Therapy and prevention of cryptosporidiosis in animals

A fractional perspective on the transmission dynamics of a parasitic infection, considering the impact of both strong and weak immunity

Infectious disease cryptosporidiosis is caused by the cryptosporidium parasite, a type of parasitic organism. It is spread through the ingestion of contaminated water, food, or fecal matter from infected animals or humans. The control becomes difficult because the parasite may remain in the environment for a long period. In this work, we constructed an epidemic model for the infection of cryptosporidiosis in a fractional framework with strong and weak immunity concepts. In our analysis, we utilize the well-known next-generation matrix technique to evaluate the reproduction number of the recommended model, indicated by [Formula: see text]. As [Formula: see text], our results show that the disease-free steady-state is locally asymptotically stable; in other cases, it becomes unstable. Our emphasis is on the dynamical behavior and the qualitative analysis of cryptosporidiosis. Moreover, the fixed point theorem of Schaefer and Banach has been utilized to investigate the existence and uniqueness of the solution. We identify suitable conditions for the Ulam-Hyers stability of the proposed model of the parasitic infection. The impact of the determinants on the sickness caused by cryptosporidiosis is highlighted by the examination of the solution pathways using a novel numerical technique. Numerical investigation is conducted on the solution pathways of the system while varying various input factors. Policymakers and health officials are informed of the crucial factors pertaining to the infection system to aid in its control.

In silico and in vivo evaluation of the anti-cryptosporidial activity of eugenol

Background

Cryptosporidiosis is an opportunistic parasitic disease widely distributed worldwide. Although Cryptosporidium sp. causes asymptomatic infection in healthy people, it may lead to severe illness in immunocompromised individuals. Limited effective therapeutic alternatives are available against cryptosporidiosis in this category of patients. So, there is an urgent need for therapeutic alternatives for cryptosporidiosis. Recently, the potential uses of Eugenol (EUG) have been considered a promising novel treatment for bacterial and parasitic infections. Consequently, it is suggested to investigate the effect of EUG as an option for the treatment of cryptosporidiosis.

Materials and methods

The in silico bioinformatics analysis was used to predict and determine the binding affinities and intermolecular interactions of EUG and Nitazoxanide (NTZ) toward several Cryptosporidium parvum (C. parvum) lowa II target proteins. For animal study, five groups of immunosuppressed Swiss albino mice (10 mice each) were used. Group I was left uninfected (control), and four groups were infected with 1,000 oocysts of Cryptosporidium sp. The first infected group was left untreated. The remaining three infected groups received NTZ, EUG, and EUG + NTZ, respectively, on the 6th day post-infection (dpi). All mice were sacrificed 30 dpi. The efficacy of the used formulas was assessed by counting the number of C. parvum oocysts excreted in stool of infected mice, histopathological examination of the ileum and liver tissues and determination of the expression of iNOS in the ileum of mice in different animal groups.

Results

treatment with EUG resulted in a significant reduction in the number of oocysts secreted in stool when compared to infected untreated mice. In addition, oocyst excretion was significantly reduced in mice received a combination therapy of EUG and NTZ when compared with those received NTZ alone. EUG succeeded in reverting the histopathological alterations induced by Cryptosporidium infection either alone or in combination with NTZ. Moreover, mice received EUG showed marked reduction of the expression of iNOS in ileal tissues.

Conclusion

Based on the results, the present study signified a basis for utilizing EUG as an affordable, safe, and alternative therapy combined with NTZ in the management of cryptosporidiosis.

MCT-Dependent Cryptosporidium parvum-Induced Bovine Monocyte Extracellular Traps (METs) under Physioxia

The apicomplexan protozoan parasite Cryptosporidium parvum is responsible for cryptosporidiosis, which is a zoonotic intestinal illness that affects newborn cattle, wild animals, and people all over the world. Mammalian monocytes are bone marrow-derived myeloid leukocytes with important defense effector functions in early host innate immunity due to their ATP purinergic-, CD14- and CD16-receptors, adhesion, migration and phagocytosis capacities, inflammatory, and anti-parasitic properties. The formation of monocyte extracellular traps (METs) has recently been reported as an additional effector mechanism against apicomplexan parasites. Nonetheless, nothing is known in the literature on METs extrusion neither towards C. parvum-oocysts nor sporozoites. Herein, ATP purinergic receptor P2X1, glycolysis, Notch signaling, and lactate monocarboxylate transporters (MCT) were investigated in C. parvum-exposed bovine monocytes under intestinal physioxia (5% O₂) and hyperoxia (21% O₂; most commonly used hyperoxic laboratory conditions). C. parvum-triggered suicidal METs were confirmed by complete rupture of exposed monocytes, co-localization of extracellular DNA with myeloperoxidase (MPO) and histones (H1-H4) via immunofluorescence- and confocal microscopy analyses. C. parvum-induced suicidal METs resulted not only in oocyst entrapment but also in hindered sporozoite mobility from oocysts according to scanning electron microscopy (SEM) analyses. Early parasite-induced bovine monocyte activation, accompanied by membrane protrusions toward C. parvum-oocysts/sporozoites, was unveiled using live cell 3D-holotomographic microscopy analysis. The administration of NF449, an inhibitor of the ATP purinergic receptor P2X1, to monocytes subjected to varying oxygen concentrations did not yield a noteworthy decrease in C. parvum-induced METosis. This suggests that the cell death process is not dependent on P2X1. Additionally, blockage of glycolysis in monocyte through 2-deoxy glucose (2-DG) inhibition reduced C. parvum-induced METosis but not significantly. According to monocyte energetic state measurements, C. parvum-exposed cells neither increased extracellular acidification rates (ECAR) nor oxygen consumption rates (OCR). Lactate monocarboxylate transporters (MCT) inhibitor (i.e., AR-C 141990) treatments significantly diminished C. parvum-mediated METs extrusion under physioxic (5% O₂) condition. Similarly, treatment with either DAPT or compound E, two selective Notch inhibitors, exhibited no significant suppressive effects on bovine MET production. Overall, for the first time, we demonstrate C. parvum-mediated METosis as P2X1-independent but as an MCT-dependent defense mechanism under intestinal physioxia (5% CO₂) conditions. METs findings suggest anti-cryptosporidial effects through parasite entrapment and inhibition of sporozoite excystation.

