Host immune response to Cryptosporidium parvum infection

Green synthesis of zinc oxide/Allium sativum nano-composite and its efficacy against murine cryptosporidiosis

Cryptosporidiosis is a global health problem threats life of immunocompromised patients. Allium sativum (A. sativum) is one of the therapeutic options for cryptosporidiosis. This study develops green synthesized ZnO-NPs based on A. sativum extract, and assesses its therapeutic application in treating experimental cryptosporidiosis in immunosuppressed mice. FTIR, scanning electron microscopy, and zeta analyzer were used for characterization of bio ZnO-NPs. The morphology of prepared materials appeared as sponge with many pores on the whole surface that allows the feasibility of bio ZnO-NPs for different biological activities. Its structural analysis was highly stabilized with negative charge surface which indicated for well distribution into the parasite matrix. Twenty-five immunosuppressed Cryptosporidium parvum infected mice, classified into 5 groups were sacrificed at 21th day after infection with evaluation of parasitological, histopathological, oxidative, and proinflammatory biomarkers. Treated mice groups with 50 and 100 mg/kg of AS/ZnO-NPs showed a highly significant decline (79.9% and 83.23%, respectively) in the total number of expelled oocysts. Both doses revealed actual amelioration of the intestinal, hepatic, and pulmonary histopathological lesions. They also significantly produced an increase in GSH values and improved the changes in NO and MDA levels, and showed high anti-inflammatory properties. This study is the first to report green synthesis of ZnO/A. sativum nano-composite as an effective therapy in treating cryptosporidiosis which gave better results than using A. sativum alone. It provides an economical and environment-friendly approach towards novel delivery synthesis for antiparasitic applications. RESEARCH HIGHLIGHTS: Green synthesis of ZnO-NPs was developed using A. sativum extract. The morphology of prepared ZnO-NPs appeared as sponge with many pores on SEM The study evaluates its therapeutic efficacy against murine cryptosporidiosis The green synthesized ZnO-NPs significantly reduced percent of oocyst shedding, improved the pathological changes, and showed high antioxidant and anti-inflammatory potentials.

Cryptosporidium sp. infection in solid organ transplant recipients: A systematic review and meta-analysis

(1) Background: Organ transplant recipients (OTRs) are vulnerable groups at risk of parasitic infections. This systematic review and meta-analysis aimed to evaluate the overall prevalence of Cryptosporidium sp. in OTRs and shed light on this potentially serious complication of organ transplantation. (2) Methods: We systematically searched studies on Cryptosporidium sp. infections in OTRs in four databases (Academia, PubMed, Scopus, and Science Direct). Random effects models were used to calculate pooled prevalence estimates with 95% confidence intervals (CIs). Sub-group and meta-regression analyses were conducted. A quality assessment of the included studies was also performed. (3) Results: Among 876 articles retrieved, 21 were included, accounting for 2,642 OTRs. Twenty studies were cross-sectional in design, of which seven reported data on a comparison group, and one was a retrospective cohort. The pooled prevalence of Cryptosporidium sp. in OTRs was 15% (95% CI: 7.4-24.6). Subgroup analysis revealed that the prevalence of Cryptosporidium sp. infection was higher in adults, symptomatics and developing countries and in studies using only non-molecular methods. However, substantial heterogeneity was reported. Low to moderate heterogeneity was observed in subgroups reporting lower prevalence Cryptosporidium sp. including children (5.8; 95% CI: 2.8-9.6), studies conducted in developed countries (5.8; 95% CI: 3.0-9.4) and studies using both molecular and non-molecular diagnostics (11.4; 95% CI: 6.4-17.4). The majority of the listed research reported low-medium quality scores. (4) Conclusion: Cryptosporidium sp. infection is a significant complication in OTRs with underreported prevalence. Preventive strategies to reduce the burden should include Cryptosporidium sp. routine screening for OTRs, particularly post-transplantation in patients with diarrhea. Additional well-designed research studies are required to determine the extent of the Cryptosporidium sp. burden in OTRs.

Dendritic Cells and Cryptosporidium: From Recognition to Restriction

Host immune responses are required for the efficient control of cryptosporidiosis. Immunity against Cryptosporidium infection has been best studied in mice, where it is mediated by both innate and adaptive immune responses. Dendritic cells are the key link between innate and adaptive immunity and participate in the defense against Cryptosporidium infection. While the effector mechanism varies, both humans and mice rely on dendritic cells for sensing parasites and restricting infection. Recently, the use of mouse-adapted strains C. parvum and mouse-specific strain C. tyzzeri have provided tractable systems to study the role of dendritic cells in mice against this parasite. In this review, we provide an overview of recent advances in innate immunity acting during infection with Cryptosporidium with a major focus on the role of dendritic cells in the intestinal mucosa. Further work is required to understand the role of dendritic cells in the activation of T cells and to explore associated molecular mechanisms. The identification of Cryptosporidium antigen involved in the activation of Toll-like receptor signaling in dendritic cells during infection is also a matter of future study. The in-depth knowledge of immune responses in cryptosporidiosis will help develop targeted prophylactic and therapeutic interventions.

C3a/C3aR Affects the Propagation of Cryptosporidium parvum in the Ileum Tissues of Mice by Regulating the Gut Barrier, Cell Proliferation, and CD4+ T Cell Main Effectors

Cryptosporidium parvum is an important zoonotic protozoon that threatens the health of humans and animals, but the interaction mechanisms between C. parvum and hosts are poorly understood. Our previous study indicated that the expression levels of C3a and C3aR were up-regulated in mice during C. parvum infection, but the mechanisms of C3a/C3aR signaling during C. parvum infection have not been elucidated. In the present study, an optimized BALB/c suckling mouse model infected with C. parvum was used to explore the function of C3a/C3aR signaling during C. parvum infection. The expression levels of C3aR in the ileum tissues of mice infected with C. parvum were analyzed using real-time PCR, Western blot and immunohistochemistry. The mRNA levels of the Cryptosporidium 18S rRNA gene, tight junction proteins (zo-1, claudin 3, and occludin), intestinal stem cell marker lgr5, cell proliferation marker ki67, Th1 cell-related cytokine ifn-γ, and Treg cell-related cytokine tgf-β in mouse ileum tissues were analyzed by real-time PCR. The pathological injury of ileal mucosa was examined by histopathology analysis. The mRNA expression levels of Cryptosporidium 18S rRNA gene were significantly up-regulated in the ileum tissues of C3aR-inhibited mice during C. parvum infection. Meanwhile, histopathology analysis of ileal mucosa in mice showed that inhibition of C3aR significantly aggravated the changes in villus length, villus diameter, mucosal thickness and the ratio of villus length to crypt depth during C. parvum infection. Further studies found inhibition of C3aR aggravated the down-regulation of occludin at most time points during C. parvum infection. The mRNA levels of ki67 and lgr5 in the ileum tissues of mice infected with C. parvum were significantly down-regulated. Inhibition of C3aR significantly down-regulated the mRNA expression levels of lgr5 at most time points, but significantly up-regulated the mRNA expression levels of ki67 at most time points. The mRNA expression levels of ifn-γ and tgf-β were significantly up-regulated and down-regulated in the ileum tissues of mice infected with C. parvum, respectively. However, inhibition of C3aR significantly increased the mRNA expression levels of ifn-γ and tgf-β in the ileum tissues of mice infected with C. parvum. Taken together, C3a/C3aR signaling could possibly affect the propagation of C. parvum in mouse ileum tissues by regulating the gut barrier, cell proliferation and CD4⁺ T cell main effectors, which would contribute to our understanding of the interaction between Cryptosporidium and hosts.

Whole transcriptome analysis of HCT-8 cells infected by Cryptosporidium parvum

BACKGROUND

Cryptosporidium species are zoonotic protozoans that are important causes of diarrhoeal disease in both humans and animals. Non-coding RNAs (ncRNAs) play an important role in the innate immune defense against Cryptosporidium infection, but the underlying molecular mechanisms in the interaction between human ileocecal adenocarcinoma (HCT-8) cells and Cryptosporidium species have not been entirely revealed.

