Intestinal parasites of the endangered European ground squirrel (Spermophilus citellus) populations in Slovakia.

The present pilot research was focused on the detection of intestinal parasites in the ground squirrel populations in various regions of Slovakia. Only a very little information is currently available on the parasitic species composition of the European ground squirrel in Slovakia and across Europe. In the Slovak Republic, there are 70 locations where the ground squirrel populations are present. A total of 600 faecal samples of the European ground squirrels, collected from 36 locations all over Slovakia, were examined by applying the coprological method. The presence of the protozoan coccidian parasite of the Eimeria genus was confirmed in all of the analysed locations. The presence of eggs of four helminths were confirmed: Capillaria spp. (66.6% of locations); the Trichostrongylidae family (42.8% of locations); Hymenolepis spp. (11.9% of locations); and Citellina spp. (7.14% of locations). Dead individuals that were found in the analysed localities were subjected to necropsy and the tissues scraped off their small intestines were stained in order to confirm the presence of parasites. The post-mortem examination of the intestines and the sedimentation of the intestinal contents in a saline solution did not result in the confirmation of the presence of the eggs, adults or the larval stages of parasites. Spermophilus citellus is one of the strictly protected animal species in Slovakia. In recent years, numerous projects aimed at supporting and protecting ground squirrels have been implemented. The present pilot study on intestinal parasites and the subsequent cooperation with environmental activists will contribute to the support and stabilisation of the presence of these animals in our country.

The corrective role of superparamagnetic iron oxide nanoparticles for the genes controlling hypothalamus-pituitary-testis-axis in male obesity-associated secondary hypogonadism.

Background: Obesity is one of the most prevalent and perilous health affairs. Male obesity-associated secondary hypogonadism (MOSH) is one of many of its complexities, which is mounting in parallel with the aggravation of obesity. Magnetic nanoparticles seem to be an advanced favorable trend in multiple biomedical fields. Aim: In this study, we explore the therapeutic effects of superparamagnetic iron oxide nanoparticles (SPIONs) coated with carboxymethyl cellulose (CMC) on an obese male rat model with MOSH syndrome, comparing their impacts with a well-known anti-obesity medication (Orlistat). Methods: 42 male albino rats split into 7 equal groups: 1-negative control: nonobese, untreated; 35 rats fed the high fat-high fructose (HFHF) diet for a period of 12 weeks. Obese rats splitted into 6 equal groups; 2-positive control: obese untreated; 3-obese given Orlistat (30 mg/kg); 4-obese given CMC-SPIONs (25 mgFe/kg); 5-obese given CMC-SPIONs (50 mgFe/kg); 6-obese given CMC-SPIONs(25 mgFe/kg) + Orlistat (30 mg/kg), 7-obese given CMC-SPIONs (50 mgFe/kg) + Orlistat (30 mg/kg); all treatments given orally for 4 weeks. During sacrifice, blood serum and sectioned hypothalamic, pituitary, testicular, and adipose tissues were collected for biochemical and biomolecular assessments. Results: The HFHF diet for 12 weeks resulted in a significant upsurge in body weight, body mass index, serum fasting glucose, insulin resistance, TAG, total cholesterol, and LDL-c; HDL-c was dropped. Serum FSH, LH, and testosterone values declined. A significant disorder in expression levels of genes regulating the hypothalamic-pituitary-testicular-axis pathway. Hypothalamic GnRH, Kisspeptin-1, Kisspeptin-r1, and Adipo-R1 values declined. GnIH and Leptin-R1 values raised up. Pituitary GnRH-R values declined. Testicular tissue STAR, HSD17B3, and CYP19A1 values declined. Adipose tissue adiponectin declined, while leptin raised up. CMC-SPIONs 25-50 mg could modulate the deranged biochemical parameters and correct the deranged expression levels of all previous genes. Co-treatments revealed highly synergistic effects on all parameters. Overall, CMC-SPIONs have significant efficiency whether alone or with Orlisat in limiting obesity and consequence subfertility. Conclusion: CMC-SPIONs act as an incoming promising contender for obesity and MOSH disorders management, and need more studies on their mechanisms.

Effect of the long-term use of a NOAEL dose of acetaminophen (paracetamol) on hepatic, renal, and neural tissues of aged albino rats.