Investigation of the prophylactic and therapeutic effectiveness of oral thyme extract in rats experimentally infected with cryptosporidium parvum

In this study, the prophylactic and therapeutic activities of thyme extract at different concentrations against experimental Cryptosporidium parvum infection in immunosuppressed rats were investigated. Thyme extract was prepared at four different concentrations (10%, 30%, 50%, and 100%) and administered as a single oral dose of 1 mL for evaluation of its prophylactic efficacy. Five consecutive days after infection was detected in all rats, therapeutic evaluations were also performed. According to the results obtained by daily counting of oocysts in stools, the prophylactic and therapeutic effects of thyme extract administration were significant in comparison to the control group (P˂0.01). Oocyst shedding continued in the control group at high numbers from the beginning to the end of the study, while oocyst counts in the prophylaxis groups remained low throughout the study. On the other hand, oocyst excretion rates were high in the therapeutic groups and decreased rapidly after thyme extract administration. At the end of the study, oocyst excretion had completely stopped for some rats administered thyme extract. There was no group in which oocyst shedding ceased for all rats. No significant differences were observed in the therapeutic or prophylaxis groups regarding the doses administered (P > 0.01). Renal and hepatic functions were monitored by measuring urea, creatinine, alanine transaminase, and aspartate transaminase levels ​​before and after thyme extract administration. As a result, it was concluded that oral thyme extract administration at the doses applied in this study is effective and safe in the prophylactic and therapeutic treatment of experimental cryptosporidiosis in rats.

Modeling cryptosporidiosis in humans and cattle: Deterministic and stochastic approaches

Cryptosporidiosis is a zoonotic disease caused by Cryptosporidium. The disease poses a public and veterinary health problem worldwide. A deterministic model and its corresponding continuous time Markov chain (CTMC) stochastic model are developed and analyzed to investigate cryptosporidiosis transmission dynamics in humans and cattle. The basic reproduction number R 0 for the deterministic model and stochastic threshold for the CTMC stochastic model are computed by the next generation matrix method and multitype branching process, respectively. The normalized forward sensitivity index method is used to determine the sensitivity index for each parameter in R 0 . Per capita birth rate of cattle, the rate of cattle to acquire cryptosporidiosis infection from the environment and the rate at which infected cattle shed Cryptosporidium oocysts in the environment play an important role in the persistence of the disease whereas Cryptosporidium oocysts natural death rate, cattle recovery rate and cattle natural death rate are most negative sensitive parameters in the dynamics of cryptosporidiosis. Numerical results for CTMC stochastic model show that the likelihood of cryptosporidiosis extinction is high when it arises from an infected human. However, there is a major outbreak if cryptosporidiosis emerges either from infected cattle or from Cryptosporidium oocysts in the environment or when it emerges from all three infectious compartments. Therefore to control the disease, control measures should focus on maintaining personal and cattle farm hygiene and decontaminating the environment to destroy Cryptosporidium oocysts.

Cryptosporidiosis: From Prevention to Treatment, a Narrative Review

Cryptosporidiosis is a water- and food-borne zoonotic disease caused by the protozoon parasite of the genus Cryptosporidium. C. hominis and C. parvum are the main two species causing infections in humans and animals. The disease can be transmitted by the fecal-oral route as well as the respiratory route. The infective stage (sporulated oocysts) is resistant to different disinfectants including chlorine. Currently, no effective therapeutic drugs or vaccines are available to treat and control Cryptosporidium infection. To prevent cryptosporidiosis in humans and animals, we need to understand better how the disease is spread and transmitted, and how to interrupt its transmission cycle. This review focuses on understanding cryptosporidiosis, including its infective stage, pathogenesis, life cycle, genomics, epidemiology, previous outbreaks, source of the infection, transmission dynamics, host spectrum, risk factors and high-risk groups, the disease in animals and humans, diagnosis, treatment and control, and the prospect of an effective anti-Cryptosporidium vaccine. It also focuses on the role of the One Health approach in managing cryptosporidiosis at the animal-human-environmental interface. The summarized data in this review will help to tackle future Cryptosporidium infections in humans and animals and reduce the disease occurrence.

Diagnosis and control of cryptosporidiosis in farm animals

Cryptosporidium is a pathogenic protozoan parasite infecting the gastrointestinal epithelium of human and animal hosts. In farm animals, cryptosporidiosis causes significant economic losses including deaths in newborn animals, retarded growth, increased labor involved and high cost of drugs. The detection of Cryptosporidium oocysts in fecal samples is traditionally dependent on examination of stained slides by light microscope or by advanced microscopical tools such as: electron microscopy and phase contrast microscopy. Immunological diagnosis using either antibody or antigen detection could offer high sensitivity and specificity. Examples for these tests are Enzyme Linked Immunosorbent Assay (ELISA), Immunochromatographic tests, Immunochromatographic lateral flow (ICLF), Immunofluorescence assays (IFA) and Flow cytometry coupled with cell sorting. Molecular methods could differentiate species and genotypes of Cryptosporidium and help in studying the epidemiological features of this parasite with rapid, simple and sensitive procedures. Nanotechnology-based platforms could improve the sensitivity and specificity of other detection methods like: ELISA, ICLF, IFA and polymerase chain reaction. As the available prophylactic and therapeutic drugs or natural products treatments are insufficient and no approved vaccines are available, the best approach to control this parasite is by following firm hygienic measures. Many vaccine attempts were performed using hyperimmune colostrum, live or attenuated vaccines, recombinant and Deoxyribonucleic acid vaccines. Also, Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 technology could help in Cryptosporidium genome editing to improve drug and vaccine discovery. Another approach that could be useful for assigning drug targets is metabolomics. Probiotics were also used successfully in the treatment of acute diarrhea and they proved a limiting effect on cryptosporidiosis in animal models. In addition, nanotherapy-based approaches could provide a good strategy for improving the potency of any type of drugs against Cryptosporidium and give good anti-cryptosporidial effects. In conclusion, accurate diagnosis using advanced techniques is the key to the control and prevention of cryptosporidiosis.

