IDCases. 2026 Mar 25;44:e02555. doi: 10.1016/j.idcr.2026.e02555. eCollection 2026.

ABSTRACT

BACKGROUND: Immunocompromised patients presenting with encephalitis can present a diagnostic conundrum as infection can be caused by a broad range of pathogens, many of which are not detected by standard of care testing pathways. Untargeted metagenomics has proven utility in the diagnosis of such infections, particularly for immunocompromised patients.

METHODS: An immunosuppressed adolescent presented with idiopathic progressive muscle weakness resulting in respiratory failure, 16 years after haematopoeitic stem cell transplant for familial haemophagocytic lymphohistiocytosis type 5. Clinical and radiological findings suggested a diagnosis of isolated central nervous system haemophagocytic lymphohistiocytosis, however the patient demonstrated no improvement on immunosuppressive therapy. Untargeted metagenomics was performed on brain biopsy tissue.

RESULTS: Clinical metagenomics detected avian paramyxovirus 1 (APMV-1) in the brain tissue 12 days after biopsy, confirmed by targeted PCR and immunohistochemistry. The metagenomics results guided treatment; immunosuppression was stopped and medication with potential activity against RNA viruses started. The patient died 8 months after symptom onset.

CONCLUSIONS: We describe the third published case of fatal encephalitis caused by APMV-1, detectable only in brain parenchyma and only by clinical metagenomics, demonstrating the utility of brain biopsy and metagenomics when investigating encephalitis in immunocompromised patients. Case series review suggests profoundly immunocompromised patients are at risk of severe infection caused by AMPV-1.

PMID:41953529 | PMC:PMC13054261 | DOI:10.1016/j.idcr.2026.e02555

Poult Sci. 2026 Mar 27;105(7):106873. doi: 10.1016/j.psj.2026.106873. Online ahead of print.

ABSTRACT

Interleukin-17A (IL-17A) is a key pro-inflammatory cytokine that plays a crucial and complex role in immune regulation, infection, and inflammation under both physiological and pathological conditions, demonstrating significant potential in these fields. However, research on its interaction with the avian respiratory system and its potential application as a mucosal immune adjuvant is limited. To investigate its functional relevance, a comparison was first performed of the genetic and structural features of chicken IL-17A (chIL-17A) with those of its mammalian homologs. Recombinant chIL-17A was subsequently produced via a prokaryotic expression system and evaluated through in vitro assays using chicken embryo fibroblasts (CEFs) and peripheral blood mononuclear cells (PBMCs), as well as in vivo experiments in specific-pathogen-free (SPF) chickens. In the in vivo study, 3-week-old SPF White Leghorn chickens (mixed sex) were nebulized with a single or double dose (20 μg/kg per dose, n = 12 per group) of chIL-17A. The results demonstrated that chIL-17A treatment markedly upregulated the transcription of proinflammatory cytokines (e.g., IL-1β, IL-6, and TNF-α), type I interferons, and multiple interferon-stimulated genes in a dose-and time-dependent manner. Notably, a second administration further enhanced its stimulatory effect on these immune mediators. In vivo, nebulized chIL-17A significantly induced pulmonary proinflammatory responses, particularly on day 5 post-treatment, with IL-1β and IL-6 mRNA levels increasing by 67.35-fold (P < 0.001) and 130.19-fold (P < 0.001), respectively, in lung tissues. Modulation of IFN responses was most pronounced in the lower trachea and lung tissues, with minimal effects in the upper tracheal region. These findings unequivocally demonstrate the potent immunomodulatory capacity of chIL-17A and underscore its potential as a mucosal immune enhancer in poultry.

PMID:41933529 | DOI:10.1016/j.psj.2026.106873

Front Microbiol. 2026 Mar 11;17:1744587. doi: 10.3389/fmicb.2026.1744587. eCollection 2026.