METHODS

The expression profiles of messenger RNAs (mRNAs), long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs) in the early phase of infection of HCT-8 cells with Cryptosporidium parvum and at 3 and 12 h post infection were analyzed using the RNA-sequencing technique. The biological functions of differentially expressed RNAs (dif-RNAs) were discovered through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The targeting relationships between three ncRNAs and mRNAs were analyzed using bioinformatics methods, followed by building a competing endogenous RNA (ceRNA) regulatory network centered on miRNAs.

RESULTS

After strictly filtering the raw data, our analysis revealed 393 dif-lncRNAs, 69 dif-miRNAs and 115 dif-mRNAs at 3 hpi, and 450 dif-lncRNAs, 129 dif-miRNAs, 117 dif-mRNAs and one dif-circRNA at 12 hpi. Of these, 94 dif-lncRNAs, 24 dif-miRNAs and 22 dif-mRNAs were detected at both post-infection time points. Eleven dif-lncRNAs, seven dif-miRNAs, eight dif-mRNAs and one circRNA were randomly selected and confirmed using the quantitative real-time PCR. Bioinformatics analyses showed that the dif-mRNAs were significantly enriched in nutritional absorption, metabolic processes and metabolism-related pathways, while the dif-lncRNAs were mainly involved in the pathways related to the infection and pathogenicity of C. parvum (e.g. tight junction protein) and immune-related pathways (e.g. cell adhesion molecules). In contrast, dif-miRNAs and dif-circRNA were significantly enriched in apoptosis and apoptosis-related pathways. Among the downregulated RNAs, the miRNAs has-miR-324-3p and hsa-miR-3127-5p appear to be crucial miRNAs which could negatively regulate circRNA, lncRNA and mRNA.

CONCLUSIONS

The whole transcriptome profiles of HCT-8 cells infected with C. parvum were obtained in this study. The results of the GO and KEGG pathway analyses suggest significant roles for these dif-RNAs during the course of C. parvum infection. A ceRNA regulation network containing miRNA at its center was constructed for the first time, with hsa-miR-324-3p and hsa-miR-3127-5p being the crucial miRNAs. These findings provide novel insights into the responses of human intestinal epithelial cells to C. parvum infection.

Garlic (Allium sativum Linnaeus) improved inflammation and reduced cryptosporidiosis burden in immunocompromised mice

ETHNOPHARMACOLOGICAL RELEVANCE

For thousands of years, garlic (Allium sativum Linnaeus) has been consumed in food and health by numerous civilizations. Cryptosporidium (C.) parvum is an apicomplexan parasite that causes a gastrointestinal disease, with the most common symptoms being watery diarrhea. Although several substances have been tried for its anti-cryptosporidial action, there is no effective treatment for Cryptosporidium disease, especially in immunocompromised individuals. The present study aimed firstly to characterize the bio-active compounds in Allium sativum L. and secondly to evaluate its efficacy as a therapy for cryptosporidiosis especially in immunocompromised mice.

MATERIALS AND METHODS

This was accomplished by evaluating the parasitological and histopathological parameters in the experimentally infected immunocompetent and immunocompromised mice. Also, the cytokine profile during the experimental time was recorded through the measuring of T helper (h)1, Th2 and Th17 cells cytokines. Immunosuppressed mice were given 0.25 μg/g per day of dexamethasone orally, before infection with Cryptosporidium parvum oocysts, for fourteen consecutive days. Starting 10 days post infection (PI), nitazoxanide (100 mg/kg per day) or Allium sativum (50 mg/kg per day) was given orally for fourteen consecutive days.

RESULTS

Our results showed that oocyst shedding, on the 32nd day PI, in immunocompromised infected group treated with Allium sativum (354.11, 99.35% PR) showed a significant decrease when compared to its corresponding group treated with nitazoxanide (4369.14, 92.05% PR). On the 32nd day PI, all cytokines levels have been decreased to levels that were similar to those of their uninfected corresponding control groups; also, the histopathological changes and the loss in animals' body weight had been improved. Treatment with nitazoxanide did not result in infection clearance or a reduction in the increased cytokines' levels.

CONCLUSION

Allium sativum L. displayed high efficacy as a potential therapeutic agent against Cryptosporidium, which supports its traditional usage in parasite diseases.

Isolation and identification of sporozoite membrane protein of Cryptosporidium parvum and evaluation of calmodulin-like protein immune protection

Until now, no completely effective parasite-specific drugs or vaccines have been approved for the treatment of cryptosporidiosis. Through the separation and identification of the sporozoite membrane protein of Cryptosporidium parvum (C. parvum), 20 related proteins were obtained. Among them, a calmodulin-like protein (CML) has a similar functional domain-exchange factor hand (EF-hand) motif as calmodulin proteins (CaMs), so it may play a similarly important role in the invasion process. A 663 bp full gene encoding the C. parvum calmodulin-like protein (CpCML) was inserted in pET28a vector and expressed in Escherichia coli. An immunofluorescence assay showed that CpCML was mainly located on the surface of the sporozoites. Three-week-old female BALB/c mice were used for modeling the immunoreactions and immunoprotection of recombinant CpCML (rCpCML) against artificial Cryptosporidium tyzzeri (C. tyzzeri) infections. The results indicated a significantly increased in anti-CpCML antibody response, which was induced by the immunized recombinant protein. Compared to rP23(recombinant P23), GST6P-1(expressed by pGEX-6P-1 transfected E. coli) , GST4T-1(expressed by pGEX-4T-1 transfected E. coli) , glutathione (GSH), adjuvant, and blank control groups, rCpCML-immunized mice produced specific spleen cell proliferation in addition to different production levels of IL-2, IFN-γ, TNF-α, IL-4 and IL-5. Additionally, immunization with rCpCML led to 34.08% reduction of oocyst shedding in C. tyzzeri infected mice faeces which was similart to rP23. These results suggest that CpCML may be developed as a potential vaccine candidate antigen against cryptosporidiosis.

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.

Hide-and-Seek: A Game Played between Parasitic Protists and Their Hosts

After invading the host organism, a battle occurs between the parasitic protists and the host's immune system, the result of which determines not only whether and how well the host survives and recovers, but also the fate of the parasite itself. The exact weaponry of this battle depends, among others, on the parasite localisation. While some parasitic protists do not invade the host cell at all (extracellular parasites), others have developed successful intracellular lifestyles (intracellular parasites) or attack only the surface of the host cell (epicellular parasites). Epicellular and intracellular protist parasites have developed various mechanisms to hijack host cell functions to escape cellular defences and immune responses, and, finally, to gain access to host nutrients. They use various evasion tactics to secure the tight contact with the host cell and the direct nutrient supply. This review focuses on the adaptations and evasion strategies of parasitic protists on the example of two very successful parasites of medical significance, Cryptosporidium and Leishmania, while discussing different localisation (epicellular vs. intracellular) with respect to the host cell.

Enteric Tuft Cells in Host-Parasite Interactions

Enteric tuft cells are chemosensory epithelial cells gaining attention in the field of host-parasite interactions. Expressing a repertoire of chemosensing receptors and mediators, these cells have the potential to detect lumen-dwelling helminth and protozoan parasites and coordinate epithelial, immune, and neuronal cell defenses against them. This review highlights the versatility of enteric tuft cells and sub-types thereof, showcasing nuances of tuft cell responses to different parasites, with a focus on helminths reflecting the current state of the field. The role of enteric tuft cells in irritable bowel syndrome, inflammatory bowel disease and intestinal viral infection is assessed in the context of concomitant infection with parasites. Finally, the review presents pertinent questions germane to understanding the enteric tuft cell and its role in enteric parasitic infections. There is much to be done to fully elucidate the response of this intriguing cell type to parasitic-infection and there is negligible data on the biology of the human enteric tuft cell—a glaring gap in knowledge that must be filled.

Circular RNA ciRS-7 affects the propagation of Cryptosporidium parvum in HCT-8 cells by sponging miR-1270 to activate the NF-κB signaling pathway

BACKGROUND

Cryptosporidium is an important zoonotic pathogen responsible for severe enteric diseases in humans and animals. However, the molecular mechanisms underlying host and Cryptosporidium interactions are still not clear.

METHODS

To study the roles of circRNAs in host cells during Cryptosporidium infection, the expression profiles of circRNAs in HCT-8 cells infected with C. parvum were investigated using a microarray assay, and the regulatory role of a significantly upregulated circRNA, ciRS-7, was investigated during C. parvum infection.

