Search Results (1,809)

Herpes simplex virus 1 (HSV-1) entry is a complex interplay of viral and host factors. The mechanisms of its regulation remain undefined. HSV-1 entry occurs via multiple distinct and cell-type dependent pathways, further complicating study of this process. HSV-1 strains with atypical entry properties aid in the elucidation of entry determinants. HSV-1 strain ANG path exhibits entry in Vero cells at 4 °C, whereas wild-type strains do not. We investigated the determinants of low temperature entry by HSV-1 ANG path in several cell types. The receptor nectin-2 mediated 4 °C entry of HSV-1 ANG path into CHO-K1 cells, but the related receptor nectin-1 did not, suggesting that gD-binding receptors are a determinant of HSV-1 entry at low temperatures. In HaCaT cells, both HSV-1 ANG path and wild-type strain KOS entered at 4 °C, while HSV-1 chimera 27/III, which contains KOS strain gB in the ANG path virus background, did not. This suggests that gB functions as a determinant of low temperature entry of HSV-1. Together, the findings suggest that there are multiple determinants and mechanisms of HSV-1 low temperature entry and that the requirements differ by cell type. Full article

African Swine Fever is a lethal hemorrhagic disease caused by a DNA virus that affects domestic and wild pigs, causing serious economic losses in the swine industry. African Swine Fever virus (ASFV) is maintained in a sylvatic cycle that includes wildlife and Ornithodoros tick species. A huge investigation about ASFV structure and its infection process in pigs has been carried out in recent years, and although these studies have increased our knowledge about its pathogenesis, there are still many unclear aspects about which immune responses protect swine hosts against the disease caused by this virus. The mechanisms of ASFV infection in ticks are even less well understood. This infection is long term and persistent, with relatively high levels of virus replication in different tick tissues. According to specific infected tissues, the Ornithodoros tick species that are ASFV-competent vectors show transstadial, transovarial and/or venereal transmissions. This review is focused on the main process taking place at the virus–vector interface, summarizing the latest findings about the molecular and cellular aspects of ASFV infection in ticks, which could constitute the basis for developing novel strategies to interrupt the arthropod transmission cycle. Full article

Gut microbial communities perform a multitude of physiological functions for their hosts; however, the drivers and distribution patterns of microbiota in wild animals remain largely underexplored. Our understanding of how these microbial communities are structured across hosts in natural environments—especially within a single host species remains limited. Here, we characterized the gut microbial communities of four species of ocean fish using 16S rRNA high-throughput sequencing to investigate the structural and functional features of these microbial communities across different fish species. By comparing the gut microbiota compositions of blue sharks (Prionace glauca), bigeye tuna (Thunnus obesus), sickle pomfret (Taractichthys steindachneri), and mackerel (Scomber japonicus), we identified several microbial taxa—including Photobacterium, Pelomonas, Ralstonia, and Rhodococcus—that were consistently detected across all samples, indicating they likely constitute a “common microbiota”. However, the relative abundances of these taxa varied significantly among species, with Photobacterium exhibiting the highest diversity. Blue sharks and bigeye tuna harbored relatively few dominant microbial species, but the abundance of these dominant bacteria was remarkably high, and inter-individual differences in microbial composition were pronounced. In contrast, mackerel and sickle pomfret contained a greater variety of dominant genera, each with low relative abundance, and inter-individual differences within the same species were minimal. Functionally, metabolic pathways, biosynthesis of secondary metabolites, and microbial metabolism represent the predominant functional categories of the intestinal microbiota in marine fish, with only minor interspecific differences observed. In contrast, biosynthesis of amino acids, ABC transporters, and two-component systems are the key functional pathways that exhibit significant variations across different fish species. Collectively, these findings reveal differences in gut microbial stability among different fish hosts. Such variations may be associated with the hosts’ energy utilization needs, and changes in the gut microbiota play a critical role in shaping the diverse survival strategies of these fish species. Full article

