Assessment of Cryptosporidium parvum infection in immunocompetent and immunocompromised mice and its role in triggering intestinal dysplasia

Cryptosporidium impacts epithelial turnover and is resistant to induced death of the host cell

Infection with the apicomplexan parasite Cryptosporidium is a leading cause of diarrheal disease. Cryptosporidiosis is of particular importance in infants and shows a strong association with malnutrition, both as a risk factor and as a consequence. Cryptosporidium invades and replicates within the small intestine epithelial cells. This is a highly dynamic tissue that is developmentally stratified along the villus axis. New cells emerge from a stem cell niche in the crypt and differentiate into mature epithelial cells while moving toward the villus tip, where they are ultimately shed. Here, we studied the impact of Cryptosporidium infection on this dynamic architecture. Tracing DNA synthesis in pulse-chase experiments in vivo, we quantified the genesis and migration of epithelial cells along the villus. We found proliferation and epithelial migration to be elevated in response to Cryptosporidium infection. Infection also resulted in significant cell loss documented by imaging and molecular assays. Consistent with these observations, single-cell RNA sequencing of infected intestines showed a gain of young and a loss of mature cells. Interestingly, enhanced epithelial cell loss was not a function of enhanced apoptosis of infected cells. To the contrary, Cryptosporidium-infected cells were less likely to be apoptotic than bystanders, and experiments in tissue culture demonstrated that infection provided enhanced resistance to chemically induced apoptosis to the host but not bystander cells. Overall, this study suggests that Cryptosporidium may modulate cell apoptosis and documents pronounced changes in tissue homeostasis due to parasite infection, which may contribute to its long-term impact on the developmental and nutritional state of children.

IMPORTANCE

The intestine must balance its roles in digestion and nutrient absorption with the maintenance of an effective barrier to colonization and breach by numerous potential pathogens. An important component of this balance is its constant turnover, which is modulated by a gain of cells due to proliferation and loss due to death or extrusion. Here, we report that Cryptosporidium infection changes the dynamics of this process increasing both gain and loss of enterocytes speeding up the villus elevator. This leads to a much more immature epithelium and a reduction of the number of those cells typically found toward the villus apex best equipped to take up key nutrients including carbohydrates and lipids. These changes in the cellular architecture and physiology of the small intestine may be linked to the profound association between cryptosporidiosis and malnutrition.

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.

Medical prospects of cryptosporidiosis in vivo control using biofabricated nanoparticles loaded with Cinnamomum camphora extracts by Ulva fasciata

Background and Aim

Global efforts are continuing to develop preparations against cryptosporidiosis. This study aimed to investigate the efficacy of biosynthesized Ulva fasciata loading Cinnamomum camphora oil extract on new zinc oxide nanoparticles (ZnONPs shorten to ZnNPs) and silver nanoparticles (AgNPs) as alternative treatments for Cryptosporidium parvum experimental infection in rats.

Materials and Methods

Oil extract was characterized by gas chromatography-mass spectrometry, loaded by U. fasciata on ionic-based ZnO and NPs, and then characterized by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. Biosafety and toxicity were investigated by skin tests. A total of 105 C. parvum oocysts/rat were used (n = 81, 2-3 W, 80-120 g, 9 male rats/group). Oocysts shedding was counted for 21 d. Doses of each preparation in addition to reference drug were administered daily for 7 d, starting on post-infection (PI) day (3). Nitazoxanide (100 mg) was used as the reference drug. After 3 weeks, the rats were sacrificed for postmortem examination and histopathological examination. Two blood samples/rat/group were collected on the 21st day. Ethylenediaminetetraacetic acid blood samples were also used for analysis of biochemistry, hematology, immunology, micronucleus prevalence, and chromosomal abnormalities.

Results

C. camphora leaves yielded 28.5 ± 0.3 g/kg oil and 20 phycocompounds were identified. Spherical and rod-shaped particles were detected at 10.47-30.98 nm and 18.83-38.39 nm, respectively. ZnNPs showed the earliest anti-cryptosporidiosis effect during 7-17 d PI. Other hematological, biochemical, immunological, histological, and genotoxicity parameters were significantly fruitful; hence, normalized pathological changes induced by infestation were observed in the NPs treatments groups against the infestation-free and Nitazoxanide treated group.

Conclusion

C. camphora, U. fasciata, ZnNPs, and AgNPs have refluxed the pathological effects of infection as well as positively improved host physiological condition by its anticryptosporidial immunostimulant regenerative effects with sufficient ecofriendly properties to be proposed as an alternative to traditional drugs, especially in individuals with medical reactions against chemical commercial drugs.