Background: Paracetamol is one of the most popular drugs; it is used daily by many people especially the elderly, without a limitation on the length of the period allowed for continuous use. Harms from long-term use are less clear, particularly in extrahepatic regions. Aim: This study aimed to investigate whether using paracetamol at a non-observable adverse effect level dose, known not to cause toxic effects, for a long period can induce toxicity in aged male albino rats. Methods: A daily dose of 500 mg per kg body weight of paracetamol was given to adult male albino rats for 12 weeks. During this period, rats were sacrificed at 4, 6, 8, 10, and 12 weeks to evaluate the toxic changes at several time intervals. Results: Chemical analysis revealed elevated serum alanine transaminase, aspartate transaminase, alkaline phosphatase, urea, creatinine, and declined level of total protein in N-acetyl-p-aminophenol (APAP)-treated group; it also caused oxidative stress, as shown by decreased glutathione, superoxide dismutase, and elevated malondialdehyde in the liver, kidney, and brain. Histopathological examination demonstrated cytoplasmic vacuolation and sinusoidal congestion with the development of single-cell necrosis in the liver. Renal tubular necrosis, glomerular atrophy, and ischemic neuronal injury, especially in the hippocampus were observed. the deleterious effects of APAP were increased in severity with increasing the period of treatment. Conclusion: Our results suggest that acetaminophen in a subtoxic dose for a long period could result in mild toxic effects on the liver but more serious lesions in the kidney and brain.

The ameliorative role of Aloe vera-loaded chitosan nanoparticles on Staphylococcus aureus induced acute lung injury: Targeting TLR/NF-κB signaling pathways.

Background: Acute lung injury (ALI) is a severe condition distinguished by inflammation and impaired gas exchange in the lungs. Staphylococcus aureus, a common bacterium, can cause ALI through its virulence factors. Aloe vera is a medicinal plant that has been traditionally used to treat a variety of illnesses due to its anti-inflammatory properties. Chitosan nanoparticles are biocompatible and totally biodegradable materials that have shown potential in drug delivery systems. Aim: To explore the antibacterial activity of Aloe vera-loaded chitosan nanoparticles (AV-CS-NPs) against S. aureus in vitro and in vivo with advanced techniques. Methods: The antibacterial efficacy of AV-CS-NPs was evaluated through a broth microdilution assay. In addition, the impact of AV-CS-NPs on S. aureus-induced ALI in rats was examined by analyzing the expression of genes linked to inflammation, oxidative stress, and apoptosis. Furthermore, rat lung tissue was scanned histologically. The rats were divided into three groups: control, ALI, and treatment with AV-CS-NPs. Results: The AV-CS-NPs that were prepared exhibited clustered semispherical and spherical forms, having an average particle size of approximately 60 nm. These nanoparticles displayed a diverse structure with an uneven distribution of particle sizes. The maximum entrapment efficiency of 95.5% ± 1.25% was achieved. The obtained findings revealed that The minimum inhibitory concentration and minimum bactericidal concentration values were determined to be 5 and 10 ug/ml, respectively, indicating the potent bactericidal effect of the NPs. Also, S. aureus infected rats explored upregulation in the mRNA expression of TLR2 and TLR4 compared to healthy control groups. AV-CS-NP treatment reverses the case where there was repression in mRNA expression of TLR2 and TLR4 compared to S. aureus-treated rats. Conclusion: These NPs can serve as potential candidates for the development of alternative antimicrobial agents.

Reservoir displacement by an invasive rodent reduces Lassa virus zoonotic spillover risk.

The black rat (Rattus rattus) is a globally invasive species that has been widely introduced across Africa. Within its invasive range in West Africa, R. rattus may compete with the native rodent Mastomys natalensis, the primary reservoir host of Lassa virus, a zoonotic pathogen that kills thousands annually. Here, we use rodent trapping data from Sierra Leone and Guinea to show that R. rattus presence reduces M. natalensis density within the human dwellings where Lassa virus exposure is most likely to occur. Further, we integrate infection data from M. natalensis to demonstrate that Lassa virus zoonotic spillover risk is lower at sites with R. rattus. While non-native species can have numerous negative effects on ecosystems, our results suggest that R. rattus invasion has the indirect benefit of decreasing zoonotic spillover of an endemic pathogen, with important implications for invasive species control across West Africa.

