Cryptosporidium and cryptosporidiosis in man and animals

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.

Cryptosporidium in pet snakes from Italy: molecular characterization and zoonotic implications

To provide information on the occurrence of Cryptosporidium species and genotypes in captive snakes from Italy, faecal specimens from 120 snakes belonging to 13 different genera of the families Boidae, Colubridae and Pythonidae were collected. Faecal samples were taken from the ground of the terrarium when available; otherwise cloacal cotton swabs were used. No clinical signs of cryptosporidiosis were observed in any animal at the time of sampling. Samples were examined for the presence of Cryptosporidium by using a direct immunofluorescence antibody test (IFAT) and two-step nested PCR at the small subunit (SSU) rRNA locus. PCR-positive samples were genotyped by restriction fragment length polymorphism (RFLP) analysis with the endonucleases SspI and VspI. By IFAT, 42 out of 120 snakes (35.0%) were found to be shedding Cryptosporidium oocysts. A significant higher percentage of positive ophidians were detected by using faecal specimens obtained from the terrarium (55.5%) than by cloacal cotton swabs (29.0%). SSU rRNA gene products were obtained from 25 isolates. Twenty samples tested positive to both microscopy and molecular techniques. Our data reveal a wide extent of cryptosporidial infections in snake-food animals since most of the identified isolates belonged to Cryptosporidium species, some of them with zoonotic potential, considered specific for rodents and resulting from ingestion of infected preys. The reptilian-specific species Cryptosporidium serpentis was identified in only one isolate. The common presence of reptile non-specific and, in some cases, zoonotic Cryptosporidium oocysts in snake faeces should to be taken into consideration in order to avoid the misidentification of the protozoan as well as the possible public health implications.

Selected emerging infectious diseases of squamata

It is important that reptile clinicians have an appreciation for the epidemiology, clinical signs, pathology, diagnostic options, and prognostic parameters for novel and emerging infectious diseases in squamates. This article provides an update on emerging squamate diseases reported in the primary literature within the past decade. Updates on adenovirus, iridovirus, rhabdovirus, arenavirus, and paramyxovirus epidemiology, divergence, and host fidelity are presented. A new emerging bacterial disease of Uromastyx species, Devriesea agamarum, is reviewed. Chrysosporium ophiodiicola-associated mortality in North American snakes is discussed. Cryptosporidium and pentastomid infections in squamates are highlighted among emerging parasitic infections.

Genetic diversity of Cryptosporidium spp. within a remote population of Soay Sheep on St. Kilda Islands, Scotland

This is the first report to characterize the genotypes and subtypes of Cryptosporidium species infecting a geographically isolated population of feral Soay sheep (Ovis aries) on Hirta, St. Kilda, Scotland, during two distinct periods: (i) prior to a population crash and (ii) as host numbers increased. Cryptosporidium DNA was extracted by freeze-thawing of immunomagnetically separated (IMS) bead-oocyst complexes, and species were identified following nested-PCR-restriction fragment length polymorphism (RFLP)/PCR sequencing at two Cryptosporidium 18S rRNA loci. Two hundred fifty-five samples were analyzed, and the prevalent Cryptosporidium species in single infections were identified as C. hominis (11.4% of all samples tested), C. parvum (9%), C. xiaoi (12.5%), and C. ubiquitum (6.7%). Cryptosporidium parvum was also present with other Cryptosporidium species in 27.1% of all samples tested. Cryptosporidium parvum- and C. hominis-positive isolates were genotyped using two nested-PCR assays that amplify the Cryptosporidium glycoprotein 60 gene (GP60). GP60 gene analysis showed the presence of two Cryptosporidium genotypes, namely, C. parvum IIaA19G1R1 and C. hominis IbA10G2. This study reveals a higher diversity of Cryptosporidium species/genotypes than was previously expected. We suggest reasons for the high diversity of Cryptosporidium parasites within this isolated population and discuss the implications for our understanding of cryptosporidiosis.

Ocorrência e fatores de risco da criptosporidiose em felinos de companhia de idosos

Pesquisou-se a prevalência de criptosporidiose em gatos domésticos de companhia em idosos de ambos os sexos (acima de 60 anos de idade) proprietários dos mesmos, residentes no município de Teresópolis-RJ, e que compareceram a um posto de vacinação do município no período da vacinação contra gripe de 2009 e 2010. A prevalência de diarreia nos idosos foi 29,4% e nos felinos 24,5%. Identificou-se presença de um ou mais oocistos em 16,7% dos idosos e em 12,7% nos felinos. A análise da razão de prevalência de diarreia evidenciou uma forte associação em idosos (RP = 4,37, IC a 95%: 2,67 - 7,16) e menor força de associação em felinos (RP = 2,16, IC a 95%: 1,06 - 4,39). Pela análise de imunofluorescência confirmada pela PCR, houve semelhante força de associação em idosos (RP = 4,43, IC a 95%: 3,04 - 6,45), mas se observou aumento na força de associação para felinos (RP = 4,67, IC a 95%: 3,9 - 6,81). Os achados obtidos com esta pesquisa são preocupantes, mas importantes para a saúde pública, por demonstrarem a relação zoonótica do Cryptosporidium spp. presente nas amostras fecais dos animais de companhia do grupo populacional de idosos estudados.

Cryptosporidium in countries of the Arab world: the past decade (2002-2011)

Introduction

Cryptosporidium is the causative agent of cryptosporidiosis. The disease is self-limited in immunocompetent persons but potentially life-threatening in immunocompromised individuals.

Methods

The data included in the present review were obtained mainly from a Highwire Press (including PubMed) search for the period 2002–2011.