Newly fabricated zinc oxide nanoparticles loaded materials for therapeutic nano delivery in experimental cryptosporidiosis

Cryptosporidiosis is a global health problem that threatens the lives of immunocompromised patients. This study targets to fabricate and investigate the efficiency of zinc oxide nanoparticles (ZnO-NPs), nitazoxanide (NTZ)-loaded ZnO-NPs, and Allium sativum (A. sativum)-loaded ZnO-NPs in treating cryptosporidiosis. Further FTIR, SEM, XRD, and zeta analysis were used for the characterization of ZnO-NPs and loaded materials. The morphology of loaded materials for ZnO-NPs changed into wrapped layers and well-distributed homogenous particles, which had a direct effect on the oocyst wall. The charge surface of all particles had a negative sign, which indicated well distribution into the parasite matrix. For anti-cryptosporidiosis efficiency, thirty immunosuppressed Cryptosporidium parvum-infected mice, classified into six groups, were sacrificed on the 21st day after infection with an evaluation of parasitological, histopathological, and oxidative markers. It was detected that the highest reduction percent of Cryptosporidium oocyst shedding was (81.5%) in NTZ, followed by (71.1%) in A. sativum-loaded ZnO-NPs-treated groups. Also, treatment with A. sativum and NTZ-loaded ZnO-NPs revealed remarkable amelioration of the intestinal, hepatic, and pulmonary histopathological lesions. Furthermore, they significantly produced an increase in GSH values and improved the changes in NO and MDA levels. In conclusion, this study is the first to report ZnO-NPs as an effective therapy for treating cryptosporidiosis, especially when combined with other treatments that enhance their antioxidant activity. It provides an economical and environment-friendly approach to novel delivery synthesis for antiparasitic applications.

Annona muricata Leaf as an Anti-Cryptosporidial Agent: An In Silico Molecular Docking Analysis and In Vivo Studies

Cryptosporidiosis is a serious parasitic diarrheal disease linked to the occurrence of colorectal cancer in immunocompromised patients. The FDA-approved drug nitazoxanide (NTZ) achieved a temporary effect, and relapses occur. Annona muricata leaf is widely used in traditional medicine to treat a wide range of disorders, including antiparasitic and anticancer effects. So, this study aimed to investigate Annona muricata leaf antiparasitic and anticancer properties compared to NTZ in Cryptosporidium parvum (C. parvum) acutely and chronically infected immunosuppressed mice. A molecular docking analysis was performed to evaluate the effectiveness of some biologically active compounds that represented the pharmacological properties of Annona muricata leaf-rich extract toward C. parvum lactate dehydrogenase compared to NTZ. For the in vivo study, eighty immunosuppressed albino mice were classified into four groups as follows: group I: infected and treated with A. muricata; group II: infected and treated with nitazoxanide; group III: infected and received no treatment; and group IV: were neither infected nor treated. Furthermore, half of the mice in groups I and II received the drugs on the 10th day post-infection (dpi), and the other half received treatment on the 90th day post-infection. Parasitological, histopathological, and immunohistochemical evaluations were performed. The docking analysis showed that the lowest estimated free energy of binding of annonacin, casuarine, L-epigallocatechin, P-coumaric acid, and ellagic acid toward C. parvum LDH, were -6.11, -6.32, -7.51, -7.81, and -9.64 kcal/mol, respectively, while NTZ was -7.03 kcal/mol. Parasitological examination displayed a significantly high difference in C. parvum oocyst mean counts in groups I and II compared to group III (p-value < 0.001), with group I demonstrating the highest efficacy. The analyses of histopathological and immunohistochemical results revealed that group I showed restoration of the normal villous pattern without evidence of dysplasia or malignancy. A. muricata leaf has proved to be a reliable agent for Cryptosporidium treatment. This paper argues for its promising use as an antiparasitic agent and for the prevention of neoplastic sequels of Cryptosporidium infection.

The potential therapeutic effect of Nigella sativa and Zingiber officinale extracts versus Nitazoxanide drug against experimentally induced cryptosporidiosis in laboratory mice

In this study, the potential anti-cryptosporidial effect of Nigella sativa (black seeds) and Zingiber officinale (ginger) alcoholic extracts versus Nitazoxanide (NTZ) medication was investigated in immunosuppressed (IS) laboratory mice. Parasitological, histopathological studies were used to assess their therapeutic efficacy. Serum level and tissue expression percentage of IFN-γ was also used. Nigella extract succeeded to reduce the mean oocyst counts in the feces of immunosuppressed mice followed by NTZ. Ginger-treated ones showed the lowest reduction percentage. Nigella sativa showed the best results in terms of restoring the normal architecture of ileal epithelium in histopathological sections stained with H&E. NTZ treatment sub-groups showed mild improvement, followed by ginger-treated mice, which showed a slight improvement in small intestine microenvironment. A significant substantial rise in serum and intestinal tissue IFN-γ cytokine levels were recorded in Nigella subgroups compared to those of NTZ and ginger respectively. According to our findings Nigella sativa outperformed Nitazoxanide in terms of anti-cryptosporidial effectiveness and regeneration characteristics revealing a promising medication. When compared to the commonly used Nitazoxanide medication or Nigella extracts, the outcomes of ginger extract were suboptimal.

Cryptosporidium uses CSpV1 to activate host type I interferon and attenuate antiparasitic defenses

Cryptosporidium infects gastrointestinal epithelium and is a leading cause of infectious diarrhea and diarrheal-related death in children worldwide. There are no vaccines and no fully effective therapy available for the infection. Type II and III interferon (IFN) responses are important determinants of susceptibility to infection but the role for type I IFN response remains obscure. Cryptosporidium parvum virus 1 (CSpV1) is a double-stranded RNA (dsRNA) virus harbored by Cryptosporidium spp. Here we show that intestinal epithelial conditional Ifnar1^-/- mice (deficient in type I IFN receptor) are resistant to C. parvum infection. CSpV1-dsRNAs are delivered into host cells and trigger type I IFN response in infected cells. Whereas C. parvum infection attenuates epithelial response to IFN-γ, loss of type I IFN signaling or inhibition of CSpV1-dsRNA delivery can restore IFN-γ-mediated protective response. Our findings demonstrate that type I IFN signaling in intestinal epithelial cells is detrimental to intestinal anti-C. parvum defense and Cryptosporidium uses CSpV1 to activate type I IFN signaling to evade epithelial antiparasitic response.