RESULTS

C. parvum infection caused notable alterations in the expression profiles of circRNAs in HCT-8 cells, and a total of 178 (including 128 up- and 50 downregulated) circRNAs were significantly differentially expressed following C. parvum infection. Among them, ciRS-7 was significantly upregulated and regulated the NF-κB signaling pathway by sponging miR-1270 during C. parvum infection. Furthermore, the ciRS-7/miR-1270/relA axis markedly affected the propagation of C. parvum in HCT-8 cells.

CONCLUSIONS

Our results revealed that ciRS-7 would promote C. parvum propagation by regulating the miR-1270/relA axis and affecting the NF-κB pathway. To the best of our knowledge, this is the first study to investigate the role of circRNA during Cryptosporidium infection, and the findings provide a novel view for implementing control strategies against Cryptosporidium infection.

Evaluation of possible prophylactic and therapeutic effect of mefloquine on experimental cryptosporidiosis in immunocompromised mice

Cryptosporidiosis is an imperative global health concern. Unfortunately, Nitazoxanide (NTZ) (the nowadays drug of choice) is not effective in treatment of immunocompromised patients. We aimed to assess the possible anti-cryptosporidial prophylactic and therapeutic effects of Mefloquine (MQ) on infected immunosuppressed murine models. Mice were divided into five groups; GI: received Mefloquine (400 mg/kg/day), GII: received NTZ (100 mg/kg/bid), GIII: received a combination, half dose regimen of both drugs, GIV: infected untreated and GV: non-infected untreated. Each treated group was divided into three subgroups; Ga prophylaxis (PX), thereafter infection, Gb first and Gc second treatment doses. Assessment was done by parasitological, histopathological and serological techniques. A significant oocyst clearance was detected in all prophylactically treated groups. GIa showed 77% reduction of the mean oocyst count in stool while GIb and GIIIc showed100% oocyst clearance. Histopathologically, the ileocecal sections from GIV showed loss of brush borders with marked villous atrophy. GIa induced a moderate improvement of those pathological changes. Moreover, the villi in GIb and GIIIc retained their normal appearance with minimal inflammatory cells. Serum interferon gamma levels showed highly significant increases in GI&GIII compared to GIV while a non-significant increase was observed in GIIa only. On the contrary, serum interleukin-17 levels showed a highly significant down-regulation in all treated groups in comparison to GIV. This study proved a marvelous effect of MQ-PX on cryptosporidiosis in immunosuppressed mice and thus it could be introduced as one of the most promising re-purposed prophylactic and therapeutic anti-cryptosporidial agents.

S-Methylcysteine (SMC) Ameliorates Intestinal, Hepatic, and Splenic Damage Induced by Cryptosporidium parvum Infection Via Targeting Inflammatory Modulators and Oxidative Stress in Swiss Albino Mice

Cryptosporidiosis has been proposed to be one of the major causes of diarrhoeal disease in humans worldwide that possesses zoonotic concern. Thereby, this study investigated the potential effects of s-Methylcysteine (SMC) on the parasite in vivo followed by the measurement of cytokines, oxidative stress parameters, and an investigation of the major histopathological changes. Sixty male Swiss albino mice weighing 20-25 g were allocated equally into five groups and orally administered saline only (control), SMC only (SMC50) (50 mg/kg b.w.), and 10⁴Cryptosporidium parvum oocysts per mouse via an esophageal tube (C + ve untreated). The fourth and fifth groups (C + SMC25, C + SMC50) administrated 10⁴C. parvum oocysts combined with SMC25 (low dose) and 50 (high dose) mg/kg b.w., respectively. At days 7 and 14 post-infection (PI), the feces was collected from each group in order to count C. parvum oocysts. After two weeks of treatment, the animals were euthanized and the serum was collected for biochemical analysis. Next, the intestinal, spleen, and liver sections were dissected for histopathological examination. The results revealed lower oocyst numbers in the C + SMC25 and C + SMC50 groups compared to the infected untreated group. Moreover, higher doses of SMC treatment significantly reduced the enteritis induced by C. parvum in a dose-dependent manner. The hepatic lesions were also mitigated as demonstrated in C + SMC25 and C + SMC50 groups unlike the infected group via lowering the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) enzymes and increasing albumin and globulin serum levels. SMC administration also reduced cytokines production (SAP, TNF-α, IL-6, and IFN-γ) mediated by Cryptosporidium infection in contrast to the infected untreated group. There were marked lymphoid depletion and amyloidosis observed in the infected untreated group, while the treated groups showed obvious increase in the lymphoid elements. Moreover, the scoring of intestinal parasites, hepatic, and splenic lesions in the SMC-treated groups exhibited significantly lower pathological lesions in different organs in a dose-dependent manner, compared to the infected untreated group. Our results also revealed a significant change in the malondialdehyde content with an elevation of glutathione and superoxide dismutase in the intestines collected from C + SMC25 and C + SMC50 mice relative to the untreated group. Taken together, our results indicated that SMC could be a promising effective compound for treating and declining C. parvum infestation via restoring structural alterations in different tissues, enhancing antioxidant enzymes, and suppressing the cytokines liberation.

Effect of immunoglobulin G concentration in dairy cow colostrum and calf blood serum on Cryptosporidium spp. invasion in calves

AIM

The research aimed to test the association between the level of immunoglobulin G (IgG) in bovine colostrum and calf blood serum and to evaluate its relation to Cryptosporidium spp. invasion in calves.

MATERIALS AND METHODS

Fresh colostrum and fecal specimens from cows (n=114) as well as blood and fecal specimens from newborn calves (n=114) were collected in the dairy cattle farm. Investigated calves were separated from their mothers directly after birth and received 2 L of colostrum in two separate feedings within the first 24 h. Blood samples were taken from calves at the age of 2 days. Coprological samples were taken from calves at the age of 1, 10, and 15 days. Both colostrum and fecal samples from cows were taken on the 1st day after calf birth. Rectal fecal samples were collected separately from each calf and cow into plastic bags. The collected calf serum samples and bovine colostrum samples were tested for bovine IgG by competitive enzyme-linked immunosorbent assay kit bovine Ig. To record oocysts of Cryptosporidium spp. in feces, the flotation method was used. Binomial logistic regression was performed to ascertain the effects of IgG in bovine colostrum and calf blood serum on the likelihood of Cryptosporidium spp. infection in calves.

RESULTS

The concentration of IgG in bovine colostrum was higher (70.7±26.6 g/L, mean±standard deviation) than that in calf blood serum (13.2±6.1 g/L); the statistically significant difference was 57.4 g/L (95% confidence interval, 52.4-62.4), t (124.872)=22.536, p<0.001. Mann-Whitney's U-test showed a significant difference between samples collected on days 10 and 15 of the experiment (U=1944, z=2.330, p=0.020). The higher number of oocysts in calf feces was recorded on day 15 (median=6.5) compared to day 10 (median=4). The prevalence of calf infection from days 10 to 15 increased from 26.3 to 45.6% and was at least 3 times higher than in cows. A statistically significant positive correlation was recorded between IgG concentration of cow colostrum and calf blood serum (r (114)=0.414, p=0.001), whereas a correlation between the concentration of IgG and the intensity of Cryptosporidium spp. infection was not recorded (p>0.05). The logistic regression model was not statistically significant (χ2(2)=0.013, p=0.99 (10 days) and χ2(2)=0.100, p=0.95 (15 days)).

CONCLUSION

Mother passive transfer of immunity to the offspring through colostrum does not influence the susceptibility of calves to Cryptosporidium infestation.

Cryptosporidium Infection: Epidemiology, Pathogenesis, and Differential Diagnosis

Cryptosporidium is a protozoan that infects a wide variety of vertebrates, including humans, causing acute gastroenteritis. The disease manifests with abdominal pain and diarrhea similar to that of choleric infection. In the immunocompromised hosts, the parasite causes prolonged infections that can also be fatal. For this reason, cryptosporidiosis is considered one of riskiest opportunistic infections for patients with acquired immunodeficiency syndrome. The best way to control the infection in these patients is setting up sensitive and specific diagnostic tests for epidemiological surveillance and morbidity reduction. Here, we summarized the general aspects of Cryptosporidium infection focusing on available diagnostic tools used for the diagnosis of cryptosporidiosis. Molecular methods currently available for its detection and progress in the development of new diagnostics for cryptosporidiosis are also discussed.

