Cryptosporidium proliferans n. sp. (Apicomplexa: Cryptosporidiidae): Molecular and Biological Evidence of Cryptic Species within Gastric Cryptosporidium of Mammals

Waterborne protozoan and microsporidian parasites in Eurasian beavers (Castor fiber)

The Eurasian beaver (Castor fiber) is an expanding species in Europe in recent decades due to reintroductions and natural population growth. Beavers expanded rapidly in the second half of the 20th century, and their expansion was particularly rapid in the Danube basin. Nowadays, the majority of the continuous population located in the central and eastern parts of the continent and a large disjunct population in Norway and Sweden. Despite the increasing population size, the role of the beaver as a source of waterborne pathogens is not firmly established or is often inferred from circumstantial data. In order to extend knowledge about the composition of the parasite fauna of beavers occurring in Slovakia, 21 faecal samples taken near their burrows from three sites (located in the Topľa, Poprad and Danube river basin) were examined microscopically and by polymerase chain reaction (PCR). PCR-positive specimens were further examined by DNA sequencing. Parasites were detected in 21% of the examined beavers, specifically the protozoa Cryptosporidium spp. (n = 2), Blastocystis sp. (n = 1), and microsporidia Enterocytozoon bieneusi (n = 1) and Encephalitozoon spp. (n = 1). Using the sequence analysis, two variants of Cryptosporidium proliferans, a new subtype of Blastocystis sp., genotype D of E. bieneusi and Encephalitozoon intestinalis were identified. A putatively novel Blastocystis subtype (ST), originated from a site near the Danube river (southwestern Slovakia), was proposed based on high genetic divergence from the closest described subtype ST12 (11.9%) and unique phylogenetic position in a clade composed of ST's 35-38. The increased risk of zoonotic transmission or transmission to other animals was particularly evident in the site near the Topľa river (northeastern Slovakia), where fungal spores of zoonotic genotype D of E. bieneusi and E. intestinalis, together with oocysts of the potentially zoonotic C. proliferans, were found.

Molecular characterization and zoonotic risk assessment of Cryptosporidium spp. in Philippine bats

Cryptosporidium is a genus of parasitic protozoa known to cause diarrheal disease that impacts both humans and animals through infection of various vertebrate species. Bats are recognized as reservoirs for zoonotic pathogens, including Cryptosporidium. The Philippines, renowned for its rich biodiversity, is home to diverse bat species, providing a unique ecological setting to investigate Cryptosporidium infection dynamics. Understanding the prevalence and genetic diversity of Cryptosporidium in Philippine bats is crucial for assessing their potential role in zoonotic disease transmission and associated public health risks. We investigated the prevalence and genotypic diversity of Cryptosporidium in bats in the Philippines. From January 2019 to March 2024, a total of 569 bats were captured and analyzed, with 14 of the bat samples testing positive for the 18 s rRNA gene of Cryptosporidium, yielding an overall infection rate of 2.46 %. One sample exhibited co-infection, with 18 s rRNA sequence analysis indicating mixed infection with a species closely related to Cryptosporidium parvum (intestinal Cryptosporidium) and Cryptosporidium sp. (gastric Cryptosporidium). Phylogenetic analysis of the 18S rRNA gene revealed that intestinal and gastric Cryptosporidium spp. form two distinct clades. Intestinal Cryptosporidium includes C. parvum, C. hominis, and most bat genotypes, while gastric Cryptosporidium, such as C. andersoni and C. serpentis, is typically found in reptiles and cattle. An unidentified Cryptosporidium species was also detected in one sample, whose sequence matched that of Cryptosporidium previously isolated from a human patient with diarrhea. Nine other samples exhibited genotypes related to C. parvum, indicating a potential for transmission to humans. The remaining three samples exhibited Cryptosporidium bat genotypes II and VI, which have previously been detected in Philippine bats. Our findings underscore the role of bats in the Philippines as potential reservoirs for Cryptosporidium and highlight the diversity of Cryptosporidium species in Philippine bats.

