Cryptosporidium hominis n. sp. (Apicomplexa: Cryptosporidiidae) from Homo sapiens

Identification of a novel GP60 subtype family of Cryptosporidium wrairi from capybaras (Hydrochoerus hydrochaeris) inhabiting urban areas in the state of Mato Grosso do Sul, Brazil

Capybaras (Hydrochoerus hydrochaeris) are hosts for several parasites of public health importance, including Cryptosporidium spp. Therefore, this study aimed to perform the molecular characterization of Cryptosporidium spp. in fecal samples from capybaras inhabiting urban areas. We analyzed 401 fecal samples from capybaras in two municipalities of the state of Mato Grosso do Sul, Brazil. Fecal samples were purified using centrifugal sedimentation with ethyl acetate. They were then screened for Cryptosporidium spp. by malachite green negative staining and a nested PCR protocol targeting the 18S rRNA gene. Samples positive by microscopy or PCR were examined by PCR protocols targeting the actin, HSP-70, and GP60 genes. Amplicons from all PCR protocols were subjected to genetic sequencing. Microscopic screening and 18S rRNA gene-targeted PCR identified 0.25 % (1/401) and 0.5 % (2/401) of samples, respectively, as positive for Cryptosporidium spp. The genetic sequences of the 18S rRNA, HSP-70, actin, and GP60 genes showed genetic similarity to Cryptosporidium wrairi sequences of 99.07 %, 99.69 %, 99.57 %, and 91.51 %, respectively. Genetic sequencing and phylogenetic analyses identified the novel GP60 subtype family VIIbA13 of C. wrairi. In conclusion, we report in this study a low prevalence of the novel GP60 subtype family VIIbA13 of C. wrairi in free-living capybaras from urban areas of the state of Mato Grosso do Sul, Brazil. We propose that capybaras act as a novel host for C. wrairi.

Stage-specific expression and divergent functions of two insulinase-like proteases associated with host infectivity in Cryptosporidium

BACKGROUND

The determinants of differences in host infectivity among Cryptosporidium species and subtypes are poorly understood. Results from recent comparative genomic studies suggest that gains and losses of multicopy subtelomeric genes encoding insulinase-like proteases (INS-19 and INS-20 in Cryptosporidium parvum and their orthologs in closely related species) may potentially contribute to these differences.

METHODOLOGY/PRINCIPAL FINDINGS

In this study, we investigated the expression and biological function of the INS-19 and INS-20 of C. parvum. CRISPR/Cas9 was used to endogenously tag both genes with the hemagglutinin epitope. Immunofluorescence analysis revealed that INS-19 and INS-20 are expressed at different developmental stages of the pathogen. Although knockout of either had no detectable effect on the in vitro growth of C. parvum, knockout of INS-20, deletion of its multiple domains, or mutation of the active motif in the functional domain reduced the intensity of C. parvum infection in IFN-γ knockout mice. Consistent with this, mice infected with the INS-20-deleted mutant had reduced intestinal damage and parasite burden.

CONCLUSIONS/SIGNIFICANCE

These results suggest that INS-19 and INS-20 have stage-specific expression with distinct biological functions, and that the presence of the INS-20 in zoonotic C. parvum contributes to its infectivity and fitness in mice.

Multicopy subtelomeric genes underlie animal infectivity of divergent Cryptosporidium hominis subtypes

The anthroponotic Cryptosporidium hominis differs from the zoonotic C. parvum in its lack of infectivity to animals, but several divergent subtypes have recently been found in nonhuman primates and equines. Here, we sequence 17 animal C. hominis isolates and generate a new IbA12G3 genome at the chromosome level. Comparative analysis with 222 human isolates shows significant genetic divergence of the animal isolates, with genetic recombination among them. They have additional subtelomeric insulinase and MEDLE genes. In interferon-γ knockout mice, three monkey isolates show differences in infectivity and induce higher and longer oocyst shedding than a reference C. parvum isolate. Deletion of the MEDLE genes significantly reduces the growth and pathogenicity of a virulent strain in mice. Co-infection of two fluorescence-tagged C. hominis subtypes produces bicolored oocysts, supporting the conclusion that mixed subtype infections can lead to genetic recombination. These data provide insight into potential determinants of host infectivity in Cryptosporidium, and a convenient animal model for biological studies of C. hominis.

Cryptosporidium spp. and Eimeria spp. (Apicomplexa: Eimeriorina) of freshwater Cyprinid fish species in the Kura River basin in Azerbaijan territory

This study aims to determine the prevalence of Cryptosporidium and Eimeria spp. oocysts in fish specimens in the river Kura. It was conducted during the 2021-2022 at two sites: Mingachevir reservoir in central Azerbaijan and in Neftchala district where the river finally enters the Caspian Sea through a delta of the Kura River estuary. The diagnosis of oocysts was performed microscopically. Fine smears from the intestine epithelial layers stained by Ziehl-Neelsen for Cryptosporidium oocysts. To identify Eimeria oocysts, each fish's faecal material and intestinal scrapings were examined directly under a light microscope in wet samples on glass slides with a coverslip. Results revealed a prevalence of Cryptosporidium and Eimeria species infections in fish hosts from both territories Rutilus caspicus, Alburnus filippi, Abramis brama orientalis and Carassius gibelio. Of 170 investigated fish specimens, 8.8% (15/170) were infected with Cryptosporidium species oocysts. Eimeria species oocysts were identified in 20.6% (35/170). The presence of Cryptosporidium and Eimeria infections in fish specimens are natural infections. However, their presence in fish species may be attributed to the age of the fish species and water pollution. This is the first report regarding the prevalence of Cryptosporidium oocysts in fish species in Azerbaijan.

Comparison of in vitro growth characteristics of Cryptosporidium hominis (IdA15G1) and Cryptosporidium parvum (Iowa-IIaA17G2R1 and IIaA18G3R1)

Cryptosporidium is a major cause of diarrhoeal disease and mortality in young children in resource-poor countries, for which no vaccines or adequate therapeutic options are available. Infection in humans is primarily caused by two species: C. hominis and C. parvum. Despite C. hominis being the dominant species infecting humans in most countries, very little is known about its growth characteristics and life cycle in vitro, given that the majority of our knowledge of the in vitro development of Cryptosporidium has been based on C. parvum. In the present study, the growth and development of two C. parvum isolates (subtypes Iowa-IIaA17G2R1 and IIaA18G3R1) and one C. hominis isolate (subtype IdA15G1) in HCT-8 cells were examined and compared at 24 h and 48 h using morphological data acquired with scanning electron microscopy. Our data indicated no significant differences in the proportion of meronts or merozoites between species or subtypes at either time-point. Sexual development was observed at the 48-h time-point across both species through observations of both microgamonts and macrogamonts, with a higher frequency of macrogamont observations in C. hominis (IdA15G1) cultures at 48-h post-infection compared to both C. parvum subtypes. This corresponded to differences in the proportion of trophozoites observed at the same time point. No differences in proportion of microgamonts were observed between the three subtypes, which were rarely observed across all cultures. In summary, our data indicate that asexual development of C. hominis is similar to that of C. parvum, while sexual development is accelerated in C. hominis. This study provides new insights into differences in the in vitro growth characteristics of C. hominis when compared to C. parvum, which will facilitate our understanding of the sexual development of both species.

