Search Results (41)

Vaccine quality control has long relied on animal testing, which involves time, cost, and ethical constraints. This study introduces a ganglioside binding (GB) assay as a complementary in vitro screening tool for tetanus toxoid quality control, which was validated in a single-laboratory environment as a foundational proof-of-concept. The assay reproduces tetanus toxin binding to gangliosides on microplates using simplified procedures. Validation with samples at different inactivation stages showed excellent linearity (0.0002–0.0156 Lf/mL), reproducibility, and a strong correlation with Ramon’s flocculation (R² = 0.999). The assay clearly distinguished between toxins and toxoids, with the toxoid results remaining at control levels. The time-course inactivation samples were consistent with the animal tests: partially inactivated samples (days 1–3) showed significant GB activity (p < 0.001) and caused 100% mortality, whereas samples from day 4 onward showed no activity and zero mortality. These findings demonstrate that the GB assay reliably differentiates active toxins from toxoids, which aligns with in vivo outcomes. The practical advantages include a simplified protocol, reduced complexity, and improved efficiency for routine testing of samples. As a complementary screening approach, this single-laboratory validation supports the 3Rs principle by demonstrating the potential for reducing animal use while ensuring quality assurance. Broader applicability requires multicenter validation and cross-reactivity, and multicenter validation is ongoing. Full article

The Sultanate of Oman boasts remarkable biodiversity, exemplified by such species as the Arabian leopard (Panthera pardus nimr) and the Arabian oryx (Oryx leucoryx), national symbols that highlight the extensive conservation efforts required to protect the country’s natural heritage. During decades, Omani authorities have taken significant measures to safeguard wildlife and preserve the natural environment. A sanctuary dedicated to the reintroduction of the Arabian Oryx, after extinction in nature in 1972, was established in 1980 in the Al Wusta Governorate under the patronage of the Royal Diwan and currently administrated by the recently established Environment Authority. During the almost 40 years since the reintroduction and the creation of the sanctuary, the oryx population has grown slowly but constantly. In 2021, the sanctuary hosted 738 oryx, allowing the start of the reintroduction of the species into the natural environment. Small groups of animals were released into the wild in selected areas. No animal health adverse events were recorded, and mortality was generally due to injuries received as a consequence of fighting, in particular during mating season. Standard veterinary care, including control of internal and external parasites, was regularly provided. In some occasions, immunization against certain diseases, such as clostridial infections, pasteurellosis, or mycoplasmosis, was also applied. In 2023, an FMD outbreak in cattle reported in Dhofar, about 500 km from the Al Wusta sanctuary, motivated specific prophylactic actions to prevent the risk of diffusion to oryx. From December 2023 to January 2024, an immunization program was undertaken using an FMD vaccine against serotypes A, O, and SAT 1, mostly in male oryx, while pregnant oryx were avoided for abortion risk due to handling. The following year, in January 2025, a severe outbreak occurred in oryx herds held in the sanctuary. The rapid onset and the spread of clinical symptoms among animals (100% morbidity in the second day after the first appearance of signs in some individuals) were suggestive of a highly contagious disease. The animals suffered from severe depression and inappetence, rapidly followed by abundant salivation, erosions of the oral mucosa and tongue, and diarrhea, with a short course characterized by prostration and death of the animal in the most severe cases. Therapeutical attempts (administration of antibiotics and rehydration) were mostly ineffective. Laboratory investigations (ELISA and PCR) ruled out contagious bovine pleuropneumonia (CBPP), Johne’s disease and Peste des petits ruminants (PPR). Both serology and antigen detection showed positiveness to foot-and-mouth disease (FMD). Out of a total population of 669 present in the sanctuary at the beginning of the outbreak, 226 (33.78%) oryx died. Despite the vaccinal status, the 38.49% of dead animals resulted being vaccinated against FMD. Taking into account the incalculable value of the species, the outbreak represented a very dangerous event that risked wiping out the decades of conservation efforts. Therefore, all the available means, such as accrued biosecurity and adequate prophylaxis, should be implemented to prevent the recurrence of such health risks. The delicate equilibrium of wild fauna in Oman requires study and support for an effective protection, in line with the national plan “Vision 2040”, targeting the inclusion of the Sultanate within the 20 best virtuous countries for wildlife protection. Full article