Risk factors for Cryptosporidium infection in small ruminants in northern Greece

The knowledge of risk factors for Cryptosporidium spp. infection in small ruminants is based on limited data. Therefore, the current research aimed to describe the prevalence and risk factors associated with the occurrence of Cryptosporidium infection in sheep and goat herds in northern Greece. Hence, 530 fresh fecal samples from 59 sheep and goat farms were collected and examined for Cryptosporidium oocysts using microscopy of fecal smears stained by the modified Ziehl-Neelsen technique. The overall prevalence of Cryptosporidium infection for both host species was 34% (180/530; 95% confidence interval (CI): 29.9-38). Specifically, the prevalence for sheep and goats was 33.5% (112/334; 95% CI: 28.4-35.6) and 34.7% (68/196; 95% CI: 28-41.4), respectively. Additionally, standardized questionnaires were filled-in to collect data regarding animals' health status, feeding, and other management practices in each farm. In total 22 risk factors hypothesized to be associated with Cryptosporidium infection were investigated. Multiple logistic regression analysis showed that farms with stagnant water were 11.78 (95% CI: 66-61.5) times more likely to be infected with Cryptosporidium than farms without stagnant water (p < 0.05). Furthermore, farms with more than 25% of their animals suffering from diarrhea were 17.39 (95% CI: 3.43-88.3) times more likely to be infected with Cryptosporidium than farms with ≤ 25% of the animals having diarrhea (p < 0.05). These results suggest that the animal health status and the prevailing environmental conditions play an important role in transmitting Cryptosporidium spp. infection.

Velásquez Z, Borggrefe T, Gärtner U, Kamena F, Taubert A, Hermosilla C. ATP Purinergic Receptor P2X1-Dependent Suicidal NETosis Induced by Cryptosporidium parvum under Physioxia Conditions

Cryptosporidiosis is a zoonotic intestinal disease that affects humans, wildlife, and neonatal cattle, caused by Cryptosporidium parvum. Neutrophil extracellular traps (NETs), also known as suicidal NETosis, are a powerful and ancient innate effector mechanism by which polymorphonuclear neutrophils (PMN) battle parasitic organisms like protozoa and helminths. Here, C. parvum oocysts and live sporozoites were utilized to examine suicidal NETosis in exposed bovine PMN under both 5% O₂ (physiological conditions within small intestinal tract) and 21% O₂ (normal hyperoxic conditions in research facilities). Both sporozoites and oocysts induced suicidal NETosis in exposed PMN under physioxia (5% O₂) and hyperoxia (21% O₂). Besides, C. parvum-induced suicidal NETosis was affirmed by total break of PMN, co-localization of extracellular DNA decorated with pan-histones (H1A, H2A/H2B, H3, H4) and neutrophil elastase (NE) by means of confocal- and immunofluorescence microscopy investigations. C. parvum-triggered NETs entrapped sporozoites and impeded sporozoite egress from oocysts covered by released NETs, according to scanning electron microscopy (SEM) examination. Live cell 3D-holotomographic microscopy analysis visualized early parasite-induced PMN morphological changes, such as the formation of membrane protrusions towards C. parvum while undergoing NETosis. Significant reduction of C. parvum-induced suicidal NETosis was measured after PMN treatments with purinergic receptor P2X1 inhibitor NF449, under both oxygen circumstances, this receptor was found to play a critical role in the induction of NETs, indicating its importance. Similarly, inhibition of PMN glycolysis via 2-deoxy glucose treatments resulted in a reduction of C. parvum-triggered suicidal NETosis but not significantly. Extracellular acidification rates (ECAR) and oxygen consumption rates (OCR) were not increased in C. parvum-exposed cells, according to measurements of PMN energetic state. Treatments with inhibitors of plasma membrane monocarboxylate transporters (MCTs) of lactate failed to significantly reduce C. parvum-mediated NET extrusion. Concerning Notch signaling, no significant reduction was detected after PMN treatments with two specific Notch inhibitors, i.e., DAPT and compound E. Overall, we here describe for the first time the pivotal role of ATP purinergic receptor P2X1 in C. parvum-mediated suicidal NETosis under physioxia (5% O₂) and its anti-cryptosporidial properties.

Chitosan Protects Immunosuppressed Mice Against Cryptosporidium parvum Infection Through TLR4/STAT1 Signaling Pathways and Gut Microbiota Modulation

Cryptosporidium parvum infection is very common in infants, immunocompromised patients, or in young ruminants, and chitosan supplementation exhibits beneficial effects against the infection caused by C. parvum. This study investigated whether chitosan supplementation modulates the gut microbiota and mediates the TLR4/STAT1 signaling pathways and related cytokines to attenuate C. parvum infection in immunosuppressed mice. Immunosuppressed C57BL/6 mice were divided into five treatment groups. The unchallenged mice received a basal diet (control), and three groups of mice challenged with 1 × 10⁶ C. parvum received a basal diet, a diet supplemented with 50 mg/kg/day paromomycin, and 1 mg/kg/day chitosan, and unchallenged mice treated with 1 mg/kg/day chitosan. Chitosan supplementation regulated serum biochemical indices and significantly (p < 0.01) reduced C. parvum oocyst excretion in infected mice treated with chitosan compared with the infected mice that received no treatment. Chitosan-fed infected mice showed significantly (p < 0.01) decreased mRNA expression levels of interferon-gamma (IFN-γ) and tumor necrosis factor-α (TNF-α) compared to infected mice that received no treatment. Chitosan significantly inhibited TLR4 and upregulated STAT1 protein expression (p < 0.01) in C. parvum-infected mice. 16S rRNA sequencing analysis revealed that chitosan supplementation increased the relative abundance of Bacteroidetes/Bacteroides, while that of Proteobacteria, Tenericutes, Defferribacteres, and Firmicutes decreased (p < 0.05). Overall, the findings revealed that chitosan supplementation can ameliorate C. parvum infection by remodeling the composition of the gut microbiota of mice, leading to mediated STAT1/TLR4 up- and downregulation and decreased production of IFN-γ and TNF-α, and these changes resulted in better resolution and control of C. parvum infection.

