Infected Rabbits Research Articles

Treponema pallidum subsp. pallidum strains DAL-1 and Philadelphia 1 differ in generation times in vitro as well as during experimental rabbit infection.

In this work, we determined that Treponema pallidum subsp. pallidum (TPA) DAL-1 (belonging to Nichols-like group of TPA strains) grew 1.53 (± 0.08) times faster compared to TPA Philadelphia 1 (SS14-like group) during in vitro cultivations. In longitudinal individual propagation in rabbit testes (n = 12, each TPA strain), infection with DAL-1 manifested clinical symptoms (induration, swelling, and erythema of testes) sooner than Philadelphia 1 infection, which resulted in a significantly shorter period of the experimental passages for DAL-1 (median = 15.0 and 23.5 days, respectively; p < 0.01). To minimize the confounding conditions during rabbit experiments, the growth characteristics of DAL-1 and Philadelphia 1 strains were determined during TPA co-infection of rabbit testes (n = 20, including controls). During two weeks of intratesticular co-infection, DAL-1 overgrew Philadelphia 1 in all twelve testes, regardless of inoculation ratio and dose (median of relative excess DAL-1 multiplication = 84.85×). Moreover, higher DAL-1 to Philadelphia 1 inoculum ratios appeared to increase differences in growth rates, suggesting direct competition between strains for available nutrients during co-infection. These experiments indicate important physiological differences between the two TPA strains and suggest growth differences between Nichols-like and SS14-like strains that are potentially linked to their virulence and pathogenicity.

Infections of reproductive organs in female rabbits

Symptomatic infertility is a temporary or permanent disturbance in reproductive function wherein the animal cannot become pregnant due to diseases of genital organs or systemic diseases. Since female rabbits, due to their precociousness and fertility, are often used for reproduction, the leading causes of symptomatic infertility in them are the absence of estrous cycles or their deficiency and inflammation of tissues of the reproductive system. Infertility is observed in female rabbits developing such infectious diseases as pasteurellosis, spirochetosis, and myxomatosis. It is due to these diseases that obstetric and gynecological pathology (vulvitis, vulvovaginitis, metritis, pyometra, mastitis), long-term infertility, and death of animals are recorded most often. External genitalia (vulva) and mammary glands are the main routes of infection in female rabbits. The most common microorganisms causing inflammatory processes in reproductive organs are non-specific, such as Staphylococcus and Pasteurella, and specific microbes, such as toxoplasma. Spirochetes, Listeria, and Salmonella are much less common. It has been found that on farms of different forms of ownership in the Dnipropetrovsk region, the most common infectious diseases in rabbits are myxomatosis (20 %), viral hemorrhagic disease (13 %), eimeriosis (30 %), pasarulosis (10 %), and spirochetosis (10 %). Inflammation of genital tissues, especially inflammatory processes in the uterus, is the most common disease in female rabbits. The general frequency of uterine diseases increases with age, reaching more than 50% in aged female rabbits. Endometritis was the most frequent inflammatory process diagnosed in 10 % of cases and was potentially purulent, catarrhal, lymphoplasmacytic, or enterohemorrhagic. Metritis was observed in 5 % of cases and pyometra in 3 %. Autopsy of forcibly slaughtered or dead animals revealed such uterine diseases as hydrometer and mucometer. Hydrometers and mucometers comprised 8 % of uterine diseases, and the average age of sick female rabbits was 3 years. The etiology remains unclear but is potentially related to endometrial hyperplasia or endometritis. However, in some cases, no underlying uterine disease was found. During acute infection of the organs of the reproductive system of female rabbits, a serous mucocatarrhal or mucopurulent exudate is released from the genital slit. Chronic inflammatory processes of the genital organs often occur without signs of disease or are manifested by decreased fertility or abortion.

