Search Results (131)

Canine vector-borne diseases (CVBDs) are caused by pathogens transmitted by several invertebrates, posing a significant threat to both animal and human health worldwide. In recent years, the geographical distribution of CVBDs has changed in many countries, driven by climate change, increased pet travel, movements of goods, and anthropization of wildlife habitats. This study investigated the exposure to major CVBDs in 423 owned dogs from Italy and Greece. Individual serum samples were analyzed using serological methods. The SNAP^® 4Dx IDEXX test was used to detect Dirofilaria immitis circulating antigens and antibodies against Anaplasma spp., Ehrlichia spp. and Borrelia burgdorferi. Additionally, an indirect immunofluorescence antibody test (IFAT) was used to detect antibodies against Rickettsia conorii and Babesia canis. Overall, 171 (40.4%) dogs were positive for at least one pathogen. Antibodies against R. conorii, Ehrlichia spp., Anaplasma spp., B. canis and B. burgdorferi were detected in 118 (27.9%), 28 (6.6%), 29 (6.8%), 5 (1.2%) and 3 (0.7%) dogs, respectively. Dirofilaria immitis antigens were found in 7 dogs (1.6%). A Binomial Logistic Regression was performed and revealed a statistically significant association between age (dogs > 7 years old) (p = 0.005; OR = 1.903; 95% CI = 1.215–2.2981) and presence of at least one clinical sign (p = 0.028; OR = 4.082; 95% CI = 1.168–14.262) and positivity to at least one vector-borne pathogen. These findings confirm that dogs in both Italy and Greece are exposed to a range of vector-borne pathogens and highlight the importance of continuous epidemiological surveillance in European regions. Full article

Candidatus Rickettsia colombiensis is a new candidate species of Rickettsiae spotted fever group that have been isolated only from ticks. The pathogenicity of Ca. R. colombiensis to human and animals is unknown. This study evaluated the pathogenic potential of Ca. R. colombiensis in Syrian hamsters and assessed the cross-reactivity between Ca. R. colombiensis and other Rickettsia in human and hamster sera. Shell vial technique was employed to isolate Ca. R. colombiensis. Subsequently, five male Syrian hamsters were inoculated intraperitoneally (IP) and five intradermally (ID) with 1 × 10⁶ Vero cells infected with Ca. R. colombiensis. One control hamster was used in each group. The health status was assessed daily, and necropsies were performed. Serum samples were tested by indirect immunofluorescence and tissues were processed by qPCR and histological stains. All Syrian hamsters remained healthy during the trial. No histopathological damages associated with rickettsial infection were observed. No Rickettsial DNA was detected in tissues. Syrian hamsters showed IgG antibody titers ranging from 1:64 to 1:1024. Control hamsters were negative. Regarding human sera, 56% (84/150) had IgG cross-reactivity antibodies against Ca. R. colombiensis. Subsequently, in a selected subset of 30 sera with moderate to high titers, all samples reacted with Ca. R. colombiensis antigen. Under specific conditions of this study, Ca. R. colombiensis did not behave as a highly virulent pathogen in the hamster model, although all infected Syrian hamsters developed IgG antibodies responses. Regarding cross-reactivity, it is possible to serologically diagnose rickettsial infection using Ca. R. colombiensis as an antigen. Full article

