Infection Levels Research Articles

Multispectral UAV-Based Disease Identification Using Vegetation Indices for Maize Hybrids

In the future, the cultivation of maize will become more and more prominent. As the world’s demand for food and animal feeding increases, remote sensing technologies (RS technologies), especially unmanned aerial vehicles (UAVs), are developing more and more, and the usability of the cameras (Multispectral-MS) installed on them is increasing, especially for plant disease detection and severity observations. In the present research, two different maize hybrids, P9025 and sweet corn Dessert R78 (CS hybrid), were employed. Four different treatments were performed with three different doses (low, medium, and high dosage) of infection with corn smut fungus (Ustilago maydis [DC] Corda). The fields were monitored two times after the inoculation—20 DAI (days after inoculation) and 27 DAI. The orthomosaics were created in WebODM 2.5.2 software and the study included five vegetation indices (NDVI [Normalized Difference Vegetation Index], GNDVI [Green Normalized Difference Vegetation Index], NDRE [Normalized Difference Red Edge], LCI [Leaf Chlorophyll Index] and ENDVI [Enhanced Normalized Difference Vegetation Index]) with further analysis in QGIS. The gathered data were analyzed using R-based Jamovi 2.6.13 software with different statistical methods. In the case of the sweet maize hybrid, we obtained promising results, as follows: the NDVI values of CS 0 were significantly higher than the high-dosed infection CS 10.000 with a mean difference of 0.05422 *** and a p value of 4.43 × 10−5 value, suggesting differences in all of the levels of infection. Furthermore, we investigated the correlations of the vegetation indices (VI) for the Dessert R78, where NDVI and GNDVI showed high correlations. NDVI had a strong correlation with GNDVI (r = 0.83), a medium correlation with LCI (r = 0.56) and a weak correlation with NDRE (r = 0.419). There was also a strong correlation between LCI and GNDVI, with r = 0.836. NDRE and GNDVI indices had the correlation coefficients with a CCoeff. of r = 0.716. For hybrid separation analyses, useful results were obtained for NDVI and ENDVI as well.

A Review of an Effective Deep Learning Network for Estimating COVID-19 severity from chest X-ray Imagery: Co Severity-Net

The COVID-19 pandemic has become an integral part of our existence and shows no signs of abating. In 2020, the World Health Organization declared it a pandemic, and its effects have impacted our lives in myriad ways. To detect COVID-19 from Chest X-Ray images, researchers have developed deep learning techniques. Given the severity of the disease, scoring the level of COVID-19 infection can aid in determining the optimal course of treatment and care for patients, as not all COVID-19 positive patients require specialized medical attention. However, the limited availability of a large-scale dataset has resulted in few studies being conducted to estimate the severity of the disease from Chest X-Ray images. Consequently, we propose CoV Severity-Net, a deep learning-based architecture trained on a public COVID-19 dataset curated by experienced radiologists for severity estimation. Our proposal is based on a review of 18 papers from reputable sources such as Google Scholar, PubMed, and Science Direct.

Ectoparasite infection levels differ between fish from upwelling-exposed and sheltered rocky reefs areas in Brazil

Ubiquitous and abundant within marine ecosystems, parasites play essential ecological roles such as shaping host population dynamics, altering competition between species, and influencing energy flows through communities. Their diversity and population dynamics are demonstrably shaped by both seasonal and geographic variations. These variations have been often explored at broad spatial scale. However, parasite communities can exhibit significant disparities even at small spatial scales, driven by factors such as wave exposure, temperature fluctuations, and benthic habitat composition. We investigated how crustacean parasites of fish – caligids and gnathiids - differed between two distinct habitats, which are separated solely by a few kilometres, at Arraial do Cabo, Brazil. These two habitats were characterised by a sheltered embayment (hereinafter referred to as “inside”) or an exposed upwelling habitat (hereinafter referred to as “outside”). Individual fish from four species were examined in both habitats. We found that the infestation rate of caligids varied among fish species and, gnathiids varied between the two sampling sites. Gnathiids were absent from fish outside, while they were present on fish inside the embayment. This disparity suggests a critical role of local environmental factors in shaping gnathiid distribution. Potential drivers include temperature fluctuations, substrate composition, and wave exposure, which differed markedly between the two sites. Conversely, caligid parasites infected fish in both locations. While environmental factors may also influence caligid abundance, they appear to exhibit greater tolerance compared to gnathiids. These findings emphasize the importance of incorporating fine-scale environmental heterogeneity when investigating parasite distribution patterns.