Curcumin mitigates Cryptosporidium parvum infection through modulation of gut microbiota and innate immune-related genes in immunosuppressed neonatal mice

Cryptosporidium parvum is a major cause of diarrheal disease in immature or weakened immune systems, mainly in infants and young children in resource-poor settings. Despite its high prevalence, fully effective and safe drugs for the treatment of C. parvum infections remain scarce, and there is no vaccine. Meanwhile, curcumin has shown protective effects against C. parvum infections. However, the mechanisms of action and relationship to the gut microbiota and innate immune responses are unclear. Immunosuppressed neonatal mice were infected with oocysts of C. parvum and either untreated or treated with a normal diet, curcumin or paromomycin. We found that curcumin stopped C. parvum oocysts shedding in the feces of infected immunosuppressed neonatal mice, prevented epithelial damage, and villi degeneration, as well as prevented recurrence of infection. Curcumin supplementation increased the relative abundance of Bacteroidetes and decreased the relative abundance of Firmicutes and Proteobacteria in mice infected with C. parvum as shown by 16S rRNA gene sequencing analysis. The relative abundance of Lactobacillus, Bacteroides, Akkermansia, Desulfovibrio, Prevotella, and Helicobacter was significantly associated with C. parvum infection inhibited by curcumin. Curcumin significantly (P < 0.01) suppressed IFN-γ and IL -18 gene expression levels in immunosuppressed neonatal C. parvum-infected mice. We demonstrate that the therapeutic effects curcumin are associated with alterations in the gut microbiota and innate immune-related genes, which may be linked to the anti-Cryptosporidium mechanisms of curcumin.

The Effects of Commercially Available Syzygium aromaticum, Anethum graveolens, Lactobacillus acidophilus LB, and Zinc as Alternatives Therapy in Experimental Mice Challenged with Cryptosporidium parvum

BACKGROUND

Waterborne cryptosporidiosis is the second cause of diarrhea in young children and immunocompromised hosts after rotavirus. Except for nitazoxanide (NTZ), there is no accredited cryptosporidiosis treatment to date. Therefore, there is an urgent need to find an effective and safe treatment for cryptosporidiosis. This study aimed to investigate the possible anti-protozoal effects of Syzygium aromaticum (clove) oil, Anethum graveolens (dill) seeds oil, Lactobacillus acidophilus LB, and zinc against Cryptosporidium parvum in comparison to NTZ.

METHODS

Besides the negative control, mice from six experimental groups (T1-T6) were infected with Cryptosporidium parvum oocysts. On the seventh day post-infection (PID), mice from five groups were treated for 8 consecutive days with NTZ, clove oil, dill seed oil, Lactobacillus acidophilus LB, and zinc commercial forms (T2-T5). Oocysts shedding rate, differences of mice body weight, serum IL10, and TNF-α, cryptosporidial antigen, and cd3 at the intestinal mucosa were evaluated at the end of the experiment.

RESULTS

The mean of the C. parvum oocysts' shedding rate was significantly lower in all treated groups than in the non-treated group. The oocysts reduction rate was the highest in zinc-treated mice (98.3%), Lactobacillus acidophilus LB and dill-treated groups (95.77%), and the NTZ-treated group (91.55%). Clove oil was the least effective, with a 74.65% reduction rate. Excluding the clove oil-treated group, immunohistochemical analysis revealed the clearance of the Cryptosporidium antigen in the intestinal tissue in all treated groups.

CONCLUSION

The study has provided a rational basis for using these safe, cheap, and commercially available alternatives in treating cryptosporidiosis combined with NTZ.

Dual transcriptomics to determine interferon-gamma independent host response to intestinal Cryptosporidium parvum infection

Animals with a chronic infection of the parasite Toxoplasma gondii are protected against lethal secondary infection with other pathogens. Our group previously determined that soluble T. gondii antigens (STAg) can mimic this protection and be used as a treatment against several lethal pathogens. Because treatments are limited for the parasite Cryptosporidium parvum, we tested STAg as a C. parvum therapeutic. We determined that STAg treatment reduced C. parvum Iowa II oocyst shedding in gamma interferon knockout (IFN-γ-KO) mice. Murine intestinal sections were then sequenced to define the IFN-γ-independent transcriptomic response to C. parvum infection. Gene Ontology and transcript abundance comparisons showed host immune response and metabolism changes. Transcripts for type I interferon-responsive genes were more abundant in C. parvum-infected mice treated with STAg. Comparisons between phosphate-buffered saline (PBS) and STAg treatments showed no significant differences in C. parvum gene expression. C. parvum transcript abundance was highest in the ileum and mucin-like glycoproteins and the GDP-fucose transporter were among the most abundant. These results will assist the field in determining both host- and parasite-directed future therapeutic targets.

Comparative proteomics reveals Cryptosporidium parvum manipulation of the host cell molecular expression and immune response

Cryptosporidium is a life-threating protozoan parasite belonging to the phylum Apicomplexa, which mainly causes gastroenteritis in a variety of vertebrate hosts. Currently, there is a re-emergence of Cryptosporidium infection; however, no fully effective drug or vaccine is available to treat Cryptosporidiosis. In the present study, to better understand the detailed interaction between the host and Cryptosporidium parvum, a large-scale label-free proteomics study was conducted to characterize the changes to the proteome induced by C. parvum infection. Among 4406 proteins identified, 121 proteins were identified as differentially abundant (> 1.5-fold cutoff, P < 0.05) in C. parvum infected HCT-8 cells compared with uninfected cells. Among them, 67 proteins were upregulated, and 54 proteins were downregulated at 36 h post infection. Analysis of the differentially abundant proteins revealed an interferon-centered immune response of the host cells against C. parvum infection and extensive inhibition of metabolism-related enzymes in the host cells caused by infection. Several proteins were further verified using quantitative real-time reverse transcription polymerase chain reaction and western blotting. This systematic analysis of the proteomics of C. parvum-infected HCT-8 cells identified a wide range of functional proteins that participate in host anti-parasite immunity or act as potential targets during infection, providing new insights into the molecular mechanism of C. parvum infection.

