan parasite Babesia bovis is responsible for bovine babesiosis, a poorly controlled tick-borne disease of global impact. The widely conserved gametocyte protein HAPLESS2/GCS1 (HAP2) is uniquely expressed on the surface of B. bovis sexual stage parasites and is a candidate for transmission-blocking vaccines (TBV). Here, we tested whether vaccination of calves with recombinant HAP2 (rHAP2) interferes with the transmission of B. bovis by competent ticks. Calves vaccinated with rHAP2 (n = 3), but not control animals (n = 3) developed antibodies specific to the vaccine antigen. Vaccinated and control animals were infested with Rhipicephalus microplus larvae and subsequently infected with virulent blood stage B. bovis parasites by needle inoculation, with all animals developing clinical signs of acute babesiosis. Engorged female ticks fed on the infected calves were collected for oviposition, hatching, and obtention of larvae. Transmission feeding was then conducted using pools of larvae derived from ticks fed on rHAP2-vaccinated or control calves. Recipient calves (n = 3) exposed to larvae derived from control animals, but none of the recipient calves (n = 3) challenged with larvae from ticks fed on rHAP2-vaccinated animals, developed signs of acute babesiosis within 11 days after tick infestation. Antibodies against B. bovis antigens and parasite DNA were found in all control recipient animals, but not in any of the calves exposed to larvae derived from HAP2-vaccinated animals, consistent with the absence of B. bovis infection via tick transmission. Overall, our results are consistent with the abrogation of parasite tick transmission in rHAP2-vaccinated calves, confirming this antigen as a prime TBV candidate against B. bovis.
ABSTRACT
Introduction: Live in vivo attenuated Babesia bovis vaccines produced by sequential passages in splenectomized calves have historically been used to control acute bovine babesiosis in endemic areas worldwide. However, several constraints prevent the widespread use of these vaccines, including the need for several splenectomized calves to produce vaccine batches, and potential inconsistent parasite attenuation, which contraindicates their use for highly Babesia-susceptible adult cattle. Thus, the use of vaccines based on well-defined in vitro culture attenuated B. bovis strains emerges as a more sustainable and efficient alternative. Previous work demonstrated that the culture attenuated strain Att-S74-T3Bo is non-tick transmissible and able to safely protect calves against needle challenge with a B. bovis virulent strain. Methods and results: Herein we evaluated safety and efficacy of Att-S74-T3Bo in preventing acute babesiosis in adult (>1.5 year of age) cattle. Results demonstrated that Att-S74-T3Bo vaccination of adult animals (n=5) induced self-limiting signs of acute infection and protected the vaccinated animals against challenge with the homologous virulent B. bovis strain Vir-S74-T3Bo. Att-S74-T3Bo-vaccinated adult cattle developed significant (P<0.05) monocytosis, with concomitant neutropenia and CD4+ leukopenia, in peripheral blood early after vaccination. Also, vaccinated animals developed a specific signature of pro- and anti-inflammatory cytokine expression in peripheral blood and significant levels of IgM, total IgG, IgG1, and IgG2 against the B. bovis immunodominant antigen RAP-1 CT. Strikingly, none of the vaccinated animals showed any signs of acute babesiosis after challenge with Vir-S74-T3Bo. In contrast, control adult cattle (n=5) showed pathognomonic symptoms of acute babesiosis, and significant decrease (P<0.05) in lymphocytes, monocytes, and neutrophils, starting on day 7 post-challenge. All control animals developed severe acute disease and were euthanized on days 10 through 12 days post-challenge. Discussion and conclusion: Evidence from this study indicates that Att-S74-T3Bo safely protects highly susceptible adult cattle against challenge with a homologous virulent strain of B. bovis. In conclusion, Att-S74-T3Bo may be considered as a potential efficient and sustainable attenuated candidate vaccine strain to control acute bovine babesiosis in highly susceptible adult cattle. Future studies should focus on increasing the number of animals vaccinated, duration of immunity, and efficacy of this attenuated strain against heterologous virulent parasite strains.