Movement of protistan trophic groups in soil-plant continuums

Protists, functionally divided into consumers, phototrophs, and parasites act as integral components and vital regulators of microbiomes in soil-plant continuums. However, the drivers of community structure, assembly mechanisms, co-occurrence patterns, and the associations with human pathogens and different protistan trophic groups remain unknown. Here, we characterized the phyllosphere and soil protistan communities associated with three vegetables under different fertilization treatments (none and organic fertilization) at five growth stages. In this study, consumers were the most diverse soil protist group, had the role of inter-kingdom connector, and were the primary biomarker for rhizosphere soils which were subjected to decreasing deterministic processes during plant growth. In contrast, phototrophs had the greatest niche breadth and formed soil protistan hubs, and were the primary biomarkers for both bulk soils and the phyllosphere. Parasites had minimal input to microbial co-occurrence networks. Organic fertilization increased the relative abundance (RA) of pathogenic protists and the number of pathogen-consumer connections in rhizosphere soils but decreased protistan richness and the number of internal protistan links. This study advances our understanding of the ecological roles and potential links between human pathogens and protistan trophic groups associated with soil-plant continuums, which is fundamental to the regulation of soil-plant microbiomes and maintenance of environmental and human health.

Cryptosporidium mortiferum n. sp. (Apicomplexa: Cryptosporidiidae), the species causing lethal cryptosporidiosis in Eurasian red squirrels (Sciurus vulgaris)

BACKGROUND

Cryptosporidium spp. are globally distributed parasites that infect epithelial cells in the microvillus border of the gastrointestinal tract of all classes of vertebrates. Cryptosporidium chipmunk genotype I is a common parasite in North American tree squirrels. It was introduced into Europe with eastern gray squirrels and poses an infection risk to native European squirrel species, for which infection is fatal. In this study, the biology and genetic variability of different isolates of chipmunk genotype I were investigated.

METHODS

The genetic diversity of Cryptosporidium chipmunk genotype I was analyzed by PCR/sequencing of the SSU rRNA, actin, HSP70, COWP, TRAP-C1 and gp60 genes. The biology of chipmunk genotype I, including oocyst size, localization of the life cycle stages and pathology, was examined by light and electron microscopy and histology. Infectivity to Eurasian red squirrels and eastern gray squirrels was verified experimentally.

RESULTS

Phylogenic analyses at studied genes revealed that chipmunk genotype I is genetically distinct from other Cryptosporidium spp. No detectable infection occurred in chickens and guinea pigs experimentally inoculated with chipmunk genotype I, while in laboratory mice, ferrets, gerbils, Eurasian red squirrels and eastern gray squirrels, oocyst shedding began between 4 and 11 days post infection. While infection in mice, gerbils, ferrets and eastern gray squirrels was asymptomatic or had mild clinical signs, Eurasian red squirrels developed severe cryptosporidiosis that resulted in host death. The rapid onset of clinical signs characterized by severe diarrhea, apathy, loss of appetite and subsequent death of the individual may explain the sporadic occurrence of this Cryptosporidium in field studies and its concurrent spread in the population of native European squirrels. Oocysts obtained from a naturally infected human, the original inoculum, were 5.64 × 5.37 μm and did not differ in size from oocysts obtained from experimentally infected hosts. Cryptosporidium chipmunk genotype I infection was localized exclusively in the cecum and anterior part of the colon.

CONCLUSIONS

Based on these differences in genetics, host specificity and pathogenicity, we propose the name Cryptosporidium mortiferum n. sp. for this parasite previously known as Cryptosporidium chipmunk genotype I.

Identification and Evaluation of Cryptosporidium Species from New York City Cases of Cryptosporidiosis (2015 to 2018): a Watershed Perspective

Watersheds that supply residents with drinking water have the potential for contamination with Cryptosporidium oocysts. To evaluate any potential similarities between Cryptosporidium species previously found in the New York City (NYC) watershed and those causing disease in NYC, the species were identified in stool specimens from residents with cryptosporidiosis. Genetic analysis was performed on 628 positive stool samples collected from NYC residents between 2015 and 2018 to determine the species present. A total of 547 samples yielded positive results by real-time PCR. Of these samples, 512 (93.6%) were identified to the species level, with 94.7% positive for either Cryptosporidium hominis or Cryptosporidium parvum (56.4% and 38.5%, respectively), including one coinfection. Less common Cryptosporidium species identified included C. felis, C. canis, C. ubiquitum, C. meleagridis, and a Cryptosporidium sp. chipmunk genotype. Results were evaluated and compared to species and genotypes of Cryptosporidium previously identified from stormwater collected within the NYC watershed. While there was overlap with some of the rare species found in case specimens, the prevalence and distribution of species did not suggest a connection between sources previously identified in the watershed and the species causing human cases of cryptosporidiosis in NYC residents. IMPORTANCE It is important to identify the species causing human cryptosporidiosis in a population in order to investigate possible sources or routes of contamination. Many species of Cryptosporidium are host-adapted and therefore have the potential to be tracked back to specific sources that can subsequently be managed. There has been no evidence to suggest that the water supply has ever been a source of cryptosporidiosis cases in NYC, and since 2013, the New York City Department of Environmental Protection has further reduced the risk of disease through the use of ultraviolet treatment to inactivate any Cryptosporidium present in the source water. However, as one of the largest unfiltered water supplies in the country, it is important to evaluate watershed sources for potential impacts to public health. In this unique study, species of Cryptosporidium causing disease in NYC residents were identified and compared with previously identified species from the watershed.

Molecular characterization and prevalence of Cryptosporidium spp. in sheep and goats in western Inner Mongolia, China

Cryptosporidium spp. are zoonotic intestinal parasites that infect fish, birds, reptiles and mammals. Cryptosporidium spp. are common cause of diarrhea. In this study, a total of 1032 fecal samples were collected from the rectums of sheep and goats. The samples were analyzed using nested polymerase chain reaction (nested PCR) based on the small subunit ribosomal RNA (SSU rRNA) gene of Cryptosporidium spp. The average infection rate of Cryptosporidium spp. was 2.23% (n = 23), and three Cryptosporidium species were identified, namely Cryptosporidium ubiquitum (8/23), Cryptosporidium andersoni (5/23) and Cryptosporidium xiaoi (10/23). Subtyping of C. ubiquitum and C. xiaoi was carried out by DNA sequence analysis of the 60-kDa glycoprotein (gp60) gene. Eight C. ubiquitum isolates were identified as zoonotic subtype XIIa. Nine C. xiaoi isolates were identified as subtypes XXIIIc (n = 1), XXIIIf (n = 3) and XXIIIg (n = 5). Subtype XXIIIg was first found in Chinese sheep. C. ubiquitum subtype XIIa was found in both sheep and goats, suggesting that sheep and goats are important sources of C. ubiquitum infections.