Results

Information on cryptosporidiosis is lacking in some Arab countries; however available data show prevalence rates of <1–43% (mean = 8.7%) of Cryptosporidium infection in diarrheic immunocompetent pediatrics and <1–82% (mean 41%) in immunocompromised patients (including children and adults). Infection rate with Cryptosporidium species among pediatrics in rural and semiurban areas was higher than in urban areas. Cryptosporidium-associated diarrhea occurs mainly in younger children and inversely correlates with age, being more prevalent in children aged 1 year or less, particularly in rural and suburban regions. Although most Arab countries are characterized by a hot summer and a mild winter, infection with Cryptosporidium appears to occur at a higher rate of incidence during the rainy months that are usually associated with the cold season of the year. Contact with animals and contaminated waters are the main modes of transmission of cryptosporidia. Reports of C. hominis from the region indicate that person-to-person transmission is also important. Foreign housekeepers in oil-rich countries may be a source of Cryptosporidium.

Conclusion

Cryptosporidium species, mainly C. parvum, are important causes of diarrhea in countries of the Arab world, particularly in children. In addition to educational programs that promote personal, household, as well as food hygiene, improving water treatment processes and protection of treated waters from contamination should be implemented by the health and environmental authorities in each country. More studies employing molecular testing methods are needed in the future to provide data on circulating species/genospecies and subtypes and their modes of transmission in the community.

Biotin- and glycoprotein-coated microspheres: potential surrogates for studying filtration of cryptosporidium parvum in porous media

Cryptosporidium parvum is a waterborne pathogen, yet no suitable surrogate has been established for quantifying its filtration removal in porous media. Carboxyl polystyrene microspheres with size, density, and shape similar to C. parvum were coated with biotin (free and containing amine, NH(2)) and glycoprotein. These biomolecules have isoelectric points similar to C. parvum (pH ≈ 2), and glycoprotein is a major type of surface protein that oocysts possess. Zeta potential (ζ) and filtration removal of particles in sand of two different grain sizes were examined. Compared to unmodified microspheres, modified microspheres achieved a superior match to the oocysts in ζ, concentration, mass recovery, and collision coefficient. They showed the same log reduction in concentration as oocysts, whereas results from unmodified microspheres deviated by 1 order of magnitude. Of the three types of modified microspheres, glycoprotein-coated microspheres best resembled oocyst concentration, despite having ζ similar to NH(2)-biotin-coated microspheres, suggesting that surface protein also played an important role in particle attachment on solid surfaces. With further validation in environmental conditions, the surrogates developed here could be a cost-effective new tool for assessing oocyst filtration in porous media, for example, to evaluate the performance of sand filters in water and wastewater treatment, water recycling through riverbank filtration, and aquifer recharge.

Occurrence and molecular diagnosis of Cryptosporidium serpentis in captive snakes in São Paulo, Brazil

The present study aimed to determine whether Cryptosporidium oocysts were present in stools from captive snakes at Fundação Parque Zoológico (Zoological Park Foundation) in São Paulo, Brazil. Two collections were performed; the first in July 2008 and the second in February 2009. Fecal samples were collected from 74 enclosures that housed 101 individuals of 23 snake species. The stool specimens collected from 16 out of the 74 enclosures (21.6%) contained Cryptosporidium spp. oocysts; all of them were confirmed as Cryptosporidium serpentis, using molecular techniques. Only in three (18.7%) out of the 16 enclosures with positive samples were there animals with clinical signs compatible with infection by C. serpentis, such as regurgitation and significant progressive weight loss. From the results, it was concluded that diagnostic examinations need to be performed periodically, even on clinically healthy animals, as a preventive measure.

Genetic characterisation of Cryptosporidium and Giardia from dairy calves: discovery of species/genotypes consistent with those found in humans

Cryptosporidium and Giardia are important genera of parasitic protists that can cause significant diarrhoeal diseases in humans and other animals. Depending on the species/genotype of parasite, human infection may be acquired via anthroponotic or zoonotic transmission routes. Here, we undertook a molecular epidemiological investigation of these two genera of parasites in pre- and post-weaned calves from eight locations in Canterbury, New Zealand, by PCR-coupled sequencing and phylogenetic analysis of sequence data for regions in the 60 kDa glycoprotein (pgp60) gene of Cryptosporidium and/or the triose-phosphate isomerase (ptpi) gene of Giardia. The pgp60 and ptpi regions were specifically amplified from 15 (8.3%) and 11 (6.1%) of the 180 individual faecal samples, respectively. The sequences derived from all of the amplicons were aligned with homologous reference sequences and subjected to phylogenetic analysis by Bayesian inference. For Cryptosporidium, three samples contained Cryptosporidium parvum genotype IIa, subgenotypes IIaA15G3R1, IIaA19G3R1 and IIaA23G4. Twelve samples contained Cryptosporidium hominis genotype Ib, subgenotype IbA10G2R2. While subgenotypes IIaA15G3R1 and IIaA23G4 are new records, IIaA19G3R1 and IbA10G2R2 are commonly found in humans in various countries. For Giardia, two samples contained Giardia duodenalis assemblage A, also common in humans. In contrast, nine samples contained G. duodenalis assemblage E, which is the first report of this assemblage in cattle in New Zealand. Therefore, the present results indicate that dairy calves on the South Island of New Zealand harbour 'zoonotic' genotypes of Cryptosporidium and Giardia, which is likely to have significant public health implications.

Factors influencing on prevalence of Cryptosporidium infection in south Indian dairy calves

The objectives of the present study were to report the influence of factors like age, sex, breed, dung consistency and rearing system on prevalence of Cryptosporidium spp. in south Indian cattle. Two-step nested PCR was employed for detection of Cryptosporidium infection in dairy calves of south Indian states viz., Andhra Pradesh, Karnataka, Kerala, Tamil Nadu and union territory i.e., Puducherry. A total of 459 dung samples from the calves were subjected to nested PCR, 182 were found positive with prevalence percent of 39.65. Age wise comparison showed a high prevalence of Cryptosporidium in the age group of one month old calves. This concludes that the cryptosporidiosis is highly age dependent with young calves showed the highest prevalence. Depending on the group had consistency of dung, the highest prevalence of Cryptosporidium was observed in semi-solid dung, followed by formed and the diarrhoeic group animals. Female calves showed slightly higher prevalence rate than male animals. Cow calves had an overall prevalence percent of 40.75 and the infection rate in buffalo calves was 36.28 %. In relation to rearing system, individual animals had 42.18 % and farm animals showed 38.46 % of Cryptosporidium infection. In conclusion, the prevalence of Cryptosporidium in dairy calves should be correlated with the factors like age, sex, breed, dung consistency and rearing system of the animal to arrive at a reliable epidemiological data on bovine cryptosporidiosis.