Background: It is still challenging to develop effective vaccines against tumorigenic human gammaherpesviruses such as Epstein–Barr virus (EBV). A major obstacle is the lack of a small animal model that reproduces the natural infection course of human gammaherpesviruses to allow for proper assessment of vaccine efficacy. Murine gammaherpesvirus 68 (MHV68) is a natural pathogen of wild rodents and laboratory mice and therefore can be used as a surrogate for human gammaherpesviruses to evaluate vaccination strategies. Methods: In this study, two mRNA vaccine candidates were generated, one encoding a fusion protein of the MHV68 gH with the gL (gHgL-mRNA) and the other expressing the MHV68 gB protein (gB-mRNA). The immunogenicity and protective efficacy of the mRNA vaccine candidates were evaluated in a mouse model of MHV68 infection. Results: The gHgL-mRNA but not the gB-mRNA candidate vaccine was able to induce neutralizing antibodies in mice, whereas both vaccines could elicit antigen-specific T-cell responses. Following MHV68 intranasal inoculation, complete blocking of the establishment of viral latency was observed in some mice immunized with individual gHgL-mRNA or gB-mRNA vaccines. Notably, co-immunization with the two mRNA vaccines appeared to be more effective than individual vaccines, achieving sterile immunity in 50% of the vaccinated mice. Conclusions: This study demonstrates that immunization with mRNA platform-based subunit vaccines is indeed capable of preventing MHV68 latent infection, thus validating a safe and efficacious vaccination strategy that may be applicable to human gammaherpesviruses. Full article

Adequate education in laboratory animal science and subsequently the attendance of relevant courses are mandatory prerequisites for animal experimentation. The course content for different stakeholders is stipulated by European and national regulations. If all of this content is covered, accreditation by competent bodies is possible and recommended. Here, we present our experiences with an EU-Function A/C/D accredited course (practical training with mice and rats) and an introductory seminar for undergraduate students, which have been running for more than ten years. All courses were organized in-house and were very relevant to the students and their needs but were also very labor intensive. The courses were systematically (and retrospectively) evaluated, showing a high degree of satisfaction and a great acquisition of knowledge, and the organizer was able to re-adjust the courses as needed over the years. Tests demonstrated the students’ progress and highlighted some parts of the lessons that were difficult to convey, such as those on legal regulations, housing and feeding, transport, GM animals, breeding, and the classification of severity. Dummies were proven to be very helpful at the beginning of the training but could not fully replace training with live animals. On-site lectures were favored over online sources, which were needed due to the pandemic. High standards in education are mandatory, and the accreditation process allows for the transferal of certificates to other institutions. Full article

Yersinia bacteria (Yersinia enterocolitica, Yersinia pseudotuberculosis) are commonly found in nature in all climatic zones and are isolated from food (mainly raw pork, unpasteurized milk, or contaminated water), soil, and surface water, rarely from contaminated blood. Yersinia infection occurs through sick or asymptomatic carriers and contact with the feces of infected animals. The invasion of specific bacterial serotypes into the host cell is based on the type 3 secretion system (T3SS), which directly introduces many effector proteins (Yersinia outer proteins—Yops) into the host cell. The course of yersiniosis can be acute or chronic, with the predominant symptoms of acute enteritis (rarely pseudo-appendicitis or septicemia develops). Clinical and laboratory diagnosis of yersiniosis is difficult. The infection requires confirmation by isolating Yersinia bacteria from feces or other biological materials, including lymph nodes, synovial fluid, urine, bile, or blood. The detection of antibodies in blood serum or synovial fluid is useful in the diagnostic process. The treatment of yersiniosis is mainly symptomatic. Uncomplicated infections (diarrhea and abdominal pain) usually do not require antibiotic therapy, which is indicated in severe cases. Surgical intervention is undertaken in the situations of intestinal necrosis. Given the diagnostic and therapeutic difficulties, this review discusses the prevalence of Y. enterocolitica and Y. pseudotuberculosis, their mechanisms of disease induction (virulence factors and host response), clinical manifestations, diagnostic and preventive methods, and treatment strategies in the context of current knowledge and available recommendations. Full article

