Research Alliance for Veterinary Science and Biodefense BSL-3 Network (RAV3N): Report on network origin and phase I activities.

Recent disease events have heightened awareness for the need for collaboration between the nation's public health and veterinary infectious disease communities to improve preparedness for current and future biological threats. To address this need, the U.S. Department of Agriculture's National Bio- and Agro-Defense Facility (USDA NBAF) has partnered with Texas A&M University through its Global Health Research Complex (TAMGHRC) to establish the Research Alliance for Veterinary Science and Biodefense BSL-3 Network (RAV3N). As a collaborative network of U.S. university and federal BSL-3Ag/BSL-3/BSL-4 laboratory research facilities, the objective of RAV3N is to establish strategic and coordinated approaches for harnessing collective large-animal biocontainment infrastructure and research capacity to improve bio-surveillance, diagnostics, and countermeasure development against high-consequence pathogens of veterinary and zoonotic importance. Here, we describe the origin and development of RAV3N, detail phase I activities, and summarize the proceedings of its first membership meeting held in August 2022.

A metabolically engineered bacterium controls autoimmunity and inflammation by remodeling the pro-inflammatory microenvironment.

Immunotherapy has led to impressive advances in the treatment of autoimmune and pro-inflammatory disorders; yet, its clinical outcomes remain limited by a variety of factors including the pro-inflammatory microenvironment (IME). Discovering effective immunomodulatory agents, and the mechanisms by which they control disease, will lead to innovative strategies for enhancing the effectiveness of current immunotherapeutic approaches. We have metabolically engineered an attenuated bacterial strain (i.e., Brucella melitensis 16M ∆vjbR, Bm∆vjbR::tnaA) to produce indole, a tryptophan metabolite that controls the fate and function of regulatory T (Treg) cells. We demonstrated that treatment with Bm∆vjbR::tnaA polarized macrophages (Mφ) which produced anti-inflammatory cytokines (e.g., IL-10) and promoted Treg function; moreover, when combined with adoptive cell transfer (ACT) of Treg cells, a single treatment with our engineered bacterial strain dramatically reduced the incidence and score of autoimmune arthritis and decreased joint damage. These findings show how a metabolically engineered bacterium can constitute a powerful vehicle for improving the efficacy of immunotherapy, defeating autoimmunity, and reducing inflammation by remodeling the IME and augmenting Treg cell function.

Research on Integrated Management for Cattle Fever Ticks and Bovine Babesiosis in the United States and Mexico: Current Status and Opportunities for Binational Coordination.

Bovine babesiosis is a reportable transboundary animal disease caused by Babesia bovis and Babesiabigemina in the Americas where these apicomplexan protozoa are transmitted by the invasive cattle fever ticks Rhipicephalus (Boophilus) microplus and Rhipicephalus(Boophilus) annulatus. In countries like Mexico where cattle fever ticks remain endemic, bovine babesiosis is detrimental to cattle health and results in a significant economic cost to the livestock industry. These cattle disease vectors continue to threaten the U.S. cattle industry despite their elimination through efforts of the Cattle Fever Tick Eradication Program. Mexico and the U.S. share a common interest in managing cattle fever ticks through their economically important binational cattle trade. Here, we report the outcomes of a meeting where stakeholders from Mexico and the U.S. representing the livestock and pharmaceutical industry, regulatory agencies, and research institutions gathered to discuss research and knowledge gaps requiring attention to advance progressive management strategies for bovine babesiosis and cattle fever ticks. Research recommendations and other actionable activities reflect commitment among meeting participants to seize opportunities for collaborative efforts. Addressing these research gaps is expected to yield scientific knowledge benefitting the interdependent livestock industries of Mexico and the U.S. through its translation into enhanced biosecurity against the economic and animal health impacts of bovine babesiosis and cattle fever ticks.

Environmental Chemical Diethylhexyl Phthalate Alters Intestinal Microbiota Community Structure and Metabolite Profile in Mice.

