Potential therapeutic role of spermine via Rac1 in osteoporosis: Insights from zebrafish and mice.

Osteoporosis is a prevalent metabolic bone disease. While drug therapy is essential to prevent bone loss in osteoporotic patients, current treatments are limited by side effects and high costs, necessitating the development of more effective and safer targeted therapies. Utilizing a zebrafish ( Danio rerio) larval model of osteoporosis, we explored the influence of the metabolite spermine on bone homeostasis. Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption. Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity. Notably, spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae. At the molecular level, Rac1 was identified as playing a pivotal role in mediating the anti-osteoporotic effects of spermine, with P53 potentially acting downstream of Rac1. These findings were confirmed using mouse ( Mus musculus) models, in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions, suggesting strong potential as a bone-strengthening agent. This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development, highlighting pivotal molecular mediators. Given their efficacy and safety, human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.

*Inactivation of encysted muscle larvae of Trichinella spiralis in pigs using Mebendazole.

We evaluated the effect of 4 anthelmintic treatments on the viability of Trichinella spiralis encysted muscle larvae (ML) 55 days post infection (PI) in experimentally infected pigs. Muscle larvae were isolated from pig muscle by artificial digestion after oral treatment of pigs with Levamisole (8 mg/kg, daily for 5 days) and Mebendazole (50 mg/kg, daily for 5 days); Doramectin (0.3 mg/kg, single IM injection), and Moxidectin (0.5 mg/kg, single pour on). Isolated larvae from treated pigs were orally inoculated into mice to assess viability of ML from each treatment. Only Mebendazole treatment of pigs significantly reduced ML viability in mice. The effect of timing of the effective Mebendazole treatment on ML from a longer term infection was then examined in a second experiment. Analysis revealed that Mebendazole treatment of pigs with 250 mg/kg over 3 days (83 mg/kg/day) or 5 days (50 mg/kg/day) reduced numbers of ML recovered from pig tissues compared to untreated, infected controls, and rendered ML non-infective to mice; Mebendazole treatment of pigs with 250 mg/kg in a single dose was not effective in reducing ML numbers recovered from pigs or in impacting ML infectivity to mice. An examination of the lowest effective dose of Mebendazole on encysted ML was determined in a third experiment. Mebendazole of pigs with 5, 50, or 100 mg/kg over 3 days demonstrated that 5 or 50 mg/kg over 3 days insufficient to reduce infectivity in recovered ML, while 100 mg/kg (and 83 g from experiment 2) over 3 days significantly reduces infectivity of ML. This procedure provides a means to evaluate the efficacy of various anthelmintic treatments on the viability of Trichinella spiralis ML in pig tissues, and identified Mebendazole, at 83-100 mg/kg administered over a 3-5 day period as an anthelmintic which renders encysted Trichinella spiralis ML from pig tissues non-infective. As risk from Trichinella significantly impacts acceptance of pork from pasture-raised pigs, these data provide a method, especially for producers of these high-risk pigs, to eliminate the potential of Trichinella transmission from infected pork.

Subcutaneous Alfaxalone-XylazineBuprenorphine for Surgical Anesthesia and Echocardiographic Evaluation of Mice (Mus musculus).