Cryptosporidium parvum is an emerging zoonotic pathogen transmitted via the fecal–oral route, and is considered a leading cause of moderate-to-severe diarrheal disease in young children in resource limited areas. After infection, C. parvum parasitizes intestinal epithelial cells and evokes an inflammatory immune response, leading to severe damage of the intestinal mucosa. The infection can be lethal to immunosuppressed individuals. However, no fully effective drug or vaccine is available for cryptosporidiosis, and the pathogenesis and immune mechanisms during C. parvum infection are obscure. Thus, an in-depth understanding of host-parasite interaction is needed. Hence, we established a C. parvum-infected HCT-8 cell model and performed comparative quantitative proteomic analyses to profile global host-parasite interactions and determine the molecular mechanisms that are activated during infection, aiming to offer new insights into the treatment of Cryptosporidium.

Prophylactic and therapeutic efficacy of clinoptilolite against Cryptosporidium parvum in experimentally challenged neonatal lambs

This study was designed to test the prophylactic and therapeutic efficacy of clinoptilolite against Cryptosporidium (C.) parvum infection in lambs. Within the first day of life, three groups of 10 lambs were each inoculated with 1 × 10⁶ oocysts of C. parvum. The prophylactic (PROP) group received orally clinoptilolite supplemented at a rate of 3% to the colostrum within the first day of life before inoculation and then to milk replacer for two weeks. The therapeutic (TREA) group was supplemented with the same rate, route and duration of clinoptilolite, starting from the day of the first appearance of oocysts in the faeces. The positive control group (pCON) was left untreated and fed only the basal diet. Disease development and clinoptilolite efficacy were assessed daily by evaluating oocyst per gram of faeces (OPG) counts, faecal consistent score (FCS), and clinical health score (CHS) from day -1 to 20 days post inoculation. A significantly (p < 0.001) lower OPG value was found in the PROP and TREA groups in comparison to the pCON group. The FCS and CHS were decreased in the PROP (p < 0.01 and p < 0.001) and TREA (p < 0.05 and p < 0.001) groups compared to the pCON group, respectively. The percentage efficacy of clinoptilolite was calculated to be 97.4 % in the PROP group and 91.6 % in the TREA group. In conclusion, this study proved for the first time that clinoptilolite has promising prophylactic and therapeutic activities against C. parvum in experimentally infected lambs.

Giardia and Cryptosporidium in Neo-Tropical Rodents and Marsupials: Is There Any Zoonotic Potential?

Cryptosporidiosis and giardiasis have been identified as emerging diseases in both developed and developing countries. Wildlife has been highlighted to play a major role in the spread of these diseases to humans. This review aims to highlight the research findings that relate to Cryptosporidium spp. and Giardia spp., with a focus on (1) parasitism of neo-tropical hystricomorphic rodents and marsupials from the genus Didelphis and (2) prevention and treatment strategies for humans and animals for the neo-tropical region. It was found that there are few studies conducted on neo-tropical rodent and marsupial species, but studies that were found illustrated the potential role these animals may play as zoonotic carriers of these two parasites for the neo-tropical region. Thus, it is recommended that further studies be done to assess the threat of protozoan parasites in neo-tropical wildlife to humans and domestic animals, and to further determine the most effective prophylaxis adapted for the unique conditions of the region.

Cryptosporidium: Host-Parasite Interactions and Pathogenesis

Purpose of Review

Cryptosporidium spp. (C. hominis and C. parvum) are a major cause of diarrhea-associated morbidity and mortality in young children globally. While C. hominis only infects humans, C. parvum is a zoonotic parasite that can be transmitted from infected animals to humans. There are no treatment or control measures to fully treat cryptosporidiosis or prevent the infection in humans and animals. Our knowledge on the molecular mechanisms of Cryptosporidium-host interactions and the underlying factors that govern infectivity and disease pathogenesis is very limited.

Recent Findings

Recent development of genetics and new animal models of infection, along with progress in cell culture platforms to complete the parasite lifecycle in vitro, is greatly advancing the Cryptosporidium field.

Summary

In this review, we will discuss our current knowledge of host-parasite interactions and how genetic manipulation of Cryptosporidium and promising infection models are opening the doors towards an improved understanding of parasite biology and disease pathogenesis.

Morphological parameters of blood of calves with cryptosporidiosis after applying different treatment regimens

Recently the livestock farmers of Baltasinsky, Kukmorsky, Sabinsky, Alkeevsky and other regions of the Republic of Tatarstan have increasingly frequently faced the young cattle diseases associated with pathology of the gastrointestinal tract that have not been treated by the classical scheme of diseases with diarrhea symptoms.Sick calves had acute and subacute catarrhal gastroenteritis mainly in the later stages of which accompanied by the inflammatory process in the posterior segment of the small intestine. The manifestations of structural changes in the subepithelial lymphoid tissue of the intestine, in the stagnant digestive glands and regional lymph nodes were increased with a severity level of the clinical symptoms of the disease.In this regard, in order to obtain a complete picture of the effect of cryptosporidiosis invasion on the peripheral blood condition of sick calves, hematological studies were conducted in the dynamics of the development of the infectious process. We have studied the content of red blood cells, white blood cells including lymphocytes, granulocytes, as well as monocytes and hemoglobin on the 7th, 14th and 30th days of the experiment. Hematological studies of calves infected with spontaneous invasion of cryptosporidiosis, and after treatment, had been carried out in 2016 2018 at the OJSC “KukmorAgroChimService” in the Kukmorsky district of the Republic of Tatarstan in the Russian federation. Cryptosporidiosis clinically insane calves had erythropenia and leukocytopenia in the blood and low hemoglobin. Reduced oxygen capacity of the blood contributed to the development of the secondary destructive changes in the organs of hematopoietic organs. The established dynamics of a decrease in the content of eosinophilic granulocytes in the blood of calves in the first and especially in the second groups indicated a high therapeutic effect of the drugs used. Starting from the 7th day, due to the therapeutic effect of the tested medications in the places of the pathogenic effects of cryptosporidia, regenerative processes were intensified. It affected the morphological parameters of the blood.