Gamma Irradiated Pasteurella multocida Vaccine induces strong humoral immunity and protects rabbits from disease

Pasteurella multocida is affecting a multitude of animals and severely affects livestock production. Existing vaccines are mostly chemically inactivated and do not lead to wide protection. Irradiated vaccines are enjoying a renaissance and the concept of “replication defficient but metabolically active” vaccines was recently evaluated in several vaccine trials. P. multocida was isolated from the nasal swab, blood, and lung swab samples from infected rabbits. Gamma irradiation of P. multocida for inhibition of replication was evaluated at an optimized irradiation dose of 10 Kgy established. Four groups of rabbits were (mock) vaccinated with a commercial P. multocida vaccine and three irradiated formulations as liquid, lyophilized formulations with added Trehalose and lyophilized-Trehalose with an “activation” culturing the irradiated bacteria for 24 in broth. Evaluation of humoral immune response by ELISA showed that all three irradiated vaccines produced an effective, protective, and continued IgG serum level after vaccination and bacterial challenge. The IFN-γ expression is maintained at a normal level, within each individual group however, the lyophilized trehalose irradiated vaccine showed peak mean of IFN-γ titer at one week after booster dose (day 21) which was statistically significant. Cumulatively, the results of this study show that gamma-irradiated P. multocida vaccines are safe and protect rabbits against disease. Moreover, Rabbits’ immunization with the three irradiated formulations avoided adverse side effects as compared to commercial polyvalent vaccine, the body weight gain for the irradiated vaccine groups indicates less stress compared to the commercial polyvalent vaccine.

Study of Toxicity Resistance of Fusarium incarantum Isolated from Broad Bean by Arum maculate Leaf Extract in Adult Male Rabbits

Fungus isolates were obtained from the roots and leaves of the infected broad bean from Hawija district of Kirkuk city and isolated on the medium of PDA by examining its morphological and phenotypic characteristics of the fungus and the shape of conidia. In this study, 16 male rabbits were brought from the local markets of the city of Kirkuk and divided into 4 groups, each group consisting of 4 rabbits, the first group includes a control group, the second group is an infected group, the third group is an infected group that was treated with 50 mg of plant leaf extract, and an infected group was treated with 100 mg of leaf extract, after which Oxidative stress factors levels were checked. Oxidative stress factors showed high levels of MDA in infected rabbits compared to normal rabbits (P &lt; 0.05), while GSH and catalase levels appeared lower compared to MDA in infected rabbits (P &lt; 0.05), while in the group of rabbits treated with leaf extract 50 mg and 100 mg) showed few changes in concentrations MDA, GSH and Catalase compared to normal rabbits (P &lt; 0.05).

Neglected Spleen Transcriptional Profile Reveals Inflammatory Disorder Conferred by Rabbit Hemorrhagic Disease Virus 2 Infection.

Rabbit hemorrhagic disease (RHD) is an acute fatal disease caused by the rabbit hemorrhagic disease virus (RHDV). Since the first outbreaks of type 2 RHDV (RHDV2) in April 2020 in China, the persistence of this virus in the rabbit population has caused substantial economic losses in rabbit husbandry. Previous failures in preventing RHDV2 prompted us to further investigate the immune mechanisms underlying the virus's pathogenicity, particularly concerning the spleen, a vital component of the mononuclear phagocyte system (MPS). For this, a previous RHDV2 isolate, CHN/SC2020, was utilized to challenge naive adult rabbits. Then, the splenic transcriptome was determined by RNA-Seq. This study showed that the infected adult rabbits had 3148 differentially expressed genes (DEGs), which were associated with disease, signal transduction, cellular processes, and cytokine signaling categories. Of these, 100 upregulated DEGs were involved in inflammatory factors such as IL1α, IL-6, and IL-8. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that these DEGs were significantly enriched in the cytokine-cytokine receptor interaction signaling pathway, which may play a vital role in CHN/SC2020 infection. At the same time, proinflammatory cytokines and chemokines were significantly increased in the spleen at the late stages of infection. These findings suggested that RHDV2 (CHN/SC2020) might induce dysregulation of the cytokine network and compromise splenic immunity against viral infection, which expanded our understanding of RHDV2 pathogenicity.

MicroRNAs participate in the regulation of apoptosis and oxidative stress-related gene expression in rabbits infected with Lagovirus europaeus GI.1 and GI.2 genotypes.