Alfaxalone is a commonly used injectable anesthetic in dogs and cats due to its minimal cardiovascular side effects. Data for its use in mice are limited and demonstrate strain- and sex-associated differences in dose-response relationships. We performed a dose-comparison study of alfaxalone-xylazine-buprenorphine (AXB) in Crl: CFW (SW) mice. Subcutaneous injection of 50 mg/kg alfaxalone-10 mg/kg xylazine-0.1 mg/kg buprenorphine HCl consistently achieved a surgical plane of anesthesia (loss of toe pinch) for 48.6 ± 4.7 and 60.8 ± 9.6 min in females and males, respectively. The same dose and route of AXB induced a surgical plane of anesthesia in C57Bl/6NCrl (females: 42.3 ± 11.2 min; males: 51.6 ± 12.3 min), NCr-Foxn1nu (females: 76.8 ± 32.5 min; males: 80.0 ± 1.2 min), and NOD. Cg-Prkdc SCID Il2rg tm1Wjl /SzJCr (females: 56.0 ± 37.2 min and males: 61.2 ± 10.2 min) mice. We found no significant difference in the duration of the surgical plane of anesthesia between males and females within the mouse strains Crl: CFW (SW), C57Bl/6NCrl, NCr-Foxn1nu, and NOD. Cg-PrkdcSCID Il2rgtm1Wjl /SzJCr. We next performed an echocardiography study (n = 5 per group) of Crl: CFW (SW) mice ( n = 5 per group) to compare subcutaneous AXB anesthesia with that produced by intraperitoneal injection of 100 mg/kg ketamine and 10 mg/kg xylazine (KX). AXB induced significantly less bradycardia (295.4 ± 29 bpm) than KX (185.8 ± 38.9 bpm) did, with no significant differences in cardiac output, ejection fraction, end-diastolic volume, end-systolic volume, or fractional shortening. These results suggest that subcutaneous administration of AXB is a viable alternative to KX for inducing a surgical plane of anesthesia in Crl: CFW (SW), C57Bl/6NCrl, NCr-Foxn1nu, and NOD. Cg-PrkdcSCID Il2rgtm1Wjl /SzJCr mice, regardless of sex. AXB may also be a better injectable anesthetic option as compared with KX for avoiding adverse cardiac effects in mice.

The combined effect of bromadiolone and ivermectin (iBr) in controlling both rodents and their fleas.

Rodent pests not only cause severe agricultural loss but also spread zoonotic pathogens to human beings. Anticoagulant rodenticides are widely used to decrease the population densities of rodents but often lead to the spillover of ectoparasites because fleas and ticks may gather on surviving rodents. Therefore, it is necessary to kill fleas and ticks before culling rodents to minimize the risk of pathogen transmission. In this study, we used a mixture of ivermectin (an antiparasitic drug) and bromadiolone (an anticoagulant rodenticide) to control both rodent and flea/tick abundances. We found that in a laboratory test, 0.01% ivermectin bait was not lethal for greater long-tailed hamsters after 7 days of treatment, while 0.1% ivermectin bait was lethal for approximately 33% of treated rodents. In a field test, bait containing 0.001%, 0.005%, 0.01%, and 0.05% ivermectin decreased the number of fleas per vole of Brandt's voles to 0.42, 0.22, 0.12, and 0.2, respectively, compared with 0.77 in the control group, indicating that 0.01% ivermectin bait performed best in removing fleas. In another laboratory test, bait containing a 0.01% ivermectin and 0.005% bromadiolone mixture caused the death of all voles within 6-14 days after the intake of the bait. In the field test, the bait containing 0.01% ivermectin and 0.005% bromadiolone reduced the average number of fleas per vole to 0.35, which was significantly lower than the 0.77 of the control group. Our results indicate that a 0.01% ivermectin and 0.005% bromadiolone mixture could be used to control both rodents and fleas to minimize the spillover risk of disease transmission when using traditional rodenticides.

The Berberis vulgaris L. extract berberine exerts its anti-oxidant effects to ameliorate cholesterol overloading-induced cell apoptosis in the primary mice hepatocytes: an in vitro study.

Cholesterol overloading stress damages normal cellular functions in hepatocytes and induces metabolic disorders to facilitate the development of multiple diseases, including cardiovascular diseases, which seriously degrades the life quality of human beings. Recent data suggest that the Berberis vulgaris L. extract berberine is capable of regulating cholesterol homeostasis, which is deemed as potential therapeutic drug for the treatment of cholesterol overloading-associated diseases, but its detailed functions and molecular mechanisms are still largely unknown. In the present study, we evidenced that berberine suppressed cell apoptosis in high-cholesterol-diet mice liver and cholesterol-overloaded mice hepatocytes. Also, cholesterol overloading promoted reactive oxygen species (ROS) generation to trigger oxidative damages in hepatocytes, which were reversed by co-treating cells with both berberine and the ROS scavenger N-acetylcysteine (NAC). Moreover, the underlying mechanisms were uncovered, and we validated that berberine downregulated Keap1, and upregulated Nrf2 to activate the anti-oxidant Nrf2/HO-1 signaling pathway in cholesterol overloading-treated hepatocytes, and both Keap1 upregulation and Nrf2 downregulation abrogated the suppressing effects of berberine on cell apoptosis in the hepatocytes with cholesterol exposure. Taken together, we concluded that berberine activated the anti-oxidant Keap1/Nrf2/HO-1 pathway to eliminate cholesterol overloading-induced oxidative stress and apoptotic cell death in mice hepatocytes, and those evidences hinted that berberine might be used as putative therapeutic drug for the treatment of cholesterol overloading-associated cardiovascular diseases.