Leptospira infection and carrier survey on rats from wet market areas in Kuala Lumpur, Malaysia.

BACKGROUND OBJECTIVES: Leptospirosis is an important zoonotic infection that has caused significant mortality and morbidity worldwide. This disease is endemic in Malaysia and as a developing tropical country, leptospirosis is concerning as it threatens Malaysian public health and the country's economic sectors. However, there is limited information on leptospirosis in Malaysia, especially regarding leptospiral seroepidemiology among carriers in Malaysia. Therefore, more epidemiological information on the source of the disease and reservoir are needed for better disease control and source intervention. The objectives of this study are to gather information on Leptospira infection and the carrier status of rats captured from selected wet markets of Kuala Lumpur metropolitan city in Malaysia. METHODS: Live rat trappings were performed in four major wet markets in Kuala Lumpur, namely, Pudu, Chow Kit, Datuk Keramat, and Petaling Street. Animal samplings were performed for 12 months in 2017, where blood and kidney samples were collected and tested for anti-leptospiral antibodies via Microscopic Agglutination Test (MAT) and pathogenic Leptospira screening via Polymerase Chain Reaction (PCR) amplification offlaB gene. RESULTS: MAT showed that 34.7% (n = 50/144) of the captured rats were positive for anti-leptospiral antibody of which the most prominent serovar was Malaya followed by a local strain, IMR LEP 175. In parallel, 50 rats were also positive for pathogenic Leptospira DNA. INTERPRETATION CONCLUSION: This study showed that there are persistent Leptospira infections among rats in Kuala Lumpur wet markets and these rats are important reservoir hosts for the bacteria.

Pasteurella multocida activates apoptosis via the FAK-AKT-FOXO1 axis to cause pulmonary integrity loss, bacteremia, and eventually a cytokine storm.

Pasteurella multocida is an important zoonotic respiratory pathogen capable of infecting a diverse range of hosts, including humans, farm animals, and wild animals. However, the precise mechanisms by which P. multocida compromises the pulmonary integrity of mammals and subsequently induces systemic infection remain largely unexplored. In this study, based on mouse and rabbit models, we found that P. multocida causes not only lung damage but also bacteremia due to the loss of lung integrity. Furthermore, we demonstrated that bacteremia is an important aspect of P. multocida pathogenesis, as evidenced by the observed multiorgan damage and systemic inflammation, and ultimately found that this systemic infection leads to a cytokine storm that can be mitigated by IL-6-neutralizing antibodies. As a result, we divided the pathogenesis of P. multocida into two phases: the pulmonary infection phase and the systemic infection phase. Based on unbiased RNA-seq data, we discovered that P. multocida-induced apoptosis leads to the loss of pulmonary epithelial integrity. These findings have been validated in both TC-1 murine lung epithelial cells and the lungs of model mice. Conversely, the administration of Ac-DEVD-CHO, an apoptosis inhibitor, effectively restored pulmonary epithelial integrity, significantly mitigated lung damage, inhibited bacteremia, attenuated the cytokine storm, and reduced mortality in mouse models. At the molecular level, we demonstrated that the FAK-AKT-FOXO1 axis is involved in P. multocida-induced lung epithelial cell apoptosis in both cells and animals. Thus, our research provides crucial information with regard to the pathogenesis of P. multocida as well as potential treatment options for this and other respiratory bacterial diseases.

Production of a new tetravalent vaccine targeting fimbriae and enterotoxin of enterotoxigenic Escherichia coli.

