Search Results (400)

Neospora caninum is a major cause of reproductive failure in cattle, responsible for epidemic abortion outbreaks that inflict annual billion-dollar losses on the global livestock industry. In water buffaloes (Bubalus bubalis), however, a phylogenetically close relative often raised in the same environments, the same parasite typically establishes a subclinical persistent infection with markedly lower rates of clinical abortion. This review inverts the traditional narrative by arguing that the key to next-generation control strategies lies in understanding the tolerant host (buffalo) rather than solely the susceptible host (cattle). By dissecting this “Neospora paradox”, we explore the molecular and immunological crosstalk that dictates pregnancy outcomes. We examine the parasite’s invasion proteins, revealed by CRISPR-Cas9 screens, and the maternal–fetal interface, where the balance between immune tolerance and parasite control determines the fate of pregnancy. We also compare N. caninum with the related zoonotic parasite Toxoplasma gondii to highlight how differential host immune recognition shapes infection outcomes. Finally, we propose that deciphering the buffalo’s successful equilibrium with N. caninum can illuminate novel pathways for vaccines and immunotherapeutic strategies, transforming the management of neosporosis worldwide. Full article

The Getah virus (GETV) is a mosquito-borne pathogen that infects diverse hosts, including pigs, horses, and humans, which can cause swine reproductive disorders such as abortion and stillbirth, posing a potential threat to animal and public health. Therefore, there is an urgent need for efficient and accurate serological diagnostic methods for surveillance and control of GETV. However, commercial diagnostic kits for swine GETV infection remain unavailable. In this study, we developed a novel enzyme-linked immunosorbent assay (ELISA) based on a GETV-specific epitope peptide (E2EP3) for serological detection. The N-terminally biotinylated E2EP3 peptide was synthesized, and the reaction conditions were systematically optimized, resulting in a cut-off value of 0.363. The assay exhibited no cross-reactivity with Japanese encephalitis virus (JEV), porcine circovirus type 2 (PCV2), porcine circovirus type 3 (PCV3), pseudorabies virus (PRV), or classical swine fever virus (CSFV). It demonstrated good reproducibility and high sensitivity, detecting GETV-positive serum diluted up to 1:640. The overall agreement rate reached 95%, consistent with a conventional recombinant GETV E2 protein-based ELISA. Benefiting from the biotin–streptavidin system, this assay achieved strong signal amplification and low background. Moreover, the procedure is simple, cost-effective, and stable, making it suitable for GETV large-scale serological surveillance and vaccine evaluation. Full article

Background: Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen that has caused repeated epidemics across Africa and the Arabian Peninsula, posing a severe and growing threat to public health and livestock. Infection in ruminants causes high neonatal mortality and catastrophic abortion storms; human disease ranges from self-limiting febrile illness to hemorrhagic fever, encephalitis, and permanent blindness. No licensed human vaccines or specific antiviral therapeutics are available, creating an urgent unmet medical need. Methods: We systematically reviewed the peer-reviewed literature on RVFV neutralizing antibodies (NAbs), extracting and synthesizing data on antibody sources, epitope specificity, in vitro neutralizing potency, in vivo protective efficacy, and molecular mechanisms of action. Results: A growing body of work has identified potent NAbs from immunized rodents, rabbits, alpacas, non-human primates, and convalescent patients. These NAbs predominantly target the Gn and Gc envelope glycoproteins. Their mechanisms include blocking host receptor (LRP1) binding, preventing the pH-dependent conformational rearrangement of the Gn–Gc complex, and directly inhibiting viral membrane fusion. Lead candidates, such as RVFV-268 and RVFV-140, achieve sub-nanogram neutralization and confer robust protection in rodent models against lethal challenge, aerosol exposure, and vertical transmission. Bispecific antibodies and combination strategies further enhance potency and the genetic barrier to viral escape. Conclusions: Substantial progress has illuminated the epitope landscape and neutralization mechanisms of RVFV, yielding promising clinical candidates. Translational challenges remain, including viral immune escape, antibody thermostability, and the need for rigorous preclinical evaluation. Future efforts should prioritize structure-guided engineering, rational antibody combinations, and testing in clinically predictive animal models. Full article