Chronic lithium treatment ameliorates ketamine-induced mania-like behavior via the PI3K-AKT signaling pathway.

Ketamine, a rapid-acting antidepressant drug, has been used to treat major depressive disorder and bipolar disorder (BD). Recent studies have shown that ketamine may increase the potential risk of treatment-induced mania in patients. Ketamine has also been applied to establish animal models of mania. At present, however, the underlying mechanism is still unclear. In the current study, we found that chronic lithium exposure attenuated ketamine-induced mania-like behavior and c-Fos expression in the medial prefrontal cortex (mPFC) of adult male mice. Transcriptome sequencing was performed to determine the effect of lithium administration on the transcriptome of the PFC in ketamine-treated mice, showing inactivation of the phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) signaling pathway. Pharmacological inhibition of AKT signaling by MK2206 (40 mg/kg), a selective AKT inhibitor, reversed ketamine-induced mania. Furthermore, selective knockdown of AKT via AAV-AKT-shRNA-EGFP in the mPFC also reversed ketamine-induced mania-like behavior. Importantly, pharmacological activation of AKT signaling by SC79 (40 mg/kg), an AKT activator, contributed to mania in low-dose ketamine-treated mice. Inhibition of PI3K signaling by LY294002 (25 mg/kg), a specific PI3K inhibitor, reversed the mania-like behavior in ketamine-treated mice. However, pharmacological inhibition of mammalian target of rapamycin (mTOR) signaling with rapamycin (10 mg/kg), a specific mTOR inhibitor, had no effect on ketamine-induced mania-like behavior. These results suggest that chronic lithium treatment ameliorates ketamine-induced mania-like behavior via the PI3K-AKT signaling pathway, which may be a novel target for the development of BD treatment.

Phytochemical profile and anthelmintic effects of Laurus nobilis essential oil against the ovine nematode Haemonchus contortus and the murine helminth model Heligmosomoides polygyrus.

Small ruminant production in tropical and temperate countries faced substantial anthelmintic resistance due to the intensive use of commercial anthelmintic drugs. Therefore, alternative treatments including natural bioactive compounds with anthelmintic potential have been investigated looking for its successfully use in the parasite control. In the present study, we describe the chemical profile of Laurus nobilis essential oil (EO), the in vitro anthelmintic activity of L. nobilis EO against Haemonchus contortus and its in vivo anthelmintic effect against the murine helminth parasite model Heligmosomoides polygyrus. Chromatographic profile of L. nobilis (EO) extracted from the leaves of L. nobilis have shown the presence of monterpens 1,8-cineol (Eucalyptol) (29.47%), D-Limonène (18.51%) and Linalool (10.84%) in high fractions. The in vitro anthelmintic potential was expressed by an ovicidal effect against H. contortus egg hatching with inhibition value of 1.72 mg/mL and 87.5% of immobility of adult worms after 8 h of exposure to 4 mg/mL of L. nobilis EO. Regarding, the in vivo anthelmintic potential, L. nobilis (EO) at 2400 mg/kg bw completely eliminated the egg output of H. polygyrus after 7 days of oral treatment, together with a 79.2% of reduction in total worm counts. Based on the obtained results, L. nobilis EO showed promising in vitro and in vivo anthelmintic capacities against gastrointestinal parasites.

Evaluation of in vivo Lethality and in vitro Cytotoxic Effect of Odontobuthus bidentatus Scorpion Venom.