Enterotoxigenic Escherichia coli (ETEC) is an important type of pathogenic bacteria that causes diarrhea in pigs. The objective of this study was to prepare a novel tetravalent vaccine to effectively prevent piglet diarrhea caused by E. coli. In order to realize the production of K88ac-K99-ST1-LTB tetravalent inactivated vaccine, the biological characteristics, stability, preservation conditions, and safety of the recombinant strain BL21(DE3) (pXKKSL4) were studied, and the vaccine efficacy and minimum immune dose were measured. The results indicated that the biological characteristics, target protein expression, and immunogenicity of the 1st to 10th generations of the strain were stable. Therefore, the basic seed generation was preliminarily set as the 1st to 10th generations. The results of the efficacy tests showed that the immune protection rate could reach 90% with 1 minimum lethal dose (MLD) virulent strain attack in mice. The immunogenicity was stable, and the minimum immune dose was 0.1 mL per mouse. Our research showed that the genetically engineered vaccine developed in this way could prevent piglet diarrhea caused by enterotoxigenic E. coli through adhesin and enterotoxin. In order to realize industrial production of the vaccine as soon as possible, we conducted immunological tests and production process research on the constructed K88ac-K99-ST1-LTB tetravalent inactivated vaccine. The results of this study provide scientific experimental data for the commercial production of vaccines and lay a solid foundation for their industrial production.

Escherichia coli entérotoxinogènes (ETEC) est un type important de bactéries pathogènes qui cause de la diarrhée chez les porcs. L'objectif de l'étude était de préparer un nouveau vaccin tétravalent pour prévenir efficacement la diarrhée causée par E. coli chez les porcelets. Afin de réaliser la production du vaccin tétravalent inactivé K88ac-K99-ST1-LTB, les caractéristiques biologiques, la stabilité, les conditions de conservation, et la sécurité de la souche recombinante (BL21(DE3)(pXKKSL4) ont été étudiées et l'efficacité du vaccin et la dose immunitaire minimum ont été mesurées. Les résultats indiquent que les caractéristiques biologiques, l'expression des protéines cibles, et l'immunogénicité de la 1ère à la 10e génération de la souche étaient stables. Ainsi, la génération germinale de base a été établie de manière préliminaire comme étant de la 1ère à la 10e générations. Les résultats des tests d'efficacité ont démontré que le taux de protection immunitaire pouvait atteindre 90 % avec une attaque au moyen de 1 dose léthale minimale (MLD) d'une souche virulente chez les souris. L'immunogénicité était stable et la dose immunitaire minimum était de 0,1 mL par souris. Nos travaux ont démontré que le vaccin génétiquement élaboré développé de cette façon pourrait prévenir la diarrhée chez les porcelets causée par des E. coli entérotoxigénique via les adhésines et les entérotoxines. Afin d'atteindre la production industrielle de ce vaccin aussitôt que possible, nous avons mené des tests immunologiques et de la recherche sur le processus de production du vaccin tétravalent inactivé K88ac-K99-ST1-LTB. Les résultats de la présente étude fournissent des données scientifiques expérimentales pour la production commerciale de vaccins et jettent une base solide pour leur production industrielle.(Traduit par Docteur Serge Messier).

Diversity of Trichinella species in carnivores from Bosnia and Herzegovina.

BACKGROUND: In Bosnia and Herzegovina, domestic and wild carnivores represent a significant driver for the transmission and ecology of zoonotic pathogens, especially those of parasitic aetiology. Nevertheless, there is no systematic research of Trichinella species in animals that have been conducted in Bosnia and Herzegovina, even though trichinellosis is considered the most important parasitic zoonosis. The available results of the few studies carried out in Bosnia and Herzegovina are mainly related to the confirmation of parasitic larvae in the musculature of domestic pigs and wild boars or data related to trichinellosis in humans. The objective of our study was to present the findings of a comprehensive investigation into the species composition of Trichinella among 11 carnivorous species within the territory of Bosnia and Herzegovina, as follows: red fox (Vulpes vulpes), grey wolf (Canis lupus), brown bear (Ursus arctos), wildcat (Felis silvestris), pine marten (Martes martes), European badger (Meles meles), weasel (Mustela nivalis), European polecat (Mustela putorius), Eurasian lynx (Lynx lynx), but also dog (Canis lupus familiaris) and cat (Felis catus). RESULTS: In the period 2013-2023, carnivore musculature samples (n = 629), each consisting of 10 g of muscle tissue, were taken post-mortem and individually examined using the artificial digestion method. In the positive samples (n = 128), molecular genotyping and identification of parasitic larvae of Trichinella spp. were performed using a PCR-based technique up to the species/genotype level. Positive samples were used for basic PCR detection of the genus Trichinella (rrnS rt-PCR technique) and genotyping (rrnl-EVS rt-PCR technique). The Trichinella infection was documented for the first time in Bosnia and Herzegovina among red foxes, grey wolves, brown bears, dogs, badgers and Eurasian lynx, with a frequency rate of 20.3%. Additionally, the presence of T. britovi infection was newly confirmed in Bosnia and Herzegovina, marking the initial documented cases. Furthermore, both T. britovi and T. pseudospiralis infections were observed in the wildcat population, whereas T. britovi and T. spiralis infections were detected in pine martens. Consistent with previous research, our findings align particularly regarding carnivores, with data from other countries such as Germany, Finland, Romania, Poland and Spain, where T. britovi exhibits a wider distribution (62.5-100%) compared to T. spiralis (0.0-37.5%). T. britovi is more common among sylvatic carnivores (89.0%), while T. spiralis prevails in wild boars (62.0%), domestic swine (82.0%) and rodents (75.0%). CONCLUSION: The results of our study represent the first molecular identification of species of the genus Trichinella in Bosnia and Herzegovina. Additionally, our findings underscore the necessity for targeted epidemiological studies to thoroughly assess trichinellosis prevalence across diverse animal populations. Considering the relatively high frequency of trichinellosis infection in investigated animal species and its public health implications, there is an evident need for establishing an effective trichinellosis surveillance system in Bosnia and Herzegovina.