Detection of unusual Cryptosporidium parvum subtype in patients with gastrointestinal cancer in Egypt

While the importance of cryptosporidiosis in immunocompromised persons is well known, the prevalence of Cryptosporidium spp. in cancer patients is not clear. The current study was designed to assess the occurrence and genetic characteristics of Cryptosporidium spp. in patients with gastrointestinal (GI) cancer in Egypt. Stool samples were collected from 100 patients with GI malignancies and 20 healthy individuals without any GI manifestations (control group). They were screened by microscopy and the immunochromatographic RIDA®QUICK Cryptosporidium kit. Subtyping of Cryptosporidium spp. was conducted by sequence analysis of the glycoprotein 60 (gp60) locus. Sociodemographic, environmental data and information on GI symptoms, cancer types, and clinical treatment were obtained via a questionnaire. By microscopy and RIDA®QUICK, only 7% (7/100) of GI cancer patients were positive for Cryptosporidium, compared with 40% (40/100) by gp60 nPCR. No positives were obtained from the control group. Male sex (P = 0.02) and younger age (P = 0.004) were major Cryptosporidium risk factors for infection. The occurrence of Cryptosporidium was also significantly more frequent (P = 0.003) in watery stool samples. Sequence analysis of the gp60 amplicons (~ 400 bp) identified a novel C. parvum subtype with nine TCA repeats and eleven ACATCA repeats. A formal subtype designation could not be made due to the short sequence length. More studies should be conducted to verify the common occurrence of this unusual C. parvum subtype and establish its genetic identity.

Evaluation of a vaccine candidate isolated from Cryptosporidium parvum oocyst in mice

Background and Aim

Cryptosporidiosis is a leading cause of diarrheal disease worldwide and is an animal and public health burden. This study aimed to evaluate the protective potential of affinity-purified Cryptosporidium parvum oocyst antigen as a vaccine candidate according to fecal oocyst shedding, humoral and cellular immune responses, histopathological changes, and the number of parasite developmental stages in ileal and hepatic tissues.

Materials and Methods

We isolated oocysts from naturally infected buffalo calves and identified them molecularly as C. parvum isolates (GenBank: ON730707 and ON730708) by targeting the Cryptosporidium oocyst wall protein gene. We propagated the C. parvum oocysts in mice. In addition, we prepared crude antigen from the isolated oocysts by purification using cyanogen bromide-activated Sepharose-4B affinity chromatography coupled with rabbit hyperimmune serum. Then, we divided 81 parasite-free mice into three groups: (1) non-vaccinated non-infected mice, (2) mice orally infected with 1 × 10⁵ C. parvum oocysts on week 4 of the experiment, and (3) mice immunized twice with 40 μg/kg of the purified fraction at 2-week intervals. Then, we challenged the vaccinated group with C. parvum oocysts after 2 weeks, and the positive control group was infected at the same time.

Results

We observed a prolonged prepatent period and decreased oocyst shedding in the vaccinated infected mice compared with the non-vaccinated infected mice (t < 0.001). The vaccinated mice had significantly higher immunoglobulin G levels than those in the other two groups at all examined weeks. In addition, the production of cytokines interferon-gamma, interleukin (IL)-10, IL-12, and IL-15 was activated post-vaccination. After the challenge, all tested cytokines were significantly increased (p < 0.001) in the two infected groups compared with the non-vaccinated non-infected group, with the highest levels in the vaccinated infected group. Vaccinated infected mice exhibited significantly fewer pathological lesions in the ileum and liver than non-vaccinated infected mice, which showed prominent histopathological lesions. Endogenous developmental stages of C. parvum indicated that the ileum was more parasitized than the liver and that vaccination resulted in a lower number of oocysts in ileal and hepatic tissues (p < 0.05).

Conclusion

Our prepared affinity-purified vaccine candidate could be promising in protecting against cryptosporidiosis.

Apoptotic changes in the intestinal epithelium of Cryptosporidium-infected mice after silver nanoparticles treatment versus nitazoxanide

Cryptosporidium has been identified as one of the prevalent opportunistic parasites that cause diarrhea, which may be persistent and fatal. Current chemotherapeutic agents, including nitazoxanide (NTZ), are frequently associated with therapeutic failure, and their roles in the induction of apoptosis in cryptosporidiosis remain to be a topic of debate. Thus, this study aimed to assess the apoptotic changes in cryptosporidiosis in immunocompetent (IC) and immunosuppressed (IS) mice after treatment with silver nanoparticles (AgNPs) and NTZ either alone or after loading. In total, 120 laboratory-bred Swiss albino mice were divided into two groups. Group A included IC mice, while Group B included IS mice. Both groups were divided into six subgroups: noninfected nontreated, infected nontreated, infected AgNP-treated, infected NTZ-treated, infected AgNP-loaded NTZ (full-dose)-treated, and infected AgNP-loaded NTZ (half-dose)-treated. The assessment was achieved through parasitological, histopathological, and apoptotic marker expression evaluation. AgNP-loaded NTZ (different doses) treatment showed the highest oocyst shedding reduction and remarkable improvement in histopathological changes, followed by individual treatment with NTZ and then AgNPs in IC and IS mice. Results of apoptotic marker expression revealed that AgNP-loaded NTZ treatment exhibited a promising role in regulating apoptotic changes in cryptosporidiosis through the expression of the lowest levels of cytochrome C and caspase-3 in IC and IS mice at the end of the experiment. Therefore, AgNP-loaded NTZ can be a potential therapeutic agent against cryptosporidiosis for IC and IS mice.