The results of numerous studies have revealed that some deadly scorpion venoms are composed of various bioactive molecules that have significant cytotoxic effects on cancer cells. In this study, the in vivo lethality and cytotoxic effect of Odontobuthus bidentatus venom were evaluated in different cancer cell lines. Through MTT assay, the cytotoxic effects of O. bidentatus scorpion venom were analyzed on the MCF-7, A549, AGS, HepG2, and Ht-29 cancer cell lines and Hu02 normal cells. To this end, six venom fractions were obtained through a Sephadex G-50 column, and the cytotoxic effects of isolated fractions were evaluated on A549 lung cancer cells. The median lethal dose of O. bidentatus scorpion venom was determined at 0.73 mg/kg by intravenous administration of different venom doses in male BALB/c mice according to the Spearman-Karber method. The O. bidentatus scorpion whole venom had a significant cytotoxic effect on MCF-7, A549, and AGS cells. The treatment of A549 cells with various concentrations of fraction F1 showed that this fraction significantly induced growth inhibitory effect on the cells in a dose-dependent manner, compared to untreated cells.

The characteristics of population structure and antimicrobial resistance of Streptococcus suis serotype 8, a non-negligible pathotype.

Streptococcus suis, the leading causative agent of swine streptococcosis, is considered as a severe zoonotic and foodborne pathogen for humans. Characteristics of population structure and pathogenicity of S. suis vary significantly by serotypes. As one of the main pathogenic serotypes causing clinical disease in pigs, very little is known about the pathogenicity, population structure, and antimicrobial resistance of S. suis serotype 8 (SS8). In this study, the genome of 26 SS8 strains isolated from healthy and diseased pigs was sequenced. Together with 38 sequences from NCBI, we found that SS8 population was clustered into 12 sequence types (ST) and 4 minimum core genome (MCG) groups, linked to the geographical distribution. Noteworthily, 10 strains belonged to MCG group 1 which was defined to possess the capacity to cause global outbreaks in our previous study. We found that 75% (9/12) of representative SS8 strains were virulent in mice and zebrafish, including all ST1241 strains. No virulence indicators were identified from 67 putative virulence-associated genes mainly identified among pathogenic serotype 2 strains. Instead, we found that the genotype of some of these genes was correlated to their evolution. All 26 isolates were classified as multidrug-resistant strains by antimicrobial susceptibility testing. The high carrying rate of tetO and ermB, mainly disseminated by integrative mobilizable elements, contributed to the prevalent resistance phenotypes to macrolides, lincosamides and tetracyclines. These findings indicated that the pathogenic potential of SS8 cannot be ignored and provided valuable information for SS8 surveillance.

Systemic murine cathelicidin CRAMP safely attenuated colonic neutrophil infiltration in pigs.

Post-weaning diarrheic colitis, often caused by enteropathogens, are severe and potentially lethal diseases in young pigs. Conventional treatment with antibiotics is problematic due to increasing prevalence of multi-drug resistant bacteria. Few alternative treatments exist, so development of antibiotic-free therapies is urgently needed for livestock. Cathelicidin peptides, produced by epithelial cells and neutrophils, are microbicidal compounds capable of modulating innate immune and inflammatory responses. However, the effects of exogenous cathelicidin on gut homeostasis is poorly understood in pigs. We administered the murine cathelicidin CRAMP systemically to healthy pigs, to establish the peptide's safety and assess its ability to modulate colonic mucosal defenses. A single intraperitoneal injection of CRAMP was well tolerated up to two weeks and pigs remained clinically healthy. CRAMP caused some alteration of mucus glycosylation patterns in the colon by increasing sialylated mucins (P < 0.05) and decreased neutrophil influx close to the epithelium (P < 0.001). This study supports further investigation of CRAMP as an immunomodulatory treatment for infectious colitis in pigs.

Combinational benefit of antihistamines and remdesivir for reducing SARS-CoV-2 replication and alleviating inflammation-induced lung injury in mice.

COVID-19 is an immune-mediated inflammatory disease caused by SARS-CoV-2 infection, the combination of anti-inflammatory and antiviral therapy is predicted to provide clinical benefits. We recently demonstrated that mast cells (MCs) are an essential mediator of SARS-CoV-2-initiated hyperinflammation. We also showed that spike protein-induced MC degranulation initiates alveolar epithelial inflammation for barrier disruption and suggested an off-label use of antihistamines as MC stabilizers to block degranulation and consequently suppress inflammation and prevent lung injury. In this study, we emphasized the essential role of MCs in SARS-CoV-2-induced lung lesions in vivo, and demonstrated the benefits of co-administration of antihistamines and antiviral drug remdesivir in SARS-CoV-2-infected mice. Specifically, SARS-CoV-2 spike protein-induced MC degranulation resulted in alveolar-capillary injury, while pretreatment of pulmonary microvascular endothelial cells with antihistamines prevented adhesion junction disruption; predictably, the combination of antiviral drug remdesivir with the antihistamine loratadine, a histamine receptor 1 (HR1) antagonist, dampened viral replication and inflammation, thereby greatly reducing lung injury. Our findings emphasize the crucial role of MCs in SARS-CoV-2-induced inflammation and lung injury and provide a feasible combination antiviral and anti-inflammatory therapy for COVID-19 treatment.