Molecular detection of Cryptosporidium parvum in wild rodents (Phyllotis darwini) inhabiting protected and rural transitional areas in north-central Chile

Wild rodents often harbor Cryptosporidium species that can be transmitted to multiple mammal hosts. In Chile, little is known about Cryptosporidium in wild rodents, and available studies have been focused on morphological findings with no molecular-based evidence. A longitudinal survey was conducted between 2021 and 2022 to investigate the occurrence of Cryptosporidium spp. in populations of the Darwin's leaf-eared mouse (Phyllotis darwini) living in protected and rural transitional areas in north-central Chile, using staining and molecular methods. A total of 247 fecal samples were collected and examined by the modified Ziehl-Neelsen (ZN) staining test, 54 of which were positive for Cryptosporidium-like oocysts. Molecular analyses were carried out by PCR of the partial 18S ribosomal RNA and 60 kDa glycoprotein (gp60) genes. Cryptosporidium infection was confirmed in 34 samples (13.7 %) based on the PCR amplification, and individual (i.e., sex, and body mass index) and ecological variables (i.e., type of site and season) were not statistically significant (p > 0.05). Using the nucleotide sequencing of the partial 18S rRNA gene, Cryptosporidium parvum was identified in nine isolates. Also, C. parvum subgenotype family IIa was determined in seven samples by the partial gp60 gene, including the subtype IIaA17G4R1 in two samples. This is the first molecular evidence of Cryptosporidium parvum IIa in Phyllotis darwini in Chile. These results indicate potential cross-species transmition between wild rodents and domestic-wild animals in north-central Chile. More research is needed to understand better the role of wild rodents in the transmission of Cryptosporidium spp. in Chile.

Critters and contamination: Zoonotic protozoans in urban rodents and water quality

Rodents represent the single largest group within mammals and host a diverse array of zoonotic pathogens. Urbanisation impacts wild mammals, including rodents, leading to habitat loss but also providing new resources. Urban-adapted (synanthropic) rodents, such as the brown rat (R. norvegicus), black rat (R. rattus), and house mouse (Mus musculus), have long successfully adapted to living close to humans and are known carriers of zoonotic pathogens. Two important enteric, zoonotic protozoan parasites, carried by rodents, include Cryptosporidium and Giardia. Their environmental stages (oocysts/cysts), released in faeces, can contaminate surface and wastewaters, are resistant to common drinking water disinfectants and can cause water-borne related gastritis outbreaks. At least 48 species of Cryptosporidium have been described, with C. hominis and C. parvum responsible for the majority of human infections, while Giardia duodenalis assemblages A and B are the main human-infectious assemblages. Molecular characterisation is crucial to assess the public health risk linked to rodent-related water contamination due to morphological overlap between species. This review explores the global molecular diversity of these parasites in rodents, with a focus on evaluating the zoonotic risk from contamination of water and wasterwater with Cryptosporidium and Giardia oocysts/cysts from synanthropic rodents. Analysis indicates that while zoonotic Cryptosporidium and Giardia are prevalent in farmed and pet rodents, host-specific Cryptosporidium and Giardia species dominate in urban adapted rodents, and therefore the risks posed by these rodents in the transmission of zoonotic Cryptosporidium and Giardia are relatively low. Many knowledge gaps remain however, and therefore understanding the intricate dynamics of these parasites in rodent populations is essential for managing their impact on human health and water quality. This knowledge can inform strategies to reduce disease transmission and ensure safe drinking water in urban and peri‑urban areas.