Objective: This study aimed to evaluate the association between T. gondii genotypes (types I, II, III) and cases of spontaneous abortion in humans. Methods: A systematic review and meta-analysis were conducted following PRISMA guidelines. Databases (PubMed, Scopus, Web of Science, EMBASE, and ScienceDirect) were searched for studies published in the last 10 years. Observational studies evaluating T. gondii genotypes in abortion cases were included. Results: Eight cross-sectional studies were included. A pooled positivity proportion for T. gondii of approximately 20% was observed among abortion cases, with substantial heterogeneity (I² > 90%). Genotype distribution varied across studies, with types I and III being the most frequently reported. Conclusions: Available evidence suggests a possible association between T. gondii infection and spontaneous abortion; however, the role of specific genotypes remains uncertain due to limited and heterogeneous data. More multicenter studies are needed to robustly address the issue. Full article

Neospora caninum is an apicomplexan parasite with a broad geographical distribution and a complex life cycle. It can cause infectious abortions in a variety of animals in the major livestock-producing nations, resulting in huge economic losses to the livestock industry. Shanxi Province in north China is one of China’s important livestock-producing provinces, but the data on the prevalence of N. caninum in sheep and goats in this province was not available prior to the present investigation. To fulfill this gap in our knowledge, serum samples were collected from 504 sheep and 300 goats across 11 cities representing three distinct geographical regions of Shanxi Province. A commercially available indirect enzyme-linked immunosorbent assay (iELISA) kit was used to determine the N. caninum prevalence by detecting N. caninum-specific IgG antibodies. Results showed that a total of 24 sheep (4.8%; 95% CI: 2.9–6.6) and 8 goat samples (2.7%; 95% CI: 0.8–4.5) tested positive for N. caninum antibodies. Geographical distribution was identified as the predominant risk factor influencing N. caninum infection in sheep and goats in Shanxi Province, with seroprevalence of N. caninum ranging from 0% to 16.7% across different sampling sites. This study reports the seroprevalence of N. caninum infection in sheep and goats in Shanxi Province for the first time, providing baseline data for the prevention and control of N. caninum infection in this northern province of China. Full article

Toxoplasmosis is a widely distributed zoonosis caused by the protozoan parasite Toxoplasma gondii. Infection during pregnancy is a major public health concern due to its potential impact on both maternal health and fetal development. Early detection of maternal infection is critical to prevent adverse outcomes; however, maternal signs are often subtle, non-specific or absent, complicating timely diagnosis. This scoping review aimed to map and synthesise existing evidence on early maternal signs, pregnancy and foetal outcomes, frequently assessed risk factors, and diagnostic approaches of toxoplasmosis in expectant mothers in Africa. The review was done in accordance with the PRISMA-ScR guidelines. A literature search of PubMed, Scopus, ResearchGate, and Google Scholar was performed to identify studies published between 2000 and 2025. Retrieved records were managed using Zotero (version 8.0.4) for deduplication and screening. Only English-language studies conducted in Africa and reporting relevant maternal or clinical data were included. A total of 28 cross-sectional studies were included. Lymphadenopathy (25.0%) was the most frequently reported maternal early sign, followed by flu-like illness, asymptomatic infection, low-grade or mild fever, and fatigue or malaise (each 10.7%). Congenital anomalies (50.0%) and miscarriage or spontaneous abortion (42.9%) were the most commonly reported foetal and pregnancy outcomes. Frequently reported risk factors were exposure to cat faeces (57.1%) and ingestion of undercooked or raw meat (42.9%). Diagnostic approaches were commonly enzyme-based immunoassays (78.6%), with limited use of RDTs and molecular methods. These findings suggest the need for improved early detection and prevention strategies in high-risk, low-resource African settings. Enhancing routine screening, health education, and access to appropriate diagnostics are considered. Future studies should consider adopting standardised reporting and integrating sensitive, affordable, rapid diagnostic approaches to enhance early detection and reduce the burden of congenital toxoplasmosis. Full article