Goose astrovirus (GoAstV) infection has become prevalent in major goose-producing regions, causing substantial economic losses to the industry. In this study, an indirect competitive ELISA (ic-ELISA) was developed based on a monoclonal antibody (mAb) targeting the GoAstV VP27 protein. The recombinant VP27 protein was expressed in E. coli and purified, followed by the generation of murine mAbs using the purified antigen. Through screening with GoAstV particles, mAb 3G11 exhibited strong immunoreactivity, which was further confirmed by Western blot and immunofluorescence assay (IFA). The ic-ELISA conditions were optimized as follows: GoAstV particle coating concentration of 10⁴ TCID₅₀ per well, 3G11 mAb dilution of 1:8000, and incubation times of 120 min for coating, 60 min for serum samples, and 60 min for mAb binding. The assay exhibited satisfactory performance in terms of sensitivity, specificity, and reproducibility. Using this method, serum samples collected from major goose farming areas in Shandong province were tested and showed an overall seropositivity rate of 11.7%. This study provided a reliable serological tool for detecting GoAstV-specific antibodies and would support future vaccine evaluation efforts. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become highly prevalent worldwide, and its pathogenesis and progression mechanisms remain incompletely understood. An increased activation of innate immune cells in the liver contributes to hepatic fibrogenesis via a chronic loop of inflammation and regeneration processes. Among them are mast cells (MCs), whose role in hepatic cirrhosis secondary to MASLD remains poorly studied. Our aim was to evaluate differences in MC density in cirrhotic liver tissue among patients with MASLD and other chronic liver disease etiologies. For this, a retrospective study of MC count was performed in cirrhotic liver explants obtained from MASLD, alcohol-related liver disease (ALD), and autoimmune hepatitis (AIH). We included a control group of subjects without liver damage. Tryptase-positive MCs were identified by indirect immunofluorescence and quantified as MC density per low-power field (MC/LPF). Group differences were analyzed using the Kruskal–Wallis test with Dunn’s multiple comparisons, considering p < 0.05 as statistically significant. A significantly higher MC density was observed in MASLD, ALD, and AIH patients compared with the control group. The group analysis showed that ALD patients exhibited higher MC density than AIH, with no observed difference between ALD and MASLD. MC density was correlated positively with tobacco smoking and alcohol use in the full analyzed group, suggesting them as risk factors of high MC liver infiltration. We conclude that MC density is augmented in MASLD-related cirrhosis, highlighting potential links between lifestyle factors and MC-mediated hepatic inflammation. Future studies should explore the mechanisms driving this association and evaluate whether targeting MCs could help mitigate fibrosis progression. Full article

Diagnosis of rickettsial infections is challenging due to nonspecific clinical symptoms and limitations of current diagnostic methods. Molecular assays allow early detection but are limited by cost and technical demands, whereas conventional serological tests often exhibit cross-reactivity and low sensitivity during the early stages of infection. This study aimed to develop and evaluate a recombinant-antigen sandwich ELISA for improved antibody detection against Rickettsia spp. Three Rickettsia akari proteins, rGroEL, rDnaK, and rA8GP63 (uncharacterized protein), were produced and validated for immunogenicity. The assay was evaluated using 94 patient serum samples, including those with positive, negative, and unknown clinical course. The optimized ELISA demonstrated high reproducibility, with IgG sensitivity of 89.47–95.39% and specificity of 90%. IgM detection, also assessed, showed lower sensitivity (42.11–82.89%) but maintained strong specificity (83.33%). The diagnostic performance was comparable to that of a commercial indirect immunofluorescence assay, with no cross-reactivity detected in sera from patients with unrelated infections. rDnaK and rA8GP63 represent newly explored diagnostic candidates. These findings highlight the potential of this recombinant protein-based ELISA as an accessible, sensitive and specific diagnostic tool, with a meaningful clinical impact for improving the early and accurate detection of rickettsial infections. Full article

Background: Brucella canis is a zoonotic pathogen associated with reproductive disorders in dogs and represents an emerging public health concern. Dogs are the only known source of infection for humans, and transmission is often associated with close contact, particularly in occupational settings. Reports of canine and human infections in Europe are increasing, underscoring the need for integrated surveillance to assess the risk of introduction and spread. Objectives: This study aimed to investigate the possible circulation of B. canis in different subgroups of dogs from Central Italy, representing diverse risk contexts (stray, breeding, blood donor, refugee-associated, and previously outbreak-linked dogs), and to generate sentinel data to inform further risk-based surveillance and zoonotic risk assessment. Methods: A comprehensive serological, molecular, and bacteriological survey was conducted on 128 dogs sampled in the Umbria region, covering animals from different backgrounds and risk contexts. Blood samples were tested using bacterial culture, real-time PCR, serum agglutination test, complement fixation test, and/or indirect immunofluorescence antibody test. Results: All tested dogs were negative for B. canis. The upper 95% confidence limit for prevalence was 3.5%, suggesting that widespread circulation is unlikely, although a low/moderate prevalence in specific groups cannot be excluded. Conclusions: Although no cases of B. canis were detected, the results provide sentinel information and highlight the need for continued risk-based surveillance, particularly in low-prevalence areas to prevent introduction of the infection and to enable early detection in case of occurrence. As dogs are the only known source of human infection, veterinary monitoring plays a pivotal role in mitigating zoonotic risks and supporting One Health strategies for evidence-based control. Full article