Background Members of the Mycobacterium avium complex (MAC) have been documented to cause severe and disseminated infections in dogs, although such cases are sporadically reported. In this study, a comprehensive account of a rare case of generalised lymphadenomegaly caused by a mixed-strain infection with drug- and multidrug-resistant Mycobacterium avium subspecies hominissuis (Mah) in a Maremma sheepdog is presented. Methods Laboratory investigations, as well as the monitoring of the clinical signs displayed by the animal, were conducted throughout the course of a two-year drug therapy (based on rifampicin, azithromycin, and ciprofloxacin) and a two-year post-treatment follow-up period, until the death of the dog. Laboratory examinations included both solid and broth cultures from fine-needle aspiration samples of lymph nodes, molecular typing by 8-locus MIRUVNTR analysis and SNPs typing of five genetic regions (gyrB, rpsA, 3′hsp65, ITS and rpoB), and drug susceptibility testing towards seven antimycobacterial drugs. Results The results indicated the presence of two distinct genotypes of Mah, which exhibited different phenotypic characteristics, such as different drug susceptibility profiles and growth abilities in broth and solid media, suggesting a mixed-strain infection. Resistances to ethambutol alone, to ethambutol and clarithromycin, and to ethambutol, clarithromycin, rifampicin, and doxycycline were detected over the study. Conclusions Although the Mah strains isolated during the course of therapy showed sensitivity to the regiment, the complete eradication of the infection was never achieved. It has been hypothesised that the presence of drug-resistant and multidrug-resistant Mah strains in the animal may have been established at the onset of the infection or soon thereafter. The exposure to therapy has been suggested as a potential factor that could have favoured the growth of resistant strains, thereby rendering the therapy ineffective. The implications that the distinct phenotypic and genotypic profiles of Mah described here may have had for disease dynamics and control are discussed. Full article

The rapid evolution of biotechnology across various sectors, including agriculture, industry, and medicine, has profoundly transformed our comprehension of the world. Virtual laboratories (VLs) provide an immersive learning experience that can enhance future generations’ understanding of biotechnology’s medical applications. This study investigated the impact of incorporating VLs into a short course on biotechnology applied to medicine on the attitudes and perceptions of third-year medical students (n = 210). A validated questionnaire was employed to assess their perspectives, attitudes, and experience with virtual laboratory platforms before and after the course. The findings revealed a significant positive change in 7/38 questionnaire items (p < 0.05), indicating that the VL experience modified perceptions about biotechnology. This study emphasizes the importance of exploring innovative teaching methods for biotechnology and highlights the advantages of VL in educating future physicians. The primary concerns of the students were the misuse of personal genetic information and biotechnological applications involving animal modification. Overall, the students had a favorable experience using the virtual laboratory platforms. These findings collectively suggest that VL can positively influence perceptions and attitudes toward biotechnology among healthcare professionals. Full article

Bite wounds due to aggression in male laboratory mice (Mus musculus) are a major welfare concern, often leading to attrition, chronic activation of the innate immune system, and significant impacts on the experimental results derived from the use of these animals as models. Bite wounding within the home-cage of spiny mice (Acomys cahirinus)—a valuable research model for wound healing and menstruation—is poorly characterized. While we have anecdotally observed frequent bite wounding in Acomys, the frequency of aggression within the home-cage, the severity of the bite wounds, and the types of dominance structures remain unstudied. Here, we report that 46% of Acomys cages in our colony had at least one bite wound over the course of a year and that same-sex pairs fought in the home-cage 10% of the time during their dark/active phase. Both sexes inflicted wounds and frequently engaged in agonistic behaviors, even with stable dominance structures. We found that females inflicted less severe bite wounds in same-sex housing. Also, aged females in same-sex pairs were never observed fighting, and no bite wounds were observed in aged Acomys. These results suggest that we should consider whether bite wounding negatively impacts our experimental results since physical trauma is known to alter menstrual cycling and healing. Full article