Subject(s)
Babesia bovis , Babesia , Babesiosis , Cattle Diseases , Cattle , Animals , Babesiosis/parasitology , Vaccination/methods , Immunoglobulin G , Vaccines, AttenuatedABSTRACT
Piroplasmids of the genera Babesia, Theileria, and Cytauxzoon are tick-transmitted parasites with a high impact on animals and humans. They have complex life cycles in their definitive arthropod and intermediate vertebrate hosts involving numerous processes, including invasion of, and egress from, host cells, parasite growth, transformation, and migration. Like other parasitic protozoa, piroplasmids are equipped with different types of protease to fulfill many of such essential processes. Blockade of some key proteases, using inhibitors or antibodies, hinders piroplasmid growth, highlighting their potential usefulness in drug therapies and vaccine development. A better understanding of the functional significance of these enzymes will contribute to the development of improved control measures for the devastating animal and human diseases caused by these pathogens.
Subject(s)
Babesia , Babesiosis , Piroplasmida , Theileria , Ticks , Animals , Humans , Peptide Hydrolases , Babesia/genetics , Ticks/parasitology , Babesiosis/parasitologyABSTRACT
Camel piroplasmosis is a tick-borne disease (TBD) caused by hemoprotozoan parasites. Hereby, we describe a cross-sectional study aiming at identifying Piroplasma spp.-infecting camels in Egypt using a multipronged molecular diagnostic approach. A total of 531 blood samples from camels (Camelus dromedarius) were collected from slaughterhouses at different governorates in Egypt for analysis during the period from June 2018 to May 2019. Piroplasma spp. was identified using microscopical examination and several different and sequential polymerase chain reaction (PCR) assays targeting the 18S rRNA genes. The overall prevalence of Piroplasma spp. in microscopical and molecular analyses in the samples was 11% (58/531) and 38% (203/531), respectively. Further discriminative multiplex PCR analysis targeting the 18S rRNA gene applied on all Piroplasma spp.-positive samples allowed the detection of Theileria equi (41%), Babesia caballi (5.4%), Babesia bigemina (0.5%), and Babesia bovis (4%). Additionally, the blast analysis of nested (n) PCR, targeting the V4 region, amplicon sequences resulted in the identification of B. vulpes (22%), Babesia sp. (9%), and Theileria sp. (3%). Overall, the results of this study confirmed the high prevalence of TBDs caused by several types of piroplasm hemoparasites in camel and suggests the need for future interventions aimed at improving the control of these potentially debilitating diseases that may be t-hreatening important economic resources and food security in Egypt.
ABSTRACT
Silanization of filler particles in a dental resin composite is achieved by the formation of Si-O-Si bonds, however, these bonds are especially vulnerable to hydrolysis because this covalent bond has a significant ionic character due to the electronegativity differences between the atoms. The objective of this study was to evaluate the use of an interpenetrated network (IPN) as alternative of silanization reaction and to assess its effect in selected properties of experimental photopolymerizable resin composites. The interpenetrate network was obtained during the photopolymerization reaction of organic matrix (BisGMA/TEGDMA) with a biobased polycarbonate. Its characterization was performed via FTIR, flexural strength, flexural modulus, depth of cure, sorption water and solubility. A resin composite formulated with non-silanized filler particles was used as control. The IPN with a biobased polycarbonate was successfully synthesized. The results showed that the IPN based resin composite had higher values of flexural strength, flexural modulus, and degree of double bond conversion than the control (p < 0.05). Polymerization shrinkage, water sorption and solubility were statistically significantly lower than the control resin (p < 0.05). Finally, this study shows there were no statistically significant differences for the biocompatibility outcomes (p > 0.05). The biobased IPN replaces the silanization reaction in resin composites, improving physical and chemical properties. Therefore, IPN with a biobased polycarbonate could be potentially useful in the formulation of dental resin composites.