Molecular Prevalence of Cryptosporidium spp. in Breeding Kennel Dogs

Cryptosporidium is a common intestinal protozoan that can lead to diarrhea in humans and dogs. The predominant species of infection are C. hominis and C. parvum in humans, and C. canis in dogs. However, C. canis can infect immunocompromised humans. Considering the close contact with humans, dogs have the potential to be reservoirs for human cryptosporidiosis. Breeding kennels are the major supply source of puppies for pet shops. The present study is to determine the molecular prevalence and characteristics of Cryptosporidium spp. found in breeding kennel dogs. A total of 314 fecal samples were collected from young and adult dogs kept in 5 breeding kennels. A polymerase chain reaction targeting the small subunit rRNA gene was employed for the detection of Cryptosporidium spp. To determine the species, the DNA sequences were compared to GenBank data. Overall, 21.0% of the fecal samples were positive for Cryptosporidium spp. infection. Cryptosporidium spp. was detected in all 5 facilities. A sequencing analysis demonstrated that all isolates shared 99–100% similarity with C. canis. The results suggest that Cryptosporidium spp. infection is present at a high-level in breeding kennel dogs. However, because dominant species in this survey was C. canis, the importance of breeding kennel dogs as reservoirs for Cryptosporidium spp. transmission to humans is likely to be low in Japan.

MicroRNA expression profile of HCT-8 cells in the early phase of Cryptosporidium parvum infection

Background

Cryptosporidium parvum is an important zoonotic parasitic disease worldwide, but the molecular mechanisms of the host–parasite interaction are not fully understood. Noncoding microRNAs (miRNAs) are considered key regulators of parasitic diseases. Therefore, we used microarray, qPCR, and bioinformatic analyses to investigate the intestinal epithelial miRNA expression profile after Cryptosporidium parvum infection.

Results

Twenty miRNAs were differentially expressed after infection (four upregulated and 16 downregulated). Further analysis of the differentially expressed miRNAs revealed that many important cellular responses were triggered by Cryptosporidium parvum infection, including cell apoptosis and the inflammatory and immune responses.

Conclusions

This study demonstrates for the first time that the miRNA expression profile of human intestinal epithelium cells is altered by C. parvum infection. This dysregulation of miRNA expression may contribute to the regulation of host biological processes in response to C. parvum infection, including cell apoptosis and the immune responses. These results provide new insight into the regulatory mechanisms of host miRNAs during cryptosporidiosis, which may offer potential targets for future C. parvum control strategies.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5410-6) contains supplementary material, which is available to authorized users.

Expression Profiles of mRNA and lncRNA in HCT-8 Cells Infected With Cryptosporidium parvum IId Subtype

Cryptosporidium parvum is one of the most important enteric protozoan pathogens, responsible for severe diarrhea in immunocompromised human and livestock. However, few effective agents were available for controlling this parasite. Accumulating evidences suggest that long non-coding RNA (lncRNA) played key roles in many diseases through regulating the gene expression. Here, the expression profiles of lncRNAs and mRNAs were analyzed in HCT-8 cells infected with C. parvum IId subtype using microarray assay. A total of 821 lncRNAs and 1,349 mRNAs were differentially expressed in infected cells at 24 h post infection (pi). Of them, all five types of lncRNAs were identified, including 22 sense, 280 antisense, 312 intergenic, 44 divergent, 33 intronic lncRNAs, and 130 lncRNAs that were not found the relationship with mRNAs’ location. Additionally, real-time polymerase chain reactions of 10 lncRNAs and 10 mRNAs randomly selected were successfully confirmed the microarray results. The co-expression and target prediction analysis indicated that 27 mRNAs were cis-regulated by 29 lncRNAs and 109 were trans-regulated by 114 lncRNAs. These predicted targets were enriched in several pathways involved in the interaction between host and C. parvum, e.g., hedgehog signaling pathway, Wnt signaling pathway, and tight junction, suggesting that these differentially expressed lncRNAs would play important regulating roles during the infection of C. parvum IId subtype.

Genome-wide analysis of differentially expressed profiles of mRNAs, lncRNAs and circRNAs during Cryptosporidium baileyi infection

Background

Cryptosporidium baileyi is the most common Cryptosporidium species in birds. However, effective prevention measures and treatment for C. baileyi infection were still not available. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) play important roles in regulating occurrence and progression of many diseases and are identified as effective biomarkers for diagnosis and prognosis of several diseases. In the present study, the expression profiles of host mRNAs, lncRNAs and circRNAs associated with C. baileyi infection were investigated for the first time.

Results

The tracheal tissues of experimental (C. baileyi infection) and control chickens were collected for deep RNA sequencing, and 545,479,934 clean reads were obtained. Of them, 1376 novel lncRNAs were identified, including 1161 long intergenic non-coding RNAs (lincRNAs) and 215 anti-sense lncRNAs. A total of 124 lncRNAs were found to be significantly differentially expressed between the experimental and control groups. Additionally, 14,698 mRNAs and 9085 circRNAs were identified, and significantly different expressions were observed for 1317 mRNAs and 104 circRNAs between two groups. Bioinformatic analyses of gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for their targets and source genes suggested that these dysregulated genes may be involved in the interaction between the host and C. baileyi.

Conclusions

The present study revealed the expression profiles of mRNAs, lncRNAs and circRNAs during C. baileyi infection for the first time, and sheds lights on the roles of lncRNAs and circRNAs underlying the pathogenesis of Cryptosporidium infection.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4754-2) contains supplementary material, which is available to authorized users.

Cryptosporidium outbreak in calves on a large dairy farm: Effect of treatment and the association with the inflammatory response and short-term weight gain

Cryptosporidium spp. infections in neonatal dairy calves can cause diarrhoea and, in rare cases, death. The infection is usually self-limiting, but halofuginone lactate (HL) can be used prophylactically. Calves (n=144) in the study were born during a 2-month period on one farm. A total of 901 serum and 767 faecal samples were collected. Based on HL treatment, the calves were divided into 3 groups: I) not treated, II) treated incorrectly (treatment started >48h after birth, or lasted <7days), and III) treated correctly (started <48h after birth, and lasted ≥7days). Over the 3-month observation period, 14.6% (n=21) of the calves died, of which most (67%) had not been treated with HL. Correctly performed treatment of cryptosporidiosis significantly delayed the onset of oocysts shedding (P<0.001) and reduced haptoglobin (HP) and serum amyloid A (SAA) concentrations in the second week of life. HP concentration and HL treatment were negatively associated with weight gain at 3months of age. Cryptosporidium positive faecal samples were significantly (P<0.001) more likely to be diarrhoeic but Giardia or Eimeria positive samples were not. Correct prophylactic treatment with HL delayed the shedding of Cryptosporidium oocysts and improved survival, but was negatively associated with weight gain. Incorrect treatment had a low impact on mortality and resembled no treatment regarding the proportion of calves shedding oocysts. Acute phase response (APR) in the second week of life seemed to be positively associated with shedding high amounts of Cryptosporidium oocysts.

The first report of Cryptosporidium spp. in Microtus fuscus (Qinghai vole) and Ochotona curzoniae (wild plateau pika) in the Qinghai-Tibetan Plateau area, China

Cryptosporidium is one of the most important genera of intestinal zoonotic pathogens, which can infect various hosts and cause diarrhoea. There is little available information about the molecular characterisation and epidemiological prevalence of Cryptosporidium spp. in Microtus fuscus (Qinghai vole) and Ochotona curzoniae (wild plateau pika) in the Qinghai-Tibetan Plateau area of Qinghai Province, Northwest China. Therefore, the aim of this study was to determine Cryptosporidium species/genotypes and epidemiological prevalence in these mammals by detecting the SSU rRNA gene by PCR amplification. The Cryptosporidium spp. infection rate was 8.9% (8/90) in Qinghai voles and 6.25% (4/64) in wild plateau pikas. Positive samples were successfully sequenced, and the following Cryptosporidium species were found: C. parvum, C. ubiquitum, C. canis and a novel genotype in Qinghai voles and C. parvum and a novel genotype in wild plateau pikas. This is the first report of Cryptosporidium infections in M. fuscus and wild O. curzoniae in Northwest China. The results suggest the possibility of Cryptosporidium species transmission among these two hosts, the environment, other animals and humans and provide useful molecular epidemiological data for the prevention and control of Cryptosporidium infections in wild animals and the surrounding environments. The results of the present study indicate the existence of Cryptosporidium species infections that have potential public health significance. This is the first report of Cryptosporidium multi-species infections in these animal hosts.

