Infection Levels Research Articles

Detecting Perkinsus-like organisms and Perkinsus marinus (Myzozoa: Perkinsidae) within new bivalve hosts in the southeastern Gulf of California.

Perkinsus marinus, a parasite myzozoa native from the Atlantic Ocean, has spread across various bivalve species in the Pacific Ocean. In the Gulf of California, clams like Larkinia grandis and Leukoma grata have become a secondary fishery, experiencing demand. During annual sampling (August 2017 - July 2018, n = 30/month), the Ray's fluid thioglycollate medium (RFTM) revealed presumptive hypnospores of Perkinsus sp. in L. grandis, with a low parasite prevalence (4.16%) and density (≤ 3.14 hypnospores g-1 tissue). From summer 2020 to summer 2021, P. marinus was seasonally identified in L. grata via staining and PCR tests, showing mean prevalence and density of 48.33% and 48 hypnospores g-1 tissue, respectively. The infection level was light in both clams. This parasite's presence in these new hosts within the southeastern Gulf of California confirms its ability to expand into non-native places, signaling a need for intervention strategies in managing and transporting mollusk species within the region.

Targeted dsRNA-mediated suppression of Phytophthora infestans infection via Avr3a

AbstractPhytophthora infestans (P. infestans) is a highly destructive oomycete that causes the late blight in Solanaceous crops, such as potatoes and tomatoes, reducing crop yield. Although many pesticides are used to control P. infestans, the pathogen has evolved resistance to these chemical pesticides over time. In this study, we employed RNAi technology as an alternative strategy to suppress P. infestans infection. We designed and synthesized two dsRNAs targeting 5' and 3' regions of the Avirulence Protein 3a (Avr3a) gene, a key effector essential for the virulence of P. infestans. Interestingly, the dsRNA targeting the 5' region which contains the conserved RxLR-EER motif of Avr3a exhibited more substantial suppression of P. infestans infection and Avr3a expression level compared to the 3' region targeting dsRNA. Additionally, we identified changes in the expression of genes related to pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) in plants treated with these dsRNAs. In leaves treated with dsRNAs targeting Avr3a, the expression of PTI-related genes was restored, while ETI-related genes showed lower expression levels compared to the mock-treated leaves. These results suggest that dsRNAs targeting Avr3a effectively suppress P. infestans infection, enabling plants to achieve balanced immunity and enhanced defense.

Determinants of HIV infection at 18 months of age among HIV-exposed infants in the context of PMTCT interventions in southern Ethiopia

IntroductionMother-to-child transmission (MTCT) of HIV accounts for over 90% of annual HIV infections among children under the age of 15. Despite the introduction of the Option B+ strategy in Ethiopia in 2013, the rate of MTCT of HIV at 18 months was 15% in 2020. This study aimed to identify determinants of HIV infection among HIV-exposed infants (HEIs) in the context of prevention of MTCT (PMTCT) care in southern Ethiopia.MethodsWe conducted a retrospective facility-based study of 299 mother-baby pairs (HIV-infected women and their HEIs up to 18 months) enrolled in PMTCT care at three health facilities in Wolaita Sodo town, southern Ethiopia, from September 2015 to October 2021. Data was collected from medical charts and PMTCT registers. Logistic regression was used to identify determinants of HIV infection among HEIs.ResultsAt enrolment into PMTCT care, most women were already on ART (75.3%) and in clinical stage I (89.6%) according to the World Health Organization's algorithm. Overall, 13 (4.3%, 95% CI: 2.5%–7.4%) HEIs were HIV-infected; the level was higher among HEIs born at home (17.9% (95% CI: 7.6%–36.5%). Being born to HIV-positive women with late WHO clinical stage (III and IV) of HIV (AOR = 9.1, 95%CI: 2.4, 34.5), being born at home (AOR = 4.8, 95%CI: 1.1–20.7), being born to women newly diagnosed with HIV (AOR = 4.8, 95%CI: 1.3–17.4), and low infant adherence to cotrimoxazole prophylaxis (AOR = 5.4, 95%CI: 1.4–20.4) increased the odds of MTCT.ConclusionHIV infection levels among breastfeeding HEIs in PMTCT care was <5%, meeting the WHO transmission rate targets. Strengthening PMTCT care to expand community-based PMTCT interventions such as improving women's and communities’ awareness of HIV, PMTCT and promoting male involvement would reduce reduce HIV infection among children to reach the 95–95–95 targets to end HIV in Ethiopia.