Subject(s)
Methacrylates , Polymethacrylic Acids , Methacrylates/chemistry , Materials Testing , Polymethacrylic Acids/chemistry , Composite Resins/chemistry , Polyethylene Glycols/chemistry , Polymerization , Water/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistryABSTRACT
OBJECTIVES: To evaluate the incorporation of halloysite nanotubes (HNTs) loaded with one of two calcium sources (i.e., calcium hydroxide/CaOH2 or beta-tricalcium phosphate/ß-TCP) on the physicochemical and biological properties of an experimental resin-based dual-cured endodontic sealer. MATERIALS AND METHODS: HNTs were encapsulated with CaOH2 or ß-TCP at 10 wt.%. HNTs containing CaOH2 or ß-TCP were added into the experimental sealers at 50 wt.%. The control sealers were the calcium-free HNT-modified resin-based experimental sealer and AH Plus™, a commercially available endodontic sealer. Degree of conversion, setting time, flow, film thickness, radiopacity, dimensional stability, and calcium ions release were determined. Antibiofilm properties and cytocompatibility of the formulated sealers and commercial control were also evaluated. One and two-way ANOVA analysis followed by Tukey's post hoc test was conducted to evaluate the effect of the independent variable on the evaluated properties. RESULTS: FTIR confirmed the encapsulation of calcium sources into HNTs. Regarding flow and film thickness, the values obtained from these sealers were in accordance with the specifications provided by ISO 6876. For radiopacity, AH Plus™ achieved the highest radiopacity (p<0.05). Among the experimental formulations, all experimental HNT-containing compositions exhibited values below 3 mm Al. The experimental sealers showed greater dimensional changes when compared to the commercial (AH Plus™) control. The release of calcium ions was observed for the HNT_CaOH2 and HNT_ß-TCP sealers without statistical differences. Experimental sealers containing HNT_CaOH2 and HNT_ß-TCP significantly reduced the CFU/mL count and showed cell compatibility. CONCLUSIONS: The findings of this study demonstrate that the incorporation of HNT_CaOH2 or HNT_ß-TCP into resin-based experimental sealers promoted antimicrobial effects and gradual calcium release without impairing cytocompatibility or physicochemical properties of the sealers. Still, an adjustment to reach the minimal radiopacity established by ISO 6876 is needed. CLINICAL RELEVANCE: The experimental resin-based sealers seemed to be an alternative for endodontics. The incorporation of calcium sources exerts promising antimicrobial effects while displaying low cell toxicity.
Subject(s)
Calcium Hydroxide , Pit and Fissure Sealants , Resins, Synthetic , Root Canal Filling Materials , Humans , Root Canal Filling Materials/pharmacology , Calcium Hydroxide/pharmacology , Calcium , Anti-Infective Agents , Materials TestingABSTRACT
PURPOSE: To evaluate the effect of adding wollastonite and bioactive glass to an experimental mineral trioxide aggregate-like cement (MTA) on the dimensional stability, compressive strength, solubility, bioactivity, and marginal adaptation by scanning electron microscopy (SEM) and X-ray diffraction (XRD). METHODS: Four groups were evaluated at 7, 14, and 21 days: MTA Angelus, experimental MTA-like cement (MTA Exp), BG10 (MTA Exp+10 wt% bioactive glass), and WO20 (MTA Exp+20 wt% wollastonite). To evaluate marginal adaptation, extracted teeth were endodontically obturated and root-end cavities were prepared and filled with the tested materials. RESULTS: Cements with bioactive materials showed minimal dimensional changes. Adding wollastonite or bioactive glass to MTA Exp reduces the compressive strength but does not affect solubility. Bismite (Bi2O3), larnite (Ca2SiO4), calcite (CaCO3) and carbonated hydroxyapatite (Ca5[PO4,CO3]3[OH]) were identified in the four cements; ettringite (Ca6Al2[SO4]3[OH]12·26H2O) and bismutite ([BiO]2CO3) were only observed in MTA Exp, BG10, and WO20. Cement-dentin interfaces were not observed after 14 days on the BG10 and WO20 cement composites due to the ettringite formation. CONCLUSION: Acicular growing crystals typical of hydroxyapatite were found on the surfaces of all cements. An improved marginal adaptation was observed with the addition of wollastonite or bioactive glass.