Deep glance on the antiparasitic anticancer activities of wheat germ oil in chronically infected immunosuppressed mice with cryptosporidiosis

Cryptosporidium species are the major cause of water-borne epidemics of diarrhea in both developing and developed countries that vary from self-limited in immunocompetent patients to severe life-threatening in the immunocompromised hosts. There was a proven correlation between cryptosporidiosis and colorectal cancers, although, studies in this field are still limited. Wheat germ oil (WGO) is a natural product with a known antiparasitic effect and potential antiproliferative activities. This study aimed to evaluate the antiparasitic and anticancer activities of WGO in chronically infected immunosuppressed mice compared to Nitazoxanide (NTZ). This experimental case-control study was performed in the period from January till September 2021. Eighty immunosuppressed bred laboratory mice were divided into 4 groups, 20 mice each; GI non-infected; negative control (NC), GII infected non treated; positive control (PC), GII infected, and treated with NTZ, GIV infected, and treated with WGO. Parasitological, histopathological, and immunohistochemical examinations were performed with estimating the rate of maximal survival for the study groups. Parasitological examination revealed a marked reduction in the mean Cryptosporidium spp. oocyst counts in the stool of GIV compared to PC, and GIII (P-value < 0.001). Histopathological and immunohistochemical examinations showed the best results with GIV which revealed restoration of normal villous pattern, with no dysplasia or malignancy could be detected. GIV showed the best survival rate compared to PC and GIII. WGO is an extremely promising agent that has an excellent therapeutic effect against cryptosporidiosis with the ability to control the tumorigenesis process in the chronically infected immunosuppressed hosts.

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.

Are Blastocystis hominis and Cryptosporidium spp. playing a positive role in colorectal cancer risk? A systematic review and meta-analysis

Objective

Intestinal protozoa Blastocystis hominis and Cryptosporidium spp. are two influential factors in intestinal complications and malignancies. In present study, we estimated the pooled prevalence and odds ratio (OR) of the two parasites in colorectal cancer (CRC) patients and their possible association with the deadly disease.

Method

Our systematic search was conducted for published researches between January 1, 2000 and April 30, 2022 by using four international databases include Scopus, PubMed, and Web of Science as well as Google scholar search engine. The random- and fixed-effects models were used to estimate the pooled prevalence, OR, and 95% confidence interval (CI) by comprehensive meta-analysis (V2.2, Bio stat) software. Inclusion and exclusion criteria were applied.

Results

Thirteen papers (seven case–control and six cross-sectional studies) for B. hominis/CRC and six papers (two case–control and four cross-sectional studies) for Cryptosporidium spp./CRC were eligible to include in data synthesis. Pooled prevalence of B. hominis and Cryptosporidium spp. in CRC patients was calculated to be 26.8% (95% CI 19.4–35.7%) and 12.7% (95% CI 6.8–22.5%), respectively. Based on case–control studies, significant difference was found between case and controls in both protozoa (B. hominis OR 2.10; 95% CI 1.39–3.18% vs. Cryptosporidium spp. OR 5.06; 95% CI 1.8–13.6%). Considering the Blastocystis subtypes, ST1 (5/6; 83.33% studies) and ST3 (5/6; 83.33% studies) had the highest number of reports in CRC patients. Regarding the Cryptosporidium species, only C. parvum and C. hominis were reported.

Conclusion

Given the significant prevalence of both parasites in CRC patients and their statistically significant association, there is a need to pay more attention to these two intestinal parasites in under treatment patients.

Cryptosporidium and colorectal cancer: a review of epidemiology and possible association

Cryptosporidiosis is an important protozoan disease with serious public health implications. The contribution of Cryptosporidium to colorectal cancer is still vaguely studied, but little evidence from experimental and epidemiological studies has suggested a possible association. This review discusses the epidemiology of cryptosporidiosis and colorectal cancer and attempts to unravel the possible link between the two diseases using epidemiological, pathological, molecular, and immunological evidence. The review stressed the need to undertake more studies in this relatively neglected field.

Bacterial and Parasitic Pathogens as Risk Factors for Cancers in the Gastrointestinal Tract: A Review of Current Epidemiological Knowledge

The oncogenic potential of viral infections is well established and documented for many years already. However, the contribution of (commensal) bacteria and parasites to the development and progression of cancers has only recently gained momentum, resulting in a rapid growth of publications on the topic. Indeed, various bacteria and parasites have been suggested to play a role in the development of gastrointestinal cancer in particular. Therefore, an overview of the current epidemiological knowledge on the association between infections with bacteria and parasites and cancers of the gastrointestinal tract is needed. In this review, we summarized the methodological characteristics and main results of epidemiological studies investigating the association of 10 different bacteria (Bacteroides fragilis, Campylobacter spp., Clostridium spp., Enterococcus faecalis, Escherichia coli, Fusobacterium nucleatum, Porphyromonas gingivalis, non-typhoidal Salmonella, Salmonella Typhi, and Streptococcus spp.) and three parasites (Cryptosporidium spp., Schistosoma spp., and Strongyloides stercoralis) with gastrointestinal cancer. While the large body of studies based on microbiome sequencing provides valuable insights into the relative abundance of different bacterial taxa in cancer patients as compared to individuals with pre-malignant conditions or healthy controls, more research is needed to fulfill Koch's postulates, possibly making use of follow-up data, to assess the complex role of bacterial and parasitic infections in cancer epidemiology. Studies incorporating follow-up time between detection of the bacterium or parasite and cancer diagnosis remain valuable as these allow for estimation of cause-effect relationships.