Background: Lyme borreliosis (LB) constitutes a major challenge for Public Health, particularly in regions where surveillance and diagnostic systems are underdeveloped or fragmented. Despite its potential as a hotspot for tick-borne diseases, Sardinia (Italy) remains poorly explored in terms of LB epidemiology. Methods: A sero-prevalence study was conducted on serum samples stored in the biobank of a hospital in Northern Sardinia. The serum library consisted of serum samples collected on the basis of a diagnostic hypothesis of rheumatic disease. Serological testing for antibodies against Borrelia was performed using the indirect immunofluorescence assay (IFA) and enzyme-linked immunosorbent assays (ELISA), followed by confirmation by Western blot for positive results. The study analyzed 58 serum samples from patients selected based on clinical symptoms compatible with Borrelia spp. infection. Results: Among the 58 patients, 9 (15.5%) yielded positive results, with absorbance values higher than those of the positive control, suggesting that the pathogen is widespread but poorly recognized in Sardinia. The results are in line with broader trends in the Mediterranean, indicating that Sardinia can no longer be considered a marginal area for Borrelia spp. circulation. Conclusions: The status of Sardinia as a sentinel territory underlines the need for enhanced epidemiological surveillance within the One Health approach, including human, animal and environmental health. Full article

Background: Antinuclear antibodies (ANAs) play a crucial role in diagnosing systemic autoimmune rheumatic diseases, particularly systemic lupus erythematosus. The recommended standard for ANA detection is indirect immunofluorescence testing (IIFT) using human epithelial (HEp-2) cells. Since visual interpretation (VI) of IIFT images is time-consuming and labor-intensive, research is focusing on automated interpretation systems that use artificial intelligence (AI). Methods: Consecutive serum samples (number of sera = 143) from routine clinical care were collected from patients visiting our tertiary rheumatology center. ANA were detected by IIFT with visual interpretation and compared with IIFT using the AI-based interpretation system akiron^® NEO (Medipan, 15827 Blankenfelde-Mahlow, Germany). ANA titer levels and patterns were analyzed according to the Competent Level of the International Consensus on ANA Pattern classification. Results: Agreement of positive/negative ANA discrimination between AI-aided and VI-IIFT at the recommended cut-off of 80 was good (Cohen’s kappa [κ] 0.69) but significantly different (McNemar test, p < 0.0001). At a cut-off of ≥1/80, the agreement was improved (κ 0.76) and the difference between both methods was non-significant (p = 1.0000). The ANA pattern recognition agreement between both approaches was moderate (κ = 0.54). The direct comparison using only the akiron^® NEO HEp-2 cell ANA assay revealed a good agreement (0.67), which improved to very good (κ = 0.80) when differences between ANA patterns anti-cell (AC)4/5 and AC2 were neglected. Notably, titer levels in the automated evaluations were frequently assessed at higher values than in the gold standard interpretation. Conclusions: Our study demonstrates a good agreement for positive/negative ANA discrimination. ANA pattern recognition by AI-aided interpretation showed moderate to very good agreement with VI. Further research and algorithm refinement (e.g., improved pattern recognition and titer calibration) are necessary to support its future implementation as a reliable screening method. Full article

Background: Anti-dsDNA is an important biomarker for the diagnosis, prognosis, and monitoring of systemic lupus erythematosus (SLE). Although several assays for anti-dsDNA antibody detection are routinely used, standardization remains limited, and differences have been reported. This study aimed to compare five methods for anti-dsDNA antibody detection and to estimate their association with complement consumption. Methods: A total of 149 samples submitted for routine laboratory testing were collected and tested on five platforms: Crithidia luciliae indirect immunofluorescence test (CLIFT), addressable laser bead immunoassay (ALBIA), a high-avidity (HA) enzyme-linked immunosorbent assay (ELISA), chemiluminescent immunoassay (CIA), and a novel particle-based multi-analyte technology (PMAT). Complements C3 and C4 were available for a subset of the total samples. Results: Correlation between anti-dsDNA assays ranged from 0.94 (CIA and PMAT) to 0.65 (ALBIA and CLIFT). The AUC from the ROC analysis using CLIFT as a reference was 0.95 for PMAT, 0.94 for CIA, 0.93 for ELISA, and 0.86 for ALBIA. The highest sensitivity relative to CLIFT at a fixed specificity of 94.4% was 84.7% for CIA and ELISA, 76.3% for PMAT, and 42.4% for ALBIA. Correlation between anti-dsDNA and C3 ranged from −0.81 for ELISA to −0.51 for ALBIA. Conclusions: Different anti-dsDNA detection methods showed varying diagnostic performance and correlation and varying agreement with CLIFT and complement consumption. ELISA, CIA, and PMAT showed high correlation to each other and to CLIFT and were in strong concordance with low C3 levels. In contrast, ALBIA revealed lower clinical performance and correlation with CLIFT and complement consumption. Full article