Gastrointestinal nematodes, particularly Haemonchus contortus, represent a major threat to ruminant health and productivity worldwide, largely due to the widespread emergence of anthelmintic resistance. In Bosnia and Herzegovina, benzimidazole resistance has previously been confirmed in domestic ruminants; however, data on wildlife remain lacking. Given the frequent spatial and temporal overlap between domestic and wild ruminants on shared pastures, this study aimed to investigate the occurrence of benzimidazole-resistant H. contortus genotypes within a multi-host system. During the 2024/2025 season, a total of 111 abomasal samples were collected from sheep (n = 20), lambs (n = 12), goats (n = 17), roe deer (n = 40) and chamois (n = 22) across four localities in Bosnia and Herzegovina (Laktaši, Banja Luka, Modriča and Višegrad). Adult H. contortus specimens were morphologically identified and confirmed using real-time quantitative PCR (rt-qPCR). Benzimidazole resistance was assessed by allele-specific rt-qPCR targeting the F200Y mutation in the β-tubulin isotype 1 gene. Statistically significant interspecies differences in β-tubulin genotype distribution were observed (p < 0.05), primarily driven by variation in the homozygous resistant (RR) genotype. High RR prevalence was detected in sheep (60%), lambs (50%) and roe deer (52.5%), whereas lower proportions were observed in chamois (27.3%) and goats (23.5%). Overall, 44.1% of all analyzed H. contortus isolates carried homozygous resistant alleles, indicating an advanced stage of benzimidazole resistance within this multi-host system. These findings demonstrate that benzimidazole resistance in H. contortus is not confined to domestic livestock but is also present in wild ruminants sharing the same grazing areas, consistent with circulation of resistant parasites within shared grazing systems. Full article

Betanodavirus infection poses a significant threat to marine fish species in the Mediterranean, affecting both aquaculture and wild populations. Despite increasing evidence of viral circulation in farmed and wild fish, data on natural outbreaks in wild groupers remain limited. This study investigated mortality episodes in wild dusky groupers (Epinephelus marginatus) within two marine protected areas (MPAs): Portofino MPA (Liguria, Italy) and Larvotto MPA (Principality of Monaco) during 2018–2019. Pathological examinations and virological diagnostics confirmed that the causative agents were betanodavirus strains belonging to the RGNNV genotype. Phylogenetic analyses revealed high genetic similarity among viral strains detected at geographically distant sites and across host species, suggesting potential regional connectivity mediated by mobile vectors or environmental transport. Seawater temperature analysis indicated that extreme and prolonged high-water temperatures were prodromal and coincided with observed outbreaks, supporting a role for thermal stress in triggering outbreak onsets. These findings highlight the susceptibility of wild dusky grouper populations to betanodavirus and underscore the interplay between host behavior, environmental conditions, and pathogen dynamics. The study emphasizes the importance of integrated health surveillance strategies within and around MPAs to monitor fish health and environmental parameters, thereby conserving wild fish populations and biodiversity. Full article

Hemotropic mycoplasmas (hemoplasmas) are uncultivable, cell wall-less bacteria that parasitizeon the surface of red blood cells of mammals, potentially causing anemia and other systemic signs. While widely distributed among domestic and wild animals, their occurrence in equids remains poorly understood, and no species has been identified as host-specific to horses or donkeys. This study presents the first systematic survey of hemoplasmas in equids from southeastern Europe and only the second molecularly confirmed case in horses in Europe. A total of 843 equids (817 horses and 26 donkeys) from different regions of Croatia, representing various ages, uses, and husbandry systems, were screened for hemoplasmas by PCR targeting the 16S rRNA gene. Only one horse tested positive, identified as Mycoplasma wenyonii, a hemoplasma typically associated with cattle. The estimated prevalence was 0.12% (95% CI: 0.003–0.68%). No donkeys were infected. The extremely low prevalence observed here—the lowest reported in any study detecting hemoplasma-positive horses—supports the hypothesis that equids do not harbor host-specific hemoplasma species and may only sporadically acquire infections from other hosts via spillover. This finding underscores the apparent absence of persistent hemoplasma lineages adapted to equids and highlights the need for further research on their epidemiology, host specificity, and transmission dynamics. Full article