Prevalence and molecular characterization of Cryptosporidium spp. in dairy cattle from farms in China

Fecal samples of 2,056 dairy cattle from 14 farms were collected in three geographical regions of China and stained using a modified acid-fast staining technique to identify Cryptosporidium oocysts. A total of 387 (18.82%) positive samples were identified and further analyzed by polymerase chain reaction (PCR) using primers designed to amplify DNA fragments from the small subunit ribosomal RNA. The PCR products were sequenced and the sequences were deposited in the GenBank database under accession numbers EU369377-84 and GU070730-33. Phylogenetic analysis was performed and a distances matrix generated from these sequences confirmed the existence of Cryptosporidium (C.) parvum 'mouse' genotype, C. bovis, C. andersoni, C. hominis, and C. serpentis in cattle. These results represent the first report on the prevalence and genetic identification of Cryptosporidium species, and may contribute to a better understanding of the epidemiology of Cryptosporidium in cattle in China.

Transport and retention of Cryptosporidium parvum oocysts in sandy soils

A series of miscible-displacement experiments was conducted to examine the retention and transport behavior of oocysts in natural porous media. Three soils and a model sand were used that differed in physical and geochemical properties. Transport behavior was examined under various treatment conditions to help evaluate retention mechanisms. Significant retention of oocysts was observed for all media despite the fact that conditions were unfavorable for physicochemical interactions with respect to DLVO theory. The magnitude of retention was not influenced significantly by alterations in solution chemistry (reduction in ionic strength) or soil surface properties (removal of soil organic matter and metal oxides). On the basis of the observed results, it appears that retention by secondary energy minima or geochemical microdomains was minimal for these systems. The porous media used for the experiments exhibited large magnitudes of surface roughness, and it is suggested that this surface roughness contributed significantly to oocyst retention.

Enteric protozoa in the developed world: a public health perspective

Several enteric protozoa cause severe morbidity and mortality in both humans and animals worldwide. In developed settings, enteric protozoa are often ignored as a cause of diarrheal illness due to better hygiene conditions, and as such, very little effort is used toward laboratory diagnosis. Although these protozoa contribute to the high burden of infectious diseases, estimates of their true prevalence are sometimes affected by the lack of sensitive diagnostic techniques to detect them in clinical and environmental specimens. Despite recent advances in the epidemiology, molecular biology, and treatment of protozoan illnesses, gaps in knowledge still exist, requiring further research. There is evidence that climate-related changes will contribute to their burden due to displacement of ecosystems and human and animal populations, increases in atmospheric temperature, flooding and other environmental conditions suitable for transmission, and the need for the reuse of alternative water sources to meet growing population needs. This review discusses the common enteric protozoa from a public health perspective, highlighting their epidemiology, modes of transmission, prevention, and control. It also discusses the potential impact of climate changes on their epidemiology and the issues surrounding waterborne transmission and suggests a multidisciplinary approach to their prevention and control.

Drug combination therapy in control of cryptosporidiosis in Ludhiana district of Punjab

The present report describes outbreak of cryptosporidiosis in neonatal cross bred cattle calves ageing 1–2 months in an organized dairy farm. The protozoan infection was confirmed by identifying bright red oocysts of Cryptosporidium spp. in the faecal samples after staining with modified acid Fast Zeihl–Neelsen stain. Metronidazole and furazolidone combination was able to induce clinically and parasitological recovery. This is believed to be the first report on the successful use of this drug combination against cryptosporidiosis.

Cryptosporidium spp. in quails (Coturnix coturnix japonica) in Henan, China: molecular characterization and public health significance

The prevalence of Cryptosporidium spp. was investigated in scale quail (Coturnix coturnix japonica) farms in Henan Province, China between September 2006 and August 2007. One thousand eight hundred and eighteen fecal samples from 47 quail farms in five areas were collected for the examination of Cryptosporidium oocysts. The overall prevalence of Cryptosporidium was 13.1% (95% CI 13.1±1.6%) (29 of 47 farms), with 72-100-day-old quails having the highest prevalence (23.6%, 95% CI 23.6±2.6%) (χ(2)=64.91; ρ<0.01). The highest prevalence was observed in autumn (21.8%, 95% CI 21.8±3.1%) and the lowest in winter (χ(2)=74.83; ρ<0.01). Two hundred and thirty-nine Cryptosporidium-positive samples were analyzed by PCR-restriction fragment length polymorphism (RFLP) analysis of the small subunit (SSU) rRNA gene, and 42 were further analyzed by DNA sequencing of the PCR products. Two Cryptosporidium species were identified, Cryptosporidium baileyi in 237 birds on 29 farms, and potentially zoonotic Cryptosporidium meleagridis in only two birds on two farms. These findings may suggest that quails are not a major source of zoonotic Cryptosporidium in the study area.

Cryptosporidium species screening using Kinyoun technique in domestic cats with diarrhea

Cryptosporidium is a coccidian that can lead to diarrhea, especially in immunosuppressed individuals. Retroviruses are considered a primary cause of immunosuppression in cats. Fecal specimens and blood collected from the 60 cats were evaluated for the presence of acid-fast cryptosporidia in three consecutive stool samples and for feline leukemia virus (FeLV) antigen and feline immunodeficiency virus (FIV) antibody by ELISA testing. Five animals (8.33%) shedding oocysts were found, one was both FIV- and FeLV-negative and four were FeLV-positive.