MicroRNAs (miRs) are a group of small, 17-25 nucleotide, non-coding RNA that regulate gene expression at the post-transcriptional level. To date, little is known about the molecular signatures of regulatory interactions between miRs and apoptosis and oxidative stress in viral diseases. Lagovirus europaeus is a virus that causes severe disease in rabbits (Oryctolagus cuniculus) called Rabbit Hemorrhagic Disease (RHD) and belongs to the Caliciviridae family, Lagovirus genus. Within Lagovirus europaeus associated with RHD, two genotypes (GI.1 and GI.2) have been distinguished, and the GI.1 genotype includes four variants (GI.1a, GI.1b, GI.1c, and GI.1d). The study aimed to assess the expression of miRs and their target genes involved in apoptosis and oxidative stress, as well as their potential impact on the pathways during Lagovirus europaeus-two genotypes (GI.1 and GI.2) infection of different virulences in four tissues (liver, lung, kidneys, and spleen). The expression of miRs and target genes related to apoptosis and oxidative stress was determined using quantitative real-time PCR (qPCR). In this study, we evaluated the expression of miR-21 (PTEN, PDCD4), miR-16b (Bcl-2, CXCL10), miR-34a (p53, SIRT1), and miRs-related to oxidative stress-miR-122 (Bach1) and miR-132 (Nfr-2). We also examined the biomarkers of both processes (Bax, Bax/Bcl-2 ratio, Caspase-3, PARP) and HO-I as biomarkers of oxidative stress. Our report is the first to present the regulatory effects of miRs on apoptosis and oxidative stress genes in rabbit infection with Lagovirus europaeus-two genotypes (GI.1 and GI.2) in four tissues (liver, lungs, kidneys, and spleen). The regulatory effect of miRs indicates that, on the one hand, miRs can intensify apoptosis (miR-16b, miR-34a) in the examined organs in response to a viral stimulus and, on the other hand, inhibit (miR-21), which in both cases may be a determinant of the pathogenesis of RHD and tissue damage. Biomarkers of the Bax and Bax/Bcl-2 ratio promote more intense apoptosis after infection with the Lagovirus europaeus GI.2 genotype. Our findings demonstrate that miR-122 and miR-132 regulate oxidative stress in the pathogenesis of RHD, which is associated with tissue damage. The HO-1 biomarker in the course of rabbit hemorrhagic disease indicates oxidative tissue damage. Our findings show that miR-21, miR-16b, and miR-34a regulate three apoptosis pathways. Meanwhile, miR-122 and miR-132 are involved in two oxidative stress pathways.

Inflammation-suppressing cornea-in-a-syringe with anti-viral GF19 peptide promotes regeneration in HSV-1 infected rabbit corneas

Pathophysiologic inflammation, e.g., from HSV-1 viral infection, can cause tissue destruction resulting in ulceration, perforation, and ultimately blindness. We developed an injectable Cornea-in-a-Syringe (CIS) sealant-filler to treat damaged corneas. CIS comprises linear carboxylated polymers of inflammation-suppressing 2-methacryloyloxyethyl phosphorylcholine, regeneration-promoting collagen-like peptide, and adhesive collagen-citrate glue. We also incorporated GF19, a modified anti-viral host defense peptide that blocked HSV-1 activity in vitro when released from silica nanoparticles (SiNP-GF19). CIS alone suppressed inflammation when tested in a surgically perforated and HSV-1-infected rabbit corneal model, allowing tissue and nerve regeneration. However, at six months post-operation, only regenerated neocorneas previously treated with CIS with SiNP-GF19 had structural and functional features approaching those of normal healthy corneas and were HSV-1 virus-free. We showed that composite injectable biomaterials can be designed to allow regeneration by modulating inflammation and blocking viral activity in an infected tissue. Future iterations could be optimized for clinical application.

The anti-parasitic activity of Thymus vulgaris (Thyme): A literature review

Thyme (Thymus vulgaris) is an enduring herb belonging to the mint family, Lamiaceae. It originates from the Mediterranean region and is characterized by its small, aromatic leaves, and sturdy stem. Appreciated for its robust and delightful scent, thyme is widely embraced as a culinary herb. However, its significance extends far beyond the kitchen, as it has been utilized medicinally for centuries. This is owing to the occurrence of active compounds like thymol and carvacrol, which possess noteworthy antibacterial, antioxidant, and anti-inflammatory attributes. Throughout history, thyme has been employed in the treatment of respiratory disorders, digestive ailments, and other diseases. The main objective of this study was to conduct an extensive review of the thyme plant, encompassing its classification, historical background, geographical distribution, chemical composition, and both economic and medicinal applications, particularly emphasizing its antiparasitic properties. In conclusion, apart from its well-known culinary and medicinal uses, scientific research has indicated that thyme exhibits promising effectiveness against diverse parasites. Notably, research has shown that thyme exhibited antiprotozoal activity against protozoan parasites such as Giardia lamblia, Trichomonas vaginalis, Toxoplasma gondii, Entamoeba histolytica, and others. Specific thyme extract components have shown great activity against these parasites. Thyme also has larvicidal properties, meaning that it can kill larvae. This includes Anisakis larvae, which can cause anisakiasis in humans. Thyme essential oil has been shown to effectively eliminate these larvae, suggesting that it could be used to prevent anisakiasis. Furthermore, it has also been studied for its potential to treat hepatic coccidiosis in rabbits. Research has shown that thyme oil, along with Moringa oleifera oil, can effectively reduce the number of oocysts shed by infected rabbits and improve the clinical signs of the infection. This suggests that thyme oil may be a promising therapeutic agent for tackling hepatic coccidiosis.