Lipoteichoic acids influence cell shape and bacterial division of Streptococcus suis serotype 2, but play a limited role in the pathogenesis of the infection.

Streptococcus suis serotype 2 is a major swine pathogen and a zoonotic agent, causing meningitis in both swine and humans, responsible for substantial economic losses to the swine industry worldwide. The pathogenesis of infection and the role of bacterial cell wall components in virulence have not been fully elucidated. Lipoproteins, peptidoglycan, as well as lipoteichoic acids (LTA) have all been proposed to contribute to virulence. In the present study, the role of the LTA in the pathogenesis of the infection was evaluated through the characterisation of a mutant of the S. suis serotype 2 strain P1/7 lacking the LtaS enzyme, which mediates the polymerization of the LTA poly-glycerolphosphate chain. The ltaS mutant was confirmed to completely lack LTA and displayed significant morphological defects. Although the bacterial growth of this mutant was not affected, further results showed that LTA is involved in maintaining S. suis bacterial fitness. However, its role in the pathogenesis of the infection appears limited. Indeed, LTA presence reduces self-agglutination, biofilm formation and even dendritic cell activation, which are important aspects of the pathogenesis of the infection caused by S. suis. In addition, it does not seem to play a critical role in virulence using a systemic mouse model of infection.

Development and preclinical evaluation of equine-derived hyperimmune serum against SARS-CoV-2 infection in K-18 hACE2 transgenic (Tg) mice.

This study aimed to develop an equine-derived hyperimmune serum against SARS-CoV-2 and evaluate its efficacy as a potential immunotherapy tool for the treatment of known and potential variants of COVID-19 in preclinical trials. The novelty of this study is the whole virus and ALUM gel adjuvant formula. The horses were immunized using a whole inactivated SARS-CoV-2 antigen, and the final purified hyperimmune serum showed high plaque reduction neutralization (PRNT 50) neutralizing titers. The efficacy of the hyperimmune serum was evaluated histopathologically and biochemically in the lungs, hearts, and serum of K18 hACE2 transgenic mice (n=45), which is an accepted model organism for SARS-CoV-2 studies and was challenged with live SARS-CoV-2. Serum treatment improved the general condition, resulting in lower levels of proinflammatory cytokines in the blood plasma, as well as reduced viral RNA titers in the lungs and hearts. Additionally, it reduced oxidative stress significantly and lessened the severity of interstitial pneumonia in the lungs when compared to infected positive controls. The study concluded that equine-derived anti-SARS-CoV-2 antibodies could be used for COVID-19 prevention and treatment, especially in the early stages of the disease and in combination with antiviral drugs and vaccines. This treatment will benefit special patient populations such as immunocompromised individuals, as specific antibodies against SARS-CoV-2 can neutralize the virus before it enters host cells. The rapid and cost-effective production of the serum allows for its availability during the acute phase of the disease, making it a critical intervention in preventing the spread of the disease and saving lives in new variants where a vaccine is not yet developed.