Nonlinear Dynamics of a Zoonotic Disease with Control Interventions through Fractional Derivative

The zoonotic infection campylobacteriosis poses a significant public health burden, contributing to widespread morbidity and, in severe cases, mortality, particularly among vulnerable populations such as children, the elderly, and immunocompromised individuals. The economic impact is considerable, with costs arising from medical care, hospitalization, lost productivity, and the need for stringent food safety measures. In this paper, we model the dynamics of campylobacteriosis with drug resistance in humans and animals using fractional derivatives. The fundamental concepts of fractional derivatives are presented to analyze the disease dynamics. Our work focuses on both the quantitative and qualitative analysis of the proposed model. The fixed-point theorem is applied to investigate the existence and uniqueness of solutions. We also examine the stability of the system through analytical techniques. To further explore the system, a numerical scheme is introduced to visualize the solution pathways and assess the influence of various factors. We demonstrate the dynamics of campylobacteriosis with drug resistance, highlighting the effects of different factors on infection levels. Furthermore, our results identify the key factors crucial for effective disease control and management.

Quercetin@β-Cyclodextrin Conjugated Keratin/Polyurethane Biocomposite Mats for Infected Diabetic Wound Healing.

Chronic diabetic wounds suffer from severe complications caused by long-term high levels of oxidative stress and bacterial infection. Quercetin (Que) has excellent anti-inflammatory, antioxidant, and antibacterial activity, making it a promising drug to address the above issues. To exploit the benefits of Que in a more effective and sustained way to treat diabetic wounds, carboxymethyl β-cyclodextrin (CMCD) was synthesized and conjugated to keratin, then complexed with Que to form Que@Ker-CMCD inclusion, followed by electrospinning with polyurethane (PU) to afford Que@Ker-CMCD/PU mats. The approach significantly enhanced water solubility, bioavailability, and sustained release of Que. Crucially, these mats exhibited robust antioxidant and antibacterial activities. Moreover, the mats fostered an environment conducive to cell proliferation, migration, angiogenesis, and re-epithelialization, pivotal processes in wound healing and remodeling. Consequently, a marked acceleration in remodeling chronic diabetic wounds was observed. In conclusion, this study introduces a novel therapeutic strategy that not only harnesses the multifaceted benefits of Que but also enhances its delivery and performance, offering a promising avenue for the effective treatment of chronic diabetic wounds.

Identification and level of ectoparasite intensity in goldfish (Carassius auratus) at fishery product inspection and certification center fish seed center

Diseases and parasites that attack the fish body are often encountered in ornamental fish cultivation, so they can reduce the quality of the fish and cause fish death. Ectoparasites are parasites found outside the fish body. This study aimed to determine the type and intensity level of ectoparasite distribution in goldfish (Carassius auratus) cultivated at the Fishery Product Inspection and Certification Production Center (PPISHP) Fish Seed Center (BBI) Ciganjur, South Jakarta. A location survey and random sampling from three different rearing ponds were used. The goldfish samples obtained were 60 fish from three ponds in BBI Ciganjur. The results showed that the highest level of intensity of the Argulus sp. parasite was found in pond 2, the highest level of intensity of the Trichodina sp. parasite was found in pool 1, and the highest level of Lernea sp. parasite intensity was found in pools 1 and 3. The average infection level of each parasite showed that the intensity was relatively low.

Could Pistachio (Pistacia vera) Be a Suitable Alternative Crop for Olive-Growing Mediterranean Areas Affected by Xylella fastidiosa subsp. pauca ST53?

