Toxoplasma gondii from Gabonese forest, Central Africa: First report of an African wild strain.

The protozoan Toxoplasma gondii is a ubiquitous and highly prevalent parasite that can theoretically infect all warm-blooded vertebrates. In humans, toxoplasmosis causes infections in both immunodeficient and immunocompetent patients, congenital toxoplasmosis, and ocular lesions. These manifestations have different degrees of severity.

Rejuvenating aged osteoprogenitors for bone repair.

Aging is marked by a decline in tissue regeneration, posing significant challenges to an increasingly older population. Here, we investigate age-related impairments in calvarial bone healing and introduce a novel two-part rejuvenation strategy to restore youthful repair. We demonstrate that aging negatively impacts the calvarial bone structure and its osteogenic tissues, diminishing osteoprogenitor number and function and severely impairing bone formation.

A Large-Scale Serological Survey in Pets From October 2020 Through June 2021 in France Shows Significantly Higher Exposure to SARS-CoV-2 in Cats Compared to Dogs.

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has the potential to infect various animals, including domestic pets like dogs and cats. Many studies have documented infection in companion animals by molecular and serological methods. However, only a few have compared seroprevalence in cats and dogs from the general population, and these studies were limited by small sample sizes and collections over short periods.

Serological evidence of natural exposure to rabies in rural populations in Gabon.

Rabies is one of the oldest known zoonotic diseases, with dogs being the main reservoir for 99% of the cases of human rabies. However, wild animals may also be rabies vectors. In most cases, contact with a rabid animal results in rabies without pre- or post-exposure prophylaxis, and the disease is nearly always fatal.

First Detection of Antibodies Specific to Crimean-Congo Hemorrhagic Fever Virus in Rural Populations of Gabon.

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease with a mortality rate reaching up to 40% in humans. Currently, CCHF affects three continents: Asia, Europe, and Africa. An increase in confirmed cases in Africa has been observed since 2000.

Enzyme-controlled, nutritive hydrogel for mesenchymal stromal cell survival and paracrine functions.

Culture-adapted human mesenchymal stromal cells (hMSCs) are appealing candidates for regenerative medicine applications. However, these cells implanted in lesions as single cells or tissue constructs encounter an ischemic microenvironment responsible for their massive death post-transplantation, a major roadblock to successful clinical therapies. We hereby propose a paradigm shift for enhancing hMSC survival by designing, developing, and testing an enzyme-controlled, nutritive hydrogel with an inbuilt glucose delivery system for the first time.

Whole-Genome Characterization of SARS-CoV-2 Reveals Simultaneous Circulation of Three Variants and a Putative Recombination (20B/20H) in Pets, Brazzaville, Republic of the Congo.

Following the emergence of SARS-CoV-2, cases of pets infected with variants circulating among humans were reported. In order to evaluate the occurrence of SARS-CoV-2 circulation among pets in the Republic of the Congo, we conducted a ten-month study of dogs and cats living in COVID-19-positive households in Brazzaville and neighboring localities. Real-time PCR and the Luminex platform were used to detect SARS-CoV-2 RNA and antibodies to SARS-CoV-2 RBD and S proteins, respectively.

Dolutegravir-containing HIV therapy reversibly alters mitochondrial health and morphology in cultured human fibroblasts and peripheral blood mononuclear cells.

Objectives: Given the success of combination antiretroviral therapy (cART) in treating HIV viremia, drug toxicity remains an area of interest in HIV research. Despite newer integrase strand transfer inhibitors (InSTIs), such as dolutegravir (DTG) and raltegravir (RAL), having excellent clinical tolerance, there is emerging evidence of off-target effects and toxicities. Although limited in number, recent reports have highlighted the vulnerability of mitochondria to these toxicities.

First Evidence of Natural SARS-CoV-2 Infection in Domestic Rabbits.

We tested 144 pet rabbits sampled in France between November 2020 and June 2021 for antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by microsphere immunoassay. We reported the first evidence of a natural SARS-CoV-2 infection in rabbits with a low observed seroprevalence between 0.7% and 1.

Serum neurofilament light chain correlates with myelin and axonal magnetic resonance imaging markers in multiple sclerosis.

Background: Neurofilaments are cytoskeletal proteins that are detectable in the blood after neuroaxonal injury. Multiple sclerosis (MS) disease progression, greater lesion volume, and brain atrophy are associated with higher levels of serum neurofilament light chain (NfL), but few studies have examined the relationship between NfL and advanced magnetic resonance imaging (MRI) measures related to myelin and axons. We assessed the relationship between serum NfL and brain MRI measures in a diverse group of MS participants.

Diffusely abnormal white matter in clinically isolated syndrome is associated with parenchymal loss and elevated neurofilament levels.

We characterized the frequency of diffusely abnormal white matter (DAWM) across a broad spectrum of multiple sclerosis (MS) participants. 35% of clinically isolated syndrome (CIS), 57% of relapsing remitting and 64% of secondary progressive MS participants demonstrated DAWM. CIS with DAWM had decreased cortical thickness, higher lesion load and a higher concentration of serum neurofilament light chain compared to CIS without DAWM.

Infection with SARS-CoV-2 variant B.1.1.7 detected in a group of dogs and cats with suspected myocarditis.

Background: Domestic pets can contract severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection; however, it is unknown whether the UK B.1.1.

Elevated levels of serum CD5 antigen-like protein distinguish secondary progressive multiple sclerosis from other disease subtypes.

CD5 antigen-like (CD5L) protein is a macrophage-secreted protein with roles in immunomodulation and lipid homeostasis. We compared serum CD5L levels in healthy controls to individuals diagnosed with clinically isolated syndrome, relapsing remitting (RR), secondary progressive (SP), and primary progressive (PP) multiple sclerosis (MS). CD5L was increased in SPMS relative to controls, RRMS, and PPMS.

