Tongtong Wang

This review article highlights the surveillance of bacterial, viral, and parasitic diseases in donkey populations in China. Key findings highlight significant threats from Equine herpesviruses (EHV-8 and EHV-1), which cause encephalitis, abortion, and respiratory distress. Several parasitic infections including Giardia duodenalis, Cryptosporidium spp., Enterocytozoon bieneusi, and Toxoplasma gondii present important zoonotic concerns across multiple regions of China. Additionally, this review synthesizes current knowledge on donkey microbiota across various body sites and examines their functional significance in health and disease. The complex relationship between the microbiota and host health represents a critical area of research in donkeys. Recent molecular advancements have enhanced our understanding of the diverse microbial ecosystems inhabiting different body sites in donkeys and their profound impact on health outcomes. As single-stomach herbivores, donkeys possess complex microbial communities throughout their digestive tracts that are essential for intestinal homeostasis and nutritional processing. Significant variations in microbiota composition exist across different intestinal segments, with the hindgut displaying greater richness and diversity compared to the foregut. Beyond the digestive system, distinct microbial profiles have been characterized across various body sites including the skin, oral cavity, reproductive tract, and body secretions such as milk. The health implications of donkey microbiota extend to critical areas including nutrition, immune function, and disease susceptibility. Research demonstrates how dietary interventions, environmental stressors, and physiological states significantly alter microbial communities, correlating with changes in inflammatory markers, antioxidant responses, and metabolic functions. Additionally, specific microbial signatures associated with conditions like endometritis and respiratory disease suggest the potential for microbiota-based diagnostics and therapeutics. The identification of antibiotic-resistant strains of Proteus mirabilis and Klebsiella pneumoniae in donkey meat highlights food safety concerns requiring enhanced monitoring systems and standardized safety protocols. These findings provide a foundation for improved donkey healthcare management, including targeted disease surveillance, microbiota-based interventions, and protective measures for those working with donkeys or consuming donkey-derived products.

Equine herpesvirus-1 (EHV-1) is a significant pathogen that causes substantial economic losses in the equine industry worldwide, which leads to severe respiratory diseases and abortions in horses. However, reports of EHV-1 infection in donkeys are limited, particularly in China. This case study reported an EHV-1-induced respiratory disease in Dezhou donkey foals in Shandong Province, China, in July 2024. Three one-month-old foals exhibited high fever, nasal discharge, and respiratory distress, with a 100% mortality rate. The causative agent, strain LC126, was isolated from a one-month-old donkey foal exhibiting severe respiratory disease. Phylogenetic analysis of the EHV-1 isolate LC126 showed close similarity to EHV-1. Overall, our study revealed that EHV-1 can cause respiratory distress as well as death in donkeys. The study underscores the emerging threat of EHV-1 in donkeys and highlights the need for veterinarians and breeders to give proper attention to the potential threat of EHV-1 outbreaks.

Salmonella Abortusequi (S. Abortusequi) is the primary cause of abortions in equine animals, and can cause serious foodborne illness. Thus, effective biocontrol strategies are needed to decontaminate and control the emergence of foodborne diseases. In recent years, phages have been used as a new strategy for modulating foodborne pathogens and food safety. In this study, a new phage, vB_SalP_LDDK01, was isolated from donkey farm bedding. The data indicated that the incubation period of vB_SalP_LDDK01 was 10 min, the burst size was 378 PFU/cell, as well as a wide range of heat resistance (40-70°C) and pH stability (4-12). Furthermore, genomic analysis and electron microscopy indicated that vB_SalP_LDDK01 belongs to the Class Caudoviricetes and genus Jerseyvirus. Moreover, its genome was 42,378 bp long, encoded 57 ORFs, was double-stranded DNA with a 49.52% GC content, and lacked virulence and drug-resistant genes. In addition, how vB_SalP_LDDK01 inhibits the growth of S. Abortusequi and removes the biofilm of S. Abortusequi was assessed in a liquid broth medium, and the results showed that vB_SalP_LDDK01 inhibited the growth of S. Abortusequi for about 8 h and significantly reduced the viable bacteria abundance compared with the phage-free positive control. Further, vB_SalP_LDDK01 treated the host bacteria for 12 h and effectively destroyed the biofilm of S. Abortusequi. This study further investigated how effectively vB_SalP_LDDK01 modulates bacterial contamination in donkey meat inoculated with S. Abortusequi LCU-S-ABORT-F at 4°C and 25°C. Furthermore, after 72 h of vB_SalP_LDDK01 treatment with different multiplicity of infection (1, 0.1, 0.01, and 0.001), the bacterial contamination on the surface of donkey meat was reduced by 4.3, 3.7, 3.3, and 3.5 log₁₀ CFU/piece at 25°C, and 4.5, 3.9, 2.8, and 2.7 log₁₀ CFU/piece at 4°C. Whereas the phage titers at different temperatures were basically comparable to the initial titers. Overall, these results indicated that vB_SalP_LDDK01, the new phage, can serve as an effective biological agent and inhibit S. Abortusequi in donkey meat.