Developing a translational murine-to-canine pathway for an IL-2/agonist anti-CD40 antibody cancer immunotherapy.

Human and canine sarcomas are difficult to treat soft tissue malignancies with an urgent need for new improved therapeutic options. Local recurrence rates for humans are between 10%-30%, and 30%-40% develop metastases. Outcomes for dogs with sarcoma vary with grade but can be similar. Pet dogs share the human environment and represent human cancer with genetic variation in hosts and tumours. We asked if our murine studies using genetically identical mice and cloned tumour cells were translatable to larger, genetically diverse domestic dogs with naturally occurring tumours, to (i) develop a canine cancer therapeutic, and (ii) to use as a translational pathway to humans. Our murine studies showed that intra-tumoral delivery of interleukin-2 (IL-2) plus an agonist anti-CD40 antibody (Ab) induces long-term curative responses ranging from 30% to 100%, depending on tumour type. We developed an agonist anti-canine-CD40 Ab and conducted a phase I dose finding/toxicology 3 + 3 clinical trial in dogs (n = 27) with soft tissue sarcomas on account of suitability for intratumoral injection and straightforward monitoring. Dogs were treated with IL-2 plus anti-CD40 antibody for 2 weeks. Three dose levels induced tumour regression with minimal side effects, measured by monitoring, haematological and biochemical assays. Importantly, our mouse and canine studies provide encouraging fundamental proof-of-concept data upon which we can develop veterinary and human immunotherapeutic strategies.

Assessment of FDA-approved drugs against Strongyloides ratti in vitro and in vivo to identify potentially active drugs against strongyloidiasis.

BACKGROUND: Infections with Strongyloides stercoralis belong to the most neglected helminth diseases, and research and development (R&D) efforts on novel drugs are inadequate. METHODS: A commercially available library containing 1600 FDA-approved drugs was tested in vitro against Strongyloides ratti larvae (L3) at 100 µM. Hits (activity > 70%) were then evaluated against S. ratti adult worms at 10 µM. Morantel, prasterone, and levamisole were tested in the S. ratti rat model using dosages of 1-100 mg/kg. RESULTS: Seventy-one of the 1600 compounds tested against S. ratti L3 revealed activity above 70%. Of 64 compounds which progressed into the adult screen, seven compounds achieved death of all worms (benzethonium chloride, cetylpyridinium chloride, Gentian violet, methylbenzethonium chloride, morantel citrate, ivermectin, coumaphos), and another eight compounds had activity > 70%. Excluding topical and toxic compounds, three drugs progressed into in vivo studies. Prasterone lacked activity in vivo, while treatment with 100 mg/kg morantel and levamisole cured all rats. The highest in vivo activity was observed with levamisole, yielding a median effective dose (ED50) of 1.1 mg/kg. CONCLUSIONS: Using a drug repurposing approach, our study identified levamisole as a potential backup drug for strongyloidiasis. Levamisole should be evaluated in exploratory clinical trials.

Plasma-based strategy for inhibiting Candida albicans growth and CaMCA1 gene expression in vitro and reducing fungal pathogenicity in a murine model of vulvovaginal candidiasis.