Subject(s)
Root Canal Filling Materials , Root Canal Filling Materials/chemistry , Dentin , Calcium Compounds/chemistry , Silicates/chemistry , Oxides , Aluminum Compounds , Drug Combinations , Hydroxyapatites/pharmacology , Materials Testing , Dental Cements/chemistryABSTRACT
BACKGROUND: COPD is diagnosed by using FEV1/FVC, which has limitations as a diagnostic test. We assessed the validity of several measures derived from the expiratory phase of the flow-volume curve obtained from spirometry to diagnose COPD: the slopes that correspond to the volume expired after the 50% and 75% of the FVC, the slope formed between the peak expiratory flow (PEF) and the FVC, and the area under the expiratory flow/volume curve. METHODS: We conducted a cross-sectional diagnostic test study in 765 consecutive subjects referred for spirometry because of respiratory symptoms. We compared the reproducibility and accuracy of the proposed measures against post-bronchodilator FEV1/FVC < 0.70. We also evaluated the proportion of respiratory symptoms for the FEV1/FVC, FEV1 per FEV in the first 6 s (FEV6), and the PEF slope. RESULTS: The subjects had a mean age of 65.8 y, 57% were women, and 35% had COPD. The test-retest intraclass correlation coefficient values were 0.89, 0.85, and 0.83 for FEV1/FVC, FEV1/FEV6, and the PEF slope, respectively. The area under the curve values were 0.93 (expiratory flow/volume), 0.96 (potential expiratory flow/volume), 0.97 (potential expiratory flow/volume at 75% of FVC), and 0.82 (potential expiratory flow/volume at 50% of FVC). The area under the receiver operating characteristic curve was 0.99 for FEV1/FEV6, 0.99 for the slope at 50% of the FVC, and 0.98 for the PEF slope. CONCLUSIONS: The FEV1/FEV6, PEF slope, and 50% FVC slopes had similar diagnostic performances compared with FEV1/FVC.
Subject(s)
Pulmonary Disease, Chronic Obstructive , Humans , Female , Aged , Male , Pulmonary Disease, Chronic Obstructive/diagnosis , Reproducibility of Results , Cross-Sectional Studies , Forced Expiratory Volume , Spirometry , Vital CapacityABSTRACT
The apicomplexan tickborne parasites Babesia bovis and B. bigemina are the major causative agents of bovine babesiosis, a disease that negatively affects the cattle industry and food safety around the world. The absence of correlates of protection represents one major impediment for the development of effective and sustainable vaccines against bovine babesiosis. Herein we superinfected cattle with attenuated and virulent strains of B. bovis to investigate immune correlates of protection against acute bovine babesiosis. Three 6-month-old Holstein calves were infected intravenously (IV) with the in vitro culture attenuated Att-S74-T3Bo B. bovis strain (106 infected bovine red blood cells (iRBC)/calf) while three age-matched Holstein calves were inoculated IV with normal RBC as controls (106 RBC/calf). All Att-S74-T3Bo-infected calves showed a significant increase in temperature early after inoculation but recovered without treatment. Att-S74-T3Bo-infected calves also developed: (a) monocytosis, neutropenia, and CD4+ lymphopenia in peripheral blood on days 3 to 7 post-inoculation; (b) significant levels of TNFα, CXCL10, IFNγ, IL-4, and IL-10 in sera at day 6 after infection; and (c) IgM and IgG against B. bovis antigens, starting at days 10 and 30 post-inoculation, respectively. At 46 days post-Att-S74-T3Bo inoculation, all experimental calves were infected IV with the homologous virulent B. bovis strain Vir-S74-T3Bo (107 iRBC/calf). All Att-S74-T3Bo-infected calves survived superinfection with Vir-S74-T3Bo without displaying signs of acute babesiosis. In contrast, control animals showed signs of acute disease, starting at day 10 post-Vir-S74-T3Bo infection, and two of them were humanely euthanized at days 13 and 14 after inoculation due to the severity of their symptoms. Also, control calves showed higher (P<0.05) parasite load in peripheral blood compared to animals previously exposed to Att-S74-T3Bo. No significant alterations in the profile of leukocytes and cytokines were observed in Att-S74-T3Bo-inoculated after Vir-S74-T3Bo infection. In conclusion, data demonstrate novel changes in the profile of blood immune cells and cytokine expression in peripheral blood that are associated with protection against acute bovine babesiosis. These identified immune correlates of protection may be useful for designing effective and sustainable vaccines against babesiosis in cattle.