Investigation of the protective effect of chitosan against arsenic-induced nephrotoxicity and oxidative damage in rat kidney tissue.

Arsenic is an important metalloid that can cause poisoning in humans and domestic animals. Exposure to arsenic causes cell damage, increasing the production of reactive oxygen species. Chitosan is a biopolymer obtained by deacetylation of chitin with antioxidant and metal ion chelating properties. In this study, the protective effect of chitosan on arsenic-induced nephrotoxicity and oxidative damage was investigated. 32 male Wistar-albino rats were divided into 4 groups of 8 rats each as control group (C), chitosan group (CS group), arsenic group (AS group), and arsenic+chitosan group (AS+CS group). The C group was given distilled water by oral gavage, the AS group was given 100 ppm/day Na-arsenite ad libitum with drinking water, the CS group was given 200 mg/kg/day chitosan dissolved in saline by oral gavage, the AS+CS group was given 100 ppm/day Na-arsenite ad libitum with drinking water and 200 mg/kg/day chitosan dissolved in saline by oral gavage for 30 days. At the end of the 30-day experimental period, 90 mg/kg ketamine was administered intraperitoneally to all rats, and blood samples and kidney tissues were collected. Urea, uric acid, creatinine, P, Mg, K, Ca, Na, Cystatin C (CYS-C), Neutrophil Gelatinase Associated Lipocalin (NGAL) and Kidney Injury Molecule 1 (KIM-1) levels were measured in serum samples. Malondialdehyde (MDA), Glutathione (GSH), Catalase (CAT) and Superoxide dismutase (SOD) levels in the supernatant obtained from kidney tissue were analyzed by ELISA method. Compared with AS group, uric acid and creatinine levels of the AS+CS group were significantly decreased (p<0.001), urea, KIM-1, CYS-C, NGAL, and MDA levels were numerically decreased and CAT, GSH, and SOD levels were numerically increased (p>0.05). In conclusion, based on both biochemical and histopathological-immunohistochemical- immunofluorescence findings, it can be concluded that chitosan attenuates kidney injury and protects the kidney.

Dynamics of ex vivo cytokine transcription during experimental Toxocara canis infection in Balb/c mice.

The cytokine microenvironment is crucial in generating and polarizing the immune response. A means of monitoring this environment would be of great value for better understanding Toxocara canis immune modulation. The aim of this study was to analyze the dynamics of cytokine transcription ex vivo, during early (24-48 hours) and late (15-30 days) times post-infection, in the mesenteric lymph nodes, spleen and intestinal mucosa of Balb/c mice experimentally infected with T. canis larvae. Mice in the treated group were infected with 100 third-stage larvae (L3), whereas mice in the control group were not infected. Analyses were performed at different times: 24-48 hours post-infection (HPI), 15-30 days post-infection (DPI). IL4, IL10, IL12 and Ym1 mRNA transcriptions were analyzed through qPCR. This study showed cytokine transcription mediated by migrating larvae in the mesenteric lymph nodes and spleen at 24-48 HPI, whereas cytokine transcription in the intestinal mucosa was observed only at late times (15-30 DPI). These results suggest that the T. canis larvae migration during infection might play a role in cytokine dynamics. Since the cytokine microenvironment is crucial in modulating immune response, knowledge of cytokine dynamics during T. canis infections pave the way to better understand its interaction with the host.

Detection of Toxoplasma gondii in artisanal salted meat products sold in street markets of the Ilhéus-Itabuna microregion.

This study aimed to detect Toxoplasma gondii in artisanal salted meat products sold in street markets in the Ilhéus-Itabuna microregion and to assess the salt concentration used in their preparation and its influence on the parasite's viability. A total of 125 samples of various artisanal meat products sold in street markets located in the Ilhéus-Itabuna microregion were collected during 2021. Serological analysis using indirect hemagglutination (HAI) and molecular analysis (PCR) were performed on these samples to detect the presence of the parasite. Möhr's method was utilized to determine the sodium chloride concentration in the samples. Of all samples, 21 were subjected to a bioassay in albino mice to verify the viability of possible tissue cysts. Among the 125 meat products, 10 (8%) tested positive in the serological analysis including four cured pork sausages, five beef sun-dried meats, and one mixed fresh sausage (pork and chicken). None of 125 samples tested positive in the molecular analysis. On bioassay, all mice tested negative for the presence of the parasite. The NaCl concentration in the positive samples ranged from 2.9% to 8%. The results demonstrated that the salt concentration in the collected samples was sufficient to inactivate the parasite T. gondii.