In vitro and in vivo anti-Cryptosporidium and anti-inflammatory effects of Aloe vera gel in dexamethasone immunosuppressed mice

Cryptosporidiosis has been considered as a serious diarrheal disease, especially in immunodeficient patients, where they failed to clear the infection leading to several consequences of infection (i.e death). The role of cell mediated immunity in clearing the infection was demonstrated by the increased susceptibility of HIV/AIDS patients to infection. To date, no specific treatment has been proven for cryptosporidiosis in immunodeficient patients. The study aimed to evaluate the efficacy of Aloe vera gel for the treatment of cryptosporidiosis in immunocompetent and dexamethasone immunosuppressed mice in comparison to that of nitazoxanide. Mice were orally administrated with Aloe vera gel, in a daily dose of 250 mg/L in drinking water, for 14 consecutive days post infection. Parasitological, molecular and immunological measurements were recorded on the 7th, 14th, 21st and 32nd days post infection. Our in vitro results showed that 250 mg/L of prepared gel achieved the highest parasitic reduction. The body weights of Aloe vera treated mice on the 21st and 32nd day post infection, either in immunocompetent or immunosuppressed groups, were nearly the same as those of their corresponding control groups. Aloe vera gel succeeded in clearing cryptosporidiosis with a percent reduction of 100% in immunocompetent mice and 99.67% in immunosuppressed mice. The anti-inflammatory effect of Aloe vera reduced the levels of IFN-γ, IL-4, -6 and -17. The success of Aloe vera gel, in clearing cryptosporidiosis in immunosuppressed mice, was obvious either from the reduction of Cryptosporidium DNA or the oocysts in stool samples; and from the improvement of histopathological sections.

Anticryptosporidium Efficacy of Olea europaea and Ficus carica Leaves Extract in Immunocompromised Mice Associated with Biochemical Characters and Antioxidative System

Cryptosporidiosis is caused by an opportunistic protozoan parasite (Cryptosporidium parvum and C. hominis) known as a parasite of humans, especially children and immunocompromised patients. The current study was designed to evaluate the therapeutic efficacy of a mixture of fig and olive leaf extracts as an alternative medicinal plant. Parasitological examination for oocysts in the stool and histopathological alterations in the small intestines were examined. Additionally, biochemical analyses of liver and kidney functions in addition to antioxidant parameters such as superoxide dismutase (SOD), glutathione peroxidase (GSH) and catalase (CAT) in the plasma were evaluated. Our results showed that marked reduction in oocysts shedding and amelioration in intestinal histopathological changes and hepatic or renal functions were detected in all treated groups compared to the control infected group. Additionally, the treated groups with tested extracts at ratios 1:3 and 1:5 showed a significant decrease in the number of oocysts compared to the other treated groups. Results exhibited a significant increase in the plasma SOD, CAT and GSH levels in treated groups compared to the infected control one. This study suggested that a mixture of fig and olive leaf extracts is a convenient promising therapeutic agent for Cryptosporidiosis.

Assessment of chitosan nanoparticles in improving the efficacy of nitazoxanide on cryptosporidiosis in immunosuppressed and immunocompetent murine models

Cryptosporidiosis is one of the major causes of diarrhea in immunocompetent and immunocompromised patients. It is self-limited in immunocompetent individuals. However, in the immunocompromised it can cause life-threatening diarrhea and results in chronic malabsorption of fluids, vitamins and electrolytes resulting in wasting. Our study is concerned with assessing and comparing the efficacy of nitazoxanide (NTZ) alone and NTZ loaded chitosan nanoparticles (NTZ loaded CS NPs) in the treatment of experimental cryptosporidiosis using parasitological and histopathological parameters. One hundred mice were divided into 5 groups (20 mice each). Each group was divided into 2 subgroups according to the immune status [a-immunocompetent, b-immunosuppressed]. group 1: control (healthy), group 2: control infected by Cryptosporidium oocysts, group 3: infected treated by NTZ, group 4: infected then treated by NTZ loaded CS NPs and group 5: infected then treated by chitosan nanoparticles (CS NPs) alone. Treatment of Cryptosporidium infected mice with NTZ loaded on CS NPs resulted in the highest significant reduction in oocysts shedding in both immunocompetent and immunosuppressed groups followed by treatment with NTZ form then by treatment with CS NPs alone. The treatment with NTZ loaded CS NPs displayed a remarkable improvement of the histopathological changes of the intestine, liver and lung while NTZ treated group showed some improvement. Treatment with NTZ loaded CS NPs in murine cryptosporidiosis gave the best results as it caused marked reduction in fecal oocysts counts and improvement of histopathological changes in immunocompetent and immunosuppressed groups.