Exposure to environmental chemicals during windows of development is a potentially contributing factor in gut microbiota dysbiosis and linked to chronic diseases and developmental disorders. We used a community-level model of microbiota metabolism to investigate the effects of diethylhexyl phthalate (DEHP), a ubiquitous plasticizer implicated in neurodevelopmental disorders, on the composition and metabolite outputs of gut microbiota in young mice. Administration of DEHP by oral gavage increased the abundance of Lachnoclostridium, while decreasing Clostridium sensu stricto Addition of DEHP to in vitro-cultured cecal microbiota increased the abundance of Paenibacillus and Lachnoclostridium Untargeted metabolomics showed that DEHP broadly altered the metabolite profile in the culture. Notably, DEHP enhanced the production of p-cresol while inhibiting butyrate synthesis. Metabolic model-guided correlation analysis indicated that the likely sources of p-cresol are Clostridium species. Monoculture of Lachnoclostridium bolteae confirmed that it is capable of producing p-hydroxyphenylacetic acid, the immediate precursor of p-cresol, and that the species' growth is enhanced upon DEHP exposure. Taken together, these findings suggest a model where DEHP increases production of p-cresol, a bacterial metabolite linked with neurodevelopmental disorders, by expanding the abundance of species that synthesize the metabolite's precursor.IMPORTANCE Several previous studies have pointed to environmental chemical exposure during windows of development as a contributing factor in neurodevelopmental disorders and correlated these disorders with microbiota dysbiosis; however, little is known about how the chemicals specifically alter the microbiota to interfere with development. The findings reported in this paper unambiguously establish that a pollutant linked with neurodevelopmental disorders can directly modify the microbiota to promote the production of a potentially toxic metabolite (p-cresol) that has also been correlated with neurodevelopmental disorders. Furthermore, we used a novel modeling strategy to identify the responsible enzymes and bacterial sources of this metabolite. To the best of our knowledge, the present study is the first to characterize the functional consequence of phthalate exposure on a developed microbiota. Our results suggest that specific bacterial pathways could be developed as diagnostic and therapeutic targets against health risks posed by ingestion of environmental chemicals.

A realist evaluation of the implementation of open visiting in an acute care setting for older people.

BACKGROUND: Open visiting refers to the principle of unrestricted visiting hours in the hospital setting to enable relatives, families and carers to visit at any time. There has been recognition that open visiting supports the principle of patient and family supported care and improves communication. Despite this there has been difficulty in implementing open visiting and barriers identified. The aims of this study were therefore to evaluate the implementation of open visiting, the barriers to implementation, sustainability and the impact of open visiting on communication between health care professionals, families and carers. METHODS: The study was conducted on two large acute wards for the older person. Realist evaluation methods were used to understand 'what works well, how, for whom and to what extent.' Mixed methods were employed including qualitative interviews and descriptive analyses of routine data sets. Following the methodology of realist evaluation, programme theories were identified a long with the context, mechanisms and outcomes of implementation, to better understand the implementation process. RESULTS: The results of this study identified some key findings, demonstrating that open visiting does improve communication and can help to build trusting relationships between families/carers and health care professionals (HCP). Barriers to implementation were based on the belief that it would impinge on routines within the ward setting. To achieve the principles of patient and family/carer centred care, the key mechanisms are the confidence and skills of individual nurses and health care assistants to engage with relatives/carers, whilst retaining a sense of control, particularly when care is being delivered to other patients. CONCLUSION: In summary, open visiting creates a positive culture which fosters better relationships between families/carers and HCPs. Involving families/carers as partners in care does not happen automatically in an environment where open visiting is the policy, but requires engagement with staff to encourage and support relatives/carers.

Effects of repeated arthrocentesis on systemic cytokine expression and leukocyte population in young horses challenged with intra-articular lipopolysaccharide.