Apoptosis activation during Lagovirus europaeus/GI.2 infection in rabbits

Rabbit Haemorrhagic Disease (RHD) is a severe disease caused by Lagovirus europaeus/GI.1 and GI.2. Immunological processes such as apoptosis are important factors involved in the pathogenesis of Rabbit Haemorrhagic Disease (RHD). The process of programmed cell death has been quite well characterized in infection with GI.1 strains, but apoptosis in infection with GI.2 strains has not been widely studied. This is particularly important as several studies have shown that significant differences in the host immune response are observed during infection with different strains of Lagovirus europaeus. In this study, we analyzed the gene expression, protein levels and activity of key apoptotic cell death factors in the spleen, kidney, lung, and heart of rabbits. As a result, we showed that there is a significant increase in caspase-3, Bax, Bcl2 and Bax/Bcl2 mRNA gene expression ratio in organs of infected animals. Our results show also increased levels of cleaved caspase-3, caspase-6 and PARP. Moreover, significant activity of caspase-3 was also detected. Our results indicate that caspase-3, caspase-6 and genes coding Bcl2 family proteins play a key role in the apoptotic response in Lagovirus europaeus/GI.2 infection in organs that are not the target of virus replication.

Apoptotic Cell Death in an Animal Model of Virus-Induced Acute Liver Failure-Observations during Lagovirus europaeus/GI.2 Infection.

Lagovirus europaeus/GI.2 causes severe and highly fatal Rabbit Hemorrhagic Disease (RHD). Because of its characteristics, this infection is used as an animal model for acute liver failure (ALF). Apoptosis is one of the key processes underlying ALF and has been described as one of the mechanisms of RHD pathogenesis. Apoptotic cell death has been quite well characterized in infection with different variants of GI.1 strains, but so far, the GI.2 genotype has not been widely studied. In this study, we performed an evaluation of apoptotic cell death in hepatocytes of rabbits infected with Lagovirus europaeus/GI.2. We analyzed the expression of genes involved in apoptotic cell death by real-time PCR and performed immunohistochemical (IHC) assays. We showed a significant increase in the expression of caspase-3 and the proapoptotic Bax and anti-apoptotic Bcl-2 in infected animals. In addition, we recorded increased Bax/Bcl-2 ratios. IHC analyses showed the presence of morphological signs of apoptosis in the hepatocytes of infected rabbits. Our results indicate that caspase-3 and proteins from the Bcl-2 families play a key role in apoptosis induced by Lagovirus europaeus/GI.2 infection.

Treponema pallidum genetic diversity and its implications for targeted vaccine development: A cross-sectional study of early syphilis cases in Southwestern Colombia.