In the olive-growing areas of Apulia (southern Italy) where Xylella fastidiosa has caused enormous damage, there is a need to identify alternative crops. These could include pistachio (Pistacia vera L.), but it is critical to define the impact of the bacterium on this crop and what are the main phytosanitary threats for this species in the areas where the bacterium is now endemic. Therefore, we started evaluating infections caused by X. fastidiosa, the fungus Neofusicoccum mediterraneum, and other pathogens on four pistachio cultivars ('Kerman', 'Aegina', 'Lost Hills', and 'Napoletana') grown in areas where X. fastidiosa has been present for a long time. X. fastidiosa was detected only in one orchard (incidence: 18% 'Napoletana' and 55% 'Kerman') out of six surveyed orchards, with low bacterium concentration (1.67 to 5.98 × 103 CFU ml-1) and no symptoms. N. mediterraneum was retrieved in three orchards just on the cultivar Kerman but with high incidence (up to 30%) and infection level quantified as molecular severity (6.82 to 7.43); no other pathogens were detected. The N. mediterraneum representative isolates characterized in this study showed similarity with Spanish and Portuguese isolates. A confocal microscope analysis for this host-pathogen association suggested no differences in plant response to fungal aggression between the cultivars Kerman and Aegina, but just lack of latent inoculum in 'Aegina' plants, pointing to a possible nursery origin of the infection. Waiting for additional targeted experiments to clearly define host response of pistachio cultivars to Xylella spp., this study also points at N. mediterraneum as a potential threat to this tree crop new for the area.

Death and survival of gut CD4 T cells following HIV-1 infection ex vivo

Abstract The gastrointestinal (GI) tract is ground zero for the massive and sustained CD4 T cell depletion during acute HIV-1 infection. To date, the molecular mechanisms governing this fundamental pathogenic process remain unclear. HIV-1 infection in the GI tract is associated with chronic inflammation due to a disrupted epithelial barrier that results in microbial translocation. Here, we utilized the Lamina Propria Aggregate Culture model to demonstrate that the profound induction of Granzyme B (GZB) by bacteria in primary gut CD4 T cells ex vivo significantly contributes to HIV-1-mediated CD4 T cell death. Counterintuitively, a substantial fraction of gut GZB+ CD4 T cells harboring high levels of HIV-1 infection survive via a pathway linked to CD120b/TNFR2. Our findings underscore novel mechanisms governing the death and survival of gut CD4 T cells during HIV-1 infection that could inform strategies to counter HIV-1 pathogenesis and persistence in this critical tissue compartment.

A recent shift in the Puccinia striiformis f. sp. tritici population in Serbia coincides with changes in yield losses of commercial winter wheat varieties

Wheat yellow (stripe) rust, caused by the fungus Puccinia striiformis f.sp. tritici (Pst), is a devastating disease of wheat worldwide. The success of Pst is largely due to the pathogens ability to rapidly overcome host resistance, generating new races that are easily dispersed between territories through wind-borne transmission of Pst urediniospores. Thus, first signs of entry of new Pst races into a region is usually captured by changes in disease severity. To examine any alterations of winter wheat variety response to Pst infection in Serbia, we analyzed yield and Pst disease severity in field trials conducted in 2014, 2021, and 2023. We specifically focused on analyzing Pst disease severity at growth stages related to yield. Associations between qualitative variables (variety, year) and quantitative variables (yield in untreated plots, yield loss, and disease index (DI) of Pst infection) were analyzed using Principal Component Analysis with mixed data. A General Linear Model was used to investigate the most influential factors on yield, yield loss, and Pst infection. The results indicated that yellow rust disease severity increased over the past decade, suggesting a potential recent change in the Pst population in Serbia. Comparative population genetic analysis of Pst samples from the 2023 wheat season and those collected in Serbia in 2014 confirmed a potential change in the Pst population. In addition, we found that yield losses across wheat varieties varied independently of Pst infection levels, indicating that wheat varieties differ in their ability to overcome damage caused by high levels of Pst infection. Given that the level of pathogen pressure triggering susceptibility reactions is cultivar-specific, our study highlights the need for a deeper focus on the mechanisms underlying these differences. Expanding our understanding of the interactions between pathogens, plant defense responses, and the ability of cultivars to mitigate yield losses will better equip us to predict and prevent potential yield losses in commercial wheat varieties due to yellow rust in the future.

Correlation between vaccine hesitancy, vaccine reliability and perceptions of infectious diseases