Mtx1 is a mosquitocidal protein that exhibits high toxicity toward Culex species. It is produced during the vegetative phase of Lysinibacillus sphaericus but at very low levels and is rapidly degraded. The low expression appears to result from a weak promoter and a potential regulatory stem-loop structure in the 5′ untranslated region. To investigate this regulation, promoter variants of mtx1 were constructed to disrupt stem-loop formation, and promoter activity was assessed using green fluorescent protein (GFP) as a reporter. Disruption of the inverted repeat resulted in approximately twofold higher fluorescence compared with the wild-type promoter in L. sphaericus 2297, indicating partial derepression of translation. To improve protein stability, Bacillus subtilis WB800N, a protease-deficient host, was employed for heterologous expression. Truncated Mtx1 (tMtx1) was secreted into the culture medium, and no obvious degradation products were detected by Western blot analysis under the conditions tested. Although the overall yield was low and not quantitatively determined, the secreted protein retained biological activity. Larvicidal assays showed elevated mortality in tMtx1-containing culture supernatants, with an estimated LC₅₀ at approximately a 1:83 dilution and detectable activity up to a 1:512 dilution relative to control cultures. These results demonstrate that the upstream inverted repeat contributes to partial repression of mtx1 expression in L. sphaericus and that protease-deficient B. subtilis can be used as a host for producing biologically active tMtx1, although further optimization will be required to improve yield. Full article

Maize (Zea mays L.) is a major economic crop highly susceptible to Colletotrichum graminicola, the causal agent of anthracnose leaf blight, which causes substantial annual yield losses. This fungal pathogen employs numerous effectors to manipulate plant immunity, yet the functions of many secreted proteins during biphasic infection remain poorly characterized. In this study, we identified CgMas2, a candidate secreted protein in C. graminicola and a homolog of Magnaporthe oryzae MoMas2. Deletion of CgMAS2 in the wild-type strain CgM2 did not affect fungal vegetative growth or conidial morphology but significantly impaired virulence on maize leaves. Leaf sheath infection assays revealed that CgMas2 is required for biotrophic invasive hyphal growth, as the mutant showed defective spreading of invasive hyphae to adjacent cells. Subcellular localization analysis indicated that CgMas2 localizes to the cytoplasm of conidia and to the primary infection hyphae. Furthermore, DAB staining demonstrated that disrupt of CgMAS2 leads to host reactive oxygen species (ROS) accumulation. Comparative transcriptome analysis of maize infected with ΔCgmas2 versus CgM2 revealed enrichment of GO terms related to peroxisome and defense response, along with up-regulation of benzoxazinoid biosynthesis genes (benzoxazinone biosynthesis 3, 4 and 5) at 60 h post-inoculation (hpi). Conversely, six ethylene-responsive transcription factors (ERF2, ERF3, ERF56, ERF112, ERF115 and ERF118) involved in ethylene signaling pathways were down-regulated at 96 hpi. These expression patterns were validated by RT-qPCR. Collectively, our results demonstrate that CgMas2 not only promotes invasive hyphal growth during the biotrophic stage but may also modulate phytohormone signaling and defense compound biosynthesis during the necrotrophic phase of infection. Full article

Fusarium oxysporum f. sp. niveum is an increasingly threatening fungal pathogen that systemically colonizes watermelon plants and severely compromises their productivity by causing destructive vascular wilt disease. While its nonribosomal peptide synthetase NPS6 has been identified as a key virulence factor, the regulatory mechanisms through which it controls downstream gene networks to cause disease remain unclear. To elucidate this regulatory pathway, we constructed a ΔFW-NPS6 knockout mutant and conducted a comparative genome-wide analysis using RNA sequencing, with the wild-type strain as a control. The results revealed 66 NPS6-dependent differentially expressed genes, which were primarily associated with secondary-metabolite biosynthesis (e.g., genes encoding nonribosomal peptide synthetases like NPS2) and pathogen–host interactions (e.g., components of the MAPK signaling pathway), and were enriched in key pathogenic pathways. This finding reveals the virulence regulatory network mediated by NPS6, providing a direct theoretical foundation and crucial molecular targets for developing novel control strategies, such as targeted fungicides or genetic interventions, against Fusarium wilt in watermelon by highlighting NPS6 itself as a potential fungicide target and its downstream pathways (e.g., siderophore biosynthesis) as points for intervention. Full article