Human Intestinal Microbiota: Interaction Between Parasites and the Host Immune Response

The human gut is a highly complex ecosystem with an extensive microbial community, and the influence of the intestinal microbiota reaches the entire host organism. For example, the microbiome regulates fat storage, stimulates or renews epithelial cells, and influences the development and maturation of the brain and the immune system. Intestinal microbes can protect against infection by pathogenic bacteria, viruses, fungi and parasites. Hence, the maintenance of homeostasis between the gut microbiota and the rest of the body is crucial for health, with dysbiosis affecting disease. This review focuses on intestinal protozoa, especially those still representing a public health problem in Mexico, and their interactions with the microbiome and the host. The decrease in prevalence of intestinal helminthes in humans left a vacant ecological niche that was quickly occupied by protozoa. Although the mechanisms governing the interaction between intestinal microbiota and protozoa are poorly understood, it is known that the composition of the intestinal bacterial populations modulates the progression of protozoan infection and the outcome of parasitic disease. Most reports on the complex interactions between intestinal bacteria, protozoa and the immune system emphasize the protective role of the microbiota against protozoan infection. Insights into such protection may facilitate the manipulation of microbiota components to prevent and treat intestinal protozoan infections. Here we discuss recent findings about the immunoregulatory effect of intestinal microbiota with regards to intestinal colonization by protozoa, focusing on infections by Entamoeba histolytica, Blastocystis spp, Giardia duodenalis, Toxoplasma gondii and Cryptosporidium parvum. The possible consequences of the microbiota on parasitic, allergic and autoimmune disorders are also considered.

Cryptosporidium in humans and animals-a one health approach to prophylaxis

Cryptosporidium is a major cause of moderate-to-severe diarrhoea in humans worldwide, second only to rotavirus. Due to the wide host range and environmental persistence of this parasite, cryptosporidiosis can be zoonotic and associated with foodborne and waterborne outbreaks. Currently, 31 species are recognized as valid, and of these, Cryptosporidium hominis and Cryptosporidium parvum are responsible for the majority of infections in humans. The immune status of the host, both innate and adaptive immunity, has a major impact on the severity of the disease and its prognosis. Immunocompetent individuals typically experience self-limiting diarrhoea and transient gastroenteritis lasting up to 2 weeks and recover without treatment, suggesting an efficient host antiparasite immune response. Immunocompromised individuals can suffer from intractable diarrhoea, which can be fatal. Effective drug treatments and vaccines are not yet available. As a result of this, the close cooperation and interaction between veterinarians, health physicians, environmental managers and public health operators is essential to properly control this disease. This review focuses on a One Health approach to prophylaxis, including the importance of understanding transmission routes for zoonotic Cryptosporidium species, improved sanitation and better risk management, improved detection, diagnosis and treatment and the prospect of an effective anticryptosporidial vaccine.

Cryptosporidium spp. Infection in Solid Organ Transplantation: The Nationwide "TRANSCRYPTO" Study

BACKGROUND

Diarrhea is a frequent complication of solid organ transplantation. Cryptosporidiosis is classically reported in patients with acquired immunodeficiency syndrome and emerged as a cause of persistent diarrhea in solid organ transplant patients.

METHODS

Through the ANOFEL Cryptosporidium National Network and the French Transplantation Society, we collected all cryptosporidiosis cases identified in solid organ transplanted patients between 2006 and 2010 in France.

RESULTS

We reported 47 solid organ transplant recipients (41 kidneys) with cryptosporidiosis, mostly men (68%), with a median age of 52 (6-70) years old. Five patients had additional immunodepression favoring cryptosporidiosis (CD40 ligand deficiency [n = 1], human immunodeficiency virus infection [n = 4]). Cryptosporidiosis occurred at a median time of 3.4 (0-19.8) years posttransplant. Exposure to environmental risk factors was found before infection onset in 18 patients. Time between first symptoms and diagnosis was 10 (2-110) days. Four patients had associated extraintestinal location (biliary tract [n = 3] and lung [n = 1]). Thirty-five patients received specific therapy against cryptosporidiosis ie nitozoxanide, 25 in monotherapy, and 10 in association with azithromycin, 13 in association with immunosuppression (IS) reduction. Four patients were cured with IS treatment tapering only. The others patients had neither IS reduction nor specific therapy against cryptosporidiosis. Cryptosporidiosis was complicated by renal failure in 15 patients. Symptoms resolved after a median of 10 days of treatment. Six patients relapsed and 3 died, 1 with evolutive infection.

CONCLUSIONS

Cryptosporidiosis is a late posttransplant infection that disseminated to biliar duct or lung in 9% of patients. When limited to digestive tract, infection may resolve without IS reduction.

Effect of Egyptian propolis on cryptosporidiosis in immunosuppressed rats with special emphasis on oocysts shedding, leukogram, protein profile and ileum histopathology

OBJECTIVES

To investigate the activity of Egyptian propolis extracts (ethanol and water) on cryptosporidiosis in experimentally infected dexamethasone-immunosuppressed rats.

METHODS

A total of 180 male rats (190-220) g BWt were randomly divided into 9 equal groups (G1-G9). Groups of rats were kept as (G1): normal control, (G2-G9): immunosuppressed with dexamethasone and (G3-G9): infected with Cryptosporidium oocysts. Rats from (G4-G9) were given orally ethanol and water extract of propolis (at a dose of 50 mg/kg BWt) and nitazoxanide (standard anti-cryptosporidial drug at a dose of 100 mg/kg BWt) to infected rats with different regimes. Faecal pellets were collected from all groups to monitor oocysts shedding from the 2nd to the 15th day post infection. At the end of the experiment, blood was collected from all groups for determination of leukogram and serum proteins. Ileum specimens were also examined histopathologically.

RESULTS

The highest reduction of oocysts shedding in faecal samples was 88% in rats prophylactically treated with propolis ethanol extract at the 4th dpi, and in rats prophylactically treated with water extract of propolis, was 91% at the 6th dpi. There was a marked increase in neutrophils count and α₂- and β-globulins levels in infected rats treated with both extracts, while a significant decrease was detected in lymphocytes compared to the infected non treated group. β-Globulin level markedly increased in the rats administered nitazoxanide. Histopathological changes were observed in the ileum of rats infected with Cryptosporidium.

CONCLUSIONS

Egyptian propolis extracts have an activity on cryptosporidiosis in rats. Moreover, propolis modulated the immunity in dexamethasone-immunosuppressed rats.

The role of chemokines and their receptors during protist parasite infections

Protists are a diverse collection of eukaryotic organisms that account for a significant global infection burden. Often, the immune responses mounted against these parasites cause excessive inflammation and therefore pathology in the host. Elucidating the mechanisms of both protective and harmful immune responses is complex, and often relies of the use of animal models. In any immune response, leucocyte trafficking to the site of infection, or inflammation, is paramount, and this involves the production of chemokines, small chemotactic cytokines of approximately 8–10 kDa in size, which bind to specific chemokine receptors to induce leucocyte movement. Herein, the scientific literature investigating the role of chemokines in the propagation of immune responses against key protist infections will be reviewed, focussing onPlasmodiumspecies,Toxoplasma gondii, Leishmaniaspecies andCryptosporidiumspecies. Interestingly, many studies find that chemokines can in fact, promote parasite survival in the host, by drawing in leucocytes for spread and further replication. Recent developments in drug targeting against chemokine receptors highlights the need for further understanding of the role played by these proteins and their receptors in many different diseases.