Vulvovaginal candidiasis (VVC) is a common mucosal infection, mainly caused by Candida albicans. The use of common antifungal drugs in treatment of VVC is limited due to emergence of resistant fungal strains and severe side effects. Cold atmospheric plasma (CAP) as a novel therapeutic approach is proven to display strong antifungal activity against C. albicans. In the present study, the effects of CAP treatment on virulence and pathogenicity of C. albicans in a murine model was investigated. Candida albicans was treated with CAP at different time exposures. Fungal cell morphology and the expression profile of CaMCA1 gene in CAP-treated fungus was evaluated using electron microscopy and quantitative RT-PCR. Moreover, the mice model of VVC was developed using CAP-treated and non-treated C. albicans and characterized in terms of vaginal fungal burden, the rate of hyphae formation in the vaginal tissue and fluid and the inflammation degree of mice vaginal tissue. Significant reduction in CaMCA1 expression and remarkable mitochondrial degradation were observed in CAP-treated C. albicans cells. The lowest fungal burden, reduced hyphae formation, poor adherence of yeast cells to vaginal epithelium, and the low degree of inflammation were observed in mice infected with CAP-treated C. albicans. Suppression of CaMCA1 gene and mitochondrial degradation in CAP-treated C. albicans yeast cells may diminish yeast to hyphae transition and reduce fungal pathogenicity in murine model of VVC. CAP treatment can be considered as a novel and efficient therapeutic strategy against C. albicans and related Candida infections in practice. LAY SUMMARY: CAP was successfully used to inhibit fungal growth and CaMCA1 gene expression in C. albicans. It caused morphological alterations in membranous structures of the yeast cells and finally led to the cell death. CAP meaningfully reduced C. albicans virulence and pathogenicity in a murine model of VVC.

Spilanthol as a promising antifungal alkylamide for the treatment of vulvovaginal candidiasis.

Spilanthol is a bioactive alkylamide from the native Amazon plant species, Acmella oleracea. However, antifungal activities of spilanthol and its application to the therapeutic treatment of candidiasis remain to be explored. This study sought to evaluate the in vitro and in vivo antifungal activity of spilanthol previously isolated from A. oleracea (spilanthol(AcO)) against Candida albicans ATCC® 10231™, a multidrug-resistant fungal strain. Microdilution methods were used to determine inhibitory and fungicidal concentrations of spilanthol(AcO). In planktonic cultures, the fungal growth kinetics, yeast cell metabolic activity, cell membrane permeability and cell wall integrity were investigated. The effect of spilanthol(AcO) on the proliferation and adhesion of fungal biofilms was evaluated by whole slide imaging and scanning electron microscopy. The biochemical composition of the biofilm matrix was also analyzed. In parallel, spilanthol(AcO) was tested in vivo in an experimental vulvovaginal candidiasis model. Our in vitro analyses in C. albicans planktonic cultures detected a significant inhibitory effect of spilanthol(AcO), which affects both yeast cell membrane and cell wall integrity, interfering with the fungus growth. C. albicans biofilm proliferation and adhesion, as well as, carbohydrates and DNA in biofilm matrix were reduced after spilanthol(AcO) treatment. Moreover, infected rats treated with spilanthol(AcO) showed consistent reduction of both fungal burden and inflammatory processes compared to the untreated animals. Altogether, our findings demonstrated that spilanthol(AcO) is an bioactive compound against planktonic and biofilm forms of a multidrug resistant C. albicans strain. Furthermore, spilanthol(AcO) can be potentially considered for therapeutical treatment of vulvovaginal candidiasis caused by C. albicans. LAY SUMMARY: This study sought to evaluate the antifungal activity of spilanthol against Candida albicans ATCC® 10 231™, a multidrug-resistant fungal strain. Our findings demonstrated that spilanthol(AcO) can be potentially considered for therapeutical treatment of vulvovaginal candidiasis caused by C. albicans.

Complexing amphotericin B with gold nanoparticles improves fungal clearance from the brains of mice infected with Cryptococcal neoformans.