Quantitative detection of Cryptosporidium oocyst in water source based on 18S rRNA by alternately binding probe competitive reverse transcription polymerase chain reaction (ABC-RT-PCR)

We describe an assay for simple and cost-effective quantification of Cryptosporidium oocysts in water samples using a recently developed quantification method named alternately binding probe competitive PCR (ABC-PCR). The assay is based on the detection of 18S rRNA specific for Cryptosporidium oocysts. The standard curve of the ABC-PCR assay had a good fitting to a rectangular hyperbola with a correlation coefficient (R) of 0.9997. Concentrations of Cryptosporidium oocysts in real river water samples were successfully quantified by the ABC-reverse transcription (RT)-PCR assay. The quantified values by the ABC-RT-PCR assay very closely resemble those by the real-time RT-PCR assay. In addition, the quantified concentration in most water samples by the ABC-RT-PCR assay was comparable to that by conventional microscopic observation. Thus, Cryptosporidium oocysts in water samples can be accurately and specifically determined by the ABC-RT-PCR assay. As the only equipment that is needed for this end-point fluorescence assay is a simple fluorometer and a relatively inexpensive thermal cycler, this method can markedly reduce time and cost to quantify Cryptosporidium oocysts and other health-related water microorganisms.

Comparison of resistance to γ-irradiation between Cryptosporidium parvum and Cryptosporidium muris using in vivo infection

In the genus Cryptosporidium, there are more than 14 species with different sizes and habitats, as well as different hosts. Among these, C. parvum and C. hominis are known to be human pathogens. As C. parvum can survive exposure to harsh environmental conditions, including various disinfectants or high doses of radiation, it is considered to be an important environmental pathogen that may be a threat to human health. However, the resistance of other Cryptosporidium species to various environmental conditions is unknown. In this study, resistance against γ-irradiation was compared between C. parvum and C. muris using in vivo infection in mice. The capability of C. muris to infect mice could be eliminated with 1,000 Gy of γ-irradiation, while C. parvum remained infective in mice after up to 1,000 Gy of γ-irradiation, although the peak number of oocysts per gram of feces decreased to 16% that of non-irradiated oocysts. The difference in radioresistance between these 2 Cryptosporidium species should be investigated by further studies.

Challenges in understanding the immunopathogenesis of Cryptosporidium infections in humans

Water and foodborne enteric cryptosporidiosis is a globally emerging public health issue. Although the clinical manifestations of enteric cryptosporidiosis are generally limited to intestinal infection and subsequent diarrhoea, extra-intestinal invasion has also been diagnosed in immunocompromised individuals, particularly in those infected with human immunodeficiency virus (HIV) or AIDS. Due to an inadequate understanding of Cryptosporidium immunopathogenesis in humans, the development of vaccines or therapeutic agents and their application in diseases management is difficult. Current therapeutic measures are not fully effective in the treatment of the disease. Therefore, the implementation of strategies designed to control the chain of cryptosporidiosis transmission (environment ↔ human ↔ food/water ↔ animal) is a critical but challenging issue to public health authorities across the world. Several excellent studies have been done on innate, acquired and mucosal immunity against Cryptosporidium infections using animal models, in vitro human cell lines and human volunteers. However, there are still multiple challenges in understanding the intestinal immune response (immunopathogenesis) to Cryptosporidium infection in humans. This paper reviews recent updates on immunopathogenesis and immune responses to Cryptosporidium infection in humans, while also discussing the current limitations that exist regarding a precise understanding of the immunopathological mechanisms.

Giardia duodenalis assemblages and Entamoeba species infecting non-human primates in an Italian zoological garden: zoonotic potential and management traits

Background

Giardia duodenalis and Entamoeba spp. are among the most common intestinal human protozoan parasites worldwide and they are frequently reported in captive non-human primates (NHP). From a public health point of view, infected animals in zoos constitute a risk for animal caretakers and visitors. In this study we carried out the molecular identification of G. duodenalis and Entamoeba spp. from nine species of primates housed in the zoological garden of Rome, to better ascertain their occurrence and zoonotic potential.

Results

G. duodenalis was found only in Lemur catta (47.0%). Entamoeba spp. were detected in all species studied, with the exception of Eulemur macaco and Varecia rubra. The number of positive pools ranged from 5.9% in L. catta to 81.2% in Mandrillus sphinx; in Pan troglodytes the observed prevalence was 53.6%. A mixed Entamoeba-Giardia infection was recorded only in one sample of L. catta. All G. duodenalis isolates belonged to the zoonotic assemblage B, sub assemblage BIV. Three Entamoeba species were identified: E. hartmanni, E. coli and E. dispar.

Conclusions

Our results highlight the importance of regularly testing animals kept in zoos for the diagnosis of zoonotic parasites, in order to evaluate their pathogenic role in the housed animals and the zoonotic risk linked to their presence. A quick detection of the arrival of pathogens into the enclosures could also be a prerequisite to limit their spread into the structure via the introduction of specific control strategies. The need for molecular identification of some parasite species/genotype in order to better define the zoonotic risk is also highlighted.

The first report on Cryptosporidium suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa) (Czech Republic)

A total of 193 faecal samples of adult Eurasian wild boars were collected at 12 enclosures across the Czech Republic and examined for Cryptosporidium infection using both microscopic and molecular tools. Cryptosporidium oocysts were not detected in any of the 193 faecal samples examined using the aniline-carbol-methyl violet staining method. Thirty-two positive cases of Cryptosporidium infection were detected using either genus- or species-specific nested PCR. Mono-infection with Cryptosporidium suis and Cryptosporidium pig genotype II were found in 13 and 7 cases, respectively. Five mixed infections of C. suis and Cryptosporidium pig genotype II were detected using PCR/RFLP with genus specific primers. The number of detected mixed infections increased 2.4 fold when a species-specific PCR was employed. No other Cryptosporidium spp. was detected. Unlike cryptosporidiosis of domestic pigs, C. suis was detected as a dominant species infecting adult Eurasian wild boars. There was no association between diarrhoea and the presence of Cryptosporidium infection in the Eurasian wild boars studied. This is the first report on the Cryptosporidium infection caused by C. suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa).

Evolution of Cryptosporidium in vitro culture

This overview discusses findings from culturing Cryptosporidium spp. in cell and axenic cultures as well as factors limiting the development of this parasite in cultivation systems during recent years. A systematic review is undertaken of findings regarding the life cycle of the parasite, taking into account physiological, biochemical and genetic aspects, in the hope that this attempt will facilitate future approaches to research and developments in the understanding of Cryptosporidium biology.