Equid herpesvirus type 8 (EqHV-8) is known to cause respiratory disease and miscarriage in horses and donkeys, which is a major problem for the equine farming industry. However, there are currently limited vaccines or drugs available to effectively treat EqHV-8 infection. Therefore, it is crucial to develop new antiviral approaches to prevent potential pandemics caused by EqHV-8. This study evaluates the antiviral and antioxidant effects of cepharanthine against EqHV-8 by employing both in vitro assays and in vivo mouse models to assess its therapeutic efficacy. To assess the effectiveness of cepharanthine against EqHV-8, we conducted experiments using NBL-6 and RK-13 cells. Additionally, we developed a mouse model to validate cepharanthine’s effectiveness against EqHV-8. In our in vitro experiments, we assessed the cepharanthine’s ability to inhibit infection caused by EqHV-8 in NBL-6 and RK-13 cells. Our results demonstrated that cepharanthine has a dose-dependent inhibitory effect, indicating that it possesses anti-EqHV-8 properties at the cellular level. Moreover, we investigated the mechanism through which cepharanthine exerts its protective effects. It was observed that cepharanthine effectively reduces the oxidative stress induced by EqHV-8 by activating the AMPK and Nrf2/HO-1 signaling pathways. Furthermore, when administered to EqHV-8 infected mice, cepharanthine significantly improved lung tissue pathology and reduced oxidative stress. The findings presented herein collectively highlight cepharanthine as a promising candidate for combating EqHV-8 infections.

Mastitis is a significant inflammatory condition of the mammary gland in dairy cows. It is caused by bacterial infections and leads to substantial economic losses worldwide. The disease can be either clinical or sub-clinical and presents challenges such as reduced milk yield, increased treatment costs, and the need to cull affected cows. The pathogenic mechanisms of mastitis involve the activation of Toll-like receptors (TLRs), specifically TLR2 and TLR4. These receptors play crucial roles in recognizing pathogen-associated molecular patterns (PAMPs) and initiating immune responses through the NF-κB signaling pathway. Recent in vitro studies have emphasized the importance of the TLR2/TLR4/NF-κB signaling pathway in the development of mastitis, suggesting its potential as a therapeutic target. This review summarizes recent research on the role of the TLR2/TLR4/NF-κB signaling pathway in mastitis. It focuses on how the activation of TLRs leads to the production of proinflammatory cytokines, which, in turn, exacerbate the inflammatory response by activating the NF-κB signaling pathway in mammary gland tissues. Additionally, the review discusses various bioactive compounds and probiotics that have been identified as potential therapeutic agents for preventing and treating mastitis by targeting TLR2/TLR4/NF-κB signaling pathway. Overall, this review highlights the significance of targeting the TLR2/TLR4/NF-κB signaling pathway to develop effective therapeutic strategies against mastitis, which can enhance dairy cow health and reduce economic losses in the dairy industry.

Equine breeding plays an essential role in the local economic development of many countries, and it has experienced rapid growth in China in recent years. However, the equine industry, particularly large-scale donkey farms, faces a significant challenge with pregnancy losses. Unfortunately, there is a lack of systematic research on abortion during equine breeding. Several causes, both infectious and non-infectious, of pregnancy losses have been documented in equines. The infectious causes are viruses, bacteria, parasites, and fungi. Non-infectious causes may include long transportation, ingestion of mycotoxins, hormonal disturbances, twinning, placentitis, umbilical length and torsion, etc. In current review, we discuss the transmission routes, diagnostic methods, and control measures for these infectious agents. Early detection of the cause and appropriate management are crucial in preventing pregnancy loss in equine practice. This review aims to provide a comprehensive understanding of the potential causes of abortion in equines, including infectious agents and non-infectious factors. It emphasizes the importance of continued research and effective control measures to address this significant challenge in the equine industry.