The variety of abomasal nematode communities of captive and free-roaming populations of European bison, Bison bonasus (L.): a morphometric and molecular approach.

Most studies concerning parasitic infections in European bison have been performed on free-ranging animals: comparatively little is known about the abomasal nematodes of captive wisents, which are widely used in reintroduction programmes. The aim of the study was to determine the infection level and species composition of abomasal nematodes in captive European bison in enclosures (including zoos) and breeding centres compared to free-ranging individuals. It also includes a morphological analysis of the parasites based on figures and measurement data. Altogether, 11 species of nematodes were detected, with both captive and free-ranging animals demonstrating similar species compositions. Among those, 2 species of blood-sucking nematodes were detected, including Ashworthius sidemi and Haemonchus contortus. Interestingly, A. sidemi was found in almost all free-roaming animals, but only in 1 captive European bison. In addition, H. contortus was predominant in captive animals. The morphological identification was confirmed molecularly for 5 nematode species: A. sidemi, H. contortus, Ostertagia kolchida, O. ostertagi and Spiculopteragia boehmi. The identification was performed using small subunit ribosomal rDNA. The study provides the first available set of specular lengths of the gastric nematodes of European bison, and the first molecular data of O. kolchida and S. boehmi derived from the same host species. Our findings may simplify the morphometrical and molecular identification of Trichostrongylidae species infecting European bison, and can be useful in developing new management strategies for populations of this near-threatened species in Europe.

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.

Prevalence of asymptomatic parasitaemia among household members of children under seasonal malaria chemoprevention coverage and comparison of the performance of standard rapid diagnostic tests versus ultrasensitive RDT for the detection of asymptomatic parasitaemia in Nanoro, Burkina Faso.

Asymptomatic carriers of Plasmodium falciparum represent important parasite reservoirs maintaining malaria transmission in the community. This study aimed on the one hand to screen the other household members living with children under seasonal malaria chemoprevention (SMC) coverage in order to determine the level of malaria infection in this population and on the other hand to determine the appropriate type of rapid diagnostic test (RDT) for this screening to detect these asymptomatic carriers in the community. During the 2022 SMC campaign (July to October), a cross-sectional survey was carried out in 745 participants who were screened by ultrasensitive rapid diagnostic test (usRDT), standard rapid diagnostic test (rRDT) and microscopy. Out of them, 395 had microscopy results available and were included in the data analysis. The prevalence of asymptomatic carriers of asexual forms of Plasmodium falciparum was 26.58% (105/395) while sexual forms were found in 5.32% (21/395) of the study population. Children from 5 to 15 years had the highest prevalence of P. falciparum asexual forms 35.76% (59/165) compared with older participants. Malaria positivity rate for rRDT and usRDT was 29.40% (219/745) and 40.49% (305/745) respectively. The usRDT had a higher sensitivity than the rRDT (72.38% (95% CI 62.8-80.66) vs. 60.95% (95% CI 50.94-70.33)). In terms of specificity, rRDT had a higher specificity 82.41% (95% CI 77.53-86.62) versus 69.66% (95% CI 64.01-74.89) for usRDT. This study reports a high prevalence of parasite carriers in household members of children under SMC coverage in Nanoro, Burkina Faso. In conclusion, usRDT seems more appropriate for strategies based on detection and treatment of parasite carriers within the community.

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