Neosporosis, caused by N. caninum, is an emerging protozoan disease responsible for significant economic losses in the global dairy and meat industries, primarily due to abortion in cattle. Dogs serve as both definitive and intermediate hosts and play a key role in the parasite transmission cycle. Currently, effective control strategies remain limited, partly due to insufficient information on infection status. In Vietnam, data on N. caninum infection are scarce and mainly limited to cattle and buffalo. In this study, an indirect enzyme-linked immunosorbent assay (iELISA) based on recombinant NcGRA4 protein was applied and evaluated for the detection of anti-N. caninum antibodies in dogs. A total of 142 shelter dogs from Hanoi, northern Vietnam, were tested to determine seroprevalence. The NcGRA4-based iELISA detected an overall seroprevalence of 28.87% (41/142), whereas the indirect fluorescent antibody test (iFAT) showed a lower prevalence of 14.08% (20/142), indicating substantial exposure to N. caninum among shelter dogs in this region. Using iFAT as the reference method, the NcGRA4-based iELISA demonstrated a sensitivity of 90.00%, a specificity of 81.15%, and an overall accuracy of 82.39%. These findings indicate that the NcGRA4-based iELISA is a suitable screening tool for seroepidemiological surveillance of N. caninum infections in dogs. Univariable and multivariable logistic regression analyses showed no significant associations between N. caninum seropositivity and the investigated variables, including age, sex, breed, and housing conditions. This study also provides the first serological evidence of canine exposure to N. caninum in Vietnam. Full article

Background: Early pregnancy loss, defined as the spontaneous loss of a pregnancy before 20 weeks of gestation or when the fetus weighs less than 500 g, remains a common obstetric complication, affecting up to 15% of clinically recognized pregnancies. Chromosomal abnormalities, particularly aneuploidies such as trisomies and monosomy X, account for 50–60% of first-trimester losses, with incidence increasing alongside maternal age. Additional risk factors include maternal medical conditions, uterine anomalies, infections, and modifiable lifestyle factors. Pregnancies conceived through assisted reproductive technologies also carry a slightly higher risk of miscarriage, often influenced by maternal age and embryo quality. Methods: Two pathologists, blinded to each other’s assessments, analyzed abortive material from patients who experienced spontaneous first-trimester abortion between January 2012 and January 2025 at Agostino Gemelli Hospital, Rome, Italy. Inclusion criteria were defined independently of patient demographics. No restrictions were applied regarding maternal age. With respect to gestational age, only first-trimester miscarriages (≤12 weeks of gestation) were considered. In cases of discordance, the case was reviewed and re-evaluated to reach a final diagnosis. Results: The findings of this study are presented as a proposed histopathological classification and diagnostic framework for first-trimester miscarriages. Specifically, a total of 1168 cases were categorized into eight distinct groups of miscarriage etiology based exclusively on the histomorphological features of chorionic villi and maternal decidua. Conclusions: Histopathological examination of products of conception is essential for confirming intrauterine pregnancy, identifying underlying maternal or fetal causes, and guiding future reproductive management, particularly in recurrent pregnancy loss. This study evaluates histopathological features of first-trimester losses, classifies findings by etiology, and proposes a practical diagnostic guide to support clinical decision-making and improve outcomes in subsequent pregnancies. Full article

Since the elimination of smallpox, mpox (monkeypox) is the most medically significant orthopoxvirus infection. As a result of numerous regional, national and global outbreaks of MPXV (mpox virus), there is an abundance of new data available on the effects of the different viral clades on clinical obstetrical and perinatal outcomes when infection occurs in pregnancy. In addition, there have been additional placentas from cases of congenital MPXV infection available for study. These recent data indicate that there are prominent differences between viral strains and their effects on the fetus, with MPXV Clade I strains (Ia, Ib) having the greatest risk for an adverse outcome in pregnancy, and Clade II strains (IIa, IIb) having far less risk. In particular, the ongoing outbreak of MPXV Clade Ib in the DRC indicates that there is a significant risk for adverse perinatal outcomes associated with infection in pregnancy, especially during the first trimester. These outcomes include spontaneous abortion, stillbirth, neonatal death and congenital mpox. The placenta in cases of congenital infection demonstrates abundant virus in the chorionic villi, with prominent involvement of Hofbauer cells. Similar to smallpox, transplacental transmission and adverse pregnancy outcomes are an important feature of certain strains of this orthopoxvirus infection when occurring in pregnant women. Full article