Enteric protozoal infections in camels: Etiology, epidemiology, and future perspectives

Camels have great potential as a safety valve for current and future food security for pastoralists, agropastoralists, and urban populations. Enteric protozoal diseases are important causes of economic losses in camels; however, they are poorly concerned globally. The most common members of enteric protozoa are Balantidium, Eimeria, Giardia, and Cryptosporidium. Some of them threaten human health as humans can be infected by consuming food or water contaminated with camel feces, particularly in poor communities with inadequate sanitation and low-quality healthcare facilities. For these reasons, a comprehensive and careful investigation was conducted on some enteric protozoal diseases of camels to present an updated insight into the etiology, epidemiology, and future trends in diagnosing and controlling camel enteric protozoa. Future studies on the camel enteric protozoa should be carried out to develop advanced diagnostic approaches in diverse farm animal species. Moreover, the protozoan zoonotic potential should be considered to secure human health.

Genomic comparisons confirm Giardia duodenalis sub-assemblage AII as a unique species

Giardia duodenalis is a parasitic flagellated protozoan which infects a wide range of mammalian hosts, including humans, and is subdivided into at least eight genetic assemblages commonly thought to represent cryptic species. Molecular studies have shown that G. duodenalis assemblage A, which parasitizes humans and animals, contains several phylogenetically distinct groupings known as sub-assemblages. Molecular studies employing poor phylogenetic-resolution markers routinely recover these sub-assemblages, implying that they represent evolutionarily distinct clades and possibly cryptic species, a hypothesis which is supported by epidemiologic trends. Here, we further tested this hypothesis by using available data from 41 whole genomes to characterize sub-assemblages and coalescent techniques for statistical estimation of species boundaries coupled to functional gene content analysis, thereby assessing the stability and distinctiveness of clades. Our analysis revealed two new sub-assemblage clades as well as novel signatures of gene content geared toward differential host adaptation and population structuring via vertical inheritance rather than recombination or panmixia. We formally propose sub-assemblage AII as a new species, Giardia hominis, while preserving the name Giardia duodenalis for sub-assemblage AI. Additionally, our bioinformatic methods broadly address the challenges of identifying cryptic microbial species to advance our understanding of emerging disease epidemiology, which should be broadly applicable to other lower eukaryotic taxa of interest. Giardia hominis n. sp. Zoobank LSID: urn:lsid: zoobank.org:pub:4298F3E1-E3EF-4977-B9DD-5CC59378C80E.

A review of the current status of Cryptosporidium in fish

Species of the genus Cryptosporidium (phylum Apicomplexa) infect the epithelium of the gastrointestinal tract of several vertebrate hosts, including humans and domestic and wild animals. In the past 20 years, several studies have focused on Cryptosporidium in fish. To date, a total of four piscine-host-specific species (Cryptosporidium molnari, Cryptosporidium huwi, Cryptosporidium bollandi and Cryptosporidium abrahamseni), nine piscine genotypes and more than 29 unnamed genotypes have been described in fish hosts. In addition, Cryptosporidium species and genotypes typical of other groups of vertebrates have also been identified. This review summarizes the history, biology, pathology and clinical manifestations, as well as the transmission, prevalence and molecular epidemiology of Cryptosporidium in wild, cultured and ornamental fish from both marine and freshwater environments. Finally, the potential role of piscine hosts as a reservoir of zoonotic Cryptosporidium species is also discussed.

Commensal Cryptosporidium colonization elicits a cDC1-dependent Th1 response that promotes intestinal homeostasis and limits other infections

Cryptosporidium can cause severe diarrhea and morbidity, but many infections are asymptomatic. Here, we studied the immune response to a commensal strain of Cryptosporidium tyzzeri (Ct-STL) serendipitously discovered when conventional type 1 dendritic cell (cDC1)-deficient mice developed cryptosporidiosis. Ct-STL was vertically transmitted without negative health effects in wild-type mice. Yet, Ct-STL provoked profound changes in the intestinal immune system, including induction of an IFN-γ-producing Th1 response. TCR sequencing coupled with in vitro and in vivo analysis of common Th1 TCRs revealed that Ct-STL elicited a dominant antigen-specific Th1 response. In contrast, deficiency in cDC1s skewed the Ct-STL CD4 T cell response toward Th17 and regulatory T cells. Although Ct-STL predominantly colonized the small intestine, colon Th1 responses were enhanced and associated with protection against Citrobacter rodentium infection and exacerbation of dextran sodium sulfate and anti-IL10R-triggered colitis. Thus, Ct-STL represents a commensal pathobiont that elicits Th1-mediated intestinal homeostasis that may reflect asymptomatic human Cryptosporidium infection.

Cryptosporidium hominis Phylogenomic Analysis Reveals Separate Lineages With Continental Segregation

Cryptosporidium is a leading cause of waterborne outbreaks globally, and Cryptosporidium hominis and C. parvum are the principal cause of human cryptosporidiosis on the planet. Thanks to the advances in Next-Generation Sequencing (NGS) sequencing and bioinformatic software development, more than 100 genomes have been generated in the last decade using a metagenomic-like strategy. This procedure involves the parasite oocyst enrichment from stool samples of infected individuals, NGS sequencing, metagenomic assembly, parasite genome computational filtering, and comparative genomic analysis. Following this approach, genomes of infected individuals of all continents have been generated, although with striking different quality results. In this study, we performed a thorough comparison, in terms of assembly quality and purity, of 100+ de novo assembled genomes of C. hominis. Remarkably, after quality genome filtering, a comprehensive phylogenomic analysis allowed us to discover that C. hominis encompasses two lineages with continental segregation. These lineages were named based on the observed continental distribution bias as C. hominis Euro-American (EA) and the C. hominis Afro-Asian (AA) lineages.

Taxonomy and molecular epidemiology of Cryptosporidium and Giardia - a 50 year perspective (1971-2021)

The protozoan parasites Cryptosporidium and Giardia are significant causes of diarrhoea worldwide and are responsible for numerous waterborne and foodborne outbreaks of diseases. Over the last 50 years, the development of improved detection and typing tools has facilitated the expanding range of named species. Currently at least 44 Cryptosporidium spp. and >120 genotypes, and nine Giardia spp., are recognised. Many of these Cryptosporidium genotypes will likely be described as species in the future. The phylogenetic placement of Cryptosporidium at the genus level is still unclear and further research is required to better understand its evolutionary origins. Zoonotic transmission has long been known to play an important role in the epidemiology of cryptosporidiosis and giardiasis, and the development and application of next generation sequencing tools is providing evidence for this. Comparative whole genome sequencing is also providing key information on the genetic mechanisms for host specificity and human infectivity, and will enable One Health management of these zoonotic parasites in the future.

Cryptosporidium spp. infections in livestock and wild animals in Azerbaijan territory

Cryptosporidium is an intracellular protozoan parasite, globally distributed and capable of infecting various vertebrate species, including humans as well as domestic and wild animals. Cryptosporidium is increasingly gaining attention as a human and an animal pathogen mainly due to its dominant involvement in worldwide waterborne outbreaks. The present paper reviews the current knowledge and understanding of Cryptosporidium spp. in terrestrial and water animals in Azerbaijan.