Abnormal retrobulbar hemodynamics have been linked to the development of various ocular diseases, including glaucoma, age-related macular degeneration, and diabetic retinopathy. Additionally, altered retrobulbar blood flow has been observed in patients with severe cardiovascular diseases, including carotid artery occlusion, stroke, heart failure, and acute coronary syndrome. Due to the complex and intricate anatomy of retrobulbar blood vessels and their location behind the eyeball, measurement of retrobulbar blood flow and vascular reactivity, as well as the interpretation of the findings, are challenging. Various methods, such as color Doppler imaging, computed tomography angiography or magnetic resonance imaging, have been employed to assess retrobulbar blood flow velocities in vivo. Color Doppler imaging represents a fast and non-invasive method to measure retrobulbar blood flow velocities in vivo. While no information about vessel diameter can be gained performing this method, computed tomography angiography and magnetic resonance imaging provide information about vessel diameter and detailed information on the anatomical course. Additionally, ex vivo studies, such as myography, utilizing genetically modified animal models may provide high optical resolution for functional vascular investigations in these small vessels. To our best knowledge, this is the first review, presenting a detailed overview of methods aiming to evaluate retrobulbar blood flow and vascular reactivity in both humans and laboratory animals. Furthermore, we will summarize the disturbances observed in retrobulbar blood flow in retinal, optic nerve, and cardiovascular diseases. Full article

Diabetes mellitus (DM) is a very serious disease, the incidence of which has been increasing worldwide. The beginning of diabetic research can be traced back to the 17th century. Since then, animals have been experimented on for diabetic research. However, the greatest development of diabetes research occurred in the second half of the last century, along with the development of laboratory techniques. Information obtained by monitoring patients and animal models led to the finding that there are several types of DM that differ significantly from each other in the causes of the onset and course of the disease. Through different types of animal models, researchers have studied the pathophysiology of all types of diabetic conditions and discovered suitable methods for therapy. Interestingly, despite the unquestionable success in understanding DM through animal models, we did not fully succeed in transferring the data obtained from animal models to human clinical research. On the contrary, we have observed that the chances of drug failure in human clinical trials are very high. In this review, we will summarize the history and presence of animal models in the research of DM over the last hundred years. Furthermore, we have summarized the new methodological approaches, such as “organ-on-chip,” that have the potential to screen the newly discovered drugs for human clinical trials and advance the level of knowledge about diabetes, as well as its therapy, towards a personalized approach. Full article

Virtual 3D models can be an animal-free alternative to cadaveric dissection to learn spatial anatomy. The aim of this study was to investigate if the learning outcome differs when studying 3D models with a 360° rotatable interactive monoscopic 3-dimensional (iM3D) or an interactive monoscopic 2-dimensional (iM2D) visualization, and whether the level of visual-spatial ability (VSA) influences learning outcome. A two-center randomized crossover trial was conducted during the Laboratory Animals Science Course (March 2021–March 2022). Participants studied a 3D rat model using iM3D and iM2D. VSA was assessed by a 24-item mental rotation test and learning outcome by two knowledge tests. Data from 69 out of 111 recruited participants were analyzed using linear regression. Participants with low VSA performed significantly worse compared to participants with medium or high VSA when using iM3D, but equally well when using iM2D. When VSA level was disregarded, participants performed equally well with both visualizations. Rotation in iM3D requires the student to construct a mental 3D image from multiple views. This presumably increases cognitive load, especially for students with low VSA who might become cognitively overloaded. Future research could focus on adapting the visualization technique to students’ personal needs and abilities. Full article

Animal welfare is a subject of increasing scientific and ethical concern in today’s society, crucial for the well-being of animals used in research and the integrity of scientific data. Equipping researchers in the life science disciplines with a science-based knowledge of animal welfare, behaviour, physiology, and health is, therefore, essential. Nevertheless, previous studies evaluating animal welfare education focused on veterinary, laboratory, or farm animal science. Consequently, the aim of this study was, for the very first time, to map the prevalence of animal welfare courses in the university education of ecologists, wildlife biologists, and conservation managers in Europe, Canada, the USA, Australia, and New Zealand. A comprehensive assessment of 1548 universities was conducted, resulting in the identification of 596 relevant programs at the bachelor’s and master’s levels. Analysis of the curricula revealed that only 1% of the programs offered a formal course on animal welfare, while 65% provided courses on animal behaviour, 59% on animal physiology, and 34% on animal health. However, the majority of these courses were listed as electives rather than mandatory components of the programs. These results underscore the need for universities to incorporate more formal and obligatory education in animal welfare in order to better prepare future ecologists, wildlife biologists, and conservation managers for the challenges of working with wildlife. Full article