Amphotericin B (AmB) is used to treat cryptococcal meningoencephalitis. However, the mortality rate remains high. Higher doses of AmB in deoxycholate buffer (AmBd) are toxic to human red blood cells (hRBC) and have no effect on brain organism load in mice. Here we show that while AmBd lysed 96% of hRBC, AmB complexed with gold nanoparticles (AuNP-SA-AmB) lysed only 27% of hRBC. In vitro growth of C. neoformans was inhibited by 0.25 µg/ml AmBd and 0.04 µg/ml of AuNP-SA-AmB. In mice infected with C. neoformans, five daily treatments with AuNP-SA-AmB containing 0.25 mg/kg AmB significantly lowered the fungal burden in the brain tissue compared to either untreated or treatment with 0.25 mg/kg of AmBd. When a single dose of AmBd was injected intravenously into BALB/c mice, 81.61% of AmB cleared in the α-phase and 18.39% cleared in the ß-phase at a rate of 0.34% per hour. In contrast, when AuNP-SA-AmB was injected, 49.19% of AmB cleared in the α-phase and 50.81% of AmB cleared in the ß-phase at a rate of 0.27% per hour. These results suggest that AmB complexed with gold nanoparticles is less toxic to hRBC, is more effective against C. neoformans and persists longer in blood when injected into mice resulting in more effective clearing of C. neoformans from the brain tissue. LAY SUMMARY: Amphotericin B (AmB) was complexed with gold nanoparticles (AuNP-SA-AmB) to improve brain delivery. AuNP-SA-AmB was more effective than AmB alone in clearing of Cryptococcus neoformans from the brain tissue of infected mice. This may be due to longer plasma half-life of AmB as AuNP-SA-AmB.

Prevention of Lyme and other tickborne diseases using a rodent-targeted approach: A randomized controlled trial in Connecticut.

Tickborne diseases are an increasing public health problem in the northeastern USA. Bait boxes that apply acaricide to rodents have been shown in small field studies to significantly reduce abundance of Ixodes scapularis ticks as well as their pathogen infection rates in treated areas. The effectiveness of this intervention for preventing human tickborne diseases (TBDs) has not been demonstrated. During 2012-2016, TickNET collaborators conducted a randomized, blinded, placebo-controlled trial among 622 Connecticut households. Each household received active (containing fipronil wick) or placebo (empty) bait boxes in their yards over two consecutive years. Information on tick encounters and TBDs among household members was collected through biannual surveys. Nymphal ticks were collected from a subset of 100 properties during spring at baseline, during treatment, and in the year post-intervention. Demographic and property characteristics did not differ between treatment groups. There were no significant differences post-intervention between treatment groups with respect to tick density or pathogen infection rates, nor for tick encounters or TBDs among household members. We found no evidence that rodent-targeted bait boxes disrupt pathogen transmission cycles or significantly reduce household risk of tick exposure or TBDs. The effectiveness of this intervention may depend on scale of use or local enzootic cycles.

Case series: Efficacy of a formulation containing selamectin and sarolaner against naturally acquired mite infestations (Demodex sp., Ornithonyssus bacoti) in degus (Octodon degus).

Ectoparasite infestations are not common in degus. Two cases are presented here where use of Stronghold® Plus/Revolution® Plus (selamectin and sarolaner topical solution) was successfully administered to a degu (Octodon degus) for treatment of naturally-occurring mite infesations. Selamectin (Stronghold®/Revolution®) has been demonstrated to be effective against naturally-occurring mite infections in dogs and selamectin is approved for use in dogs for the treatment of sarcoptic mange (caused by Sarcoptes scabiei) at a dose of 6 mg/kg. In the first case, a 2.6-years-old female degu housed in a group with four other degus was presented with pruritic skin reactions, restlessness and hairloss. Mites morphologically similar to Demodex sp. were detected in the deep skin scrapings. All four degus were treated with Stronghold® Plus/Revolution® Plus (30 mg/kg selamectin and 5 mg/kg sarolaner) once a week for a total of six treatments. The spot-on was administered topically on the dorsal cervical region. Following treatment the degu presenting with clinical signs showed a rapid improvement with the pruritus and overall dermatitis resolving within 2 weeks of treatment. Skin scrapes and microscopic examination of epidermal debris collected from the affected degu were negative for mites from day 14 onwards. In the second case, a group of four 4-6.5-years-old female and male degus that were housed together were infested with Ornithonyssus bacoti. All animals were treated with 30 mg/kg selamectin and 5 mg/kg sarolaner in four total weekly doses. One week later no living mites were found on the patients or in their environment. The four degus improved visibly, and within three weeks of treatment the skin lesions associated with the infestation subsided. The antiparasiticides showed a satisfactory efficacy and were well tolerated (n = 9 animals treated in a total).