Opportunities and Challenges in Developing a Cryptosporidium Controlled Human Infection Model for Testing Antiparasitic Agents

Cryptosporidiosis is a leading cause of moderate-to-severe diarrhea in low- and middle-income countries, responsible for high mortality in children younger than two years of age, and it is also strongly associated with childhood malnutrition and growth stunting. There is no vaccine for cryptosporidiosis and existing therapeutic options are suboptimal to prevent morbidity and mortality in young children. Recently, novel therapeutic agents have been discovered through high-throughput phenotypic and target-based screening strategies, repurposing malaria hits, etc., and these agents have a promising preclinical in vitro and in vivo anti-Cryptosporidium efficacy. One key step in bringing safe and effective new therapies to young vulnerable children is the establishment of some prospect of direct benefit before initiating pediatric clinical studies. A Cryptosporidium controlled human infection model (CHIM) in healthy adult volunteers can be a robust clinical proof of concept model for evaluating novel therapeutics. CHIM could potentially accelerate the development path to pediatric studies by establishing the safety of a proposed pediatric dosing regimen and documenting preliminary efficacy in adults. We present, here, perspectives regarding the opportunities and perceived challenges with the Cryptosporidium human challenge model.

Cryptosporidium myocastoris n. sp. (Apicomplexa: Cryptosporidiidae), the Species Adapted to the Nutria (Myocastor coypus)

Cryptosporidium spp., common parasites of vertebrates, remain poorly studied in wildlife. This study describes the novel Cryptosporidium species adapted to nutrias (Myocastor coypus). A total of 150 faecal samples of feral nutria were collected from locations in the Czech Republic and Slovakia and examined for Cryptosporidium spp. oocysts and specific DNA at the SSU, actin, HSP70, and gp60 loci. Molecular analyses revealed the presence of C. parvum (n = 1), C. ubiquitum subtype family XIId (n = 5) and Cryptosporidium myocastoris n. sp. XXIIa (n = 2), and XXIIb (n = 3). Only nutrias positive for C. myocastoris shed microscopically detectable oocysts, which measured 4.8-5.2 × 4.7-5.0 µm, and oocysts were infectious for experimentally infected nutrias with a prepatent period of 5-6 days, although not for mice, gerbils, or chickens. The infection was localised in jejunum and ileum without observable macroscopic changes. The microvilli adjacent to attached stages responded by elongating. Clinical signs were not observed in naturally or experimentally infected nutrias. Phylogenetic analyses at SSU, actin, and HSP70 loci demonstrated that C. myocastoris n. sp. is distinct from other valid Cryptosporidium species.

Molecular characterization of the waterborne pathogens Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi, Cyclospora cayetanensis and Eimeria spp. in wastewater and sewage in Guangzhou, China

Background

The waterborne pathogens Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi and Cyclospora cayetanensis can cause intestinal diseases in humans. An understanding of their occurrence and transport in the environment is essential for accurate quantitative microbial risk assessment.

Methods

A total of 238 influent samples were collected from four wastewater treatment plants (WWTPs) and 88 samples from eight sewer locations in Guangzhou, China. PCR-based tools were used to detect and genetically characterize Cryptosporidium spp., G. duodenalis and E. bieneusi. Eimeria spp. and Cyclospora spp. were also analyzed to assess the sources of Cryptosporidium spp., G. duodenalis and E. bieneusi in wastewater.

Results

The overall occurrence rates in the WWTP and sewer samples were 14.3% (34/238) and 13.6% (12/88) for Cryptosporidium spp., 55.5% (132/238) and 33.0% (29/88) for G. duodenalis, 56.3% (134/238) and 26.1% (23/88) for E. bieneusi and 45.4% (108/238) and 47.7% (42/88) for Eimeria spp., respectively. Altogether, 11 Cryptosporidium species and genotypes, six G. duodenalis genotypes, 11 E. bieneusi genotypes and four C. cayetanensis were found, together with the presence of nine Eimeria species. The common occurrence of Cryptosporidium rat genotype IV, C. muris and Eimeria papillata and E. nieschulzi suggested that rodents were significant sources of the enteric pathogens detected in the wastewater samples.

Conclusions

While the dominant Cryptosporidium spp. detected in the raw wastewater sampled in this study are not pathogenic to humans, the widely detected G. duodenalis assemblage A and E. bieneusi genotypes D and Type IV are well-known zoonotic pathogens. Further studies are needed to monitor the occurrence of these waterborne pathogens in WWTPs to better understand their transmission and environmental transport in China.

Cryptosporidium ratti n. sp. (Apicomplexa: Cryptosporidiidae) and genetic diversity of Cryptosporidium spp. in brown rats (Rattus norvegicus) in the Czech Republic

The diversity and biology of Cryptosporidium that is specific for rats (Rattus spp.) are not well studied. We examined the occurrence and genetic diversity of Cryptosporidium spp. in wild brown rats (Rattus norvegicus) by microscopy and polymerase chain reaction (PCR)/sequencing targeting the small subunit rDNA (SSU), actin and HSP70 genes. Out of 343 faecal samples tested, none were positive by microscopy and 55 were positive by PCR. Sequence analysis of SSU gene revealed the presence of Cryptosporidium muris (n = 4), C. andersoni (n = 3), C. ryanae (n = 1), C. occultus (n = 3), Cryptosporidium rat genotype I (n = 23), Cryptosporidium rat genotype IV (n = 16) and novel Cryptosporidium rat genotype V (n = 5). Spherical oocysts of Cryptosporidium rat genotype I obtained from naturally-infected rats, measuring 4.4-5.4 μm × 4.3-5.1 μm, were infectious to the laboratory rats, but not to the BALB/c mice (Mus musculus) nor Mongolian gerbils (Meriones unguiculatus). The prepatent period was 3 days post infection and the patent period was longer than 30 days. Naturally- and experimentally-infected rats showed no clinical signs of disease. Percentage of nucleotide similarities at the SSU, actin, HSP70 loci between C. ratti n. sp. and the rat derived C. occultus and Cryptosporidium rat genotype II, III, IV, and V ranged from 91.0 to 98.1%. These genetic variations were similar or greater than that observed between closely related species, i.e. C. parvum and C. erinacei (93.2-99.5%). Our morphological, genetic and biological data support the establishment of Cryptosporidium rat genotype I as a new species, Cryptosporidium ratti n. sp.

Cryptosporidium Genotyping for Epidemiology Tracking

Cryptosporidium genotyping has made significant contributions to the species structure and population genetics of Cryptosporidium spp. In addition, the standardized method has shown utility in epidemiologic investigations identifying case linkages and contamination sources that could not be determined with traditional epidemiologic tools. The standardized method for Cryptosporidium genotyping from stool specimens described here comprises multiple individual protocols to amplify and sequence regions of the SSU rRNA and gp60 genes of Cryptosporidium.