Modulation of the immune response by infection with Cryptosporidium spp. in children with allergic diseases

It has been demonstrated that the allergic response can be ameliorated by the administration of pathogen derivatives that activate Toll-like receptors and induce a Th1-type immune response (IR). Cryptosporidium is a parasite that promotes an IR via Toll-like receptors and elicits the production of Th1-type cytokines, which limit cryptosporidiosis. The aim of this study was to investigate allergy-related immune markers in children naturally infected with Cryptosporidium. In a cross-sectional study, 49 children with or without clinical diagnosis of allergies, oocysts of Cryptosporidium spp. in the faeces were screened microscopically. We microscopically screened for leucocytes, examined T and B cells for allergy-related activation markers using flow cytometry and evaluated serum for total IgE using chemiluminescence. Children with allergies and Cryptosporidium in the faeces had significantly lower levels of total IgE, B cells, CD19(+) CD23(+) and CD19(+) CD124(+) cells as well as a greater percentage of interferon-gamma (IFN-γ(+) ) and IL-4(+) CD4(+) cells than children with allergies without Cryptosporidium. This is the first description of the modulation of the IR in children with allergic diseases in the setting of natural Cryptosporidium infection. Our findings suggest the involvement of CD4(+) cells producing IL-4 and IFN-γ in the IR to Cryptosporidium in naturally infected children.

Dynamics of Th17 associating cytokines in Cryptosporidium parvum-infected mice

Cryptosporidium parvum commonly inhabits the intestinal tract of animals and humans and can cause acute watery diarrhea and weight loss. However, host immune responses to Cryptosporidium infections are not fully understood. IL-17 (also called IL-17A) is a pro-inflammatory cytokine of Th17 cells that plays a role in the host response to Cryptosporidium baileyi infection. The present study examined levels of IL-17-specific messenger RNA (mRNA) and Th17 associating cytokines in C. parvum-infected immune-suppressed BALB/c mice using real-time quantitative PCR (qPCR). Levels of IL-17 protein were determined by ELISA. The results showed that levels of IL-17 mRNA and Th17 cell-related cytokines, namely TGF-β, IL-6, STAT-3, RORγt, IL-22, TNF-α, and IL-23, were significantly increased (P < 0.05) in gut-associated lymphoid tissue (GALT) and spleen. IL-17 protein levels in GALT were also significantly increased (P < 0.05) after infection. The present study suggested that Th17 cells play a role in host-C. parvum interaction. These results could inform future studies of the immune response against C. parvum infection in transient immunosuppressed populations.

Household Socioeconomic and Demographic Correlates of Cryptosporidium Seropositivity in the United States

BACKGROUND

Cryptosporidium are parasitic protozoa that infect humans, domestic animals, and wildlife globally. In the United States, cryptosporidiosis occurs in an estimated 750,000 persons annually, and is primarily caused by either of the Cryptosporidium parvum genotypes 1 and 2, exposure to which occurs through ingestion of food or water contaminated with oocytes shed from infected hosts. Although most cryptosporidiosis cases are caused by genotype 1 and are of human origin, the zoonotic sources of genotype 2, such as livestock, are increasingly recognized as important for understanding human disease patterns. Social inequality could mediate patterns of human exposure and infection by placing individuals in environments where food or water contamination and livestock contact is high or through reducing the availability of educational and sanitary resources required to avoid exposure.

METHODOLOGY/PRINCIPAL FINDINGS

We here analyzed data from the National Health and Nutritional Examination Survey (NHANES) between 1999 and 2000, and related seropositivity to Cryptosporidium parvum to correlates of social inequality at the household and individual scale. After accounting for the complex sampling design of NHANES and confounding by individual demographics and household conditions, we found impaired household food adequacy was associated with greater odds of Cryptosporidium seropositivity. Additionally, we identified individuals of non-white race and ethnicity and those born outside the United States as having significantly greater risk than white, domestic-born counterparts. Furthermore, we provide suggestive evidence for direct effects of family wealth on Cryptosporidium seropositivity, in that persons from low-income households and from families close to the poverty threshold had elevated odds of seropositivity relative to those in high-income families and in households far above the poverty line.

CONCLUSIONS/SIGNIFICANCE

These results refute assertions that cryptosporidiosis in the United States is independent of social marginalization and poverty, and carry implications for targeted public health interventions for Cryptosporidium infection in resource-poor groups. Future longitudinal and multilevel studies are necessary to elucidate the complex interactions between ecological factors, social inequality, and Cryptosporidium dynamics.

Rapid microfluidic immunoassay for surveillance and diagnosis of Cryptosporidium infection in human immunodeficiency virus-infected patients

Cryptosporidiosis has been reported to be associated with HIV/acquired immune deficiency syndrome, which greatly reduces the quality of life and shortens the life expectancy of HIV-infected patients. In order to properly treat the infected patients, accurate and automatic diagnostic tools need to be developed. In this study, a novel microfluidic immunochip system was presented for the surveillance and the rapid detection of Cryptosporidium infection in 190 HIV-infected patients from Guangxi, China, using the P23 antigen of Cryptosporidium. The procedure of detection can be completed within 10 min with 2 μl sample consumption. The system also was evaluated using the standard ELISA method. Among 190 HIV-infected individuals, the rate of P23 positivity was 13.7%. Seropositivity in HIV-infected individuals was higher in female patients. The seropositivity to P23 was higher in HIV-infected individuals with high viral load, although the difference was statistically insignificant. Significantly higher Cryptosporidium seropositivity was observed in HIV-infected individuals with a CD4(+) T-cell count of <200 cells/μl than in those with ≥200 cells/μl. Our results also demonstrate that a lower CD4(+) T-cell count may reflect an increased accumulated risk for cryptosporidiosis. The detection system was further validated using the standard ELISA method and good correlation between the two methods was found (r = 0.80). Under the same sensitivity, this new microfluidic chip device had a specificity of 98.2%. This developed system may provide a powerful platform for the fast screening of Cryptospordium infection in HIV-infected patients.

Molecular characterization of Cryptosporidium spp. in pre-weaned calves in Shaanxi Province, north-western China

Cryptosporidium, a worldwide protozoan parasite, is one of the most common causes of diarrhoea in humans and animals. The aim of the present study was to determine Cryptosporidium species/genotypes in pre-weaned calves in Shaanxi Province using PCR and sequencing based on the small subunit rRNA gene. A total of 258 faecal samples were collected from pre-weaned calves in 19 different farms from six areas in Shaanxi Province, north-western China. Cryptosporidium infection was detected in 14 of 19 farms (73.7 %), with a total prevalence of 20.2 % (52/258). Both dairy and Qinchuan (beef) cattle were found with Cryptosporidium infection. Three Cryptosporidium species, namely Cryptosporidium bovis (n = 26), Cryptosporidium andersoni (n = 14) and Cryptosporidium ryanae (n = 12), were detected in pre-weaned calves in Shaanxi Province, with C. bovis (in 12 farms) identified as the most common species on cattle farms. Two additional and previously unknown C. ryanae genotypes, CRTypes III and IV, were observed in the present study. However, the zoonotic species, Cryptosporidium parvum, was not detected in this study, which suggested a low zoonotic potential in Cryptosporidium-infected pre-weaned calves in this province.

First report of Cryptosporidium spp. in white yaks in China

BACKGROUND

Cryptosporidium is an enteric apicomplexan parasite, which can infect yaks, leading to reduction of milk production and poor weight gain. White yak (Bos grunniens) is a unique yak breed inhabiting only in Tianzhu Tibetan Autonomous County, Gansu province, northwestern China. The objective of the present study was to molecularly determine Cryptosporidium infection and species in white yaks.

FINDINGS

Seventy-six fecal samples from white yaks in Tianzhu Tibetan Autonomous County, Gansu province were collected. The small subunit ribosomal RNA (SSU rRNA) gene of each sample was amplified using nested PCR and sequenced. The Cryptosporidium species was determined by comparison of the obtained sequences with that of corresponding Cryptosporidium sequences available in GenBank by BLAST (http://www.ncbi.nlm.nih.gov/BLAST/) and phylogenetic analysis with maximum likelihood (ML) using PAUP*. The overall prevalence of Cryptosporidium infection in white yak was 5.26% (4/76). Species identification showed C. andersoni in one sample (collected in September), and C. bovis in three samples (one collected in November and two collected in September).