Antibacterial activity of the antimicrobial peptide PMAP-36 in combination with tetracycline against porcine extraintestinal pathogenic Escherichia coli in vitro and in vivo.

The increase in the emergence of antimicrobial resistance has led to great challenges in controlling porcine extraintestinal pathogenic Escherichia coli (ExPEC) infections. Combinations of antimicrobial peptides (AMPs) and antibiotics can synergistically improve antimicrobial efficacy and reduce bacterial resistance. In this study, we investigated the antibacterial activity of porcine myeloid antimicrobial peptide 36 (PMAP-36) in combination with tetracycline against porcine ExPEC PCN033 both in vitro and in vivo. The minimum bactericidal concentrations (MBCs) of AMPs (PMAP-36 and PR-39) against the ExPEC strains PCN033 and RS218 were 10 µM and 5 µM, respectively. Results of the checkerboard assay and the time-kill assay showed that PMAP-36 and antibiotics (tetracycline and gentamicin) had synergistic bactericidal effects against PCN033. PMAP-36 and tetracycline in combination led to PCN033 cell wall shrinkage, as was shown by scanning electron microscopy. Furthermore, PMAP-36 delayed the emergence of PCN033 resistance to tetracycline by inhibiting the expression of the tetracycline resistance gene tetB. In a mouse model of systemic infection of PCN033, treatment with PMAP-36 combined with tetracycline significantly increased the survival rate, reduced the bacterial load and dampened the inflammatory response in mice. In addition, detection of immune cells in the peritoneal lavage fluid using flow cytometry revealed that the combination of PMAP-36 and tetracycline promoted the migration of monocytes/macrophages to the infection site. Our results suggest that AMPs in combination with antibiotics may provide more therapeutic options against multidrug-resistant porcine ExPEC.

Clinacanthus nutans leaf extract reduces pancreatic ß-cell apoptosis by inhibiting JNK activation and modulating oxidative stress and inflammation in streptozotocin-induced diabetic rats.

Background: Controlling apoptosis induced by oxidative stress in pancreatic ß-cells provides promising strategies for preventing and treating diabetes. Clinacanthus nutans leaves possess bioactive constituents with potential antioxidant and anti-diabetic properties. Aim: This study aimed to investigate the molecular mechanisms by which C. nutans extract protects pancreatic ß-cells from apoptotic damage in streptozotocin (STZ)-induced diabetic rats. Methods: Diabetes was induced in male Wistar rats by intraperitoneal injection of 45 mg/kg STZ, followed by 28 days of treatment with C. nutans leaf extract and Glibenclamide as the standard drug. At the end of the study, blood samples were collected to measure glucose levels, oxidative stress markers, and inflammation. Pancreatic tissue was stained immunohistochemically to detect c-Jun N-terminal kinase (JNK) and Caspase-3 expression. Results: The administration of C. nutans leaf extract to diabetic rats significantly reduced fasting blood glucose, malondialdehyde, and tumor necrosis factor-α levels, while concurrently enhancing the activity of superoxide dismutase. The immunohistochemical studies revealed a decrease in the expression of JNK and caspase-3 in the pancreatic islets of diabetic rats. Conclusion: Clinacanthus nutans exhibits the potential to protect pancreatic ß-cells from apoptosis by suppressing oxidative stress and inflammation.

Inflammatory responses to Opisthorchis viverrini infection in animal models: A comparison between susceptible and nonsusceptible hosts in different anatomical locations.