Micro-RNA expression profile of BALB/c mouse glandular stomach in the early phase of Cryptosporidium muris infection

Cryptosporidiosis is a zoonotic disease in humans and animals that is caused by infection with the oocysts of Cryptosporidium. MicroRNAs (miRNAs) are important players in regulating the innate immune response against parasitic infection. Public miRNAs data for studying pathogenic mechanisms of cryptosporidiosis, particularly in natural hosts, are scarce. Here, we compared miRNA profiles of the glandular stomach of C. muris-infected and uninfected BALB/c mice using microarray sequencing. A total of 10 miRNAs (including 3 upregulated and 7 downregulated miRNAs) with significant differential expression (|FC| ≥ 2 and P value < 0.05) were identified in the glandular stomach of BALB/c mice 8 h after infection with C. muris. MiRWalk and miRDB online bioinformatics tools were used to predict the target genes of differentially expressed miRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to annotate the target genes. GO analysis indicate that gene transcription-related and ion transport-related GO terms were significantly enriched. In addition, the KEGG analyses showed that the target genes were strongly related to diverse types of tumor disease progression and anti-pathogen immunity pathways. In the current study, we firstly report changes in miRNA expression profiles in the glandular stomach of BALB/c mice at the early phase of C. muris invasion. This dysregulation in miRNA expression may contribute to our understanding of cryptosporidiosis pathology. This study provides a new perspective on the miRNA regulatory mechanisms of cryptosporidiosis, which may help in the development of effective control strategies against this pathogen.

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.

Molecular characterization of Cryptosporidium spp., Enterocytozoon bieneusi and Giardia duodenalis in laboratory rodents in China

Cryptosporidium spp., Enterocytozoon bieneusi and Giardia duodenalis are significant zoonotic intestinal pathogens that can cause gastrointestinal symptoms such as diarrhea and induce a host immune response. A total of 1237 fecal samples were collected from laboratory rodents (rats, mice and guinea pigs) from four different locations in China to investigate the infection rates and molecular characterization of these pathogens on experimental animals. Genomic DNA was extracted from each sample, and PCR amplifications were done. Overall, the Cryptosporidium spp. infection rate was 3.8% (47/1237). Four known Cryptosporidium species were identified, namely C. parvum, C. muris, C. tyzzeri and C. homai, the three former being zoonotic species. The overall E. bieneusi infection rate was 3.0% (37/1237). Seven known E. bieneusi genotypes, namely S7, BEB6, J, Henan-IV, CHG10, D and WL6, were detected by sequence analysis. Among these, genotypes D, Henan-IV and CHG10 have a high zoonotic risk. Giardia duodenalis was not detected at any of the three loci (SSU rRNA, bg and gdh) after PCR amplification. This study provides basic data for these pathogens in laboratory rodents in China and lays the foundation for their prevention and control in laboratory animals.

Molecular detection and genetic characteristics of Cryptosporidium spp. in Chinese racehorses

BACKGROUND

Cryptosporidium is a protozoan parasite causing diarrhoea in humans and animals. Although Cryptosporidium has been found in domestic horses (farmed or kept at pasture), there has been only one published study of Cryptosporidium infections in Chinese racehorses, which was restricted to a very small geographical area.

OBJECTIVES

To investigate the presence of Cryptosporidium spp. in the faeces of racehorses in China and to perform molecular characterisation of the parasite.

STUDY DESIGN

Cross-sectional.

METHODS

A total of 621 fresh faecal samples were collected for DNA extraction from racehorses at 17 equestrian clubs from 12 provinces of China from December 2016 to May 2018. All the DNA were analysed for the presence of Cryptosporidium species/genotypes and subtypes by PCR amplification of the small subunit ribosomal RNA and 60 kDa glycoprotein genes, respectively.

RESULTS

PCR analysis revealed that 11 samples (1.8%) were positive for Cryptosporidium spp. Among them 7 samples were identified as C. parvum and 4 were C. hominis. The C. parvum isolates were identified as subtype IIdA14G1 (n = 4) and IIdA15G1 (n = 3), while all C. hominis isolates were identified as subtype IkA18G1 (n = 4).

MAIN LIMITATIONS

A single faecal sample from each horse was used instead of multiple samples that could improve the detection rates of the parasite.

CONCLUSIONS

Although Cryptosporidium infection rate was relatively low in the investigated racehorses, the presence of zoonotic subtypes IIdA14G and 1IIdA15G1 of C. parvum and IkA18G1 of C. hominis, suggesting that these animals are a potential source of Cryptosporidium in humans.