ABSTRACT

INTRODUCTION: Hepatitis E virus (HEV) is a globally prevalent zoonotic pathogen posing major public health risks. Swine, a major meat source, carry HEV strains genetically similar to those in humans, highlighting the risk of zoonotic foodborne transmission. This study aimed to investigate the evolutionary history of HEV through phylogenetic and recombination analyses, further provide key reference bases for public health management, improve food safety standards, and offer support for developing effective strategies to prevent foodborne hepatitis E infections.

METHODS: We analyzed 348 full-length genomes of HEV isolated from humans and pigs in Asia over the past three decades. Phylogenetic analysis was conducted using the neighbor-joining method in MEGA11. Recombination analysis was performed with seven methods in RDP4, and sequence similarity was visualized using Simplot.

RESULTS: HEV-4 predominated in Asia, especially China, whereas HEV-3 was regionally endemic. Through genomic analysis, we identified 34 potential natural recombination events, predominantly occurring in the RNA-dependent RNA polymerase (RdRp) region; 14 events occurred between swine and human strains, supporting the hypothesis of cross-species transmission. Moreover, 20 recombination events occurred in China and mainly involved HEV-4 strains, suggesting that HEV has distinct evolutionary dynamics. The detection of five inter-genotypic recombination events may highlight ongoing genetic exchange within HEV populations in Asia, and the biological significance of these events remains to be determined.

DISCUSSION: These findings highlight the importance of tracking the evolutionary dynamics of HEV through genomic surveillance, and further underscore the necessity of conducting ongoing HEV surveillance and research to inform prevention strategies.

PMID:41889644 | PMC:PMC13013505 | DOI:10.3389/fmicb.2026.1744587

Front Microbiol. 2026 Feb 17;17:1708036. doi: 10.3389/fmicb.2026.1708036. eCollection 2026.

ABSTRACT

The detrimental effects of microplastics on environmental and biological health have been extensively documented, encompassing various aspects such as growth inhibition, metabolic disorders, and organ damage. However, current research predominantly focuses on model organisms, with limited studies investigating their effects on broiler chickens. Therefore, this study aims to examine the impact of microplastics exposure on the gut microbiota and antioxidant function in broiler chickens. The results indicated that microplastics significantly affect serum biochemical and antioxidant parameters, evidenced by marked increases in AST, ALT, and MDA levels, alongside decreases in SOD and GSH-Px levels. Microbiome analysis revealed a significant decrease in the alpha diversity of the gut microbiota, accompanied by significant alterations in microbial structure. Additionally, metastats analysis demonstrated a significant increase in the relative abundances of one phylum and 12 genera during microplastics exposure, contrasted with a significant decrease in the relative abundances of three phyla and 108 genera. Importantly, microplastics exposure also led to changes in gut microbial function, affecting energy metabolism, coenzyme transport and metabolism, and amino acid metabolism, etc. In summary, our study demonstrates that microplastics can adversely affect the health of broiler chickens by reducing their antioxidant capacity, and causing gut microbial dysbiosis. In light of the increasing pollution from microplastics, this study provides crucial information for assessing the risks posed by microplastics to livestock production. Furthermore, future research should prioritize monitoring the migration of microplastics within the food chain and examining their long-term effects on biological behavior and ecological functions.

PMID:41783496 | PMC:PMC12953438 | DOI:10.3389/fmicb.2026.1708036

Virology. 2026 May;618:110848. doi: 10.1016/j.virol.2026.110848. Epub 2026 Feb 25.

ABSTRACT

Orthoflavivirus are single-stranded positive-sense RNA viruses that pose a significant threat to human and animal health globally, accounting for more than 400 million infections annually. They are predominantly transmitted by arthropods and cause a plethora of clinical manifestations, ranging from mild self-limiting infections to lethal encephalitis, with the potential to cause epidemics and pandemics. The complication in effectively treating Orthoflavivirus infections stems from the intricate interactions between virus and host proteins. A prominent hallmark of Orthoflavivirus infection is the use of sophisticated strategies to cleverly evade and dampen the host's innate immune response, which is a vital defence mechanism against viral invasion. This review provides substantial information on the mechanism of virus hijacking key components of the host immune response, featuring physical interactions between viral and host protein components, in the light of the innate immune system. Understanding and targeting these complex interactions would be instrumental in discovering novel antivirals against these viruses.