The Efficacy of Citrus maxima Peels Aqueous Extract Against Cryptosporidiosis in Immunecompromised Mice

INTRODUCTION

 Cryptosporidiosis is an opportunistic globally distributed parasitic disease caused by protozoan Cryptosporidium where its development is closely related to the host's immune status. New therapeutic agents are a high priority as chemotherapeutics are impractical and vaccines are unavailable for young as well as immune-compromised patients or animals. The current study was designed to evaluate the therapeutic effect of the internal white (albedo) and external yellow (flavedo) peels of Citrus maxima (C. maxima) as an alternative medicinal plant. MATERIALS AND METHODS : Parasitological examination for oocysts in the stool was determined. Histopathological alterations and immunohistochemical expression of APC and cyclin D1 as well as an assessment of interferon-γ (IFN-γ) and interleukin 1β (IL-1β) in ileal tissues was carried out. In addition, the biochemical examination of serum albumin, globulin and liver enzymes were evaluated. Results revealed a significant decrease of oocysts count correlated with an amelioration of histopathological and immunohistochemical changes in ileal tissue with an enhancement of liver enzymes and inflammatory cytokines levels.

CONCLUSION

 It could be concluded that treatment with C. maxima peel extracts have a potential therapeutic and an immunoregulatory efficacy against Cryptosporidiosis. Obtained results showed that the white peel was found to have more immunological effect that could significantly enhance inflammatory cytokines response towards normal status. Hence, it can be used in the daily animal diet to give protective effects against infection.

Current status and challenges in drug discovery against the globally important zoonotic cryptosporidiosis

The zoonotic cryptosporidiosis is globally distributed, one of the major diarrheal diseases in humans and animals. Cryptosporidium oocysts are also one of the major environmental concerns, making it a pathogen that fits well into the One Health concept. Despite its importance, fully effective drugs are not yet available. Anti-cryptosporidial drug discovery has historically faced many unusual challenges attributed to unique parasite biology and technical burdens. While significant progresses have been made recently, anti-cryptosporidial drug discovery still faces a major obstacle: identification of systemic drugs that can be absorbed by patients experiencing watery diarrhea and effectively pass through electron-dense (ED) band at the parasite-host cell interface to act on the epicellular parasite. There may be a need to develop an in vitro assay to effectively screen hits/leads for their capability to cross ED band. In the meantime, non-systemic drugs with strong mucoadhesive properties for extended gastrointestinal exposure may represent another direction in developing anti-cryptosporidial therapeutics. For developing both systemic and non-systemic drugs, a non-ruminant animal model exhibiting diarrheal symptoms suitable for routine evaluation of drug absorption and anti-cryptosporidial efficacy may be very helpful.

The immunomodulatory activity of secnidazole-nitazoxanide in a murine cryptosporidiosis model

Introduction. Cryptosporidium parvum causes intestinal parasitic infections affecting both immunosuppressed and immunocompetent individuals.Gap statement. Given the absence of effective treatments for cryptosporidiosis, especially in immunodeficient patients, the present study was designed to assess the therapeutic efficacy of secnidazole (SEC) and its combination with nitazoxanide (NTZ) in comparison to single NTZ treatment in relation to the immune status of a murine model of C. parvum infection.Methodology. The infected groups were administered NTZ, SEC or NTZ-SEC for three or five successive doses. At days 10 and 12 post-infection (p.i.), the mice were sacrificed, and the efficacy of the applied drugs was evaluated by comparing the histopathological alterations in ileum and measuring the T helper Th1 (interferon gamma; IFN-γ), Th2 [interleukin (IL)-4 and IL-10] and Th17 (IL-17) cytokine profiles in serum.Results. The NTZ-SEC combination recorded the maximal reduction of C. parvum oocyst shedding, endogenous stages count and intestinal histopathology, regardless of the immune status of the infected mice. The efficacy of NTZ-SEC was dependent on the period of administration, as the 5 day-based treatment protocol was also more effective than the 3 day-based one in terms of immunocompetence and immunosuppression. The present treatment schedule induced an immunomodulatory effect from SEC that developed a protective immune response against C. parvum infection with reduced production of serum IL-17, IFN-γ, IL-4 and IL-10.Conclusions. Application of NTZ-SEC combined therapy may be useful in treatment of C. parvum, especially in cases involving immunosuppression.

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.

Cryptosporidium and Colon Cancer: Cause or Consequence?

The number of cancers attributable to infectious agents represents over 20% of the global cancer burden. The apicomplexan intracellular parasite Cryptosporidium is currently considered one of the major causes of mild and severe diarrhea worldwide. However, less attention has been paid to its tumorigenic potential despite the high exposure of humans and animals to this ubiquitous parasite. Herein, we discuss the potential causal link between Cryptosporidium infection and digestive cancer, with particular emphasis on colon cancer, based on increasing clinical, epidemiological and experimental pieces of evidence supporting this association. In addition, we highlight the current knowledge about the potential mechanisms by which this parasite may contribute to cell transformation and parasite-induced cancer.

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.