Cryptosporidium: Still Open Scenarios

Cryptosporidiosis is increasingly identified as a leading cause of childhood diarrhea and malnutrition in both low-income and high-income countries. The strong impact on public health in epidemic scenarios makes it increasingly essential to identify the sources of infection and understand the transmission routes in order to apply the right prevention or treatment protocols. The objective of this literature review was to present an overview of the current state of human cryptosporidiosis, reviewing risk factors, discussing advances in the drug treatment and epidemiology, and emphasizing the need to identify a government system for reporting diagnosed cases, hitherto undervalued.

Diagnosis, risk factors analysis and first molecular characterization of Cryptosporidium spp. in horses from Rio de Janeiro, Brazil

An analysis was made of the frequency of Cryptosporidium spp. in fecal samples from horses raised on farms in the Teresópolis city, state of Rio de Janeiro, Brazil, and the risk factors that favored this infection. Between 2019 and 2020, 314 samples of equine feces were collected, 287 of which came from English Thoroughbred horses and 27 from ponies. Information on the horses and their management were retrieved from a stud book and forms filled out by trainers. The fecal samples were subjected to macroscopic analysis, modified Sheather's and Lutz parasitological techniques, safranin staining, and to enzyme-linked immunosorbent assay (ELISA) for the detection of coproantigens. All the samples that tested positive by these techniques underwent partial sequence analysis of the 18S rRNA gene to characterize the protozoan species. Cryptosporidium spp. was identified in 35 (11.1%) of the samples, 34 from English Thoroughbred horses and one from a pony. Based on a logistic regression model, it was found that the presence of dogs and small ruminants on the farms, and drinking water from a spring, were significantly associated with the animals' infection by the protozoan (p < 0.05). Eight of the English Thoroughbred horse samples underwent molecular characterization, which revealed the presence of Cryptosporidium felis in one sample and Cryptosporidium parvum in seven. The seven samples containing C. parvum were subjected to gp60 gene analysis, based on which nucleotide sequences typical of the IIa family were identified, which are usually transmitted from animals to humans. In addition, the genotype IIaA15G2R1, which is considered to have the highest profile of zoonotic transmissibility, was identified in one Thoroughbred horse. This is the first study conducted in the state of Rio de Janeiro that molecularly characterized Cryptosporidium spp. in horses, and the first on the American continent to detect C. felis in the feces of these animals.

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.

FIRST REPORT OF GENUS Cryptosporidium IN CERVIDS SPECIES: Mazama americana, Mazama nana AND Blastocerus dichotomus

We analyzed Cryptosporidium spp. in fecal samples of wild cervids (Ozotoceros bezoarticus, Blastocerus dichotomus, Mazama nana, Mazama americana, and Mazama bororo) from many Brazilian regions, a fact unprecedented in the literature. Sniffer dogs were used to collect 936 fecal samples of cervids from 14 Brazilian localities. Cervids species were identified using polymerase chain reaction (PCR) performed from genomic DNA extracted from 563 fecal samples of Ozotoceros bezoarticus, Blastocerus dichotomus, Mazama nana, Mazama americana, and Mazama bororo. Cryptosporidium spp. oocyst screening was performed using malachite green negative staining. Nested PCR (nPCR) protocols targeting the 18S rRNA and GP60 genes followed by genetic sequencing were performed for Cryptosporidium spp. detection and Cryptosporidium parvum subtyping, respectively. Nested PCR targeting actin gene and genetic sequencing were performed in samples with non-identified Cryptosporidium species by 18S rRNA amplicon sequencing. The association between the occurrence of Cryptosporidium and the presence of bovines in the same locality was evaluated using Fisher's exact test. The positivity rates of diagnostic methods were compared by McNemar test and the Kappa correlation coefficient. The prevalence rates of Cryptosporidium spp. in cervids were 1.42% (8/563) and 0.36% (2/563) by nPCR and malachite green negative staining, respectively. C. parvum IIaA16G3R1 isolate was identified in three fecal samples from M. americana, two from M. nana and one from B. dichotomus. Cryptosporidium ryanae were found in one sample from B. dichotomus. We identified a new Cryptosporidium genotype, named Cryptosporidium deer genotype BR, from one M. americana fecal sample.