PMID:41780167 | DOI:10.1016/j.virol.2026.110848

Vet Microbiol. 2026 Apr;315:110959. doi: 10.1016/j.vetmic.2026.110959. Epub 2026 Feb 27.

ABSTRACT

Fowl aviadenovirus (FAdV) is widely prevalent and often co-infects with other pathogens. During clinical sample testing in our laboratory, samples of FAdV and Pasteurella multocida（PM） co-infection were identified. Compared with single infections, co-infected chickens exhibited more severe clinical symptoms. However, the current epidemic situation of the two pathogens and whether there is synergistic pathogenic effect between them remains unclear. To address this, we established an in vivo model using specific-pathogen-free (SPF) chickens to study FAdV-4 secondary PM infection. The results demonstrated that FAdV-4 infection significantly promoted PM colonization in the host, leading to more severe clinical symptoms and hepatic pathological damage. Meanwhile, serum levels of inflammation-related cytokines, including TNF-α, CCL-4, IL-6 and IL-1β were markedly elevated. To further investigate the underlying mechanism, we performed transcriptome sequencing of liver tissues. Multiple genes closely associated with inflammatory responses (such as IL6) were significantly upregulated. Notably, TLR4, which is intimately linked to inflammatory reactions, was significantly upregulated after FAdV-4 infection. In an in vitro infection model established using leghorn male hepatocellular cells (LMH) cells, we also observed that FAdV-4 infection promoted PM adherence and invasion, accompanied by increased TLR4 expression. Furthermore, upregulation of TLR4 expression using the TLR4 agonist LPS enhanced PM adherence and invasion, whereas downregulation of TLR4 expression using the inhibitor Resatorvid (TAK-242) decreased PM adherence and invasion. In summary, this study confirms the synergistic pathogenic effect between FAdV-4 and PM and reveals that the TLR4 plays a critical role in this process.

PMID:41764915 | DOI:10.1016/j.vetmic.2026.110959

Lett Appl Microbiol. 2026 Mar 6;79(3):ovag008. doi: 10.1093/lambio/ovag008.

ABSTRACT

This study characterized Bacillus subtilis (B. subtilis) BS-Q as a novel probiotic candidate against Clostridium perfringens (C. perfringens). Polyphasic analysis, including 16S rRNA gene sequencing (>99% similarity to reference B. subtilis strains), identified the isolate as BS-Q. It exhibited robust growth, and sporulation was observed. Its cell-free supernatant (CFS) demonstrated potent, broad-spectrum inhibition against C. perfringens types A, C, and G with a minimum inhibitory concentration (MIC) of 33.06 ± 0.53 μg/mL. The antibacterial activity was localized to the CFS and showed remarkable stability after exposure to harsh conditions: high temperature (100°C for 30 min), a broad pH range (3.0-11.0), and high salinity (up to 10% NaCl). Protease treatment markedly reduced the activity, confirming the proteinaceous nature of the antimicrobial compounds, which was supported by the presence of unique protein bands (25-35 kDa) in the CFS as revealed by SDS-PAGE. In conclusion, B. subtilis BS-Q produces highly stable, proteinaceous antimicrobials effective against C. perfringens. Its strong anti-clostridial activity and resilience position it as a promising probiotic and a potential antibiotic alternative for controlling necrotic enteritis in poultry.

PMID:41728919 | DOI:10.1093/lambio/ovag008

Poult Sci. 2026 Feb 10;105(5):106610. doi: 10.1016/j.psj.2026.106610. Online ahead of print.