The determination of treatment effect of chitosan oligosaccharide in lambs with experimentally cryptosporidiosis

•

Chitosan oligosaccharide contributes to clinical improvement in lambs with experimentally cryptosporidiosis.

•

Chitosan oligosaccharide reduces C. parvum oocysts.

•

Chitosan oligosaccharide can be used in the treatment of cryptosporidiosis.

In this study, it was aimed to investigate the efficacy of chitosan oligosaccharide administrations in different doses of experimental infected lambs with Cryptosporidium parvum. 32 male lambs were used in the study and the lambs were divided into 4 groups with 8 lambs in each group. Groups 1, 2 and 3, twice a day, were administered chitosan oligosaccharide at a dose of 100, 500, and 1000 mg/kg for 7 days, respectively, with milk replacer. In group 4, lambs with cryptosporidiosis were subjected to normal feeding as control without drug administration. Clinical examinations of lambs were made before treatment (day 0) and on days 1, 3, 5 and 7 after treatment and 5 ml of blood was collected from vena jugularis for blood analysis of all lambs. Weight changes of lambs were recorded at 0, 7, 14, and 21 days. Stool specimens were collected pre-treatment (day 0) and on days 1, 3, 5, 7, 14 and 21 post-treatment to determine oocyst excretion of lambs with cryptosporidiosis. Lambs with a mean oocyte counts >10 after stool examination were included to the treatment. Changes in clinical hematology, blood gases and biochemical parameters were observed during the course of treatment, but these changes were limited. Weight loss was observed at 7th day according to 0th day the lambs with experimental cryptosporidiosis but gradually weight increase was observed at 14th and 21st days and these changes were similar in all groups. Oocyst excretion decreased in all groups during treatment. According to 0th day, there was a significant (p < 0.05) decrease in oocyte excretions in the third day in group 1 and 2, and in day 5 in the group 3 and 4. Significant changes (p < 0.05) were observed in oocyst excretions on the third and fifth days among the groups. As a result, in lambs with experimental cryptosporidiosis, chitosan oligosaccharide improved in clinical signs and stool character shorter than the positive control group and the administration of chitosan oligosaccharide at doses of 100, 500 and 1000 mg/kg for 7 days significantly reduced oocyst excretion but not enough to remove cryptosporidiosis completely.

Inhibitory activity of chitosan nanoparticles against Cryptosporidium parvum oocysts

Cryptosporidium is a ubiquitous harsh protozoan parasite that resists many disinfectants. It remains viable and infective for a long time in water and food causing global outbreaks. Chitosan (the deacetylated chitin molecule) was used in its nanosuspension form to evaluate its effect against Cryptosporidium parvum. The experiments were performed in vitro in serial concentrations and confirmed in mice in vivo infectivity assay. Chitosan nanoparticles (Cs NPs) were toxic to Cryptosporidium oocysts. The effect appeared to decrease the number of Cryptosporidium oocysts and altered their content. The destruction rate of oocysts was dependent on the dose of chitosan and the time of exposure (P < 0.05). Higher doses of Cs NPs over a prolonged period exhibited a significantly higher destruction rate. Using staining and light microscopy, remarkable destructive changes were observed in the oocysts' morphology. The minimal lethal dose for > 90% of oocysts was 3000 μg/ml, no mice infections in vivo were observed. The results in this study elucidate Cs NPs as an effective anti-cryptosporidial agent.

Long-term use of yeast fermentation products in comparison to halofuginone for the control of cryptosporidiosis in neonatal calves

•

Prophylactic effect of halofuginone against bovine cryptosporidiosis is equivocal.

•

Saccharomyces cerevisiae fermentation products (SCFP) are feed additives.

•

SCFP feeding showed similar clinical effects in newborn calves as halofuginone.

•

Pre-weaning supplementation with SCFP may be an alternative in bovine cryptosporidiosis.

The objective of this study was to compare the effect of non-GMO Saccharomyces cerevisiae fermentation products (SCFP) with that of a halofuginone treatment against Cryptosporidium parvum infection in pre-weaned calves on a commercial dairy farm. A total of 123 neonatal female calves, housed in individual hutches, were enrolled sequentially based on date of birth in 41 blocks of 3 animals each. Calves within each block were allocated to one of 3 treatments: remaining untreated, fed with SCFP (Diamond V SmartCare^® at 1 g/d in milk and NutriTek^® at 5 g/d in starter grain) for the first 63 days of life, or treated with halofuginone (0.1 mg/kg/d) for the first 7 days of life. Fecal samples collected on days 4–21 post-partum were examined for both Cryptosporidium oocysts and coproantigen. The presence and intensity of diarrhea were monitored by scoring daily for the first 4 weeks of life. Calves were weighed at 0, 21, 42 and 63 days of age. Almost all calves were Cryptosporidium-positive at least once during the study. Halofuginone significantly reduced the number of Cryptosporidium-positive fecal samples as compared to the two other groups. Based on the coproantigen scores, both halofuginone and SCFP feeding significantly reduced the intensity of Cryptosporidium infection as compared to the untreated group. Diarrhea was recorded in almost all calves at least once. Neither the proportion of diarrheic calves nor the intensity and duration of diarrhea differed among the 3 treatment groups significantly. The mean daily weight gain during the first 3 weeks of life was significantly lower in halofuginone treated calves than in both other groups; however, at the end of the study period the total weight gain did not significantly differ among the 3 treatment groups. In conclusion, the clinical results and weight gains of pre-weaning supplementation with the SCFP were neither better nor worse than the 7-day halofuginone treatment suggesting that the SCFP feeding may be from the clinical point of view a natural alternative measure, instead of halofuginone treatment, in bovine cryptosporidiosis.