Exploration of Zoo felids in North-East China for the prevalence and molecular identification of Cryptosporidium spp

Cryptosporidium spp. is a protozoan having the potential to cause zoonosis in humans and animals. Despite the zoonotic importance of this protozoan parasite, limited data are available about its prevalence in zoo felids in North-Eastern China. Hence, the current study was designed to determine the occurrence and molecular characterization of Cryptosporidium spp. from the fecal samples of captive zoo felids. Fecal samples (N = 244) were collected from different felids from five different zoos of North-Eastern China. 18S rRNA gene was amplified from the genomic DNA using species specific primers in nested polymerase chain reaction (nPCR) and Cryptosporidium parvum and Cryptosporidium spp. was found. The overall prevalence of Cryptosporidium was 9.43% (23/244). The 18S rRNA gene similarity analysis showed that 6 Cryptosporidium isolates were Cryptosporidium parvum and the remaining 17 Cryptosporidium isolates were resembling to a Cryptosporidium spp., which is similar to Cryptosporidium NEV10. Phylogenetic tree was constructed based on 18S rRNA of Cryptosporidium spp. The similarity of Cryptosporidium parvum was with its other isolates in China, India, Iran, Iraq, Turkey, Czech Republic, Spain and USA while Cryptosporidium NEV10 alike had a close relationship with Turkish isolates. In conclusion, Cryptosporidium was prevailing in feline animals of China zoo and zoo officials are directed to consider their control policy as it can be a cause of zoonosis.

CRYPTOSPORIDIUM SPP. IN PET DWARF WINTER WHITE RUSSIAN HAMSTERS (PHODOPUS SUNGORIS SUNGORIS) IN CHINA

Cryptosporidium spp. have been identified in a wide range of hosts, such as humans and domestic and wild animals, while less information about the prevalence of Cryptosporidium spp. in pet hamsters is documented. A total of 351 dwarf winter white Russian hamsters' fecal specimens were collected from 6 pet markets from the cities of Luzhou and Ziyang in Sichuan province in the southwestern part of China. The prevalence of Cryptosporidium spp. determined with nested-PCR amplification of the partial small-subunit (SSU) rRNA gene was 39.32% (138/351). The highest prevalence of Cryptosporidium spp. was in pet market 5 (79.49%, 62/78), followed by pet market 6 (38.64%, 17/44). The lowest prevalence of Cryptosporidium spp. was observed in pet market 3 (14.89%, 7/47). Statistically significant differences in the prevalence of Cryptosporidium spp. were observed among different pet markets (χ2 = 76.386, df = 5, P < 0.05), and a further post hoc test revealed that only pet market 5 was significantly different from other pet markets. Molecular analysis showed that 4 different Cryptosporidium species or genotypes were identified: Cryptosporidium parvum (n = 127), Cryptosporidium chipmunk genotype III (n = 6), Cryptosporidium andersoni (n = 4), and Cryptosporidium wrairi (n = 1). The identification of Cryptosporidium spp. was further tested with the 60-kDa glycoprotein (GP60) gene, and the positive rate was 29.7% (41/138). This is the first molecular report on Cryptosporidium spp. infection in dwarf winter white Russian hamsters in China. With C. parvum and C. andersoni being identified in both humans and pet hamsters, these findings suggest that pet hamsters may be potential reservoirs of zoonotic Cryptosporidium species and subtypes.

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.

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.

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.