Venereal syphilis, caused by the spirochete Treponema pallidum subsp. pallidum (TPA), is surging worldwide, underscoring the need for a vaccine with global efficacy. Vaccine development requires an understanding of syphilis epidemiology and clinical presentation as well as genomic characterization of TPA strains circulating within at-risk populations. The aim of this study was to describe the clinical, demographic, and molecular features of early syphilis cases in Cali, Colombia. We conducted a cross-sectional study to identify individuals with early syphilis (ES) in Cali, Colombia through a city-wide network of public health centers, private sector HIV clinics and laboratory databases from public health institutions. Whole blood (WB), skin biopsies (SB), and genital and oral lesion swabs were obtained for measurement of treponemal burdens by polA quantitative polymerase chain reaction (qPCR) and for whole-genome sequencing (WGS). Among 1,966 individuals screened, 128 participants met enrollment criteria: 112 (87%) with secondary (SS), 15 (12%) with primary (PS) and one with early latent syphilis; 66/128 (52%) self-reported as heterosexual, while 48 (38%) were men who have sex with men (MSM). Genital ulcer swabs had the highest polA copy numbers (67 copies/μl) by qPCR with a positivity rate (PR) of 73%, while SS lesions had 42 polA copies/μl with PR of 62%. WB polA positivity was more frequent in SS than PS (42% vs 7%, respectively; p = 0.009). Isolation of TPA from WB by rabbit infectivity testing (RIT) was achieved in 5 (56%) of 9 ES WB samples tested. WGS from 33 Cali patient samples, along with 10 other genomic sequences from South America (9 from Peru, 1 from Argentina) used as comparators, confirmed that SS14 was the predominant clade, and that half of all samples had mutations associated with macrolide (i.e., azithromycin) resistance. Variability in the outer membrane protein (OMP) and vaccine candidate BamA (TP0326) was mapped onto the protein's predicted structure from AlphaFold. Despite the presence of mutations in several extracellular loops (ECLs), ECL4, an immunodominant loop and proven opsonic target, was highly conserved in this group of Colombian and South American TPA isolates. This study offers new insights into the sociodemographic and clinical features of venereal syphilis in a highly endemic area of Colombia and illustrates how genomic sequencing of regionally prevalent TPA strains can inform vaccine development.

Dynamics of morphofunctional parameters in experimental pseudomonosis of rabbits

Among the most frequently reported diseases of rabbits, the main place is occupied by diseases of bacterial etiology, the pathogens of which are characterized by multidrug resistance. The aim of the study was to analyze the dynamics of morphometric indicators during experimental infection of rabbits with Pseudomonas aeruginosa bacteria. When assessing colonization resistance of organs, the following indicators were taken into account: colonization index, ratio of the number of microorganisms isolated from nasal cavity washes, contents of cecum of clinically healthy and sick animals. Significant changes in morphological parameters (p 0.05) were revealed during the isolation of P. aeruginosa from blood, lymph nodes, spleen, liver, and kidneys of sick rabbits. Overgrowth of isolates producing adhesive antigens, hemolysins, bacteriocins should be considered as prognostic markers of connective tissue dysplasia. The initiation, development, and outcome of microbial overgrowth syndrome are mediated by morphofunctional changes in compensatory mechanisms of mucociliary clearance system and colonization resistance.

The effect of enterocin A/P dipeptide on growth performance, glutathione-peroxidase activity, IgA secretion and jejunal morphology in rabbits after experimental methicillin-resistant Staphylococcus epidermidis P3Tr2a Infection

The increasing frequency of methicillin-resistant (MR) staphylococci in humans and animals need special attention for their difficult treatment and zoonotic character, therefore novel antimicrobial compounds on a natural base against antibiotic-resistant bacteria are requested. Currently, bacteriocins/enterocins present a new promising way to overcome this problem, both in prevention and treatment. Therefore, the preventive and medicinal effect of dipeptide enterocin EntA/P was evaluated against MR Staphylococcus epidermidis SEP3/Tr2a strain in a rabbit model, testing their influence on growth performance, glutathione-peroxidase (GPx) enzyme activity, phagocytic activity (PA), secretory (s)IgA, and jejunal morphometry (JM). Eighty-eight rabbits (aged 35 days, meat line M91, both sexes) were divided into experimental groups S (SEP3/Tr2a strain; 1.0 × 105 CFU/mL; dose 500µL/animal/day for 7 days, between days 14 and 21 to simulate the pathogen attack), E (EntA/P; 50 µL/animal/day, 25,600 AU/mL in two intervals, for preventive effect between days 0 and 14; for medicinal effect between days 28 and 42), E + S (EntA/P + SEP3/Tr2a; preventive effect; SEP3/Tr2a + EntA/P; medicinal effect) and control group (C; without additives). Higher body weight was recorded in all experimental groups (p < 0.001) compared to control data. The negative influence/attack of the SEP3Tra2 strain on the intestinal immunity and environment was reflected as decreased GPx activity, worse JM parameters and higher sIgA concentration in infected rabbits. These results suggest the promising preventive use of EntA/P to improve the immunity and growth of rabbits, as well as its therapeutic potential and protective role against staphylococcal infections in rabbit breeding.