Introduction: The Nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway has been extensively studied for its role in regulating antioxidant and antiviral responses. The Equid herpesvirus type 8 (EqHV-8) poses a significant threat to the equine industry, primarily manifesting as respiratory disease, abortions, and neurological disorders in horses and donkeys. Oxidative stress is considered a key factor associated with pathogenesis of EqHV-8 infection. Unfortunately, there is currently a dearth of therapeutic interventions available for the effective control of EqHV-8. Rutin has been well documented for its antioxidant and antiviral potential. In current study we focused on the evaluation of Rutin as a potential therapeutic agent against EqHV-8 infection.Methods: For this purpose, we encompassed both in-vitro and in-vivo investigations to assess the effectiveness of Rutin in combatting EqHV-8 infection.Results and Discussion: The results obtained from in vitro experiments demonstrated that Rutin exerted a pronounced inhibitory effect on EqHV-8 at multiple stages of the viral life cycle. Through meticulous experimentation, we elucidated that Rutin’s antiviral action against EqHV-8 is intricately linked to the Nrf2/HO-1 signaling pathway-mediated antioxidant response. Activation of this pathway by Rutin was found to significantly impede EqHV-8 replication, thereby diminishing the viral load. This mechanistic insight not only enhances our understanding of the antiviral potential of Rutin but also highlights the significance of antioxidant stress responses in combating EqHV-8 infection. To complement our in vitro findings, we conducted in vivo studies employing a mouse model. These experiments revealed that Rutin administration resulted in a substantial reduction in EqHV-8 infection within the lungs of the mice, underscoring the compound’s therapeutic promise in vivo.Conclusion: In summation, our finding showed that Rutin holds promise as a novel and effective therapeutic agent for the prevention and control of EqHV-8 infections.

Equid alphaherpesvirus type 8 (EqHV-8) is the causative agent of severe respiratory disease, abortions, and neurological syndromes in equines and has resulted in huge economic losses to the donkey industry. Currently, there exist no therapeutic molecules for controlling EqHV-8 infection. We evaluated the potential antiviral activity of cobalt protoporphyrin (CoPP) against EqHV-8 infection. Our results demonstrated that CoPP inhibited EqHV-8 infection in susceptible cells and mouse models. Furthermore, CoPP blocked the replication of EqHV-8 via HO-1 (heme oxygenase-1) mediated type I interferon (IFN) response. In conclusion, our data suggested that CoPP could serve as a novel potential molecule to develop an effective therapeutic strategy for EqHV-8 prevention and control.

Equine herpesvirus type 8 (EHV-8), associated with abortion and severe respiratory disease in donkeys and horses, causes significant economic losses in the global equine industry. However, the pathogenicity of EHV-8 is still unknown. Mice are widely used as an animal model to evaluate virus replication and virulence. The present study aimed to evaluate the pathogenicity of the EHV-8 SDLC66 strain in BALB/c mice. Mice were used to test for infection-associated parameters (such as clinical signs, body weights, virus replication in tissues, viremia, and cytokines) and sacrificed at 0, 2, 4, and 6 days post-infection (dpi). The mice inoculated with EHV-8 exhibited lethargy, dyspnea signs, loss in body weight, and viremia. EHV-8 was detected in the liver, spleen, brain, and lung by PCR at 4 dpi and 6 dpi, effectively replicating these tissues detected by TCID₅₀ at 6 dpi. Proinflammatory cytokines, including IL-6, IL-1β, and TNF-α, were significantly increased at the 4 dpi and 6 dpi in the lung than in the control group. However, IFN-γ was only increased at 6 dpi in the EHV-8-infected group. These data showed that EHV-8 could enter the lungs of mice and cause respiratory disease in the mouse model, which helps reveal the pathogenicity of EHV-8.