Epstein–Barr virus (EBV) establishes lifelong infection in most humans, yet its biology in immunocompetent hosts is commonly framed as a binary alternation between latency and productive lytic replication. Accumulating molecular and single-cell evidence challenges this view, indicating that EBV frequently enters abortive forms of lytic reactivation that do not culminate in virion production. Here, we propose a conceptual framework in which EBV persistence is governed by feedback-regulated interactions and permissive conditions for reactivation rather than a strictly sequential life cycle. Immediate-early and early gene expression can be repeatedly induced by inflammatory signaling, cellular stress, and epigenetic changes. However, progression to viral DNA replication represents a highly functional barrier that likely requires the coordinated convergence of multiple viral and host conditions. Failure to reach this threshold arrests reactivation before late gene expression, generating a stable partial lytic state characterized by sustained immunomodulatory viral protein expression without the production of infectious particles. Immune surveillance reinforces this bottleneck by eliminating cells undergoing full lytic replication while sparing those stalled in early phases. We argue that EBV persistence reflects a dynamic equilibrium shaped by regulatory interactions between viral gene expression and host immunity, with implications for biomarker interpretation and therapeutic strategies in chronic inflammatory and autoimmune disease. Full article

The family Caliciviridae encompasses a diverse group of non-enveloped, positive-sense RNA viruses that are significant pathogens in veterinary medicine. This narrative review summarizes the current state of knowledge regarding the clinical, molecular, and epidemiological features of the three calicivirus genera identified in bovine hosts: Norovirus, Nebovirus, and Vesivirus. Bovine noroviruses and neboviruses are neglected enteric pathogens, frequently detected in association with neonatal calf diarrhea and often present in co-infections with other enteric agents. Clinical presentations for these enteric viruses range from severe, watery diarrhea to asymptomatic shedding, with distinct pathogenic profiles observed between norovirus genotypes GIII.1 and GIII.2. In contrast, the genus Vesivirus exhibits a broad host range, and bovine vesivirus strains are phylogenetically linked to vesiviruses identified in pigs and marine animals. Bovine vesivirus infections are associated with a broader spectrum of clinical manifestations, including respiratory disease, vesicular lesions, and abortion. Serological and virological surveys indicate that exposure to these viruses is ubiquitous in cattle populations globally. While direct evidence of human infection by bovine noroviruses and neboviruses remains limited, vesiviruses possess a confirmed capacity for cross-species transmission to humans. Significant knowledge gaps remain, particularly regarding in vitro culture systems, necessitating further research to facilitate vaccine development and clarify transmission dynamics. Full article

The Ralstonia solanacearum species complex (RSSC) is a globally significant plant pathogenic bacterium. Given the lack of effective chemical controls, phage therapy has emerged as a promising biocontrol alternative. While combining phages with antibiotics can counteract phage resistance, RSSC may still evolve concurrent resistance to both agents. However, the fitness consequences and underlying mechanisms of such resistance remain unclear. In this study, a novel RSSC phage was isolated to experimentally investigate the trade-offs between resistance and virulence in evolved strains. Compared to the wild-type, phage-resistant, antibiotic-resistant, and dual-resistant mutants showed no significant differences in growth rate, exopolysaccharide and lipopolysaccharide production. However, their motility, soil survival, and biofilm formation were significantly impaired, with the most severe decline observed in the dual-resistant mutants. Furthermore, phage-resistant strains exhibited enhanced antibiotic resistance, while antibiotic-resistant strains displayed cross-resistance. The antibiotic resistance gene bla_OXA-249 was upregulated only in antibiotic-resistant strains. In phage-resistant bacteria, the abortive infection system was activated. A reduction in bacterial cell numbers post-infection indicated that phage resistance limits phage propagation via a “suicidal” mechanism. These findings reveal that resistance evolution in RSSC carries substantial fitness costs and highlight phage steering as a novel strategy for designing phage agents. Full article