Molecular characterization of Cryptosporidium spp. from patients with diarrhoea in Lusaka, Zambia

Cryptosporidium is a major etiological agent of diarrhoeal diseases among children and immune-compromised individuals in sub-Saharan African countries. We conducted a study to determine the prevalence and genetic characteristics of Cryptosporidium spp. in stool samples from patients with diarrhoea who presented at the University Teaching Hospital in Lusaka, Zambia. Cryptosporidium species and subtypes from 71 microscopically confirmed cryptosporidiosis stool samples collected between 2017 and 2019 were determined by polymerase chain reaction followed by partial sequencing of the small subunit rRNA and 60-kDa glycoprotein (gp60) gene. Additionally, data for the period between 2014 and 2019 were reviewed and analysed for cryptosporidiosis seasonal and age distribution. Cryptosporidium was more prevalent in the rainy season. The highest number of cases was reported among the 1–4 year age group. By sequence analysis of the 71 positive isolates, Cryptosporidium hominis (n = 42; 59.2%), C. parvum (n = 27; 38%), C. felis (n = 1; 1.4%), and C. meleagridis (n = 1; 1.4%) were identified. Four C. hominis subtype families (Ia, Ib, Id, and Ie) and three C. parvum subtype families (IIc, IIe, and IIs) were identified. The most frequent subtypes were IeA11G3T3 (n = 20; 28.2%), IIcA5G3 (n = 12; 16.9%), IIeA12G1 (n = 11; 15.5%) and IaA30R3 (n = 10; 14.1%). The observed species/subtypes of C. hominis and C. parvum indicated that the infection was mainly transmitted through the anthroponotic route. The identification of C. felis and C. meleagridis suggests that an atypical zoonotic transmission cycle also exists.

Cryptosporidium Infections in Africa-How Important Is Zoonotic Transmission? A Review of the Evidence

Cryptosporidium, a protozoan parasite in the phylum Apicomplexa, is the etiological agent of cryptosporidiosis, an intestinal infection characterized by profuse watery diarrhea. Over 30 species of Cryptosporidium are recognized, some host specific whereas others infect a broader host range. Cryptosporidium hominis and Cryptosporidium parvum are the species most commonly associated with human infection; C. hominis is largely associated only with human infections, but C. parvum is also associated with infection in animals, especially young ruminants. In some regions, cryptosporidiosis is a serious veterinary problem, particularly for calves, and lambs. Many outbreaks of human cryptosporidiosis have been associated with zoonotic transmission following contact with infected animals. In Africa, where cryptosporidiosis is a major contributor to pediatric morbidity and mortality, evidence suggests transmission is principally anthroponotic. Given the frequent close contact between humans and animals in Africa, the apparent predominance of human-to-human transmission is both interesting and puzzling. In this article, after a brief "text book" introduction to the parasite, we consider in separate sections the different aspects of relevance to Cryptosporidium transmission in African countries, describing different aspects of the various species and subtypes in human and animal infections, considering livestock management practices in different African countries, and looking for any characteristic "hot spots" where zoonotic transmission has apparently occurred. Studies where transmission networks have been investigated are particularly relevant. Finally, in a separate section, we try to gather these different strands of evidence together in order to assess the reasons behind the apparent predominance of anthroponotic transmission in Africa. Reviewing the available evidence provides an opportunity to re-think transmission pathways, not only in Africa but also elsewhere, and also to pose questions. Does the predominance of human-to-human transmission in Africa reflect a relative absence of zoonotic C. parvum in African livestock? Are Africans less susceptible to zoonotic Cryptosporidium infection, perhaps resulting from early immunostimulation by C. hominis or due to inherent genetic traits? Is the African environment-in all its variety-simply more detrimental to oocyst survival? Will the so-called hypertransmissible subtypes, currently relatively rare in Africa, be introduced from Europe or elsewhere, and, if so, will they fade out or establish and spread? Our intention with this manuscript is not only to summarize and consolidate diverse data, thereby providing an overview of data gaps, but also to provide food for thought regarding transmission of a parasite that continues to have a considerable impact on both human and animal health.

Apicomplexan lineage-specific polytopic membrane proteins in Cryptosporidium parvum

Apicomplexans are a group of parasitic protozoans, including Plasmodium and Cryptosporidium species, which harbor a specialized organelle called an apicoplast. Of the 145-apicomplexan lineage-specific proteins identified in Cryptosporidium parvum, 30 are surface proteins. In Plasmodium falciparum, a heteromeric complex of three related apicomplexan lineage-specific membrane proteins containing 6 transmembrane domains (m6t) have been identified. These proteins are Pfm6t α, Pfm6t β, and Pfm6t γ and these proteins are localized on merozoite as an inner membrane complex (Rayavara et al. in Mol Biochem Parasitol 167(2):135-143, 2009). In C. parvum, homologs of these proteins are identified and are Cpm6t α, Cpm6t β, and Cpm6t γ. Mass spectrometric analysis of C. parvum (Iowa II) protein extracts of oocyst, sporozoite and soluble and insoluble fractions of cytoplasm identified the presence of Cpm6t α, Cpm6t β, and Cpm6t γ specific peptides in these fractions. The expression of Cpm6t α, Cpm6t β, and Cpm6t γ proteins on various developmental stages of C. parvum suggests that this novel group of apicomplexan lineage-specific proteins in Cryptosporidium may be involved in multiple cellular processes apart from the invasion into host epithelial cells as suggested for P. falciparum merozoites onto host erythrocytes.

Fungal and Parasitic Infections of the Liver

Hepatosplenic candidiasis and other fungal infections of the liver are uncommon in healthy individuals; however, high index of suspicion is essential in immunocompromised patients with prolonged fever. Parasitic infections are protozoan or helminthic; their distribution and epidemiology are variable among different world regions. Clonorchiasis, opisthorchiasis, fascioliasis, and ascariasis are helminthic infections that commonly involve the biliary systems. Signs and symptoms of cholangitis require prompt management to relieve biliary obstruction; addition of antihelminthic agents is essential. Parasitic infections are mostly transmitted to humans by fecally contaminated food and water. Proper hand and food sanitation measures are essential in preventing disease transmission.

Cryptosporidium hominis infections in non-human animal species: revisiting the concept of host specificity

Parasites in the genus Cryptosporidium, phylum Apicomplexa, are found worldwide in the intestinal tract of many vertebrate species and in the environment. Driven by sensitive PCR methods, and the availability of abundant sequence data and reference genomes, the taxonomic complexity of the genus has steadily increased; 38 species have been named to date. Due to its public health importance, Cryptosporidium hominis has long attracted the interest of the research community. This species was initially described as infectious to humans only. This perception has persisted in spite of an increasing number of observations of natural and experimental infections of animals with this species. Here we summarize and discuss this literature published since 2000 and conclude that the host range of C. hominis is broader than originally described. The evolving definition of the C. hominis host range raises interesting questions about host specificity and the evolution of Cryptosporidium parasites.

Cryptosporidiosis among solid organ transplant recipient attendees at a summer camp

We report a cluster of pediatric cryptosporidiosis infections among solid organ transplant recipients at a summer camp in Georgia, USA. A retrospective cohort study was conducted to investigate the risk factors for infection. A total of 118 campers attended the camp during July 23-28, 2017. The overall attack rate among campers during the outbreak was 11% (13/118). Sanger-based amplicon sequencing of stool specimens from 7 (80%) campers identified Cryptosporidium hominis as the suspected etiologic agent. All infected campers were heart or kidney transplant recipients receiving immunosuppressive therapy. The median reported symptom duration was 12 days (range 6-18 days) and 9 (69.2%) were hospitalized for at least one night (median length of stay 5 days, range 2-16 days). There were no deaths or acute rejection events attributed to infection. The results of the epidemiologic and environmental investigation suggest a recreational pool as the presumed source, although there was no direct evidence to support this. Many long-term interventions were implemented, and there have been no further outbreaks at the camp in the following two years. This outbreak demonstrates that cryptosporidiosis may be associated with notable burden in pediatric transplant recipients, and illustrates the challenges associated with source identification and containment.