Treatment of cryptosporidiosis in captive green iguanas (Iguana iguana)

There are no standard guidelines for the treatment of cryptosporidiosis in reptiles. The aim of this study was to evaluate the efficacy of two cryptosporidiosis therapies in captive green iguanas. Eight green iguanas aged 2-6 years, including 6 (1 ♂ and 5 ♀) animals with chronic diarrhea, received treatment for cryptosporidiosis. The presence of Cryptosporidium sp. oocysts was determined in 8 iguanas (100%), Isospora sp. oocysts were detected in 3 animals (37.5%), and Oxyuridae eggs were observed in 5 iguanas (62.5%). The animals were divided into two therapeutic groups (A and B). Group A iguanas were administered halofuginone (Halocur, 0,50 mg/ml Intervet Productions S.A., France) at a dose of 110 mg/kg body weight (BW) every 7 days for 5 weeks. Group B animals were administered sulfadiazine and trimethoprim (Norodine Vet Oral Paste sulfadiazine 288,3 mg/g, trimethoprim 58 mg/g, ScanVet Animal Health A/S, Denmark) at 75 mg/kg BW per os every 5 days for 5 weeks and spiramycin and metronidazole (Stomorgyl, spiramycin 1500000 IU, metronidazole 250 mg, Merial, France) at 200 mg/kg BW every 5 days for 5 weeks. Both groups received hyperimmune bovine colostrum and subcutaneous fluids. Before treatment, the average number of Cryptosporidium sp. oocysts in 1 g of feces was determined at 1.71 * 10⁵ (±313,262.44) in group A and 1.56 * 10⁵ (±262,908.53) in group B; the average number of Isospora sp. oocysts was determined at 3.53 * 10³ (±1747.38), and the average number of Oxyuridae eggs was determined at 810 (±496.74). Blood tests were performed once before treatment. The results of blood morphology and biochemistry tests before treatment revealed leukocytosis with a significant increase in heterophile and monocyte counts in all animals. Dehydration, elevated hematocrit values and low levels of Na⁺, Ca²⁺, PO₄^- and Cl^- ions were observed in 6 iguanas. Two iguanas died during treatment. The gross necropsy revealed acute inflammation of gastric and duodenal mucosa, mucosal ecchymoses in the gastrointestinal tract, hepatomegaly and liver congestion, cholecystitis, enlarged kidneys and renal edema and congestion, cystitis, and an absence of fat bodies. Parasites were not detected in any developmental form after 40 days of therapy and during an monthly 18-month follow-up period. Effective treatment of cryptosporidiosis in reptiles minimizes the adverse consequences of disease, improves the animals' well-being and decreases euthanasia rates.

In vitro inhibitory effects of plant-derived by-products against Cryptosporidium parvum

Disposal of organic plant wastes and by-products from the food or pharmaceutical industries usually involves high costs. In the present study, 42 samples derived from such by-products were screened in vitro against Cryptosporidium parvum, a protozoan parasite that may contaminate drinking water and cause diarrhoea. The novel bioassay was previously established in the microtitre plate format. Human ileocaecal adenocarcinoma (HCT-8) cell cultures were seeded with C. parvum oocysts and parasite development was monitored by an indirect fluorescent antibody technique (IFAT) and microscopic assessment for clusters of secondary infection (CSI). Minimum inhibitory concentrations (MICs) and potential detrimental effects on the host cells were determined. An ethanolic extract from olive (Olea europaea) pomace, after oil pressing and phenol recovery, reproducibly inhibited C. parvum development (MIC = 250-500 μg mL(-1), IC50 = 361 (279-438) μg mL(-1), IC90 = 467 (398-615) μg mL(-1)). Accordingly, tyrosol, hydroxytyrosol, trans-coniferyl alcohol and oleuropein were selected as reference test compounds, but their contributions to the observed activity of the olive pomace extract were insignificant. The established test system proved to be a fast and efficient assay for identifying anti-cryptosporidial activities in biological waste material and comparison with selected reference compounds.

Far beyond Phagocytosis: Phagocyte-Derived Extracellular Traps Act Efficiently against Protozoan Parasites In Vitro and In Vivo

Professional mononuclear phagocytes such as polymorphonuclear neutrophils (PMN), monocytes, and macrophages are considered as the first line of defence against invasive pathogens. The formation of extracellular traps (ETs) by activated mononuclear phagocytes is meanwhile well accepted as an effector mechanism of the early host innate immune response acting against microbial infections. Recent investigations showed evidence that ETosis is a widely spread effector mechanism in vertebrates and invertebrates being utilized to entrap and kill bacteria, fungi, viruses, and protozoan parasites. ETs are released in response to intact protozoan parasites or to parasite-specific antigens in a controlled cell death process. Released ETs consist of nuclear DNA as backbone adorned with histones, antimicrobial peptides, and phagocyte-specific granular enzymes thereby producing a sticky extracellular matrix capable of entrapping and killing pathogens. This review summarizes recent data on protozoa-induced ETosis. Special attention will be given to molecular mechanisms of protozoa-induced ETosis and on its consequences for the parasites successful reproduction and life cycle accomplishment.

Veterinary drugs in the environment and their toxicity to plants

Veterinary drugs used for treatment and prevention of diseases in animals represent important source of environmental pollution due to intensive agri- and aquaculture production. The drugs can reach environment through the treatment processes, inappropriate disposal of used containers, unused medicine or livestock feed, and manufacturing processes. Wide scale of veterinary pharmaceuticals e.g. antibiotics, antiparasitic and antifungal drugs, hormones, anti-inflammatory drugs, anaesthetics, sedatives etc. enter the environment and may affect non-target organisms including plants. This review characterizes the commonly used drugs in veterinary practice, outlines their behaviour in the environment and summarizes available information about their toxic effect on plants. Significant influence of many antibiotics and hormones on plant developmental and physiological processes have been proved. However, potential phytotoxicity of other veterinary drugs has been studied rarely, although knowledge of phytotoxicity of veterinary drugs may help predict their influence on biodiversity and improve phytoremediation strategies. Moreover, additional topics such as long term effect of low doses of drugs and their metabolites, behaviour of mixture of veterinary drugs and other chemicals in ecosystems should be more thoroughly investigated to obtain complex information on the impact of veterinary drugs in the environment.