ABSTRACT

The residual bacteria in bacteriophage (phage) preparations have hindered their application in poultry disease. We isolated eight phages from aquatic environment samples and selected two phages (vB_StyS_SP03 and vB_StyM_SP07) for amplification using the diaminopimelic acid (DAP)-dependent Salmonella YB1 strain. Both healthy and Salmonella-infected broilers were intraperitoneally injected with phages amplified by Salmonella YB1 and their cocktail to evaluate the safety and therapeutic efficacy. The results showed that Salmonella YB1 effectively amplified phages, whose form and function remained unchanged after amplification. Salmonella YB1 in the phage preparations did not proliferate without DAP supplementation. Phage administration caused no mortality, and did not significantly affect the weight gain, immune organ indexes, and gut microbiota composition in healthy broilers. In Salmonella-challenged broilers, phage administration significantly improved weight gain, reduced organ indexes, alleviated clinical symptoms and pathological changes, and restored the intestinal microbial community. Collectively, we have developed a method for amplifying phages using Salmonella YB1, which effectively addresses the problem of residual bacteria in phage preparations.

PMID:41702339 | PMC:PMC12925554 | DOI:10.1016/j.psj.2026.106610

BMC Vet Res. 2026 Jan 27;22(1):158. doi: 10.1186/s12917-025-05236-3.

ABSTRACT

Parrot bornavirus (PaBV) is a neurotropic virus that causes chronic infection in parrots, affecting their nervous and gastrointestinal systems and often resulting in high mortality in captive populations. It is a major threat to the parrot breeding industry and the ornamental bird trade. We used Enzyme-Mediated Dual Exponential Amplification (EmDEA) rapid nucleic acid detection technology to create a novel, simple, and highly sensitive method for detecting parrot bornavirus type 4 (PaBV-4). Primers and probes specific to the M gene of PaBV-4 were designed. After two rounds of screening and optimization, the optimal primer pair was identified as F4R7RNA1. The assay was tested for specificity, sensitivity, and clinical usefulness. The test showed no cross-reactivity with H5N2, H7N9, H9N2, NDV, IBV, or IBDV. It had a detection limit of 5 copies/µL and a repeatability coefficient of variation of less than 5%. Among 270 clinical tissue samples from parrots, the assay achieved a 100% positive concordance rate and an overall agreement of 97.03% with conventional RT-PCR results. The entire detection process takes only 30 min and allows for direct RNA detection of PaBV-4. The method is simple to use, fast, sensitive, and accurate, making it an invaluable tool for on-site detection of PaBV-4.

PMID:41593665 | PMC:PMC12973659 | DOI:10.1186/s12917-025-05236-3

PLoS Pathog. 2026 Jan 20;22(1):e1013812. doi: 10.1371/journal.ppat.1013812. eCollection 2026 Jan.

ABSTRACT

Highly pathogenic H5Ny influenza A viruses are causing unprecedented, season-independent outbreaks across avian and mammalian species, including dairy cattle, a novel reservoir. The sialoside-binding properties of influenza A hemagglutinin (HA) are strongly related to its ability to infect and transmit between hosts. Mucin-like O-glycans, omnipresent in respiratory tracts, have been understudied as viral receptors due to their complexity. To address this, we synthesized 25 O-linked glycans with diverse sialosides, including modifications by fucosides and sulfates. Our findings reveal that H5Ny 2.3.4.4b viruses bind core 3 sialyl-Lewisx and Sia-Gal-β3GalNAc, O-linked glycans not recognized by classical H5 or other avian viruses. By determining crystal structures, we resolved the structural features of four glycans in an H5 hemagglutinin (HA) from a 2016 2.3.4.4b virus. While these viruses do not bind human-type receptors, their broad receptor specificity enhances binding to human tracheal tissues, suggesting that O-glycan recognition could contribute to the continues spillover of this clade.

PMID:41557749 | PMC:PMC12904578 | DOI:10.1371/journal.ppat.1013812