Checklist of marine mammal parasites in New Zealand and Australian waters

Marine mammals are long-lived top predators with vagile lifestyles, which often inhabit remote environments. This is especially relevant in the oceanic waters around New Zealand and Australia where cetaceans and pinnipeds are considered as vulnerable and often endangered due to anthropogenic impacts on their habitat. Parasitism is ubiquitous in wildlife, and prevalence of parasitic infections as well as emerging diseases can be valuable bioindicators of the ecology and health of marine mammals. Collecting information about parasite diversity in marine mammals will provide a crucial baseline for assessing their impact on host and ecosystem ecology. New studies on marine mammals in New Zealand and Australian waters have recently added to our knowledge of parasite prevalence, life cycles and taxonomic relationships in the Australasian region, and justify a first host-parasite checklist encompassing all available data. The present checklist comprises 36 species of marine mammals, and 114 species of parasites (helminths, arthropods and protozoans). Mammal species occurring in New Zealand and Australian waters but not included in the checklist represent gaps in our knowledge. The checklist thus serves both as a guide for what information is lacking, as well as a practical resource for scientists working on the ecology and conservation of marine mammals.

NMR metabolomics reveals effects of Cryptosporidium infections on host cell metabolome

Background

Cryptosporidium is an important gut microbe whose contributions towards infant and immunocompromise patient mortality rates are steadily increasing. Over the last decade, we have seen the development of various tools and methods for studying Cryptosporidium infection and its interactions with their hosts. One area that is sorely overlooked is the effect infection has on host metabolic processes.

Results

Using a ¹H nuclear magnetic resonance approach to metabolomics, we have explored the nature of the mouse gut metabolome as well as providing the first insight into the metabolome of an infected cell line. Statistical analysis and predictive modelling demonstrated new understandings of the effects of a Cryptosporidium infection, while verifying the presence of known metabolic changes. Of note is the potential contribution of host derived taurine to the diarrhoeal aspects of the disease previously attributed to a solely parasite-based alteration of the gut environment, in addition to other metabolites involved with host cell catabolism.

Conclusion

This approach will spearhead our understanding of the Cryptosporidium-host metabolic exchange and provide novel targets for tackling this deadly parasite.

A protocol to count Cryptosporidium oocysts by flow cytometry without antibody staining

Cryptosporidiosis caused by the protozoan parasites Cryptosporidium hominis and C. parvum, threatens the lives of young children in developing countries. In veterinary medicine, C. parvum causes life-threatening diarrhea and dehydration in newborn dairy calves. Protocols to detect Cryptosporidium spp. oocysts using flow cytometry have been reported; however, these protocols use antibodies against the parasite and typically focus on detection of oocysts, not quantification. These techniques are not well-suited for studies that generate large variations in oocyst burdens because the amount of antibody required is proportional to the number of oocysts expected in samples. Also, oocysts are lost in washes in the staining protocol, reducing accuracy of oocyst counts. Moreover, these protocols require costly fluorochrome-conjugated monoclonal antibodies and are not optimal for studies involving large numbers of samples. Here we present an optimized protocol for purifying oocysts from mouse stool and intestine samples combined with a reliable method to quantify oocysts in a relatively pure population without the need for antibody staining. We used morphology (SSC-A vs FSC-A) and the innate characteristics of C. parvum oocysts compared to fecal and intestinal contaminants to develop a two-step gating strategy that can differentiate oocysts from debris. This method is a fast, reliable, and high-throughput technique to promote research projects on C. parvum infections in mice and potentially other animal hosts.

Diarrheal diseases are the second leading cause of death in children < 5 years old. Cryptosporidiosis caused by the unicellular parasite Cryptosporidium spp. is one of these diarrheal diseases. C. hominis and C. parvum cause moderate-to-severe diarrhea and dehydration that threaten the lives of young children in developing countries. Flow cytometry is a state-of-the-art technique to detect Cryptosporidium spp. oocysts, the infectious form of the parasite. Reported protocols typically focus on detection of oocysts using antibody staining. However, these techniques present several complications: oocysts are lost in washes used in the staining protocol and the amount of antibody required is proportional to the number of oocysts expected in samples; thus, parasite burden needs first to be estimated by optical microscopy. In addition, these protocols require costly antibodies. We developed a reliable method to quantify Cryptosporidium spp. oocysts in a relatively pure population without the need for antibody staining. We used known characteristics of the structure of oocysts to develop a strategy that can differentiate oocysts from debris. This method is fast, affordable and reliable and will facilitate pre-clinical projects on interventions to treat or prevent Cryptosporidium spp. infection.

First report and molecular characterization of Cryptosporidium spp. in humans and animals in Khartoum state, Sudan

BACKGROUND AND AIM

Cryptosporidium is recognized to infect several mammalian species as well as humans, causing substantial economic losses and serious public health concern. Infected animals can be a source of environmental contamination and human infections. In general, the occurrence of Cryptosporidium species in animals and human in Sudan and zoonotic importance is not well documented. This study aimed to identify Cryptosporidium spp. infecting different animal species and humans and to compare between different isolates obtained.

MATERIALS AND METHODS

To provide molecular information about Cryptosporidium in animals and humans, both modified Ziehl-Neelsen (MZN) specific stain and molecular assay were used. Concentration techniques followed by three protocols of DNA extraction were carried out. After microscopic screening of 263 fecal samples (goats [n=197], cattle [n=12], sheep [n=12], and human [n=42]), 61 positive and 30 negative, randomly selected samples were used in nested polymerase chain reaction (PCR) targeting part of the 18S RNA.

RESULTS

Nested PCR amplification confirmed 91.8% (56/61) of microscopic-positive samples. 8.2% (5/61) of negative samples by PCR (positive by microscopy) were considered false negatives. Sequencing followed by alignment of the 14 isolates indicated that all samples were identical (100%) and belonged to Cryptosporidium parvum.

CONCLUSION

MZN staining procedure is reliable for the routine diagnosis of Cryptosporidium; cetyltrimethylammonium bromide extraction buffer and nested PCR targeting 18S rRNA gene are reliable and useful in epidemiological studies of this parasite.