Abstract Background Vaccine hesitancy is a delay in vaccine acceptance or refusal despite the availability of vaccination services. In recent years, the rise in vaccine hesitancy has attracted attention. This study aimed to evaluate the perception of vaccine hesitancy, vaccine safety, and infectious diseases among parents. Methods This cross-sectional study was conducted with 503 parents who applied to the pediatrics outpatient clinic of a university hospital. The questionnaire used in the study included questions on sociodemographic characteristics, factors related to vaccine hesitancy, The Vaccine Hesitancy Scale (VAS), the Vaccine Safety Scale (VSS), and the Perception Scale for Infectious Diseases (PPSID). Multivariate Linear Regression Analysis was used to find the variables associated with vaccine hesitancy. Results The mean age of the parents was 37.6±7.6 years. Parents’ scores on the ATS ranged from 17-85, with a mean score of 20.1±6.6 points. A moderate negative correlation was found between parents’ VAS and VSS scores, and between VAS and PPSID scores (r=-0.412, p < 0.001; r=-0.409, p < 0.001, respectively). According to the multivariate linear regression analysis the variables found to be associated with vaccine hesitancy, income status, maternal education level, child’s age group, having information about childhood vaccination schedule, child’s immunization status, the necessity of childhood vaccines, having sufficient information about the safety of vaccines, vaccine safety level, and infectious disease perception level were found to be significant predictors of vaccine hesitancy (F: 12,844, p ≤ 0.001, R2: 0.334). Conclusions This study determined that vaccine hesitancy was higher in families with lower income, who have not completed the schedule nor been vaccinated, doubt the necessity of vaccines to prevent infectious diseases, lack of knowledge about the reliability of vaccines, and whose children are still in primary school. Key messages • Health professionals have a critical role in reducing vaccine hesitancy. • It would be appropriate to plan face-to-face or online programs with parents.

The impact of major infectious disease events and government relief packages on the film industry: evidence from Taiwan

This study focuses on the impact of COVID-19 on the film industry and the effectiveness of government relief policies. Taiwan was a region with a low level of infection at the beginning of the COVID-19 pandemic (2020), and the film industry could be maintained under government policies; therefore, this case study was conducted. Multiple regression models were used to explore the explanatory factors for movie box offices based on running size, production studios and countries, vacations, and the COVID-19 pandemic. The analysis covered a period from September 30, 2019, to September 27, 2020, encompassing a 52-week sample of 5686 films. The results indicated that weekly box office receipts (number of tickets sold) experienced a steep decline of more than 50% despite the implementation of various relief measures. While the number of locally produced films screened diminished significantly, the number of theatres, films, and rerun films and their market share increased substantially. This suggests that although the quantity of films remained stable during the pandemic, their quality or novelty did not correspondingly improve. Key findings from the regression models included the following: (1) there is a size effect (number of theaters screening the film) on the box office; (2) box offices decrease with the number of weeks since the opening week, and films from well-known producers and major studios, as well as products from the US, Japan, and Taiwan, can have positive effects on the box office; (3) student vacations have had a positive effect; and (4) the COVID-19 pandemic has had a negative effect.

Respiratory Syncytial Virus Infection in Children with Bronchiolitis

Background: Respiratory Syncytial Virus (RSV) is the most common organism causing bronchiolitis. Bronchiolitis is almost always diagnosed clinically. As a result, the availability of bedside sensitive rapid RSV antigen tests is critical for timely RSV acute respiratory infection diagnosis. Methods and materials: This study was conducted to detect RSV antigen positivity and the sociodemographic profile of children with RSV antigen positive bronchiolitis. From October 2022 to March 2023, this observational study was conducted in the pediatrics department of Chattogram Medical College Hospital. Ninety-two nasopharyngeal swabs from children younger than two years, were tested for RSV antigen. The mean and standard deviation were used to express the demographic data. Chi-square analysis was used to examine differences in group proportions. Results: RSV antigen positivity was detected in 45.7% of the 92 cases, with a mean age of 4.18±3.08 months. Severe bronchiolitis cases were more common (22.8%) among antigen positive cases and had the longest hospital stay. During the months of November (42.4%) and December (29.3%), RSV infection levels peaked. This study describes that during the seasonal epidemics, RSV was the main concern, as the number of positive cases decreased in the months that followed. The signs and symptoms of RSV positive and negative cases were not significantly different. Conclusion: A simple, low-cost and bedside RSV test can be considered as a valuable diagnostic tool in a low resource setting. J Bangladesh Coll Phys Surg 2024; 42: 368-378

An Expression Quantitative Trait Locus of Fc Gamma Receptor Genes is Associated with Anti-Malarial IgG Responses and Infection Levels in Burkinabe Families.