The T-2 toxin is one of the most toxic mycotoxins, to which the population is exposed through the diet. T-2 toxins are especially found in cereals and cereal-based products. To deepen our understanding of the mechanisms of T-2 toxin action, the morphological changes, oxidative stress, and inflammatory response of this mycotoxin have been evaluated in HepG2 cells. The mRNA and protein expression levels of inflammatory cytokines such as IL-1β, IL-6, and TNF-α and proteins such as Nrf2 and HO-1 were analyzed after T-2 exposure (7.5, 15, and 30 nM) by qPCR and Western blot assays. Firstly, changes in the morphology of HepG2 cells after T-2 exposure from circular to elongated shape were observed in a concentration-dependent manner by indirect immunofluorescence. These alterations may reflect early signs of cell stress. The results revealed an upregulation of the mRNA of IL-1β, IL-6, and TNF-α after T-2 exposure, with the highest increase in TNF-α after 30 nM T-2, suggesting a proinflammatory effect. Regarding the oxidative response, HO-1 at the lowest T-2 concentration was upregulated. However, the Nrf2 at all T-2 concentrations tested was downregulated. These findings were corroborated by Western blot analysis. These results confirm that T-2 hepatotoxicity produces an increase in key inflammatory cytokines, modulates the Nrf2/HO-1 pathway, and produces morphological changes in HepG2 cells. The next step would be to test whether a co-exposure of natural antioxidants with T-2 exerts a cytoprotective effect. Full article

Group A rotavirus (RVA) is a leading causative agent of diarrhea in both young animals and humans. In China, multiple genotypes are commonly found within the bovine population. In this study, we investigated 1917 fecal samples from calves with diarrhea between 2022 and 2025, with 695 testing positive for RVA, yielding an overall detection rate of 36.25%. The highest positivity rate was observed in Hohhot (38.98%), and annual detection rates ranged from 26.75% in 2022 to 42.22% in 2025. A bovine rotavirus (BRV) strain, designated 0205HG, was successfully isolated from a fecal sample of a newborn calf. Its presence was confirmed through cytopathic effects (CPEs), the indirect immunofluorescence assay (IFA), electron microscopy (EM), and high-throughput sequencing. Genomic characterization identified the strain as having the G6-P[1]-I2-R2-C2-M2-A3-N2-T6-E2-H3 genotype constellation. The structural proteins VP2 and VP7, along with nonstructural genes NSP1–NSP4, shared high sequence identity with Chinese bovine strains, whereas VP1, VP4, and NSP5 clustered more closely with human rotaviruses, and VP3 was related to feline strains. These findings highlight the genetic diversity and interspecies reassortment of BRVs in China, underlining the importance of continued surveillance and evolutionary analysis. Full article

Via a One Health approach, this study concomitantly assessed the susceptibility of humans and dogs to Trypanosoma cruzi infections on three islands and in two mainland seashore areas of southern Brazil. Human serum samples were tested using an enzyme-linked immunosorbent assay (ELISA) to detect anti-T. cruzi antibodies, while dog serum samples were tested using indirect fluorescent antibodies in an immunofluorescence assay (IFA). Seropositive human and dog individuals were also tested using quantitative polymerase chain reaction (qPCR) in corresponding blood samples. Overall, 2/304 (0.6%) human and 1/292 dog samples tested seropositive for T. cruzi by ELISA and IFA, respectively, and these cases were also molecularly positive for T. cruzi by qPCR. Although a relatively low positivity rate was observed herein, these cases were likely autochthonous, and the individuals may have been infected as a consequence of isolated events of disturbance in the natural peridomicile areas nearby. Such a disturbance could come in the form of a fire or deforestation event, which can cause stress and parasitemia in wild reservoirs and, consequently, lead to positive triatomines. In conclusion, T. cruzi monitoring should always be conducted in suspicious areas to ensure a Chagas disease-free status over time. Further studies should also consider entomological and wildlife surveillance to fully capture the transmission and spread of T. cruzi on islands and in seashore mainland areas of Brazil and other endemic countries. Full article