Canine Distemper Virus (CDV) is a highly contagious disease that affects a wide range of wildlife species, posing a serious threat to biodiversity and conservation efforts. Despite its ecological significance, the transmission dynamics of CDV in wildlife remain poorly understood, especially in tropical ecosystems. One of the main challenges in studying CDV transmission is the lack of reliable epidemiological data and the difficulty in capturing and monitoring wild animals for surveillance purposes. Thus, this study aims to develop a model to estimate the potential transmission of CDV in wildlife populations using spatial heat mapping and the basic reproduction number (R₀) as key indicators. A combination of field observation records, environmental data, and reported CDV cases were used to generate predictive heat maps and simulate disease spread across susceptible wildlife hosts. Results showed that certain environmental factors and animal density hotspots significantly contribute to higher transmission potential of CDV. Preliminary results suggest that high-risk zones can be identified based on overlapping wildlife movement corridors and human interface areas. This modeling approach offers a valuable tool to guide targeted monitoring, early detection and conservation strategies against CDV outbreaks in wildlife. Full article

Avian influenza viruses are predominantly associated with waterfowl and shorebirds, and are rarely detected in other avian hosts in nature. In 2021, an H1N1 virus was isolated from a Fieldfare Turdus pilaris in Zaporizhzhia Oblast, Ukraine. A phylogenetic analysis revealed that all eight gene segments belonged to the Eurasian low-pathogenic avian influenza lineages. The highest nucleotide identity of the HA gene was observed with viruses detected in Georgia, Sweden, and Ukraine (99.11%), while the NA gene showed the greatest identity to viruses from Western Europe (99.14–99.57%). Genetic analysis of the HA cleavage site showed a sequence (PSIQSR↓GLF) that contained a single basic amino acid. No deletions were detected in the stalk region of NA gene, and no specific mutations in PB2 protein were found. However, several amino acid substitutions were identified in the HA gene (D204E, S207T, and D239G) that may affect the binding affinity to specific antibodies. The occurrence of this virus in a wild, seemingly healthy thrush indicate that additional surveillance in poorly studied ecological groups such as Passeriformes is warranted. Full article

Gut microbes play a crucial role in regulating physiological processes such as host energy metabolism, nutrient absorption, and environmental adaptation. The predicted functions of gut microbes can be influenced by many factors, both extrinsic and intrinsic to the hosts. The plateau pika is a key species in the alpine ecosystem of the Qinghai–Tibet Plateau. Previous research on the plateau pika primarily examined how extrinsic factors affected its gut microbiota. However, studies on intrinsic factors are scarce. Here, we used live-trapping to capture plateau pikas and collect cecum contents. Using metagenomic sequencing of cecum content samples, we characterized and compared the gut microbial composition and predicted function of plateau pika in adult (n = 9) and juvenile (n = 9) populations. The results indicated that Bacillota and Bacteroidete were the major bacterial phyla. The core gut microbial genera were the same, but the relative abundance of Oscillospira in juveniles was significantly lower than that in adults. The changes in the proportion of cellulose-degradation-related bacterial communities in juveniles suggest that they tend to choose low-fiber diets. In this study, we found no significant differences in the gut microbial composition and diversity, KEGG level 1 metabolic pathways, or CAZy class level between adult and juvenile plateau pikas. In total, the composition and predicted functions of cecal microorganisms in juvenile and adult male plateau pikas were not different. Regarding KEGG level 2 metabolic pathways, the juvenile group had a higher relative abundance of metabolic pathways for cofactors and vitamins, terpenoids, and polyketides, whereas the adult group had a higher relative abundance of energy metabolism. However, the resulting differences remain unclear. Therefore, future research should validate the above findings on a broader spatio-temporal scale and conduct cross-species comparisons to construct a microbial ecological framework for the health management of plateau wild animals. Full article