Association between Cryptosporidium infection and cancer: A systematic review and meta-analysis

The link between cryptosporidiosis and cancer has been suggested by some epidemiological studies. This systematic review and meta-analysis was conducted to further understand this relationship. In the current study, six electronic databases were reviewed for Cryptosporidium infection in cancer patients. We used random effects model and 95% confidence intervals (CI) to determine the overall odds ratio (OR). Heterogeneity was calculated with Cochran's Q test and I²statistic. In total, 19 studies involving 3562 individuals with case-control (nine) and cross-sectional (ten) designs were included in our project. The pooled overall random effect favored a statistically significant increased risk of Cryptosporidium infection in cancer patients compared with non-cancer individuals [OR = 3.3; 95% CI: 2.18-4.98]. The overall heterogeneity was medium (χ² = 25.77; I² = 30.2%, P = .11). The pooled ORs in case-control and cross-sectional studies were [OR = 5.60; 95% CI: 3.43-9.13; χ² = 5.51; I² = 0.00%, P = .70] and [OR = 2.08; 95% CI: 1.18-3.67; χ² = 13.69; I² = 34.3, P = .13], respectively. T-value and P-value were 0.54 and 0.57 based on the results of Harbord's modified's regression test. In summary, this meta-analysis demonstrates that Cryptosporidium infection is associated with cancer. Also, it found that study design and year of publication are the specific sources of heterogeneity. Further studies should be carried out to investigate the impact of Cryptosporidium infection in the onset or development of cancer in the future.

Antiprotozoal activity of silver nanoparticles against Cryptosporidium parvum oocysts: New insights on their feasibility as a water disinfectant

Cryptosporidium is a protozoan of extremely medical and veterinary impact; whose oocysts donate a considerable resistant to the water treatment processes. Therefore, this study aimed to explore the impacts of silver nanoparticles (AgNPs) on count and viability of the Cryptosporidium parvum (CP) isolated from different tap water samples. The oocysts were exposed to AgNPs at different dosages of 0.05, 0.1 and 1 ppm for several contact times (30 min to 4 h). The results showed a significant decrease in oocyst count and viability in a dose-dependent manner. Additionally, AgNPs at a conc. of 1 ppm for 30 min and 0.1 ppm for 1 h reduced the oocysts by 97.2 and 94.4%, respectively. Comparatively, there was a noticeable increase in the oocyst's viability at 2 and 4 h, which emphasized that the time of contact between AgNPs and CP was not a major influencing factor for successful application of AgNPs in the nano-water treatment.

Massive Cryptosporidium infections and chronic diarrhea in HIV-negative patients

Protozoa of the genus Cryptosporidium are common parasites of domestic and wild animals—mammals, birds, reptiles, and fishes. The invasive forms are thick-walled oocysts, which can be present in water supplies, on fruits, vegetables, or in the soil contaminated with feces. In this work, we describe three cases of middle-aged persons with massive Cryptosporidium hominis infection and chronic diarrhea with no immunological abnormalities and no history of previous travels to tropical countries. The lesions discovered during colonoscopy within the large intestine–cryptitis and the histopathological changes were related to massive cryptosporidiosis. All these statements indicate necessity of parasitological stool examination in cases with chronic diarrhea in which no etiological agents are detected, but not only in HIV positive individuals. Parasite’s eradication leads to symptom disappearance as well as improvement of histopathological mucosa alterations.

Anticryptosporidial effect of pomegranate peels water extract in experimentally infected mice with special reference to some biochemical parameters and antioxidant activity

Cryptosporidiosis is a zoonotic disease caused by a well-known parasitic protozoan called Cryptosporidium. Infection in livestock causes important economic losses among farm animals and its control has a global concern. In this study, internal white and external red layers were separated from pomegranate peels (Punica granatum) then; they were grinded to reach Nano form. Anticryptosporidial effect of their water extracts was investigated in experimentally infected mice. Also, their antioxidant activity, biochemical and histopathological changes were studied. Briefly, hot aqueous extracts of pomegranate peels were prepared regarding its good sensory attributes at concentration of 10% W/V. Analysis of total phenolics, individual phenolics by HPLC-DAD and antioxidant activities have been done. Forty-five mice were divided into five groups each one containing nine mice. The first group was healthy mice and the 2nd one was infected orally with 10⁴ Cryptosporidium parvum (C. parvum) oocysts/mice and not treated. The other 3 groups were infected and orally treated with Nitazoxanide (NTZ) for the 3rd group, pomegranate red peel extract for the 4th group and pomegranate white peel extract for the 5th group. Blood samples were collected after 1 and 2 weeks post treatment for protein profile, liver enzymes and antioxidant activity evaluation. After 3 weeks, all animals were sacrificed and ileal tissues were embedded in paraffin for histopathological examination. The results showed that pomegranate peel extracts were rich in phenolic compounds, had high antioxidant activity and therapeutic effect on C. parvum in experimentally infected mice. Red peel extract diminished C. parvum oocysts count significantly in experimentally infected mice than white peel and NTZ treatments. Also, the histopathological examination revealed that red peel treated mice ileal sections showed a great enhancement in the shape and structure of villi towards normal structure than other treated groups. Most of the measured biochemical parameters after 2 weeks' treatment with red pomegranate peel and NTZ were enhanced in their concentrations towards the healthy normal status. In conclusion, this study showed the effectiveness of Nano-form of pomegranate white and red peel extracts against C. parvum oocysts. Pomegranate red peel extract was found to have antioxidant activity that could significantly enhance the serum biochemical parameters and oxidative stress towards the healthy normal status. Furthermore, it is suggested that pomegranate peel should be separated and used in the daily animal diet or as a functional beavarage for human as accepted from the panelists to give protective effects against this parasite as well as to improve health benefits.