Development and evaluation of the first immunochromatographic test that can detect specific antibodies against Cryptosporidium parvum

Cryptosporidium parvum is a major cause of diarrhea among human and calves, resulting in severe health hazards and drastic economic losses, respectively. Although C. parvum infection leads to high morbidity and mortality in immunocompromised patients and bovine calves, this infection remains a neglected disease. Currently available diagnostic tests for C. parvum are primarily based on detection of oocysts, DNA, or secreted antigens in fecal specimens. Demonstration of specific antibodies with a rapid immunochromatographic test (ICT) will be advantageous not only in providing a simple, rapid, accurate, and affordable tool but also in surveillance because of the ability to recognize recent and past infections. Herein, we developed two ICTs using the diagnostic antigen CpP23 and immunodominant antigen CpGP15 to detect C. parvum-specific antibodies in cattle sera. Because of unavailability of a reference test for antibody detection, evaluation and validation of our developed ICTs were conducted using reference cattle samples and unknown field cattle sera. Serum samples were simultaneously tested by a previously validated enzyme-linked immunosorbent assay (ELISA) using the same antigens (CpGP15 and CpP23). ICTs showed substantial ability to discriminate between positive and negative control cattle sera for both CpGP15 and CpP23. Even against field sera, high sensitivity, specificity, and agreement rates were recorded for ICTs compared with the previously validated ELISA with the same antigens (CpGP15 = 78.78%, 100%, and 85.11%; CpP23 = 80%, 100%, and 80.56%, respectively). Moreover, a high correlation was observed between the test band intensity of ICTs and optical density of ELISA, particularly in the case of CpP23-specific IgM. To our knowledge, this study represents the first development of ICTs that can detect C. parvum-specific antibodies. Our tests will contribute greatly to C. parvum infection control in cattle by providing a method for on-site diagnosis of early and latent infections.

Genomics and molecular epidemiology of Cryptosporidium species

Cryptosporidium is one of the most widespread protozoan parasites that infects domestic and wild animals and is considered the second major cause of diarrhea and death in children after rotavirus. So far, around 20 distinct species are known to cause severe to moderate infections in humans, of which Cryptosporidium hominis and Cryptosporidium parvum are the major causative agents. Currently, ssurRNA and gp60 are used as the optimal markers for differentiating species and subtypes respectively. Over the last decade, diagnostic tools to detect and differentiate Cryptosporidium species at the genotype and subtype level have improved, but our understanding of the zoonotic and anthroponotic transmission potential of each species is less clear, largely because of the paucity of high resolution whole genome sequencing data for the different species. Defining which species possess an anthroponotic vs. zoonotic transmission cycle is critical if we are to limit the spread of disease between animals and humans. Likewise, it is unclear to what extent genetic hybridization impacts disease potential or the emergence of outbreak strains. The development of high resolution genetic markers and whole genome sequencing of different species should provide new insights into these knowledge gaps. The aim of this review is to outline currently available molecular epidemiology and genomics data for different species of Cryptosporidium.

DETECTION OF WATER-BORNE PARASITES IN DRINKING WATER OF BAGHDAD, IRAQ

Background:

Within the past few decades, there has been an increase in the number of water-borne disease outbreaks and emergence of newly recognized waterborne parasites. Several factors which contribute to the spread of these diseases include: water, heavy rains and agricultural residues which transfer the parasites to water surface from the soil. The aim of this study was to detect the presence of parasites in the river and drinking water of Al-Wahdaa and Al-Rasheed Drinking Project and household water tanks from some regions of Baghdad.

Method:

Forty samples were collected from river and drinking water of Drinking Project. Fifty four samples of household water tanks were collected from some regions of Baghdad.

Results:

Cryptosporidium oocyst, which was founded in river water samples are more than those in drinking water. Furthermore, it was existed in Diyala Bridge &Taha Mosque from April – August and oocyst was diagnosed by using of Zheil-Neelson. Wet mount slide method was applied to detect cysts of free-living amoeba Acanthomoeba, Naegleria. The number of cysts in July and August were higher than other months for Drinking Project and the water tanks for all regions.

Conclusion:

These results emphasize the importance screening of the water to prevent possible of the spread of parasitic protozoan and that the cracks occurrence in drinking water pipes between the stations and houses led to contamination of water with the infective stage of parasites, especially in the areas that are near agricultural fields which polluted with the cows’ waste.

Common occurrence of Cryptosporidium hominis in asymptomatic and symptomatic calves in France

BACKGROUND

Cryptosporidium spp. infections are the most frequent parasitic cause of diarrhea in humans and cattle. However, asymptomatic cases are less often documented than symptomatic cases or cases with experimentally infected animals. Cryptosporidium (C.) hominis infection accounts for the majority of pediatric cases in several countries, while C. parvum is a major cause of diarrhea in neonatal calves. In cattle Cryptosporidium spp. infection can be caused by C. parvum, C. bovis, C.andersoni and C. ryanae, and recently, reports of cattle cases of C. hominis cryptosporidiosis cases suggest that the presence of C. hominis in calves was previously underestimated.

METHODOLOGY/PRINCIPAL FINDINGS

From February to November 2015, Cryptosporidium spp. infected calves were detected in 29/44 randomly included farms from 5 geographic regions of France. C. hominis and C. parvum were found in 12/44 and 26/44 farms, respectively with higher C. hominis prevalence in the western region. In 9 farms, both C. parvum and C. hominis were detected. Eighty-six of 412 (73/342 asymptomatic and 13/70 symptomatic) one to nine-week-old calves shed C. hominis or C. parvum oocysts (15 and 71 calves, respectively), with no mixed infection detected. The predominant C. hominis IbA9G3 genotype was present in all regions, and more frequent in the western region. An incompletely characterized Ib, and the IbA13G3, IbA9G2 and IbA14G2 genotypes were present only in the western region. For C. parvum, the most frequent genotype was IIaA16G3R1 with no geographic clustering. Most C. hominis infected calves were asymptomatic, with some exceptions of IbA9G2 and IbA9G3 isolates, while C. parvum IIaA16G3R1 was associated with symptoms.

CONCLUSIONS/SIGNIFICANCE

Present results indicate for the first time that in several geographic regions of France, C. hominis was present in about one fifth of both asymptomatic and symptomatic infected calves, with isolated genotypes likely associated with human infection. Further investigations are aimed at documenting direct or indirect transmissions between livestock and humans.

An advanced uracil DNA glycosylase-supplemented loop-mediated isothermal amplification (UDG-LAMP) technique used in the sensitive and specific detection of Cryptosporidium parvum, Cryptosporidium hominis, and Cryptosporidium meleagridis in AIDS patients

The rapid and accurate detection of Cryptosporidium spp. is critically important for the prevention and timely treatment of cryptosporidiosis in AIDS patients (APs). This study was conducted to examine a UDG-LAMP technique for the first time to diagnose cryptosporidiosis in APs. After collecting demographic and clinical data, three stool samples were collected from the participants (120 volunteering APs). The microscopic examination of stained smears using the acid-fast method and the UDG-LAMP assay were performed for each sample. 10% of APs were infected with Cryptosporidium spp. The number of detected cryptosporidiosis cases using the acid-fast staining and UDG-LAMP methods were significantly different (P < 0.001). Diarrhea and weight loss were found to be significantly associated with cryptosporidiosis in patients (P < 0.05). The pretreatment of LAMP reagents with UDG successfully eliminated the likelihood of product re-amplification remaining from previous reactions. The UDG-LAMP technique could detect cryptosporidiosis in APs with high sensitivity and rapidity without carryover contamination.