West Nile virus (WNV) circulates endemically in Romania, yet prevention of WNV infection in horses largely depends on owner-driven decisions that require accurate risk perception and veterinary guidance. A cross-sectional online survey was carried out between May and November 2025 to evaluate the knowledge, attitudes, and preventive practices (KAP) regarding WNV among 227 horse owners from various Romanian regions. In total, 67.4% of respondents had previously heard of WNV. The main transmission route was correctly identified as mosquito bites by 49.8% of participants, while 32.2% answered “don’t know” or presented misconceptions: horse-to-horse contact (9.3%), tick bites (10.6%) and blood transfusion (0.4%). Recognition of clinical signs was limited, with fever (31.3% of respondents) and gait abnormalities or ataxia (24.7% of respondents) being most frequently mentioned, followed by inappetence (19.4% of respondents), seizures (18.1% of respondents), coughing (8.8% of respondents), and abortions (10.6% of respondents); 47.6% of respondents were unable to identify any specific signs. Awareness of the existence of an equine WNV vaccine was reported by 23.8% of respondents, while only 4.0% indicated that their horses had been vaccinated. The most common preventive measures included the use of insecticides in stables (61.2%) and topical repellents on horses (55.5%), whereas environmental control actions such as removing standing water (14.1%) or avoiding swampy areas (11.9%) were less frequent; 19.4% reported taking no preventive measures. Veterinary communication was limited, with only 17.2% of respondents having received information about WNV from a veterinarian, and 21.6% perceiving a real risk of infection in Romania. Overall, the data show a marked disconnect between awareness and actionable prevention (particularly vaccination and environmental mosquito control), indicating that targeted owner education must be paired with structured veterinary communication to translate knowledge into preventive uptake in endemic settings. Full article

Minute virus of canines (MVC) is an autonomous canine parvovirus that causes severe pathological outcomes, including embryo mortality, spontaneous abortion, and congenital malformations in neonatal puppies. Although MVC infection has been shown to induce host cell cycle arrest and apoptosis, the underlying regulatory mechanisms that coordinate cell proliferation and control apoptotic responses during viral replication remain poorly understood. Sirtuin 1 (SIRT1) is an NAD⁺-dependent deacetylase that plays a critical role in regulating cell cycle progression, DNA damage responses, and apoptosis. However, its involvement in MVC infection has not been fully elucidated. Herein, we show that MVC infection markedly upregulates the mRNA and protein expression levels of SIRT1 in a time-dependent manner. MVC infection activates the SIRT1-p53 signaling axis and modulates the acetylation status of p53. In addition, MVC alters the subcellular distribution of SIRT1, promoting its nuclear translocation and colocalization with the viral protein VP2. Functional analyses demonstrated that pharmacological activation of SIRT1 enhanced the viability of MVC-infected WRD cells (virus-tropic cell), promoting viral replication, prolonging S-phase arrest, and reducing apoptosis. Conversely, inhibition of SIRT1 produced the opposite effects, which were closely associated with regulation of the SIRT1-p53 signaling axis. Moreover, SIRT1 knockdown accelerated apoptosis and attenuated S-phase arrest, whereas SIRT1 overexpression further strengthened S-phase retention. Collectively, our findings identify the SIRT1-p53 signaling axis as an important regulator of cell cycle progression and apoptosis during MVC infection, highlighting SIRT1 as a key host factor that supports viral replication and persistence and a potential target for antiviral intervention. Full article

Toxoplasmosis is a globally prevalent protozoan parasitic disease of livestock, among others, with significant zoonotic potential. This study aimed to assess the seroprevalence of Toxoplasma gondii antibodies in serum samples from water buffaloes (Bubalus bubalis) in Sohag governorate, Upper Egypt. In addition, several factors related to animals, management, and environment were analyzed to identify the risk factors for T. gondii infection. A cross-sectional epidemiological approach was employed, with samples collected from various locations across the region and tested using a commercially available indirect enzyme-linked immunosorbent assay (iELISA). Animal and environmental factors were evaluated to identify potential risk factors for the disease. The overall seroprevalence of T. gondii among the tested buffaloes was 7% (24/342). Seasonal variations were observed, with the highest seropositivity recorded in spring (10.7%; 11/103), followed by autumn (8%; 2/25), summer (5.6%; 7/125), and winter (2.2%; 2/89). High seropositivity was detected in aborted females, at 19% (4/21), and in repeated breeders, at 10.5% (4/38), in relation to buffaloes showing anestrus (no positive cases), although the differences were not statistically significant. Our findings suggest that T. gondii is endemic in Sohag, with water buffaloes serving as sentinel animals for the disease. The spring season appears to be a risk factor for infection. Further studies are needed to assess the potential risk to humans, particularly regarding the consumption of raw or undercooked buffalo meat infected with T. gondii. Full article