The new trend in the treatment of experimental cryptosporidiosis and the resulting intestinal dysplasia

Aim: Cryptosporidiosis causes colon dysplasia. This research aimed to evaluate the effect of a novel combination between artesunate and nitazoxanide on intensity of infection and the resulting intestinal dysplasia. Materials & methods: Subjects were divided into five groups. Artesunate was used alone, then combined with nitazoxanide. Results: The highest efficacy in reducing oocyst shedding obtained from the combined therapy (68.5, 75.9, 99%) after 7, 14 and 21 days. The histopathology of infected colonic mucosa showed marked improvement and low-grade of dysplasia in the infected and treated group with the combined therapy. The immunohistochemistry of the same group revealed mild dysplastic changes in colonic epithelium without nuclear expression for cyclin D1. Conclusion: These results give hope for treatment of Cryptosporidium and improving intestinal dysplasia.

Colorectal cancer and Cryptosporidium spp. infection

Transient or constant impaired immunity is often associated with neoplastic disease or oncological treatment. Among the most common pathogens found in patients with HIV or patients undergoing chemotherapy are protozoans of the Cryptosporidium genus, which cause diarrhea in humans and animals. The present study determined the frequency of Cryptosporidium spp. infections in patients with colorectal cancer (N = 108; 42 women; 66 men; median age, 65 years), before beginning oncological treatment, compared to a control group (N = 125; 56 women, 69 men; median age, 63 years) without colorectal cancer or a history of oncological disease. We also assessed whether Cryptosporidium spp. infections were associated with age, gender, cancer stage (based on Astler-Coller or TNM classification), histological grade, or cancer location. Patients were treated at the Pomeranian Medical University, in 2009-2014. The presence of Cryptosporidium spp. antigen was determined in stool samples, analyzed with a commercial immunoenzymatic test. Cryptosporidium spp. infections occurred significantly more often (p = 0.015) in patients (13%) compared to controls (4%). The patient group showed no significant relationship between Cryptosporidium spp. infection and sex, age, tumor location, cancer grade, or stage. A multivariate logistic regression analysis adjusted for age and sex that included all subjects (patient + control groups, n = 233) showed that the odds of a Cryptosporidium spp. infection were more than three-fold higher in patients than in controls, and more than six-fold higher among men than among women.

CONCLUSIONS

1) Cryptosporidium spp. infections occurred significantly more frequently in patients with colorectal cancer (before oncological treatment) compared to controls, independent of age and sex. 2) Cryptosporidium spp. infections were not associated with the colorectal cancer stage, grade, or location or with patient age. 3) Male gender was significantly related to the frequency of Cryptosporidium spp. infections, independent of age and the presence of colorectal cancer.

Prevalence of Cryptosporidium species and subtypes in paediatric oncology and non-oncology patients with diarrhoea in Jordan

Cryptosporidiosis is a protozoan parasitic disease which affects human and animals worldwide. In adult immunocompetent individuals, cryptosporidiosis usually results in acute and self-limited diarrhoea; however, it can cause life threatening diarrhoea in children and immunocompromised individuals. In the present study, we compared the prevalence of Cryptosporidium species and gp60 subtypes amongst paediatric oncology patients with diarrhoea (n=160) from King Hussein Medical Centre for Cancer in Jordan, and non-oncology paediatric patients with diarrhoea (n=137) from Al-Mafraq paediatric hospital. Microscopy results using modified acid fast staining identified a significantly (p≤0.05) higher prevalence of Cryptosporidium in paediatric oncology patients with diarrhoea (14.4% - 23/160), compared to non-oncology paediatric patients with diarrhoea only (5.1% - 7/137). With the exception of one sample, all microscopy-positive samples (n=29) and an additional 3/30 microscopy-negative controls were typed to species and subtype level at the 18S and gp60 loci, respectively. All Cryptosporidium positives were typed as C. parvum. Of the 22 typed Cryptosporidium positives from the paediatric oncology patients, 21 were subtyped as IIaA17G2R1 and one as IIaA16G2R1 C. parvum subtypes. The 7 typed positives from the paediatric patients from Al-Mafraq hospital were subtyped as IIaA17G2R1 (n=5) and IIaA16G2R1 (n=2). The 3 additional positives from the 30 microscopy negative control samples were subtyped as IIaA17G2R1. The high prevalence of the IIaA17G2R1 subtype, particularly amongst oncology patients, suggests that an outbreak of cryptosporidiosis may have been occurring in oncology patients during the collection period (April to December, 2016). New therapies for cryptosporidiosis in immunocompromised patients are urgently required.

[Parasites and cancer: is there a causal link?]

Over 20 % of cancers have infectious origins, including well-known examples of microbes such as viruses (HPV, EBV) and bacteria (H. pylori). The contribution of intracellular eukaryotic parasites to cancer etiology is largely unexplored. Epidemiological and clinical reports indicate that eukaryotic protozoan, such as intracellular apicomplexan that cause diseases of medical or economic importance, can be linked to various cancers: Theileria and Cryptosporidium induce host cell transformation while Plasmodium was linked epidemiologically to the "African lymphoma belt" over fifty years ago. These intracellular eukaryotic parasites hijack cellular pathways to manipulate the host cell epigenome, cellular machinery, signaling pathways and epigenetic programs and marks, such as methylation and acetylation, for their own benefit. In doing so, they tinker with the same pathways as those deregulated during cancer onset. Here we discuss how epidemiological evidence linking eukaryotic intracellular parasites to cancer onset are further strengthened by recent mechanistic studies in three apicomplexan parasites.