The interaction between antibodies and Fc gamma receptors (FcγRs) plays a critical role in regulating immune responses to Plasmodium falciparum. Polymorphisms in genes encoding FcγRs influence the host's capacity to control parasite infection. This study investigates whether non-coding variants influencing FcγR expression are associated with anti-malarial immunization and infection traits. We utilized eQTL databases and functional annotations to identify non-coding variants, specifically rs1771575, rs2099684, and rs6700241, within the FCGR gene cluster. In addition, we examined the coding variants rs1801274 (p.His167Arg) and rs1050501 (p.Ile231Thr), which affect the affinity of FcγRIIa and FcγRIIb for IgG. These variants were genotyped in 163 individuals from Burkinabe families. Family-based linear mixed regression and Quantitative Transmission Disequilibrium Tests (QTDT) analyses were performed to assess associations with IgG levels and malaria infection, accounting for relevant covariates. Linear mixed models identified rs1771575 as associated with total IgG levels, while both rs1771575 and rs1801274 were linked to IgG2, and rs1050501 to IgG1 levels. A haplotype combining rs2099684 and rs6700241 was positively associated with IgG1. The rs1771575-CC and rs1050501-TT genotypes correlated with higher infection levels in children. QTDT models confirmed the association of rs1771575 with IgG2 and infection in children. Our findings suggest that the intergenic variant rs1771575 serves as an independent marker for IgG levels and blood infection in children. This highlights the interplay between regulatory variants and coding mutations in FCGR, which may influence immune function and antibody production. These results underscore the potential for personalized strategies to monitor humoral responses in malaria-endemic regions.

Antioxidant and anti-glycation activities of Mandevilla velutina extract and effect on parasitemia levels in Trypanosoma cruzi experimental infection: In vivo, in vitro and in silico approaches

Ethnopharmacological relevanceMandevilla velutina (Mart. Ex Stadelm.) Woodson, known in Brazil as "infalível" and "jalapa", is a medicinal plant native from the Cerrado region (Brazilian Savannah). The underground organ (xylopodium) of this species is prepared as ethanolic extract or infusion and it is commonly used in traditional medicine to treat snake venom. Although, locals and indigenous populations from Cerrado have used M. velutina for the treatment of infection by Trypanosoma cruzi (Chagas’ disease). Aim of the studyThis study aimed to evaluate the in vitro antioxidant and anti-glycation activities of the crude hydroethanolic extract of M. velutina xylopodium. Besides, it aimed to evaluate its effect on parasitemia levels in vivo T. cruzi experimental infection. In addition, this study aimed to determine possible interactions between the main compound of the extract and molecular targets associated with survival and virulence of T. cruzi in silico approaches. Materials and methodsDetermination of total polyphenols, flavonoids and steroidal aglycones content were performed. In addition, high performance liquid chromatography (HPLC) was carried out to identify main compounds of the extract. Antioxidant activity was determined by DPPH radical scavenging, ferric ion reducing power (FRAP), Thiobarbituric acid reactive species (TBARS) and Oxygen Radical Absorbance Capacity (ORAC) methods. Anti-glycation activity was demonstrated through relative mobility in electrophoresis (RME), determination of free amino groups and inhibition of AGEs formation. Determination of the action of extract in parasitemia levels was performed by T. cruzi experimental infection of mice and nitrite levels were measured in the serum of animals evaluated in this study. Molecular docking analyses of the main compound (Velutinol A) with DNA and molecular targets associated with survival and virulence of T. cruzi. ResultsPhytoconstituents evaluation exhibited the presence polyphenols, flavonoids and steroidal aglycone, and HPLC identified the major presence of Velutinol A. Antioxidant and anti-glycation evaluations showed that the extract present significant activity in all methods evaluated. In addition, extract reduced the number of trypomastigotes and increased the survival of treated animals. The treatment using extract showed an interference in the synthesis of physiological nitric oxide as an immune response to infection. In silico assays demonstrated interaction between Velutinol A and DNA and molecular targets of T. cruzi. ConclusionsThe results showed that the hydroethanolic extract of M. velutina xylopodium contains bioactive compounds including polyphenols, flavonoids and steroidal aglycones (mainly Velutinol A) of which may be responsible for the antioxidant, anti-glycation and anti-parasitic activity against T. cruzi. Trypanocidal activity of M. velutina compounds may be linked to their influence on NO synthesis during infection and/or their capacity to bind and inhibit molecules associated to virulence and survival of T. cruzi.