Evaluation of Orally Administered Anthelmintic Treatment Options for Dentostomella translucida in Naturally Infected Mongolian Gerbils (Meriones unguiculatus)

Objective: This study aimed to evaluate the efficacy of eprinomectin, moxidectin and fenbendazole for treating Dentostomella translucida infections in naturally infected Mongolian gerbils (Meriones unguiculatus). Methods: A total of 28 gerbils were placed in individually numbered cages to determine the individual animal parasite load. Eggs per gram (EPG) counts were used to estimate the efficacy of the drugs. The day before the anthelmintic administration was denoted as day 0, and the EPG counts were determined by the McMaster technique from the stool removed from the cage bottom on days 7, 14, 21 and 28. The animals were assigned to one of four treatment groups according to their day 0 EPG counts. The orally administered drugs in the treatment groups were eprinomectin (15 mg/kg), moxidectin (0.4 mg/kg) and fenbendazole (12 mg/kg) for groups 1-3, respectively. The fourth group served as the control (without any drug administration). Results: Treatment efficacy was evaluated based on weekly EPG counts. The values decreased to zero in the fenbendazole group at 4 weeks of follow-up after treatment, and no parasite was found in any of the repeated examinations. The eprinomectin and moxidectin groups exhibited a fluctuating EPG state on both individual and group basis. Conclusion: D. translucida, which is known as the specific parasite of gerbils, can easily affect other members of the animal colony; thus, the control of its presence in gerbil breeding units is necessary. Therefore, the reported effective drug treatments are important for the fight against the investigated parasitic infection.

Meta-analyses of Schistosoma japonicum infections in wild rodents across China over time indicates a potential challenge to the 2030 elimination targets.

China once suffered greatly from schistosomiasis japonica, a major zoonotic disease. Nearly 70 years of multidisciplinary efforts have achieved great progress in disease control, with infections in both humans and bovines significantly reduced to very low levels. However, reaching for the target of complete interruption of transmission at the country level by 2030 still faces great challenges, with areas of ongoing endemicity and/or re-emergence within previously 'eliminated' regions. The objectives of this study were, by using meta-analytical methods, to estimate the overall prevalence of Schistosoma japonicum infections in abundant commensal rodent species in mainland China after the introduction of praziquantel for schistosomiasis treatment in humans and bovines in 1980s. In doing so we thereby aimed to further assess the role of wild rodents as potential reservoirs in ongoing schistosome transmission. Published studies on infection prevalence of S. japonicum in wild rodents in mainland China since 1980 were searched across five electronic bibliographic databases and lists of article references. Eligible studies were selected based on inclusion and exclusion criteria. Risks of within and across study biases, and the variations in prevalence estimates attributable to heterogeneities were assessed. The pooled infection prevalence and its 95% confidence intervals (CIs) were calculated with the Freeman-Tukey double arcsine transformation. We identified a total of 37 relevant articles involving 61 field studies which contained eligible data on 8,795 wild rodents across mainland China. The overall pooled infection prevalence was 3.86% (95% CI: 2.16-5.93%). No significant change in the overall pooled prevalence was observed between 1980-2003 (n = 23 studies) and 2004-current (n = 38 studies). However, whilst the estimated prevalence decreased over time in the marshland and lake regions, there was an apparent increase in prevalence within hilly and mountainous regions. Among seven provinces, a significant prevalence reduction was only seen in Jiangsu where most endemic settings are classified as the marshland and lakes. These estimates changed over season, ranging from 0.58% in spring to 22.39% in winter, in association with increases in rodent density. This study systematically analyzed S. japonicum infections in wild rodents from the published literature over the last forty years after the introduction of praziquantel for schistosomiasis treatment in humans and bovines in 1980s. Although numbers of schistosomiasis cases in humans and bovines have been greatly reduced, no such comparable overall change of infection prevalence in rodents was detected. Furthermore, there appeared to be an increase in S. japonicum prevalence in rodents over time within hilly and mountainous regions. Rodents have been projected to become the dominant wildlife in human-driven environments and the main reservoir of zoonotic diseases in general within tropical zones. Our findings thus suggest that it is now necessary to include monitoring and evaluation of potential schistosome infection within rodents, particularly in hilly and mountainous regions, if we are ever to reach the new 2030 elimination goals and to maximize the impact of future public, and indeed One Health, interventions across, regional, national and international scales.