Subject(s)
Babesia bovis , Babesiosis , Blood Group Antigens , Neutropenia , Cattle , Animals , Babesiosis/prevention & control , Vaccination , CytokinesABSTRACT
Bovine babesiosis is caused by apicomplexan pathogens of the genus Babesia, including B. bovis. This protozoan parasite has a complex life cycle involving dynamic changes to its transcriptome during the transition between the invertebrate and vertebrate hosts. Studying the role of genes upregulated by tick stage parasites has been hindered by the lack of appropriate tools to study parasite gene products in the invertebrate host. Herein, we present tfBbo5480, a transfected B. bovis cell line, constitutively expressing enhanced green fluorescent protein (eGFP) created by a whole gene replacement transfection strategy, that was capable of completing the parasite's entire life cycle in both the vertebrate and invertebrate hosts. tfBbo5480 was demonstrated to respond to in vitro sexual stage induction and upon acquisition by the female tick vector, Rhipicephalus microplus, the tick specific kinete stage of tfBbo5480 was detected in tick hemolymph. Larvae from tfBbo5480 exposed R. microplus female ticks successfully transmitted the transfected parasite to a naïve calf. The development of the whole gene replacement strategy will permit a deeper understanding of the biology of parasite-host-vector triad interactions and facilitate the evaluation of upregulated genes during the parasite's journey through the tick vector leading to new intervention strategies for the control of bovine babesiosis.
ABSTRACT
Babesia bigemina is a tick-borne apicomplexan hemoprotozoan responsible for bovine babesiosis. The current drugs used for bovine babesiosis treatment have several drawbacks, including toxicity, the lack of effectiveness to clear the parasite, and potential to develop resistance. Identifying compounds that target essential and unique parasite metabolic pathways is a rational approach toward finding alternative drug treatments. Based on the genome sequence and transcriptomics analysis, it can be inferred that anaerobic glycolysis is the dominant adenosine triphosphate (ATP) supply for Babesia, and lactate dehydrogenase (LDH) is one of the essential enzymes in this pathway. Furthermore, the Babesia LDH sequence is distinct from its bovine homologue and thus a potential chemotherapeutic target that would result in decreasing the ATP supply to the parasite but not to the host. Gossypol is a known efficient specific inhibitor of LDH in the sensu stricto B. bovis and the sensu lato B. microti, among other related parasites, but no such data are currently available in the sensu stricto B. bigemina parasites. Hereby, we show that the LDH amino acid sequence is highly conserved among sensu stricto but not in sensu lato Babesia spp. A predictive structural analysis of B. bigemina LDH showed the conservation of the key amino acids involved in the binding to gossypol compared to B. bovis. Gossypol has a significant (P < 0.0001) inhibitory effect on the in vitro growth of B. bigemina, with IC50 of 43.97 mM after 72 h of treatment. The maximum IC (IC98) was observed at 60 mM gossypol. However, a significant effect on the viability of cattle PBMC was observed when the cells were cultured with 60 mM (IC98) gossypol compared with DMSO-exposed control cells. Interestingly, B. bigemina cultured at 3% oxygen expresses significantly higher levels of LDH and is more resistant to gossypol than the parasites maintained at ambient conditions containing ~20% oxygen. Altogether, the results suggest the potential of gossypol as an effective drug against B. bigemina infection, but the risk of host toxicity at therapeutic doses should be further evaluated in in vivo studies.