Background: Inflammation caused by Opisthorchis viverrini infection increases the risk of cholangitis, cholecystitis, and leads to bile duct cancer (cholangiocarcinoma or CCA). However, only certain infected individuals are susceptible to CCA, suggesting the involvement of host factors in cancer development. In addition, there are reports indicating differences in the locations of CCA. Aim: This study aims to investigate cellular inflammatory responses in the common bile duct (CB), intrahepatic bile duct (IHB), and gallbladder (GB) in susceptible and non-susceptible hosts following O. viverrini infection. Methods: Thirty Syrian golden hamsters (a susceptible host) and 30 BALB/c mice (a non-susceptible host) infected with O. viverrini were studied at six time points (five animals per group). Histopathological evaluations were conducted on samples from the IHB, CB, and GB. Inflammatory cell infiltration was quantitatively assessed and compared between groups and time points. Statistical analysis was performed using one-way ANOVA, with a significance level of p < 0.05. Results: Inflammation was significantly more pronounced in the IHB compared to the other two biliary locations. In comparison between susceptible and non-susceptible hosts, the intensity of inflammation was higher in the OV+H group than in the OV+M group (p < 0.05). Conclusion: This study highlights the association between host response to inflammation, tissue location, and host susceptibility, with the IHB showing particular susceptibility to inflammation and pathological changes. These findings contribute to our understanding of the increased risk of CCA in susceptible hosts.

Complex effects of testosterone level on ectoparasite load in a ground squirrel: an experimental test for the immunocompetence handicap hypothesis.

BACKGROUND: The immunocompetence handicap hypothesis suggests that males with a higher testosterone level should be better at developing male secondary traits, but at a cost of suppressed immune performance. As a result, we should expect that males with an increased testosterone level also possess a higher parasite load. However, previous empirical studies aimed to test this prediction have generated mixed results. Meanwhile, the effect of testosterone level on parasite load in female hosts remains poorly known. METHODS: In this study, we tested this prediction by manipulating testosterone level in Daurian ground squirrels (Spermophilus dauricus), a medium-sized rodent widely distributed in northeast Asia. S. dauricus is an important host of ticks and fleas and often viewed as a considerable reservoir of plague. Live-trapped S. dauricus were injected with either tea oil (control group) or testosterone (treatment group) and then released. A total of 10 days later, the rodents were recaptured and checked for ectoparasites. Fecal samples were also collected to measure testosterone level of each individual. RESULTS: We found that testosterone manipulation and sex of hosts interacted to affect tick load. At the end of the experiment, male squirrels subjected to testosterone implantation had an averagely higher tick load than males from the control group. However, this pattern was not found in females. Moreover, testosterone manipulation did not significantly affect flea load in S. dauricus. CONCLUSIONS: Our results only lent limited support for the immunocompetence handicap hypothesis, suggesting that the role of testosterone on regulating parasite load is relatively complex, and may largely depend on parasite type and gender of hosts.

Microbiome diversity and zoonotic bacterial pathogen prevalence in Peromyscus mice from agricultural landscapes and synanthropic habitat.

Rodents are key reservoirs of zoonotic pathogens and play an important role in disease transmission to humans. Importantly, anthropogenic land-use change has been found to increase the abundance of rodents that thrive in human-built environments (synanthropic rodents), particularly rodent reservoirs of zoonotic disease. Anthropogenic environments also affect the microbiome of synanthropic wildlife, influencing wildlife health and potentially introducing novel pathogens. Our objective was to examine the effect of agricultural development and synanthropic habitat on microbiome diversity and the prevalence of zoonotic bacterial pathogens in wild Peromyscus mice to better understand the role of these rodents in pathogen maintenance and transmission. We conducted 16S amplicon sequencing on faecal samples using long-read nanopore sequencing technology to characterize the rodent microbiome. We compared microbiome diversity and composition between forest and synanthropic habitats in agricultural and undeveloped landscapes and screened for putative pathogenic bacteria. Microbiome richness, diversity, and evenness were higher in the agricultural landscape and synanthropic habitat compared to undeveloped-forest habitat. Microbiome composition also differed significantly between agricultural and undeveloped landscapes and forest and synanthropic habitats. We detected overall low diversity and abundance of putative pathogenic bacteria, though putative pathogens were more likely to be found in mice from the agricultural landscape. Our findings show that landscape- and habitat-level anthropogenic factors affect Peromyscus microbiomes and suggest that landscape-level agricultural development may be important to predict zoonotic pathogen prevalence. Ultimately, understanding how anthropogenic land-use change and synanthropy affect rodent microbiomes and pathogen prevalence is important to managing transmission of rodent-borne zoonotic diseases to humans.