Some Opportunistic Parasitic Infections in AIDS: Candidiasis, Pneumocystosis, Cryptosporidiosis, Toxoplasmosis

Almost 80% of patients with AIDS die from infections other than human immunodeficiency virus (HIV). These infections usually occur late in the course of disease when CD4(+) T-cell count has fallen below 200 permm(3) cells per milliliter. Most of these infections are caused by organisms that do not normally afflict healthy individuals and are thus considered to be opportunistic. In this article, Lloyd Kasper and Dominique Buzoni-Gatel review the host-parasite interaction for four important pathogens: Candida albicans and Pneumocystis carinii (usually non-invasive pathogens), Cryptosporidium parvum (invades the cells but remains localized in the gut) and Toxoplasma gondii (penetrates through the gut to cause systemic infection). These organisms, which generally cause limited or even insignificant clinical evidence of infection in the normal host, were chosen because of their high prevalence in AIDS patients and because they exhibit different invasive abilities. The reason why individuals with AIDS are susceptible to this particular group of pathogens is uncertain.

Zoonotic enteric protozoa

A growing number of enteric protozoan species are considered to have zoonotic potential. Their clinical impact varies and in many cases is poorly defined. Similarly, the epidemiology of infections, particularly the role of non-human hosts, requires further study. In this review, new information on the life cycles and transmission of Giardia, Cryptosporidium, Entamoeba, Blastocystis and Balantidium are examined in the context of zoonotic potential, as well as polyparasitism and clinical significance.

Cryptosporidiosis in intensively reared Barramundi (Lates calcarifer)

Two outbreaks of mortality in juvenile barramundi (Lates calcarifer) with a high prevalence of gastrointestinal cryptosporidiosis are described. Juvenile barramundi at a separate hatchery and grow-out facility were demonstrating markedly increased mortality rates. Histological examination in all cases indicated a heavy infection of Cryptosporidium-like organisms within the distal stomach and proximal small intestine. Electron microscopy confirmed a diagnosis of cryptosporidiosis; however, speciation was not possible.

Cryptosporidium spp. in pet birds: genetic diversity and potential public health significance

To characterize the prevalence and assess the zoonotic transmission burden of Cryptosporidium species/genotypes in pet birds in Henan, China, 434 fecal samples were acquired from 14 families of birds in pet shops. The overall prevalence of Cryptopsoridium was 8.1% (35/434) by the Sheather's sugar flotation technique. The Cryptosporidium-positive samples were analyzed by DNA sequence analysis of the small subunit (SSU) rRNA gene. Three Cryptosporidium species and two genotypes were identified, including C. baileyi (18/35 or 51.4%) in five red-billed leiothrixes (Leiothrix lutea), four white Java sparrows (Padda oryzivora), four common mynas (Acridotheres tristis), two zebra finches (Taeniopygia guttata), a crested Lark (Galerida cristata), a Gouldian finch (Chloebia gouldiae), and a black-billed magpie (Pica pica); Cryptosporidium meleagridis (3/35 or 8.6%) in a Bohemian waxwing (Bombycilla garrulus), a Rufous turtle dove (Streptopelia orientalis), and a fan-tailed pigeon (Columba livia); Cryptosporidium galli (5/35 or 14.3%) in four Bohemian waxwings (Bombycilla garrulus) and a silver-eared Mesia (Leiothrix argentauris); Cryptosporidium avian genotype III (3/35 or 8.6%) in two cockatiels (Nymphicus hollandicus) and a red-billed blue magpie (Urocissa erythrorhyncha); and Cryptosporidium avian genotype V (6/35 or 17.1%) in six cockatiels (Nymphicus hollandicus). Among the pet birds, 12 species represented new hosts for Cryptosporidum infections. The presence of C. meleagridis raises questions on potential zoonotic transmission of cryptosporidiosis from pet birds to humans.

Ultrastructural changes in Cryptosporidium parvum oocysts by gamma irradiation

Cryptosporidium parvum is known as one of the most highly resistant parasites to gamma irradiation. To morphologically have an insight on the radioresistance of this parasite, ultrastructural changes in C. parvum sporozoites were observed after gamma irradiation using various doses (1, 5, 10, and 25 kGy) following a range of post-irradiation incubation times (10 kGy for 6, 12, 24, 48, 72, and 96 hr). The ultrastructures of C. parvum oocysts changed remarkably after a 10-kGy irradiation. Nuclear membrane changes and degranulation of dense granules were observed with high doses over 10 kGy, and morphological changes in micronemes and rhoptries were observed with very high doses over 25 kGy. Oocyst walls were not affected by irradiation, whereas the internal structures of sporozoites degenerated completely 96 hr post-irradiation using a dose of 10 kGy. From this study, morphological evidence of radioresistance of C. parvum has been supplemented.

Large-scale survey of Cryptosporidium spp. in chickens and Pekin ducks (Anas platyrhynchos) in Henan, China: prevalence and molecular characterization

Few data are available on the molecular characterization of Cryptosporidium spp. in chickens and ducks in China. In this study, 2579 faecal samples from 46 chicken farms and eight Pekin duck farms in 21 prefectures in Henan Province were examined. The overall infection rate of Cryptosporidium was 10.6% (163/1542) in layer chickens (10 out of 17 farms), 3.4% (16/473) in broilers (five out of 29 farms), and 16.3% (92/564) in Pekin ducks (four out of eight farms), respectively. The highest infection rates were observed in 31-day-old to 60-day-old layer chickens (24.6%) and 11-day-old to 30-day-old Pekin ducks (40.3%). The season of highest prevalence in chickens was spring (15.6%) and the lowest was winter (P<0.01). One hundred and eighty-seven Cryptosporidium-positive samples were analysed by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis of the small subunit rRNA gene, and 55 were further analysed by DNA sequencing of the PCR products. Two Cryptosporidium species were identified: Cryptosporidium baileyi (184/187) on 15 chicken farms and four duck farms, and Cryptosporidium meleagridis (3/187) on three layer chicken farms. C. baileyi was the predominant Cryptosporidium species, found in all age groups of chickens and all Cryptosporidium-positive ducks examined, whereas C. meleagridis was only identified in 31-day-old to 120-day-old layer chickens. Considering the large size of the chicken industry and the close contact between chickens and humans, and that C. meleagridis is the third most common Cryptosporidium parasite in humans, then C. meleagridis could potentially become an emerging zoonosis in some areas in China.