Galba truncatula acts as an intermediate host for several parasitic flukes of veterinary importance, but a targeted study on its spatial presence as well as the impact of environmental factors in Southeastern Europe has not been conducted. During the summer months of 2017 and 2018, a survey of 191 water bodies in 14 districts in Central, Southern and Western Bulgaria was conducted, with a focus on animal drinking fountains. Each site was assessed for snail presence and characterized by altitude, temperature, precipitation, shade and type of water body. Logistic regression modeling was used to identify the important factors related to the occurrence of snail species. The frequency of habitats found was 29.3%, with no differences observed between the studied districts (p > 0.05). Snails were present across a wide range of altitudes (78–1926 m), annual mean temperature (7.8–14.0 °C) and annual mean precipitation (523–796 mm). The high habitat frequencies were recorded in streams (60.0%) and on the banks on small rivers (50.0%). The presence of snails in the two studied types of fountains (without or with a concrete platform) was 24.1% and 17.2%, respectively, with no significant difference between them (p > 0.05). Regression analysis revealed temperature, shade, and type of water body as factors that could significantly influence the spatial presence of G. truncatula. The findings demonstrate the ecological adaptability of G. truncatula and highlight its presence in habitats with high potential for contact with domestic and wild ruminants. This information fills a regional knowledge gap and can support risk assessment and control measures for fluke-borne diseases in livestock and wildlife. Full article

Background: Artificial inoculation of Epichloë endophytes into elite forage germplasm aims to establish beneficial symbioses for developing high-yield, high-quality, and stress-tolerant cultivars, but host specificity of the fungi often causes compatibility issues in non-natural hosts. Methods: The E. bromicola isolated from native wild barley was inoculated into cultivated wild barley (Hordeum brevisubulatum) and cultivated barley (Hordeum valgare), forming Hb+Eb and Hv+Eb. The NHb+Eb (native wild barley naturally infected with E. bromicola) served as a control. We analyzed fungal colonization patterns and symbiotic gene regulation to clarify the compatibility between E. bromicola and non-natural hosts. Results: Compared with NHb+Eb and Hb+Eb, E. bromicola in Hv+Eb showed obvious hyphal vacuolization. E. bromicola colonization altered host trichome morphology and induced stomatal closure. Correspondingly, expression of the siderophore biosynthesis gene sidN and the NADPH oxidase complex genes (NoxA, NoxB, NoxR, RacA) was significantly lower (p < 0.05) in Hv+Eb than in Hb+Eb and NHb+Eb. Conclusions: This study reveals that the incompatibility between cultivated barley and E. bromicola is characterized by altered hyphal morphology, which is linked to the downregulation of sidN and Nox. These findings provide a critical theoretical foundation for developing highly compatible cereal-Epichloë germplasms. Full article

Canine parvovirus type 2 (CPV-2) is a primary etiological agent of acute gastroenteritis in domestic dogs. Although molecular and serological evidence have confirmed its circulation in wild carnivores, the clinical impact of spillover events in wildlife hosts remain insufficiently characterized. In this study, we investigated CPV-2 from wild coyote pups (Canis latrans) presenting with clinical gastroenteritis in northeastern Mexico. CPV-2 was successfully isolated in MDCK cells, and whole-genome sequencing was performed on two isolates, B55 and B56 (GenBank accession numbers PQ065988 and PQ065989). A comprehensive analysis identified 23 nucleotide mutations, eight of which were missense mutations resulting in amino acid substitutions in structural (VP) and non-structural (NS) proteins. Notably, amino acid substitution L354V was identified in the NS1 helicase domain of both isolates, a region critical for viral replication. Phylogenetic analysis confirmed that isolates B55 and B56 cluster within the CPV-2c subtype, showing high genetic relatedness to circulating Mexican and US canine strains which strongly suggests recent cross-species transmission between domestic dogs and wild coyotes. This study provides the first complete genomic characterization of a clinical CPV-2 infection in wild coyotes in Mexico, underscoring the immediate risk of CPV-2c transmission at the domestic animal–wildlife interface. Full article