Herpes Infections in Suspected Cases of Yellow Fever in the Democratic Republic of the Congo.

In the battle to quickly identify potential yellow fever arbovirus outbreaks in the Democratic Republic of the Congo, active syndromic surveillance of acute febrile jaundice patients across the country is a powerful tool. However, patients who test negative for yellow fever virus infection are too often left without a diagnosis. By retroactively screening samples for other potential viral infections, we can both try to find sources of patient disease and gain information on how commonly they may occur and co-occur.

Detection of Ebola Virus Antibodies in Fecal Samples of Great Apes in Gabon.

Based on a large study conducted on wild great ape fecal samples collected in regions of Gabon where previous human outbreaks of Ebola virus disease have occurred between 1994 and 2002, we provide evidence for prevalence of (EBOV)-specific antibodies of 3.9% (immunoglobulin G (IgG)) and 3.5% (immunoglobulin M (IgM)) in chimpanzees and 8.

High prevalence of SARS-CoV-2 antibodies in pets from COVID-19+ households.

In a survey of household cats and dogs of laboratory-confirmed COVID-19 patients, we found a high seroprevalence of SARS-CoV-2 antibodies, ranging from 21% to 53%, depending on the positivity criteria chosen. Seropositivity was significantly greater among pets from COVID-19+ households compared to those with owners of unknown status. Our results highlight the potential role of pets in the spread of the epidemic.

Enhanced expression of complement and microglial-specific genes prior to clinical progression in the MOG-experimental autoimmune encephalomyelitis model of multiple sclerosis.

Understanding the biological changes responsible for failures in repair and the development of progressive MS is paramount for therapeutic intervention. In a well characterized experimental autoimmune encephalomyelitis (EAE) model of MS the clinical phenotype features an acute attack with partial recovery followed by a chronic or progressive disease phase. Neuropathology-focused gene expression profiles were generated from spinal cord, hindbrain and forebrain of mice 25 days after the induction of EAE, the time when recovery plateaus and transitions to a chronic or worsening phase.

Oligodendrocyte ARNT2 expression is altered in models of MS.

Objective: We examined expression of aryl hydrocarbon receptor nuclear translocator 2 (ARNT2), a basic-loop-helix transcription factor implicated in neuronal development and axonal health, in oligodendrocyte (OL) cultures and over the course of chronic experimental autoimmune encephalomyelitis (EAE), the murine model of multiple sclerosis (MS).

Methods: We assessed OL ARNT2 expression in EAE compared with sham-immunized controls and also in OL primary cultures and over the course of dibutyryl cyclic adenosine monophosphate (dbcAMP)-mediated maturation of the immortalized Oli-neu cell line. We also tested the functional role of ARNT2 in influencing OL characteristics using small interfering RNA (siRNA).

Exposure to Ebola Virus and Risk for Infection with Malaria Parasites, Rural Gabon.

An association between malaria and risk for death among patients with Ebola virus disease has suggested within-host interactions between Plasmodium falciparum parasites and Ebola virus. To determine whether such an interaction might also influence the probability of acquiring either infection, we used a large snapshot surveillance study from rural Gabon to test if past exposure to Ebola virus is associated with current infection with Plasmodium spp. during nonepidemic conditions.

Next-Generation Sequencing on Insectivorous Bat Guano: An Accurate Tool to Identify Arthropod Viruses of Potential Agricultural Concern.

Viruses belonging to the family have attracted a great deal of attention from scientists owing to their negative impact on agricultural economics, as well as their recent identification as potential aetiological agents of febrile illness in human patients. On the other hand, some Dicistroviruses are also studied for their potential biopesticide properties. To date, Dicistrovirus characterized in African mainland remain scarce.

Mucosal Administration of E-selectin Limits Disability in Models of Multiple Sclerosis.

E-selectin plays an important role in mediating the rolling of leukocytes along and thus, the subsequent extravasation across activated endothelial cells comprising the microvasculature of the blood brain barrier (BBB). In multiple sclerosis (MS) and other inflammatory disorders of the central nervous system (CNS), the microvasculature is altered and immune cells infiltrate the brain and spinal cord contributing to damage, demyelination and ultimately disability. While mucosal administration is typically used to affect lymphocyte hyporesponsiveness or tolerance to suspect autoantigens, intranasal administration to E-selectin has previously been shown to protect against CNS inflammatory insults.

Re-emergence of chikungunya in the Republic of the Congo in 2019 associated with a possible vector-host switch.

In January 2019, an outbreak of chikungunya virus fever was reported in a rural region near Pointe-Noire, Republic of the Congo. Molecular and phylogenetic analysis of this new CHIKV strain demonstrated the presence of the A226V substitution and a surprisingly close relation with Aedes aegypti-associated Central Africa chikungunya strains. These results, combined with the preponderance of Aedes albopictus in the outbreak area, suggest a recent vector-host switch facilitated by the emergence and spread of the A226V mutation from a related CHIKV strain previously circulating in Aedes aegypti.

Expression of the neuroprotective protein aryl hydrocarbon receptor nuclear translocator 2 correlates with neuronal stress and disability in models of multiple sclerosis.

Background: Axonal degeneration and neuronal loss have been described as the major causes of irreversible clinical disability in multiple sclerosis (MS). The aryl-hydrocarbon receptor nuclear translocator 2 (ARNT2) protein has been associated with neuroprotection in models of ischemia and neuronal responses to stressors.

Methods: To characterize its potential to influence inflammatory neurodegeneration, we examined ARNT2 expression in the experimental autoimmune encephalomyelitis (EAE) model of MS and characterized mediators that influence ARNT2 expression as well as plausible partners and targets.