Antisalmonella Activities of Essential Oil of Psidium guajava Leaves: An In vitro and In vivo Study

Background: Life-threatening typhoidal salmonella infection is becoming more difficult to treat due to rising resistance to commonly used antibiotics. This resistance is aided by the biofilm-forming ability of the bacteria. This study investigated the in vitro and in vivo antisalmonella activities of essential oil of Psidium guajava leaves. Methods: Essential oil was extracted from the leaves of Psidium guajava with solvents. The sensitivity of Salmonella Typhi to the essential oil of Psidium guajava (EOPG) was assessed via the agar well diffusion method. Minimum inhibitory, bactericidal and biofilm-inhibitory concentrations (MIC, MBC and MBIC respectively) were measured using micro-broth dilution and crystal violet assay respectively. The effect of EOPG on the bacterial cell membrane was evaluated by measuring the efflux of potassium ions, inorganic phosphate and pyruvic acid. Bioautography and GC-MS were employed to identify the constituents of the active fraction of the EOPG. Effects of EOPG on the level of bacteremia and bone marrow infection in male Wistar rats were determined by plating caudal blood on salmonella-shigella agar. Selected serum cytokines were measured using ELISA kits. Effect on hepatic DNA was measured by comet assay while histological evaluation of the liver of infected rats was done by Hematoxylin and Eosin staining. Results: Essential oil of Psidium guajava leaves (EOPG) inhibited the growth of S. Typhi with a zone of inhibition of 13±0.2mm compared to 31±0.3mm recorded by ciprofloxacin. Minimum inhibitory, minimum bactericidal and minimum biofilm inhibitory concentrations were 25, >50 and 12.5 mg/mL respectively. Exposure to EOPG caused efflux of potassium ions, inorganic phosphate and pyruvic acid in S. Typhi. Oral administration of 50 mg/mL of EOPG reduced bacterial load in the blood and bone marrow of S. Typhi-infected rats significantly (P<0.05) when compared to untreated animals. Infection-induced reduction of serum IL-1β and rise in serum IFN-γ were ameliorated considerably in treated animals. The hepatic DNA of infected animals were protected from breakage in the group administered 50 mg/mL/day of EOPG compared with untreated, ciprofloxacin-treated as well as those administered 100 mg/mL/day of EOPG. Conclusion: EOPG has both in vitro and in vivo anti-salmonella activities, this could be exploited in developing new drug leads for treatment of typhoid fever

Seeds Priming with Bio-Silver Nanoparticles Protects Pea (Pisum sativum L.) Seedlings Against Selected Fungal Pathogens

Nano-priming is a relatively new seed treatment technique using metal and metal oxide nanoparticles (NPs), and such application of NPs may support the plants' immunity. Recently we have shown that the that biologically synthesized silver nanoparticles (bio-AgNPs) used as short-term foliar treatment protect pea seedlings against D. pinodes and F. avenaceum. In the present study, the protection of peas against both fungal pathogens via seed priming with bio-AgNPs was analyzed. Moreover, the changes in the polar metabolic profiles of the seedlings caused by priming and infection were also compared. Seed priming with bio-AgNPs at concentrations of 50 and 100 mg/L considerably reduced the symptoms and infection levels of both pathogens by over 70% and 90% for F. avenaceum and D. pinodes, respectively. Pathogens infection and nano-priming affected the metabolic profile of pea seedlings. The major changes in the primary metabolism were observed among carbohydrates and amino acids. In turn, this may result in changes in the expression and accumulation of secondary metabolites. Therefore, further investigation of the effect of nano-priming should focus on the changes in the secondary metabolism.

A single immunization of Borreliella burgdorferi-infected mice with Vanguard crLyme elicits robust antibody responses to diverse strains and variants of outer surface protein C.

Lyme disease, caused by Borreliella burgdorferi and related species, is a growing health threat to companion animals across North America and Europe. Vaccination is an important preventive tool used widely in dogs living in, or near, endemic regions. In this report, we assessed anti-outer surface protein (Osp) A and anti-OspC antibody responses in B. burgdorferi-infected and -naïve mice (C3H/HeN) after immunization with a murine-optimized single dose of the Lyme disease subunit vaccine, Vanguard crLyme. crLyme is comprised of OspA and an OspC chimeritope-based immunogen designated as CH14. Mice that were infected and immunized developed higher levels of anti-OspC antibodies (Abs) than those infected only or that received one vaccine dose. The anti-OspC Abs that developed in the infected/immunized mice bound to all OspC variants tested (n = 22), whereas OspC Abs in serum from infected mice bound predominantly to the OspC variant (type A) produced by the infecting B. burgdorferi strain. Consistent with the absence of OspA expression in infected mammals, none of the infected mice developed Abs to OspA and did not develop anti-OspA Abs after single dose immunization. Lastly, serum from infected/immunized mice displayed significantly higher and broader killing activity than serum from non-immunized infected mice. The results of this study demonstrate that a single vaccination of actively infected mice results in strong anti-OspC Ab responses. This study contributes to our understanding of Ab responses to vaccination in actively infected mammals.