Prevalência de Cryptosporidium spp. em animais domésticos de companhia da população idosa em Teresópolis, Rio de Janeiro, Brasil

OBJETIVO: Este estudo visa a destacar a prevalência da criptosporidiose em animais de companhia doméstica. MÉTODO: Foram elegíveis para o estudo todos os idosos (acima de 60 anos de idade) de ambos os sexos que tenham cães e / ou gatos em casa, vivendo na cidade de Teresópolis e que foram a um posto de vacinação no município durante o período das campanhas nacionais de vacinação contra a gripe em 2007 e 2008. RESULTADOS: Em 29,0% dos animais pesquisados detectou-se a presença de oocistos e em 28,7% foram observados 2 ou mais oocistos por campo. A prevalência de história de diarreia entre os 300 animais examinados foi de 27%, atingindo 29,5% em cães e 24,7% em gatos, não mostrando diferença estatisticamente significativa entre as espécies. CONCLUSÃO: Este fato indica lacunas a serem mais aprofundadas, uma vez que são poucos estudos que exploram a relação da criptosporidiose com os animais de companhia na população humana. Os resultados demonstram a importância de realização periódica de exames parasitológicos em cães com e sem diarreia para tratamento específico e adoção medidas de controle e profilaxia.

Efficacy of amine-based disinfectant KENO™COX on the infectivity of Cryptosporidium parvum oocysts

Cryptosporidium parvum is a zoonotic protozoan parasite that may cause severe neonatal diarrhoea or even mortality in newborn ruminants: its oocysts are extremely resistant to normal environmental conditions and to most common disinfectants. KENO™COX, a patent pending amine-based formula, was tested for its ability to inactivate C. parvum oocysts. The Daugschies assay (2002), a standardized assay for chemical disinfection initially described for Eimeria spp., was adapted for C. parvum oocysts. KENO™COX diluted in water at 2% and 3% concentration and incubated with oocyst suspensions for 2h, allowed a significant reduction in viability, lysing 89% and 91% of oocysts respectively. Infectivity of the remaining C. parvum oocysts was assessed by inoculation to C57 Bl/6 neonatal mice. Each mouse received 2.5 μl of a suspension initially containing 500,000 oocysts before contact with KENO™COX. Six days post inoculation, the intestinal parasite load was significantly reduced by 97.5% with KENO™COX 2% compared to that of the mice inoculated with untreated parasites. KENO™COX 3% completely eliminated infectivity of oocysts. The number of oocysts remaining infectious in the inoculum treated with KENO™COX 2% was calculated from an inoculated dose-response curve: it was estimated at about 48.6 oocysts among the 500,000 oocysts initially treated corresponding to 99.99% of inhibition. These results demonstrate the high efficacy of KENO™COX against C. parvum oocysts. Combined with an appropriate method of cleaning, the application of KENO™COX may be a useful tool to reduce cryptosporidial infectious load on farm level.

Identification of novel Cryptosporidium genotypes in kangaroos from Western Australia

A total of 763 faecal samples were collected from western grey kangaroos (Macropus fuliginosus) in Western Australia and screened for the presence of Cryptosporidium by PCR at the 18S ribosomal RNA (rRNA) locus. Samples that were positive at the 18S locus were also amplified at the actin locus. The overall prevalence was 9.3% (71/763). At the 18S rRNA locus, sequences were obtained for 28 of the 71 positives. Sequence analysis identified four species; Cryptosporidium fayeri in seven isolates, Cryptosporidium marcopodum in four isolates, Cryptosporidium xiaoi in six isolates and a novel genotype (kangaroo genotype I) in eleven isolates. Analysis at the actin locus confirmed the genetic distinctness of the novel genotype. The results of the present study indicate that in addition to C. fayeri and C. marcopodum, kangaroos may be capable of being infected with a wider range of Cryptosporidium species and genotypes including livestock species such as C. xiaoi. The novel genotype identified in the kangaroos most likely represents a cryptic species that requires further analyses to confirm its species status.

Cryptosporidium contamination of surface and water supplies in Haiti

Cryptosporidiosis is one of the most frequent causes of diarrhea in Haiti. Transmission in children less than five years-old, HIV-infected individuals, and people living in low socio-economic conditions is frequently due to consumption of water or food contaminated by Cryptosporidium oocysts. This study examined the circulation of Cryptosporidium oocysts in surface waters and in public water supplies in the district of Port-au-Prince. Data were gathered from December 2000 to June 2002 in 37 sites. In the district of Port-au-Prince, 24/37 samples of water collected (65%) were contaminated by Cryptosporidium oocysts and 10/11 (91%) of those collected in reservoirs used by people living in peripheral areas. The rate of contamination was 7/13 (54%) in water from public standpipes provided by the public company of water distribution. All surface water (4/4) collected was highly contaminated.

Multiplex PCR detection of waterborne intestinal protozoa: microsporidia, Cyclospora, and Cryptosporidium

Recently, emerging waterborne protozoa, such as microsporidia, Cyclospora, and Cryptosporidium, have become a challenge to human health worldwide. Rapid, simple, and economical detection methods for these major waterborne protozoa in environmental and clinical samples are necessary to control infection and improve public health. In the present study, we developed a multiplex PCR test that is able to detect all these 3 major waterborne protozoa at the same time. Detection limits of the multiplex PCR method ranged from 10(1) to 10(2) oocysts or spores. The primers for microsporidia or Cryptosporidium used in this study can detect both Enterocytozoon bieneusi and Encephalitozoon intestinalis, or both Cryptosporidium hominis and Cryptosporidium parvum, respectively. Restriction enzyme digestion of PCR products with BsaBI or BsiEI makes it possible to distinguish the 2 species of microsporidia or Cryptosporidium, respectively. This simple, rapid, and cost-effective multiplex PCR method will be useful for detecting outbreaks or sporadic cases of waterborne protozoa infections.