Solid Dispersion Incorporated into Dissolving Microneedles for Improved Antifungal Activity of Amphotericin B: In Vivo Study in a Fungal Keratitis Model.

Fungal keratitis (FK) is a fungal infection of the cornea, which is part of the eye and causes corneal ulcers and an increased risk of permanent blindness, which is often found in Candida albicans species. Amphotericin B (AMB), which is a group of polyenes as the first-line treatment of FK, is effective in annihilating C. albicans. However, AMB preparations such as eye drops and ointments have major drawbacks, for instance, requiring more frequent administrations, loss of the drug by the drainage process, and rapid elimination in the precornea, which result in low bioavailability of the drug. An ocular dissolving microneedle containing the solid dispersion amphotericin B (DMN-SD-AMB) had been developed using a mixture of poly(vinyl alcohol) (PVA) and poly(vinylpyrrolidone) (PVP) polymers, while the solid dispersion AMB (SD-AMB) was contained in the needle as a drug. This study aims to determine the most optimal and safest DMN-SD-AMB formula for the treatment of FK in the eye as well as a solution to overcome the low bioavailability of AMB eye drops and ointment preparations. SD-AMB had been successfully developed, which was characterized by increased antifungal activity and drug release in vitro compared to other treatments. Furthermore, DMN-SD-AMB studies had also been successfully performed with the best formulation, which exhibited the best ex vivo corneal permeation profile and antifungal activity as well as being safe from eye irritation. In addition, an in vivo antifungal activity using a rabbit infection model shows that the number of fungal colonies was 0.98 ± 0.11 log10 CFU/mL (F3), 5.76 ± 0.32 log10 CFU/mL (AMB eye drops), 4.01 ± 0.28 log10 CFU/mL (AMB ointments), and 9.09 ± 0.65 log10 CFU/mL (control), which differed significantly (p < 0.05). All of these results evidence that DMN-SD-AMB is a new approach to developing intraocular preparations for the treatment of FK.

A preclinical model of TB meningitis to determine drug penetration and activity at the sites of disease.

Tuberculosis meningitis (TBM) is essentially treated with the first-line regimen used against pulmonary tuberculosis, with a prolonged continuation phase. However, clinical outcomes are poor in comparison, for reasons that are only partially understood, highlighting the need for improved preclinical tools to measure drug distribution and activity at the site of disease. A predictive animal model of TBM would also be of great value to prioritize promising drug regimens to be tested in clinical trials, given the healthy state of the development pipeline for the first time in decades. Here, we report the optimization of a rabbit model of TBM disease induced via inoculation of Mycobacterium tuberculosis into the cisterna magna, recapitulating features typical of clinical TBM: neurological deterioration within months post-infection, acid-fast bacilli in necrotic lesions in the brain and spinal cord, and elevated lactate levels in cerebrospinal fluid (CSF). None of the infected rabbits recovered or controlled the disease. We used young adult rabbits, the size of which allows for spatial drug quantitation in critical compartments of the central nervous system that cannot be collected in clinical studies. To illustrate the translational value of the model, we report the penetration of linezolid from plasma into the CSF, meninges, anatomically distinct brain areas, cervical spine, and lumbar spine. Across animals, we measured the bacterial burden concomitant with neurological deterioration, offering a useful readout for drug efficacy studies. The model thus forms the basis for building a preclinical platform to identify improved regimens and inform clinical trial design.

Camellia sinensis Aqueous Extract: A Promising Candidate for Hepatic Eimeriosis Treatment in Rabbits.