Osteoarthritis (OA) is a prevalent and economically costly source of lameness in the athletic horse. Previous studies investigating OA pathology have focused on localized trauma to the articular cartilage of a joint, largely ignoring the systemic immune status of the animal. In this study, yearling Quarter Horses were used to evaluate systemic cytokine gene expression and circulating leukocytes following a localized intra-articular inflammatory insult of the endotoxin, lipopolysaccharide (LPS). Treatments for the 35-d experiment included an intra-articular injection of 0.25 ng (n = 7) or 0.50 ng (n = 6) of LPS obtained from Escherichia coli O55:B5 or sterile lactated Ringer's solution (n = 6; control) into the radial carpal joint. Blood and synovial fluid samples were collected at preinjection hour 0 and 2, 6, 12, and 24 h postinjection. Synovial fluid was obtained for a companion study. Total RNA was isolated from plasma leukocytes and real-time PCR was used to determine relative gene expression of the cytokines interleukin (IL)-1beta (ß), IL-6, IL-8, IL-10, and tumor necrosis factor-alpha (TNF-α). Total leukocyte subpopulations and differentials were performed using a cell counter. Data were analyzed using the PROC MIXED procedure of SAS. Gene expression of all cytokines were unaffected by intra-articular treatment. However, IL-1ß increased above baseline beginning at hour 6 and remained elevated to 24 h (P = 0.04). In contrast, IL-6 decreased from hours 6 to 12 and then increased to 24 h (P = 0.02). Levels of TNF-α increased at 6 and 12 h (P = 0.01) postinjection. Only IL-8 exceeded a 2-fold change in expression (P = 0.01), peaking at 12 h and indicating greater responsiveness to arthrocentesis when compared with other cytokines. No treatment effects on the leukocyte population were observed; however, total circulating leukocytes increased over time (P = 0.04), peaking at 6 h postinjection. Similarly, an increase over time was observed in monocytes (P = 0.02) and in platelets (P = 0.01) at 24 h postinjection. The results indicate that regardless of treatment, a mild immune response was elicited, which may be due to repeated arthrocentesis. Future experiments should consider the effects of arthrocentesis and potential systemic inflammatory response, even in control animals, when administering intra-articular LPS to young horses.

The microbiota-derived metabolite indole decreases mucosal inflammation and injury in a murine model of NSAID enteropathy.

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most frequently used classes of medications in the world. Unfortunately, NSAIDs induce an enteropathy associated with high morbidity and mortality. Although the pathophysiology of this condition involves the interaction of the gut epithelium, microbiota, and NSAIDs, the precise mechanisms by which microbiota influence NSAID enteropathy are unclear. One possible mechanism is that the microbiota may attenuate the severity of disease by specific metabolite-mediated regulation of host inflammation and injury. The microbiota-derived tryptophan-metabolite indole is abundant in the healthy mammalian gut and positively influences intestinal health. We thus examined the effects of indole administration on NSAID enteropathy. Mice (n = 5 per group) were treated once daily for 7 days with an NSAID (indomethacin; 5 mg/kg), indole (20 mg/kg), indomethacin plus indole, or vehicle only (control). Outcomes compared among groups included: microscopic pathology; fecal calprotectin concentration; proportion of neutrophils in the spleen and mesenteric lymph nodes; fecal microbiota composition and diversity; small intestinal mucosal transcriptome; and, fecal tryptophan metabolites. Co-administration of indole with indomethacin: significantly reduced mucosal pathology scores, fecal calprotectin concentrations, and neutrophilic infiltration of the spleen and mesenteric lymph nodes induced by indomethacin; modulated NSAID-induced perturbation of the microbiota, fecal metabolites, and inferred metagenome; and, abrogated a pro-inflammatory gene expression profile in the small intestinal mucosa induced by indomethacin. The microbiota-derived metabolite indole attenuated multiple deleterious effects of NSAID enteropathy, including modulating inflammation mediated by innate immune responses and altering indomethacin-induced shift of the microbiota.