DNA barcoding of Cryptosporidium

Cryptosporidium spp. (Apicomplexa) causing cryptosporidiosis are of medical and veterinary significance. The genus Cryptosporidium has benefited from the application of what is considered a DNA-barcoding approach, even before the term 'DNA barcoding' was formally coined. Here, the objective to define the DNA barcode diversity of Cryptosporidium infecting mammals is reviewed and considered to be accomplished. Within the Cryptosporidium literature, the distinction between DNA barcoding and DNA taxonomy is indistinct. DNA barcoding and DNA taxonomy are examined using the latest additions to the growing spectrum of named Cryptosporidium species and within-species and between-species identity is revisited. Ease and availability of whole-genome DNA sequencing of the relatively small Cryptosporidium genome offer an initial perspective on the intra-host diversity. The opportunity emerges to apply a metagenomic approach to purified field/clinical Cryptosporidum isolates. The outstanding question remains a reliable definition of Cryptosporidium phenotype. The complementary experimental infections and metagenome approach will need to be applied simultaneously to address Cryptosporidium phenotype with carefully chosen clinical evaluations enabling identification of virulence factors.

Foodborne cryptosporidiosis

Foodborne illness, the majority of which is caused by enteric infectious agents, costs global economies billions of dollars each year. The protozoan parasite Cryptosporidium is particularly suited to foodborne transmission and is responsible for >8 million cases of foodborne illness annually. Procedures have been developed for sensitive detection of Cryptosporidium oocysts on fresh produce and molecular diagnostic assays have been widely used in case linkages and infection source tracking, especially during outbreak investigations. The integrated use of advanced diagnostic techniques with conventional epidemiological studies is essential to improve our understanding of the occurrence, source and epidemiology of foodborne cryptosporidiosis. The implementation of food safety management tools such as Good Hygienic Practices (GHP), Hazard Analysis and Critical Control Points (HACCP), and Quantitative Microbial Risk Assessment (QMRA) in industrialised nations and Water, Sanitation, and Hygiene (WASH) in developing countries is central for prevention and control and foodborne cryptosporidiosis in the future.

Molecular investigation of Cryptosporidium and Giardia in pre- and post-weaned calves in Hubei Province, China

Background

The protistan pathogens Cryptosporidium and Giardia can cause significant intestinal diseases in animals and humans. Cattle, particularly calves, carrying these protists can be significant reservoirs for human infections and disease. However, little is known about the genetic make-up of Cryptosporidium and Giardia populations in cattle and other ruminants in some regions of China.

Results

In the present study, PCR-based tools were used to genetically characterise these protists in faecal samples from a total of 339 pre- and post-weaned calves from four distinct locations in Hubei Province using markers in the large (LSU) or small (SSU) subunits of nuclear ribosomal RNA genes. Cryptosporidium andersoni, C. bovis, C. ryanae and Giardia duodenalis assemblage E were detected in 0.6%, 10.9%, 4.1% and 22.6% of calves, respectively.

Conclusions

This study is the first to report the prevalence of Cryptosporidium and Giardia in pre- and post-weaned calves in Hubei Province, and encourages large-scale molecular studies of animals and humans, in an effort to better understand the epidemiology of these enteric pathogens in China.

Electronic supplementary material

The online version of this article (10.1186/s13071-017-2463-3) contains supplementary material, which is available to authorized users.

Rodents as a reservoir of infection caused by multiple zoonotic species/genotypes of C. parvum, C. hominis, C. suis, C. scrofarum, and the first evidence of C. muskrat genotypes I and II of rodents in Europe

Cryptosporidium spp. is an important causative agent of intestinal parasitoses-induced diarrhoea in humans and animals worldwide. Rodents (small mammals), the main reservoir of infections, are globally expanded and overpopulated, which increases the risk of transfer of human and zoonotic pathogens from the genus Cryptosporidium. In this study, Cryptosporidium was detected in wild immunocompetent asymptomatic small mammals. Altogether 262 fecal samples were collected from five areas in Eastern Slovakia from four different rodent species (Myodes glareolus, Apodemus agrarius, Apodemus flavicollis, Rattus norvegicus), eight samples originated from two insectivore species (Sorex araneus, Crocidura suaveolens), and two sample from a carnivore Mustela nivalis. The samples were examined using a method modified in our laboratory, based on the use of specific primers on a small subunit rRNA (18S rRNA) gene for species identification, and amplification of GP60 gene coding 60-kDa glycoprotein for genotype determination. The following species were identified: Cryptosporidium parvum (n=15), genotypes IIaA18G3R1 (n=11; KU311673), IIaA10G1R1 (n=1; KU311670), IIcA5G3a (n=1; KU311669), IIiA10 (n=2; KU311672); Cryptosporidium suis (n=4; KU311671); Cryptosporidium scrofarum (n=28); Cryptosporidium environment sp. (n=12; KU311677); Cryptosporidium muskrat genotype I (n=3; KU311675); Cryptosporidium muskrat genotype II (n=3; KU311676). From one of the rodent, the species Cryptosporidium hominis genotype IbA10G2 (KU311668) was identified for the first time. The results of this study indicate low host specificity of the detected Cryptosporidium species and imply the importance of free-living small mammals in urban and suburban habitats as a potential source of human cryptosporidiosis.

Cryptosporidium and Giardia Infections in Children: A Review

Diarrheal disease remains the second leading cause of mortality in children in developing countries. Cryptosporidium is a leading cause and its importance stands to increase as rotavirus vaccine becomes used around the world. Cryptosporidium is particularly problematic in children younger than 2 years old and in the immunocompromised. Giardia lamblia is a common intestinal protozoan that is associated with diarrhea and, perhaps, growth faltering in impoverished settings. This review establishes the current prevalence of these infections in global settings and reviews current diagnosis and management approaches.

Cryptosporidium: Identification and Genetic Typing

Cryptosporidium spp. are obligate protozoan parasites of the gastrointestinal tract of vertebrates, including humans. In the majority of human cases, the diarrheal disease cryptosporidiosis is caused by either the human-adapted species Cryptosporidium hominis or the zoonotic Cryptosporidium parvum 'bovine genotype' (also known as Cryptosporidium pestis). The infectious stage, environmentally resilient Cryptosporidium oocysts, are shed by the infected host. Cryptosporidium parasites are transmitted by the fecal-oral route and are one of the major water-borne pathogens. The cryptic nature of the microscopic Cryptosporidium oocysts coupled with the existence of several host-adapted and zoonotic species requires molecular tools to identify Cryptosporidium spp. in either fecal or environmental samples. This unit describes methods for Cryptosporidium identification and typing using genotyping based on nuclear loci. We also provide a protocol for morphological confirmation of Cryptosporidium oocysts based on antibody labeling of the Cryptosporidium oocyst wall and a protocol for purification of oocysts from fecal material. © 2017 by John Wiley & Sons, Inc.

Surgical Pathologic Diagnosis

Surgical pathology results can play a crucial role in the management of immunocompromised patients. Here we highlight factors that differ between immunocompromised and immunocompetent hosts, such as variation in inflammatory response. Conditions that are covered include drug reactions, disease within solid organ allografts, immune reconstitution inflammatory syndrome, specific immunodeficiency syndromes, neoplasms related to viral infections, and viral, bacterial, fungal, and parasitic infections. Special techniques including immunohistochemistry, in situ hybridization and molecular detection of pathogen nucleic acid from formalin-fixed, paraffin-embedded tissue are discussed.