Eimeria stiedae (E. stiedae) is a common coccidian species that infects the liver and causes economic losses for the rabbit industry. This study aimed to determine the efficiency of green tea aqueous extract (GTE) as a natural treatment for eimeriosis caused by E. stiedae. Male rabbits Cuniculus L. (Oryctolagus) of the New Zealand White rabbit strain (4-4.5 months) were used, as they are suitable for research and conducting experiments. Thirty rabbits were allocated into six groups, with five rabbits in each group; the G1 group (non-infected untreated) served as a negative control group; the G2 group was not infected and treated with 250 mg GTE; the G3 group was not infected and treated with 500 mg GTE; the G4 group was untreated and was infected with 3 × 104 Sporulated E. stiedae oocysts, which served as a positive control group; the G5 group was infected and treated with 250 mg GTE; and the G6 group was infected and treated with 500 mg GTE. The hematological and biochemical analyses of each group of rabbit sera were carried out. Phytochemical analysis was performed to evaluate the active components in GTE leaves using the following methods: IR spectroscopy, liquid chromatography-mass spectrometry (LC-MS), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy. The infected rabbit groups treated with GTE at both doses of 250 and 500 mg/kg exhibited a significant decrease in the extent of E. stiedae oocyst shedding compared with the infected untreated group at 14, 21, and 28 days post-infection. Also, treatment with green tea showed improvement in liver weight compared with the enlarged livers of infected, untreated rabbits. The disturbance in serum liver enzymes' gamma-glutamyl transferase (GGT) and aspartate aminotransferase (AST/GOT) levels, as well as serum glucose, potassium, uric acid, cholesterol, and urea levels, were improved after the treatment of infected rabbit groups with green tea compared with the infected untreated group. Moreover, in this study, the images of the egg stages of the parasite were taken using a fluorescence microscope at 25 µm and 26 µm magnifications. This study provides promising results for the effective cell absorption of the aqueous extract of green tea, which was confirmed in the analyzed images using a scanning electron microscope at 5 µm and 20 µm magnifications.

Evaluation of liver and renal function tests together with histopathological alterations in rabbits infected with a virulent strain of Proteus vulgaris

Introduction and Aim: Gram-negative bacterium Proteus vulgaris is found in animal and human guts. This bacterium can cause renal and vesical calculi, septicemia, and wound infection-related pyrexia. Antibiotics may not cure respiratory infections. This study infected rabbits with a virulent strain of P. vulgaris from bovine mastitis to examine metabolic and histological changes in various organs. Materials and Methods: This study was carried out on twenty domestic rabbits of both sexes which were divided into two groups. The first group received 1010 CFU\ml\ of virulent Proteus vulgaris subcutaneously. While the second group (control) received subcutaneously 1 cc of phosphate buffered saline (pH = 7.2). On 3,7, 14 days of infection, the animals were checked for their biochemical parameters (AST, ALT, ALP, blood urea and creatinine). Histological alterations in various organs were also studied. Results: The infected group showed substantial increases (P0.01) in liver enzymes (AST, ALT, and ALP) at 3, 7, and 14 days compared to the control group. In contrast, the infected group showed a substantial rise (P 0.01) in blood urea and creatinine levels at 3, 7, and 14 days compared to pre-infection levels and the control group. Histological analysis of lung tissue showed dilated alveolar gaps with hemorrhagic and fibrinous exudates and many alveolar macrophages. These findings included pulmonary vasodilation and congestion. Intramuscular edema, cellular infiltration, intramuscular hemorrhage, and congestion was present in heart tissue with little muscle fiber separation. The intestines had significant patch proliferation and mononuclear cell infiltration. Blood vascular congestion and mononuclear cell infiltration were also seen in the liver and kidney. Conclusion: Experimental infection with pathogenic bacterium Proteus vulgaris raised rabbits' blood urea, creatinine, and liver enzymes AST, ALT, and alkaline phosphatase. Cardiovascular, renal, hepatic, intestinal, and pulmonary tissues showed significant postmortem changes.

Does cold storage of blood before transfusion prevent the transmission of syphilis? A systematic review and meta-analysis.

Although screening of donated blood for syphilis is almost universally applied, its cost-effectiveness is questioned because of the low prevalence of transfusion-transmitted syphilis and a widespread belief that the syphilis-causing bacterium Treponema pallidum is very vulnerable to cold storage. Since the latter claim is not yet supported by a systematic review, we investigated whether syphilis can be transmitted via transfusion following prolonged (cold or room temperature) storage of blood products. MEDLINE, PMC and NCBI bookshelf (PubMed interface), Cochrane Library, Embase, Web of Science and CINAHL were searched up to 17 January 2023. Nine experimental animal studies and one observational human study were included. Meta-analysis showed that storing artificially infected human (six studies; risk ratio [RR] = 0.37, 95% confidence interval [CI]: 0.22-0.64, p = 0.0003) or rabbit (two studies; RR = 0.08, 95% CI: 0.01 to 0.55, p = 0.01) blood for more than 72 h before intratesticular injection significantly decreased the number of recipient animals that develop syphilis. Nonetheless, the possibility of syphilis transmission remained for up to 7 days. Differences could not be found for rabbit plasma (p = 0.60) or naturally infected rabbit blood (p = 0.28). There was limited evidence from one study in favour of the storage of artificially infected human platelets for over 72 h at cold temperatures (RR = 0.13, 95% CI: 0.03-0.52, p = 0.004) but not at room temperature (p = 0.12). Even though the infectivity of T. pallidum-spiked blood may decrease after 72 h of cold storage, the possibility for transfusion-transmitted syphilis may remain for several days after. The evidence is very uncertain, and conclusions are hindered by a lack of sufficiently powered studies and studies in humans. In addition, T. pallidum concentrations used in animal studies may be unrealistically high.