Dual-lock-and-key virus-mimicking nanoprobes for ultra-high accurate and sensitive imaging of viral infections in vivo

Fluorescence in situ imaging of viral infection lesions in vivo is crucial for precise diagnosis of viral diseases and evaluation of the extent of viral infection. Nevertheless, achieving highly specific and sensitive fluorescence imaging of viral infection sites in vivo has posed a persistent challenge. Here, we developed a dual-lock-and-key virus-mimicking nanoprobe that consisted of polyamide dendrimers (PAMAM) loaded internally with molecular beacons double-triggered by apurinic/apyrimidinic nucleic acid endonuclease 1 (APE1) and viral RNA (vRNA), and surface-modified with the E protein of Japanese encephalitis virus (JEV). This activatable nanoprobe generated dramatically amplified fluorescent signals stimulated by expressed vRNA and APE1 during viral infection, enabling ultrahigh specific and sensitive imaging of the lesions of JEV infection in vivo. This study provides a potential approach for accurate and sensitive detection of viral infection levels and assessment of the efficacy of antiviral drugs in vivo.

Contribution to a study on the seroprevalence of Equine Infectious Anemia in Tiaret province northwestern Algeria

A serological survey was conducted in equines in the province of Tiaret, in order to estimate the prevalence level of infection of equine infectious anemia (EIA). This survey has allowed to study the rate of infection by EIAV equine, to clarify the current situation of the EIA in the province of Tiaret, constitute a first step towards a national approach to control the emergence of this disease. Serum samples were collected from 293 horses and donkeys 30 and tested by ELISA technique. All results obtained by the ELISA test proved totally negative for all the samples studied. The equine infectious anemia is a topical disease. It is not well known and rarely sought on the ground. Yet the consequences of an outbreak can be very heavy on the economy.

Demographic and genetic impacts of powdery mildew in a young oak (Quercus robur L.) cohort

Key messageBy monitoring a field experiment over nine years, we investigated the impacts of the two main pathogen species Erysiphe quercicola S. Takam. and U. Braun and Erysiphe alphitoides (Griffon and Maubl.) U. Braun and S. Takam causing powdery mildew on a young cohort of pedunculate oak (Quercus robur L.), both from a demographic and genetic point of view using SNP markers. We show that survival rate is affected by mean disease severity. But while the growth-related tolerance to infection of the oak individual seems to be more determinant than resistance against infection, no equalizing effect of the disease could be detected.ContextStudies on the effects of pathogens on the survival and population dynamics of forest trees are scarce. Yet a better understanding of these interactions could prove strategic in the challenging context of climate change.AimsOur general objective was to characterize the demographic and genetic impact of the two main pathogen species Erysiphe quercicola S. Takam. and U. Braun and Erysiphe alphitoides (Griffon and Maubl.) U. Braun and S. Takam causing powdery mildew in the early stages of a Quercus robur L. population.MethodsAn ad hoc field design with two disease exposures, natural and protected, was surveyed over nine years. This enabled a detailed phenotypic monitoring of 1733 emerging individuals from 15 progenies, and the genotyping of 68% of them.ResultsThe pathogen induced high levels of seedling mortality several years after sowing, associated with reduced growth and capacity to overwinter. Fast-growing families showed the highest survival rate under both natural and protected disease exposure. Contrary to a possible trade-off hypothesis between growth and defense, family height potential was not negatively related to disease resistance across the studied oak mother trees. While supporting a deleterious effect of very low individual heterozygosity on the probability of survival, average genomic diversity was not significantly affected by mortality associated with powdery mildew. Our study also points to a few candidate genes for several fitness-related traits.ConclusionOverall, our results suggest that in oak natural populations, infection levels (related to resistance sensu stricto) may be less determinant than growth-related tolerance to infection for the fate of seedlings. However, an equalizing effect of powdery mildew on relative oak genotype performances cannot be excluded at later stages.