NADPH oxidase, MPO, NE, ERK1/2, p38 MAPK and Ca2+ influx are essential for Cryptosporidium parvum-induced NET formation

Cryptosporidium parvum causes a zoonotic infection with worldwide distribution. Besides humans, cryptosporidiosis affects a wide range of animals leading to significant economic losses due to severe enteritis in neonatal livestock. Neutrophil extracellular trap (NET) formation has been demonstrated as an important host effector mechanism of PMN acting against several invading pathogens. In the present study, C. parvum-mediated NET formation was investigated in human and bovine PMN in vitro. We here demonstrate that C. parvum sporozoites indeed trigger NET formation in a time-dependent manner. Thereby, the classical characteristics of NETs were demonstrated by co-localization of extracellular DNA with histones, neutrophil elastase (NE) and myeloperoxidase (MPO). A significant reduction of NET formation was measured following treatments of PMN with NADPH oxidase-, NE- and MPO-inhibitors, confirming the key role of these enzymes in C. parvum-induced NETs. Additionally, sporozoite-triggered NETosis revealed as dependent on intracellular Ca(++) concentration and the ERK 1/2 and p38 MAPK-mediated signaling pathway. Moreover, sporozoite-triggered NET formation led to significant parasite entrapment since 15% of the parasites were immobilized in NET structures. Consequently, PMN-pre-exposed sporozoites showed significantly reduced infectivity for epithelial host cells confirming the capability of NETs to prevent active parasite invasion. Besides NETs, we here show that C. parvum significantly up-regulated CXCL8, IL6, TNF-α and of GM-CSF gene transcription upon sporozoite confrontation, indicating a pivotal role of PMN not only in the bovine and human system but most probably in other final hosts for C. parvum.

Cryptosporidium infections in birds - a review

Cryptosporidiosis is one of the main protozoan infections in birds. It manifests as either a respiratory or a digestive illness, and it affects a very large number of avian species across several continents. The aim of this review is to report on the main results of studies on cryptosporidiosis among birds and the importance of these results to veterinary medicine and public health.

Interactions between parasitic infections and reproductive efficiency in sheep

This review article summarises the many reports in the literature, confirming that, in sheep, parasitic infections can adversely affect reproductive efficiency; examples, which refer to all parts of the reproductive cycle of sheep, are as follows: trichostrongylosis in ewe-lambs (which can lead to delayed attainment of puberty), myiosis of the prepuce (which can cause impediment of mating), chorioptic mange or trypanosomosis in rams (which can lead to testicular degeneration or azoospermia, respectively), trypanosomosis or sarcoptic mange in pre-conceptual ewes (which can lead to poor conception rates or reduced number of ovulations, respectively), toxoplasmosis or neosporosis in pregnant ewes (which are causes of abortion), trichostrongylosis or trematode infections in lactating ewes (which can cause reduction of milk yield and can be a risk factor for mastitis, respectively), cryptosporidiosis in newborn lambs (which can be a cause of deaths), coccidiosis in growing pre-weaned lambs (which can cause suboptimal growth rate). In other cases, the reproductive status of the animal can influence the parasitic infection; examples are as follows: the increase in faecal parasitic output during the peri-parturient period (as a consequence of the peri-parturient relaxation of immunity), the heavier trichostrongylid infections of twin lambs compared to lambs from single parities (as a consequence of developmental origin issues in twin lambs). All the above examples support the idea of presence of interactions between parasitic infections and reproductive efficiency in sheep.

CDPKs of Cryptosporidium parvum--stage-specific expression in vitro

Cryptosporidium parvum is a zoonotic agent that bears a high risk for the health of particularly immunocompromised humans and animals. As currently available drugs and therapies against cryptosporidiosis do not turn out satisfactory, more intensive research on the control of this parasite is necessary. The genus Cryptosporidium is unique within the phylum Apicomplexa as its localisation is intracellular but extracytoplasmatic. Infection of host cells is initially a parasite-driven process, but the signalling events and their downstream actions within Cryptosporidium are poorly understood. Calcium-dependent protein kinases (CDPKs) are probably involved in the regulation of invasion and egress. Previously described in plants, algae and other Apicomplexa, CDPKs are not found in vertebrates. They are thus promising targets for pharmaceutical intervention. While CDPK1 is well characterised in Toxoplasma gondii (TgCDPK1) and Plasmodium falciparum (PfCDPK1), only little information exists about the expression and function of CDPK in C. parvum. Here, we describe results of the in silico analysis of seven CpCDPKs. Five CpCDPKs contain potential sites for N-myristoylation and N-palmitoylation. In a nested 3' rapid amplification of cDNA ends (RACE)-PCR, expression of six CpCDPKs resulted in distinct bands in infected cell cultures and extracts of freshly excysted sporozoites. The length of the 3' untranslated region (3' UTR) is described as well. Our results indicate CDPK expression to be stage specific on the mRNA level.

Intravenous injection of a foamy virus vector to correct canine SCID-X1

Current approaches to hematopoietic stem cell (HSC) gene therapy involve the collection and ex vivo manipulation of HSCs, a process associated with loss of stem cell multipotency and engraftment potential. An alternative approach for correcting blood-related diseases is the direct intravenous administration of viral vectors, so-called in vivo gene therapy. In this study, we evaluated the safety and efficacy of in vivo gene therapy using a foamy virus vector for the correction of canine X-linked severe combined immunodeficiency (SCID-X1). In newborn SCID-X1 dogs, injection of a foamy virus vector expressing the human IL2RG gene resulted in an expansion of lymphocytes expressing the common γ chain and the development of CD3(+) T lymphocytes. CD3(+) cells expressed CD4 and CD8 coreceptors, underwent antigen receptor gene rearrangement, and demonstrated functional maturity in response to T-cell mitogens. Retroviral integration site analysis in 4 animals revealed a polyclonal pattern of integration in all dogs with evidence for dominant clones. These results demonstrate that a foamy virus vector can be administered with therapeutic benefit in the SCID-X1 dog, a clinically relevant preclinical model for in vivo gene therapy.