Protection against Eimeria intestinalis infection in rabbits immunized with the recombinant elongation factors EF1α and EFG.

Eimeria intestinalis is the most pathogenic species of rabbit coccidiosis, causing weight loss, diarrhea, and even acute death. The currently used anticoccidial drugs against E. intestinalis in rabbits are associated with drug resistance and residues. Immunological control might be a potential alternative. We cloned and expressed the E. intestinalis recombinant EF1α and EFG (rEi-EF1α and rEi-EFG, respectively). Rabbits were immunized subcutaneously every 14 days with 100 µg of rEi-EF1α and rEi-EFG and followed by 5 × 104 E. intestinalis sporulated oocysts orally challenge. Serum samples were collected every 7 days to measure the levels of specific antibodies and cytokines. On post-challenge day 14, rabbits were sacrificed and the anticoccidial index was evaluated. The rabbits of PBS challenged groups exhibited anorexia, diarrhea, marked intestinal wall thickening, and white nodules that formed patches, while rabbits from the rEi-EF1α or rEi-EFG challenged group exhibited milder symptoms. The rEi-EF1α group showed a 75.18% oocyst reduction and 89.01%wt gain; the rEi-EFG group had a 60.58% oocyst reduction and 56.04%wt gain. After vaccination, specific IgG levels increased and stayed high (P < 0.05). The IL-4 and IL-2 levels of rEi-EF1α immunized groups showed a significant increase after immunization (P < 0.05). Both rEi-EF1α and rEi-EFG could induce humoral and cellular immune responses. In contrast, rabbits immunized with rEi-EF1α were better protected from challenge by E. intestinalis than rEi-EFG.

Morphological and molecular phylogenetic analyses of the apicomplexan parasites, Eimeria media and Eimeria stiedai, infecting the domestic rabbits, Oryctolagus cuniculus

The eimerian infection is one of the most serious infections that can decrease rabbit productivity since it can lead to serious diseases. There is little information about Eimeria media and Eimeria stiedai infections in Saudi Arabia, and molecular data is particularly weak. To establish the prevalence, morphological and molecular characterization of E. media and E. stiedai isolated from spontaneously infected rabbits, the current study was conducted. Ten healthy rabbits, Oryctolagus cuniculus, whose feces were collected and kept at the laboratory were examined for protozoan parasite infection using the floatation method. Purified oocysts were used to extract DNA, which was then used in a polymerase chain reaction (PCR) with primers that amplified a partial sequences of the 18S rDNA gene. Seven rabbits had coinfections with two eimerian species. Sporulated oocysts of E. media had an obvious micropyle and were oval, measuring 24.92–30.03 (28.04) µm in length and 16.33–19.63 (18.31) µm in width. In contrast, E. stiedai were ellipsoid and measured 31.03–36.47 (33.79) µm in length and 18.21–20.93 (19.32) µm in width. The identity of the species of Eimeria parasites detected from the host (rabbits) was verified by the results of the sequences for the 18S rDNA gene. Both organisms (E. media and E. stiedai) grouped with rabbit eimerian parasites with distinct association with the group that contains oocysts residual body. Sequences from E. stiedai revealed insertions on two sites that had never been detected in E. stiedai sequences previously deposited in GenBank. The current parasite species are closely related to the previously described and deposited E. media and E. stiedai and are deeply embedded in the genus Eimeria (family Eimeriidae). This study emphasized the significance of combining taxonomy with morphological and genetic data in the identification of Eimeria species.