CONCLUSIONS

The present investigation revealed the existence of Cryptosporidium infection in white yaks in China, for the first time, and two Cryptosporidium species, namely C. andersoni and C. bovis, were identified. These findings extend the host range for Cryptosporidium spp., and also provide base-line information for further studies of molecular epidemiology and control of Cryptosporidium infection in the unique white yaks.

Non-coding RNAs in epithelial immunity to Cryptosporidium infection

Cryptosporidium spp. is a protozoan parasite that infects the gastrointestinal epithelium and causes diarrhoeal disease worldwide. It is one of the most common pathogens responsible for moderate to severe diarrhoea in children younger than 2 years. Because of the 'minimally invasive' nature of Cryptosporidium infection, mucosal epithelial cells are critical to the host's anti-Cryptosporidium immunity. Gastrointestinal epithelial cells not only provide the first and most rapid defence against Cryptosporidium infection, they also mobilize immune effector cells to the infection site to activate adaptive immunity. Recent advances in genomic research have revealed the existence of a large number of non-protein-coding RNA transcripts, so called non-coding RNAs (ncRNAs), in mammalian cells. Some ncRNAs may be key regulators for diverse biological functions, including innate immune responses. Specifically, ncRNAs may modulate epithelial immune responses at every step of the innate immune network following Cryptosporidium infection, including production of antimicrobial molecules, expression of cytokines/chemokines, release of epithelial cell-derived exosomes, and feedback regulation of immune homoeostasis. This review briefly summarizes the current science on ncRNA regulation of innate immunity to Cryptosporidium, with a focus on microRNA-associated epithelial immune responses.

The expression dynamics of IL-17 and Th17 response relative cytokines in the trachea and spleen of chickens after infection with Cryptosporidium baileyi

BACKGROUND

Cryptosporidium baileyi is the dominant Cryptosporidium species in birds causing emerging health problems in the poultry industry, and is also a model to study the biology of Cryptosporidium spp.. IL-17 (also called IL-17A) is a hallmark pro-inflammatory cytokine of Th17 cells that plays an important role in several human autoimmune diseases and microbial infection disease of many animals, and it may play a role in Cryptosporidium infection.

METHODS

The present study examined the mRNA level of IL-17 and Th17 response relative cytokines in the trachea and spleen of C. baileyi-infected chickens at different time points using real-time quantitative PCR (qPCR).

RESULTS

All examined cytokines in the trachea were up-regulated in the infected chickens compared with the uninfected control during C. baileyi infection. Significant increased IL-17 mRNA level in the trachea was observed as early as 12 h post infection (pi), peaking at 24 h pi and 10 d pi, and declining thereafter. The transcription levels of IL-17 and Th17 response relative cytokines in spleen were also significantly increased at different time points during the infection.

CONCLUSIONS

IL-17 was indicated to participate in the induction of inflammation during infection of some intracellular protozoan parasites. The results in the present study suggest that IL-17 may play a role in immunity against Cryptosporidium infection, and provide basic information for determining the role of Th17 cell in Cryptosporidium infection.

Cryptosporidium pathogenicity and virulence. Clin Microbiol Rev. 2013;26:115-134. [PMID: 23297262 DOI: 10.1128/cmr.00076-12]

Cryptosporidium is a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported different degrees of pathogenicity and virulence among Cryptosporidium species and isolates of the same species as well as evidence of variation in host susceptibility to infection. The identification and validation of Cryptosporidium virulence factors have been hindered by the renowned difficulties pertaining to the in vitro culture and genetic manipulation of this parasite. Nevertheless, substantial progress has been made in identifying putative virulence factors for Cryptosporidium. This progress has been accelerated since the publication of the Cryptosporidium parvum and C. hominis genomes, with the characterization of over 25 putative virulence factors identified by using a variety of immunological and molecular techniques and which are proposed to be involved in aspects of host-pathogen interactions from adhesion and locomotion to invasion and proliferation. Progress has also been made in the contribution of host factors that are associated with variations in both the severity and risk of infection. Here we provide a review comprised of the current state of knowledge on Cryptosporidium infectivity, pathogenesis, and transmissibility in light of our contemporary understanding of microbial virulence.

Histone deacetylases and NF-kB signaling coordinate expression of CX3CL1 in epithelial cells in response to microbial challenge by suppressing miR-424 and miR-503

The NF-kB pathway is key to epithelial immune defense and has been implicated in secretion of antimicrobial peptides, release of cytokines/chemokines to mobilize immune effector cells, and activation of adaptive immunity. The expression of many inflammatory genes following infection involves the remodeling of the chromatin structure. We reported here that histone deacetylases (HDACs) and NF-kB signaling coordinate expression of CX3CL1 in epithelial cells following Cryptosporidium parvum infection. Upregulation of CX3CL1 was detected in cultured human biliary epithelial cells following infection. Expression of miR-424 and miR-503 was downregulated, and was involved in the induction of CX3CL1 in infected cells. C. parvum infection suppressed transcription of the mir-424-503 gene in a NF-kB- and HDAC-dependent manner. Increased promoter recruitment of NF-kB p50 and HDACs, and decreased promoter H3 acetylation associated with the mir-424-503 gene were observed in infected cells. Upregulation of CX3CL1 in biliary epithelial cells and increased infiltration of CX3CR1⁺ cells were detected during C. parvum infection in vivo. Induction of CX3CL1 and downregulation of miR-424 and miR-503 were also detected in epithelial cells in response to LPS stimulation. The above results indicate that HDACs and NF-kB signaling coordinate epithelial expression of CX3CL1 to promote mucosal antimicrobial defense through suppression of the mir-424-503 gene.

Infection of cattle with Cryptosporidium parvum: mast cell accumulation in small intestine mucosa

Mast cells might play an important role as the major effector cells in the immune response against Cryptosporidium parvum. C. parvum is a protozoan parasite that causes cryptosporidiosis in animals and humans worldwide. To investigate the interaction between C. parvum and mast cells during infection, nine 3-day-old male calves were orally challenged with 10(6) oocysts of C. parvum per calf. The distribution of mast cells in the mucosa of the small intestine was analyzed by toluidine blue staining. The concentrations of histamine and the cytokines interferon-γ, interleukin-4, interleukin-2, and interleukin-12 were measured in the serum, and the histamine levels were also determined from the intestinal contents. The following clinical signs were monitored: nausea, watery diarrhea, dehydration, and weight loss. Oocysts were shed in the feces during the infection period. C. parvum infection induced an increase in mast cell numbers in the mucosa of the small intestine in distinct temporal and spatial patterns. Infection with C. parvum can induce mastocytosis in the entire small intestinal mucosa in immune-competent calves, and the presence of the parasites influences the distribution profile of the mast cells.

SOCS proteins in infectious diseases of mammals

As for most biological processes, the immune response to microbial infections has to be tightly controlled to remain beneficial for the host. Inflammation is one of the major consequences of the host's immune response. For its orchestration, this process requires a fine-tuned interplay between interleukins, endothelial cells and various types of recruited immune cells. Suppressors of cytokine signalling (SOCS) proteins are crucially involved in the complex control of the inflammatory response through their actions on various signalling pathways including the JAK/STAT and NF-κB pathways. Due to their cytokine regulatory functions, they are frequent targets for exploitation by infectious agents trying to escape the host's immune response. This review article aims to summarize our current knowledge regarding SOCS family members in the different mammalian species studied so far, and to display their complex molecular interactions with microbial pathogens.

Parasites in ungulates of Arctic North America and Greenland: a view of contemporary diversity, ecology, and impact in a world under change

Parasites play an important role in the structure and function of arctic ecosystems, systems that are currently experiencing an unprecedented rate of change due to various anthropogenic perturbations, including climate change. Ungulates such as muskoxen, caribou, moose and Dall's sheep are also important components of northern ecosystems and are a source of food and income, as well as a focus for maintenance of cultural traditions, for northerners. Parasites of ungulates can influence host health, population dynamics and the quality, quantity and safety of meat and other products of animal origin consumed by people. In this article, we provide a contemporary view of the diversity of nematode, cestode, trematode, protozoan and arthropod parasites of ungulates in arctic and subarctic North America and Greenland. We explore the intricate associations among host and parasite assemblages and identify key issues and gaps in knowledge that emerge in a regime of accelerating environmental transition.