Background/Objectives: Anti-p200 pemphigoid is a rare and likely underdiagnosed autoimmune blistering disorder. Laminin γ1 and laminin β4 have been implicated as potential target antigens in its pathogenesis. Recently, a novel indirect immunofluorescence assay targeting anti-laminin β4 antibodies has been developed, demonstrating high sensitivity and specificity, and offering a valuable tool for improved diagnosis. Methods: Of the 451 patients, 21 were selected for further laboratory analysis based on medical records. Sera from 10 patients, which showed a positive direct immunofluorescence (DIF) result and negative results in multiplex enzyme-linked immunosorbent assays (ELISAs) and/or mosaic six-parameter indirect immunofluorescence (IIF) for various autoimmune bullous diseases, were tested for the presence of anti-laminin β4 antibodies. Additionally, sera from 11 patients with positive DIF and positive ELISA for antibodies against BP180 and/or BP230 were analyzed. Results: Among the 10 patients with positive DIF and negative ELISA and/or mosaic six-parameter IIF, 6 sera were positive for anti-laminin β4 antibodies. These patients presented with atypical clinical features. In contrast, all 11 sera from patients with both positive DIF and positive ELISA for BP180 and/or BP230 were negative for anti-laminin β4 antibodies. Conclusions: In patients with a positive DIF result but negative ELISA and/or mosaic six-parameter IIF findings, testing for anti-laminin β4 antibodies should be considered. Furthermore, in cases presenting with atypical clinical features—such as acral distribution of lesions, intense pruritus, or erythematous–edematous plaques—the possibility of anti-p200 pemphigoid should be included in the differential diagnosis. Full article

Background: Antinuclear antibodies (ANAs) serve as crucial biomarkers for diagnosing systemic autoimmune diseases; however, their interpretation can be complex and may not always correlate with clinical symptoms. Methods: A comprehensive narrative review was conducted to evaluate the peer-reviewed literature published between 1961 and 2025. Databases, including PubMed and Scopus, were searched using combinations of controlled vocabulary and free-text terms relating to antinuclear antibodies and their clinical significance. The objective was to gather and synthesize information regarding the diagnostic utility and interpretation of ANA testing in routine medical practice. Discussion: The indirect immunofluorescence assay (IIF) on HEp-2 cells is established as the gold standard for detecting ANAs, facilitating the classification of various fluorescent patterns. While a positive ANA test can suggest autoimmune disorders, the presence and titre must be interpreted alongside clinical findings, as low titres often lack diagnostic significance. Findings indicate that titres higher than 1:160 may provide greater specificity in differentiating true positives from false positives in healthy individuals. The study also emphasizes the relevance of fluorescence patterns, with specific patterns linked to particular diseases, although many do not have strong clinical correlations. Moreover, certain autoantibodies demonstrate high specificity for diseases like systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). Ultimately, while ANA testing is invaluable for diagnosing connective tissue diseases, healthcare providers must consider its limitations to avoid misdiagnosis and unnecessary treatment. Conclusions: ANA testing is a valuable tool in the diagnosis of connective tissue diseases, but its interpretation must be approached with caution. Clinical context remains crucial when evaluating ANA results to avoid misdiagnosis and overtreatment. This review is about the diagnostic aspects and clinical consequences of ANA testing, as well as highlighting both the diagnostic benefits and the potential limitations of this procedure in everyday clinical practice. The review fills a gap in the literature by integrating the diagnostic and clinical aspects of ANA testing, with a focus on real-world interpretation challenges. Full article

Human granulocytic anaplasmosis is an emerging tick-borne disease. Although Anaplasma phagocytophilum has been identified in vectors and animal reservoirs in Romania, evidence of human exposure has not yet been reported. This study aimed to generate initial evidence of human infection by evaluating A. phagocytophilum antibodies in individuals with recent tick exposure. We conducted a cross-sectional serosurvey between 2023 and 2024 at a tertiary care hospital in Bucharest, enrolling 80 participants 4 to 12 weeks following a tick bite. Serum IgG antibodies against A. phagocytophilum were detected using an indirect immunofluorescence assay, with a titer of ≥1:64 considered indicative of seropositivity. Eight (10%) participants tested positive for A. phagocytophilum IgG antibodies. Seropositivity was not significantly associated with demographics, geographical region, or clinical symptoms. However, fatigue and myalgia were more frequently seen in A. phagocytophilum IgG seropositive individuals. Notably, 43.8% of all participants reported erythema migrans, including five of the eight individuals with positive A. phagocytophilum IgG serology. This study provides the first serological evidence of human exposure to A. phagocytophilum in Romania. A 10% seroprevalence in this high-risk group suggests that anaplasmosis may be underrecognized. Clinicians should consider it in patients with tick exposure and compatible symptoms. Full article