Cloaca prolapse and cystitis in green iguana (Iguana iguana) caused by a novel Cryptosporidium species

Cryptosporidium infection was associated with colitis and cystitis in 2 green iguanas (Iguana iguana). The disease was characterized by a chronic clinical course of cloacal prolapses and cystitis. Histological examination of the gut and urinary bladder showed numerous Cryptosporidium developmental stages on the surface of the epithelium with mixed inflammatory response in the lamina propria. Cryptosporidium oocysts were visualised in a cytological preparation of the faeces. Based on the small subunit ribosomal RNA gene the cryptosporidia were characterized as belonging to the intestinal cryptosporidial lineage, but not to Cryptosporidium saurophilum or Cryptosporidium serpentis species.

Cryptosporidium baileyi infection associated with an outbreak of ocular and respiratory disease in otus owls (Otus scops) in a rehabilitation centre

Cryptosporidiosis has been reported in more than 30 avian species worldwide. Although some cases of cryptosporidiosis have been described in captive birds of prey in the order Falconiformes, to date there have been no reports of the disease in wild raptors. Here we describe for first time an ocular and respiratory disease associated with Cryptosporidium baileyi in wild scops owl (Otus scops, order: Strigiformes). Sixteen otus owl fledglings born in the wild during the summer of 2008 were admitted to the Torreferrussa Wildlife Rehabilitation Centre (Catalonia, northern Spain) in July and August of the same year. In the middle of September, blepharoedema, conjunctival hyperaemia and mucopurulent ocular discharge were diagnosed unilaterally in 75% (12/16) of the birds and bilaterally in 25% (4/16). Moreover, five birds (31%) developed diffuse epithelial corneal oedema, one owl (6%) displayed mild anterior exudative uveitis and another developed rhinitis (6%). Two birds were euthanized because of the severity of disease. The histopathology demonstrated cryptosporidia-like structures in the conjunctival cells and in the nasal respiratory epithelium of one owl. Cryptosporidium spp. oocysts (6.5 to 7.0 x 5.0 to 5.5 microm) were identified by immunofluorescent antibody test (IFAT) in histological sections from eyelids, trachea and respiratory sinuses and in swab samples from the glottis, choanal slit and conjunctival sac. Polymerase chain reaction and DNA sequence analysis confirmed the presence of C. baileyi. Birds were treated orally with azithromycin (40 mg/kg) once a day for 15 days, and by the end of the treatment all owls tested negative for the parasites, by IFAT, and did not display further signs of disease.

Sporadic Cryptosporidium infection in Nigerian children: risk factors with species identification

A cross-sectional study was conducted to investigate risk factors for sporadic Cryptosporidium infection in a paediatric population in Nigeria. Of 692 children, 134 (19·4%) were infected with Cryptosporidium oocysts. Cryptosporidium spp. were identified in 49 positive samples using PCR-restriction fragment length polymorphism and direct sequencing of the glycoprotein60 (GP60) gene. Generalized linear mixed-effects models were used to identify risk factors for all Cryptosporidium infections, as well as for C. hominis and C. parvum both together and separately. Risk factors identified for all Cryptosporidium infections included malaria infection and a lack of Ascaris infection. For C. hominis infections, stunting and younger age were highlighted as risk factors, while stunting and malaria infection were identified as risk factors for C. parvum infection.

Morphological changes and viability ofCryptosporidium parvumsporozoites after excystation in cell-free culture media

Cryptosporidium parvum,belonging to the phylum Apicomplexa, is a major cause of waterborne gastroenteritis throughout the world. The sporozoites are thought to invade host enterocytes using an active process termed gliding motility. However, the biological and morphological changes within the sporozoites during this process are not fully understood. In the present study, excysted sporozoites ofC. parvumwere analysed ultrastructurallyin vitroand their viability was evaluated using fluorescent dyes. The sporozoites excysted from oocysts changed morphologically from banana-shaped to rod-shaped and finally to a rounded shape, in culture media in 3 h. Transmission microscopy revealed that the distance between the apical end and the nucleus was markedly reduced, dense granules were present close to the rhoptry in the apical region, amylopectin granules were absent, and membranes of round sporozoites were less clear. A fluorescent assay showed that the rate of survival decreased from 89% to 56% at 0–3 h (84·3% for banana-shaped and 49·2% for rod-shaped sporozoites). Therefore, post-excysted sporozoitesin vitrounderwent morphological changes and a rapid loss of viability. This staining method is useful, inexpensive and provides an alternative to more costly and intensive flow cytometric assays or infectivity assays with host cellsin vitro.

Validation of multiple diagnostic techniques to detect Cryptosporidium sp. and Giardia sp. in free-ranging western lowland gorillas (Gorilla gorilla gorilla) and observations on the prevalence of these protozoan infections in two populations in Gabon

Anthropozoonotic diseases threaten the survival of western lowland gorillas (Gorilla gorilla gorilla). Use of accurate diagnostic techniques in gorilla health monitoring contributes to the conservation of gorillas by providing robust information for appropriate management decisions. To identify suitable protozoa diagnostic techniques for wild gorillas, 95 fecal specimens were collected in Lopé National Park and east of Moukalaba-Doudou National Park in Gabon, areas with high and low levels of human activity, respectively. The samples were examined for Cryptosporidium sp. and Giardia sp. by using the following diagnostic techniques: a commercially available immunofluorescent antibody test kit, Merifluor, and a rapid immune-assay, ImmunoCard STAT!, to detect Cryptosporidium sp. and Giardia sp., and a modified Ziehl-Neelsen stain to detect Cryptosporidium sp. oocysts. The results obtained from the Merifluor test, considered the "gold standard" in human studies, were used to estimate the prevalence of Cryptosporidium sp. and Giardia sp. infections in Lopé National Park (19.0% and 22.6%, respectively) and east of Moukalaba-Doudou National Park (0% and 9.1%, respectively). The difference in prevalence in both areas may be associated with differing levels of anthropogenic disturbance. The sensitivity and specificity of the latter two diagnostic techniques were calculated by using the Merifluor test as a control. The ImmunoCard STAT! was found suitable for Giardia sp. antigen detection (specific but not sensitive) and inappropriate for Cryptosporidium sp. antigen detection (not specific or sensitive). The modified Ziehl-Neelsen stain was found to be highly specific but not sensitive in the detection of Cryptosporidium sp. oocysts. These results underline the necessity of using ancillary tests and concentration methods to correctly identify positive samples. This is the first report of Cryptosporidium sp. and Giardia sp. infections in free-ranging western lowland gorillas and highlights the importance of verifying the accuracy of diagnostic techniques developed for human use before applying these to non-human primates.