Prevalence and distribution of Cryptosporidium and Giardia in wastewater and the surface, drinking and ground waters in the Lower Rhine, Germany

Samples from different water sources (n = 396) were collected during 2009 and 2011. Wastewater (2-5 l) was purified by aluminium sulphate flocculation. Surface, ground and drinking waters (400-6400 l) were collected by filtration. Cryptosporidium oocysts and Giardia cysts were further concentrated by sucrose centrifugation. (Oo)cysts were identified by IFT (immunofluorescence test), DAPI (4',6-diamidino-2-phenylindole) staining and DICM (difference interference contrast microscopy). Out of 206 wastewater samples, 134 (65·0%) were found to be positive for Giardia cysts and 64 (31·1%) for Cryptosporidium oocysts. Parasite numbers ranged from 0 to 2436 cysts/l and 0 to 1745 oocysts/l. Eight (4·2%) surface and drinking water samples (n = 190) were found to be positive for Giardia cysts (0-56000/100 l), and 18 (9·5%) for Cryptosporidium oocysts (2400/100 l). The purpose of this study was to establish the prevalence and concentrations of Giardia lamblia and Cryptosporidium spp. by detecting (oo)cysts from water samples. This study provides substantial evidence that G. lamblia cysts and Cryptosporidium spp. oocysts are able to enter and circulate in the aquatic environment with negative implications for public health.

Host-Parasite interactions in Entamoeba histolytica and Entamoeba dispar: what have we learned from their genomes?

Invasive amoebiasis caused by Entamoeba histolytica is a major global health problem. Virulence is a rare outcome of infection, occurring in fewer than 1 in 10 infections. Not all strains of the parasite are equally virulent, and understanding the mechanisms and causes of virulence is an important goal of Entamoeba research. The sequencing of the genome of E. histolytica and the related avirulent species Entamoeba dispar has allowed whole-genome-scale analyses of genetic divergence and differential gene expression to be undertaken. These studies have helped elucidate mechanisms of virulence and identified genes differentially expressed in virulent and avirulent parasites. Here, we review the current status of the E. histolytica and E. dispar genomes and the findings of a number of genome-scale studies comparing parasites of different virulence.

miR-27b targets KSRP to coordinate TLR4-mediated epithelial defense against Cryptosporidium parvum infection

Cryptosporidium is a protozoan parasite that infects the gastrointestinal epithelium and causes a diarrheal disease. Toll-like receptor (TLR)- and NF-κB-mediated immune responses from epithelial cells, such as production of antimicrobial peptides and generation of reactive nitrogen species, are important components of the host's defense against cryptosporidial infection. Here we report data demonstrating a role for miR-27b in the regulation of TLR4/NF-κB-mediated epithelial anti-Cryptosporidium parvum responses. We found that C. parvum infection induced nitric oxide (NO) production in host epithelial cells in a TLR4/NF-κB-dependent manner, with the involvement of the stabilization of inducible NO synthase (iNOS) mRNA. C. parvum infection of epithelial cells activated NF-κB signaling to increase transcription of the miR-27b gene. Meanwhile, downregulation of KH-type splicing regulatory protein (KSRP) was detected in epithelial cells following C. parvum infection. Importantly, miR-27b targeted the 3′-untranslated region of KSRP, resulting in translational suppression. C. parvum infection decreased KSRP expression through upregulating miR-27b. Functional manipulation of KSRP or miR-27b caused reciprocal alterations in iNOS mRNA stability in infected cells. Forced expression of KSRP and inhibition of miR-27b resulted in an increased burden of C. parvum infection. Downregulation of KSRP through upregulating miR-27b was also detected in epithelial cells following LPS stimulation. These data suggest that miR-27b targets KSRP and modulates iNOS mRNA stability following C. parvum infection, a process that may be relevant to the regulation of epithelial anti-microbial defense in general.

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the posttranscriptional level. Accumulating data indicate that miRNAs are an essential part of the complex regulatory networks that control various cellular processes, including host antimicrobial immune responses. Toll-like receptors (TLRs) play an essential role in the activation of innate immunity by recognizing specific patterns of microbial components and activating downstream intracellular signaling pathways, including NF-κB. However, the role of miRNAs in the regulation of TLR/NF-κB-mediated epithelial antimicrobial defense is still unclear. Cryptosporidium is a protozoan parasite that infects the gastrointestinal epithelium in humans. Here, we show that KSRP, an RNA-binding protein and a key mediator of mRNA decay, is a target for miR-27b. Infection by Cryptosporidium parvum activates TLR4/NF-κB signaling and increases miR-27b expression, causing a suppression of KSRP in infected host epithelial cells. Functionally, downregulation of KSRP stabilizes iNOS mRNA and promotes epithelial production of nitric oxide, a molecule with antimicrobial activity. Therefore, miR-27b confers TLR4/NF-κB-mediated epithelial cell anti-Cryptosporidium parvum defense though regulating KSRP. Our study provides a new area of exploration for fine-tuning TLR/NF-κB-mediated host reactions in response to microbial challenge.

Induction of protective immunity against Eimeria tenella, Eimeria maxima, and Eimeria acervulina infections using dendritic cell-derived exosomes

This study describes a novel immunization strategy against avian coccidiosis using exosomes derived from Eimeria parasite antigen (Ag)-loaded dendritic cells (DCs). Chicken intestinal DCs were isolated and pulsed in vitro with a mixture of sporozoite-extracted Ags from Eimeria tenella, E. maxima, and E. acervulina, and the cell-derived exosomes were isolated. Chickens were nonimmunized or immunized intramuscularly with exosomes and subsequently noninfected or coinfected with E. tenella, E. maxima, and E. acervulina oocysts. Immune parameters compared among the nonimmunized/noninfected, nonimmunized/infected, and immunized/infected groups were the numbers of cells secreting T(h)1 cytokines, T(h)2 cytokines, interleukin-16 (IL-16), and Ag-reactive antibodies in vitro and in vivo readouts of protective immunity against Eimeria infection. Cecal tonsils, Peyer's patches, and spleens of immunized and infected chickens had increased numbers of cells secreting the IL-16 and the T(h)1 cytokines IL-2 and gamma interferon, greater Ag-stimulated proliferative responses, and higher numbers of Ag-reactive IgG- and IgA-producing cells following in vitro stimulation with the sporozoite Ags compared with the nonimmunized/noninfected and nonimmunized/infected controls. In contrast, the numbers of cells secreting the T(h)2 cytokines IL-4 and IL-10 were diminished in immunized and infected chickens compared with the nonimmunized/noninfected and the nonimmunized/infected controls. Chickens immunized with Ag-loaded exosomes and infected in vivo with Eimeria oocysts had increased body weight gains, reduced feed conversion ratios, diminished fecal oocyst shedding, lessened intestinal lesion scores, and reduced mortality compared with the nonimmunized/infected controls. These results suggest that successful field vaccination against avian coccidiosis using exosomes derived from DCs incubated with Ags isolated from Eimeria species may be possible.

Cryptosporidiosis-an overview

Apicomplexan protozoan parasites of the genus Cryptosporidium infect the gastrointestinal tract and lungs of a wide variety of animals, including humans. The majority of human infections are due to either Cryptosporidium hominis (C. hominis) and/or Cryptosporidium parvum (C. parvum). The parasite has a complex life cycle that includes both asexual and sexual stages. While there are invasive free living stages, proliferation and differentiation take place within a unique parasitrophorous vacuole under the host cell brush border but outside the host cell cytoplasm. Infection is spread by environmentally resistant spores that primarily contaminate drinking water and occasionally food sources, which may cause significant outbreaks of diarrhea that generally lasts less than 2 w in immunocompetent individuals. In immunodeficient or immunosuppressed individuals, diarrhea may be copious and can result in significant morbidity and mortality, particularly in AIDS patients. Although diagnosis is relatively simple, effective drug treatment, particulary for infections in immunodeficient patients, has not been uniformly successful. This overview summarizes the species known to infect humans, aspects of the parasite life cycle, sources of infection, the pathophysiology of cryptosporidiosis, the immune response to infection, diagnosis, treatment and some aspects of cryptosporidiosis in China.