Streptococcus equi subsp. zooepidemicus is a rare etiologic agent of bacterial meningitis in humans. The disease is a zoonotic infection and is transmitted through close contact with domestic animals, mainly horses. Only 37 cases of Streptococcus zooepidemicus meningitis have been reported in the literature until July 2023. The aim of this study is to present a rare clinical case of S. zooepidemicus-related meningitis in a human immunodeficiency virus (HIV)-positive patient and analyze the literature. We present a 23-year-old horse breeder patient with advanced immunosuppression due to acquired immunodeficiency syndrome (AIDS) and S. zooepidemicus meningitis, admitted at the Clinic of Infectious Diseases, St. George University Hospital, Plovdiv. The course of meningitis was severe since the beginning, with significant cerebral edema, disturbances in consciousness, persistent fever, and the development of complications against the background of AIDS-related conditions. S. zooepidemicus was microbiologically detected from cerebrospinal fluid culture. After prolonged treatment and a long hospital stay, the patient’s condition improved, and eventually he was discharged and recovered from the acute neuroinfection. Although extremely rare, S. zooepidemicus should be considered in patients with clinical and laboratory evidence of bacterial meningitis who have contact with animals, especially horses, other domestic animals, and their dairy products, as well as in immunocompromised patients. To the best of our knowledge, the current clinical case is the first report of S. zooepidemicus-related meningitis in a patient with HIV/AIDS. Full article

An attempt to improve the functional characteristics of a degradable Fe-Mn-5Si shape memory alloy by means of structure refinement by equal-channel angular pressing (ECAP) was made. In the course of ECAP, an austenitic ultrafine-grained structure was obtained. In shear bands with a thickness of 301 ± 31 nm, twins 11 ± 1 nm in size were formed. Due to the resulting structure, the tensile strength was doubled up to 1419 MPa, and the yield strength was increased up to 1352 MPa, four times higher compared with the annealed state. Dynamic indentation tests revealed a decrease in Young’s modulus by more than 2.5 times after ECAP compared to values measured in the annealed state. The results of the study of hemolytic and cytotoxic activity in vitro, as well as the local and systemic reactivity of the body of laboratory animals after implantation of the test samples indicate the biocompatibility of the alloy after ECAP. Biocompatibility, high specific strength and low modulus of elasticity open prospects for Fe-Mn-5Si alloy after ECAP to be used for the production of degradable implants that can effectively provide the fastening function in osteoreconstruction. Full article

The increasing threat of arboviruses such as West Nile virus (WNV) and Usutu virus (USUV) requires the fast and efficient surveillance of these viruses. The examination of mosquitoes takes up an important part; however, these investigations are usually very time-consuming. An alternative sample type for arbovirus surveillance might be mosquito excreta. In order to determine the excretion dynamics under laboratory conditions, laboratory colonies of Aedes vexans and Culex pipiens biotype molestus were infected with WNV, USUV or tick-borne encephalitis virus (TBEV). After infection, the excreta were sampled and investigated for viral RNA. Excretion of viral RNA together with infectious blood meal could be detected up to five days after infection. Further excretion seemed to correlate with a disseminated infection in mosquitoes, at least after USUV infection. In addition, it could be determined that the amount of viral RNA in the excretions correlated positively with the viral load in the mosquito bodies. Overall, this study shows that the usage of mosquito excreta as a sample type for surveillance enables the detection of endemic viruses (WNV, USUV) as well as non-mosquito-borne viruses (TBEV). In addition, examination of viral shedding during vector competence studies can provide insights into the course of infection without sacrificing animals. Full article