Control of cryptosporidiosis in neonatal calves: use of halofuginone lactate in two different calf rearing systems

To date there is no effective treatment for bovine cryptosporidiosis. This study describes the use of halofuginone lactate in preventing cryptosporidiosis in naturally infected neonatal calves on a dairy farm with a high prevalence of infection. The animals were kept in two different calf rearing systems. A randomized double-blind trial was carried out with 32 naturally infected calves, divided into four groups. The two prophylactic halofuginone lactate treated groups were kept in either individual or group pens. Similarly, the animals receiving the placebo were housed in either individual pens or together in a large pen. A total of ten faecal samples were collected periodically during the 28 days study from each calf and tested for the presence of Cryptosporidium spp. using microscopic and molecular methods. Generalized estimating equations models were used to determine if the effects of the various treatments and/or rearing systems on the presence of diarrhoea and infection were statistically significant. Further analysis (classification trees models) was carried out to explore possible risk factors for cryptosporidiosis and interactions between treatments and rearing systems. Halofuginone lactate was shown to be effective in reducing clinical signs of cryptosporidiosis and environmental contamination. However, the treatment did not delay the onset of diarrhoea and did not reduce the risk of infection amongst calves reared together in a highly contaminated environment. The use of halofuginone lactate in combination with good hygienic measures, such as rearing animals in clean individual pens, was the most effective method to reduce the risk of cryptosporidiosis amongst 7-13 days old calves. It was concluded that the control of the parasite could be achieved by the combination of using effective preventive drugs, such as halofuginone lactate and good animal husbandry procedures.

Solar radiation induces non-nuclear perturbations and a false start to regulated exocytosis in Cryptosporidium parvum

Stratospheric ozone depletion, climate warming and acidification of aquatic ecosystems have resulted in elevated levels of solar radiation reaching many aquatic environments with an increased deleterious impact on a wide range of living organisms. While detrimental effects on living organisms are thought to occur primarily through DNA damage, solar UV can also damage cellular proteins, lipids and signalling pathways. Cryptosporidium, a member of the eukaryotic phylum Apicomplexa, contain numerous vesicular secretory organelles and their discharge via regulated exocytosis is essential for the successful establishment of infection. Using flow cytometric techniques we demonstrate that solar UV rapidly induces sporozoite exocytosis resulting in a significant reduction in the ability of sporozoites to attach and invade host cells. We found that solar UV induced sporozoite membrane depolarization, resulting in reduced cellular ATP and increased cytosolic calcium. These changes were accompanied by a reduction in the internal granularity of sporozoites, indicative of apical organelle discharge, which was confirmed by analysis of sporozoites with an exocytosis-sensitive dye. The precise timing of apical organelle discharge in the presence of a compatible host cell is critical for sporozoite attachment and invasion. Our results demonstrate for the first time how solar UV radiation can interfere with exocytosis, a fundamental cellular process in all eukaryotic cells. We contend that not only may the forecast increases in solar radiation in both aquatic and terrestrial environments significantly affect members of the Apicomplexa, solar UV-induced membrane depolarizations resulting in cytosolic calcium perturbation may affect a wider range of eukaryotic organisms through antagonistic effects on a myriad of calcium dependant cellular functions.

Induction of immune responses in mice by a DNA vaccine encoding Cryptosporidium parvum Cp12 and Cp21 and its effect against homologous oocyst challenge

Cp12 and Cp21 surface proteins on the sporozoite of Cryptosporidium parvum have been identified as the immunodominant antigens involved in the immune response to C. parvum infection. In the present study, the efficacy of Cp12 and Cp21 antigens as vaccine candidates was investigated in BALB/c mice that were susceptible to C. parvum infection. DNA sequences of Cp12, Cp21, Cp12-Cp21, and C (CpG oligodeoxynucleotide (ODN))-Cp12-Cp21 were amplified and then cloned into pVAX1 vector to form the four recombinant plasmids pVAX1-Cp12, pVAX1-Cp21, pVAX1-Cp12-Cp21, and pVAX1-C-Cp12-Cp21. Recombinant protein expression from these four plasmids in HeLa cells were confirmed by indirect immunofluorescence staining and Western blot analysis. The in vivo efficacies of the four DNA vaccines were tested in BALB/c mice. The results indicated that the four DNA vaccines elicited significant antibody responses and specific cellular responses when compared to control mice that received vector only or PBS. Among those four plasmids, pVAX1-C-Cp12-Cp21 elicited significantly higher levels of IgG. Also, the percentages of CD4(+) and CD8(+) T cells were significantly higher in the group with pVAX1-C-Cp12-Cp21 nasal sprays. Their efficacy in immunoprotection against homologous challenge was also detected after administration of the four DNA vaccines. The results showed that mice in the pVAX1-C-Cp12-Cp21 nasal group had a 77.5% reduction in the level of oocyst shedding and a significant difference was detected when this group was compared with the pVAX1, PBS, pVAX1-Cp12, and pVAX1-Cp21 groups. The reduction in the level of oocysts shedding from the group of pVAX1-C-Cp12-Cp21 nasal spray was also higher than that of pVAX1-Cp12-Cp21 group. These results suggested that C-Cp12-Cp21-DNA may provide an effective means of eliciting humoral and cellular responses and generating protective immunity against C. parvum infections in BALB/c mice.