Proteome size reduction in Apicomplexans is linked with loss of DNA repair and host redundant pathways

Apicomplexans are alveolate parasites which include Plasmodium falciparum, the main cause of malaria, one of the world's biggest killers from infectious disease. Apicomplexans are characterized by a reduction in proteome size, which appears to result from metabolic and functional simplification, commensurate with their parasitic lifestyle. However, other factors may also help to explain gene loss such as population bottlenecks experienced during transmission, and the effect of reducing the overall genomic information content. The latter constitutes an 'informational constraint', which is proposed to exert a selective pressure to evolve and maintain genes involved in informational fidelity and error correction, proportional to the quantity of information in the genome (which approximates to proteome size). The dynamics of gene loss was examined in 41 Apicomplexan genomes using orthogroup analysis. We show that loss of genes involved in amino acid metabolism and steroid biosynthesis can be explained by metabolic redundancy with the host. We also show that there is a marked tendency to lose DNA repair genes as proteome size is reduced. This may be explained by a reduction in size of the informational constraint and can help to explain elevated mutation rates in pathogens with reduced genome size. Multiple Sequentially Markovian Coalescent (MSMC) analysis indicates a recent bottleneck, consistent with predictions generated using allele-based population genetics approaches, implying that relaxed selection pressure due to reduced population size might have contributed to gene loss. However, the non-randomness of pathways that are lost challenges this scenario. Lastly, we identify unique orthogroups in malaria-causing Plasmodium species that infect humans, with a high proportion of membrane associated proteins. Thus, orthogroup analysis appears useful for identifying novel candidate pathogenic factors in parasites, when there is a wide sample of genomes available.

Cryptosporidiosis and Giardiasis in Buffaloes (Bubalus bubalis)

Cryptosporidium spp. and Giardia duodenalis infect the gastrointestinal tracts of animals and humans. Both parasite groups are distributed worldwide and cause significant economic losses in animal productivity. Infected hosts presenting with and without clinical manifestations can eliminate infective forms of these protozoa, which are particularly important to One Health. Compared to the published research on cattle, relatively few studies have examined the epidemiology of cryptosporidiosis and giardiasis in buffaloes. This short review describes the global occurrence of Cryptosporidium spp. and G. duodenalis in buffaloes, including the molecular techniques employed for the identification of species/assemblages and genotypes of these protozoa. Genetic analyses of isolates of G. duodenalis and Cryptosporidium spp. from various sources (environmental, animal, and human) have been performed to investigate their epidemiology. In buffaloes, the species Cryptosporidium parvum, Cryptosporidium ryanae, Cryptosporidium bovis, and Cryptosporidium suis-like have been characterized, as well as assemblages A and E of G. duodenalis. We demonstrate that buffaloes can be infected by species of Cryptosporidium spp. and G. duodenalis assemblages with zoonotic potential. Epidemiological studies that utilize molecular biology techniques represent an important resource for efforts to control and prevent the spread of these protozoans.

Non-invasive sampling in Itatiaia National Park, Brazil: wild mammal parasite detection

Background

Non-invasive sampling through faecal collection is one of the most cost-effective alternatives for monitoring of free-living wild mammals, as it provides information on animal taxonomy as well as the dynamics of the gastrointestinal parasites that potentially infect these animals. In this context, this study aimed to perform an epidemiological survey of gastrointestinal parasites using non-invasive faecal samples from carnivores and artiodactyls identified by stool macroscopy, guard hair morphology and DNA sequencing in Itatiaia National Park. Between 2017 and 2018, faeces from carnivores and artiodactyls were collected along trails in the park. The host species were identified through macroscopic and trichological examinations and molecular biology. To investigate the parasites, the Faust, Lutz and modified Ritchie and Sheather techniques and enzyme immunoassays to detect Cryptosporidium sp. antigens were used.

Results

A total of 244 stool samples were collected. The species identified were Chrysocyon brachyurus, Leopardus guttulus, Canis familiaris, Cerdocyon thous, Puma yagouaroundi, Leopardus pardalis, Puma concolor and Sus scrofa. There were 81.1% samples that were positive for parasites distributed mainly in the high part of the park. Helminths, especially eggs of the family Ascarididae, were more frequently detected in carnivore faeces (70.9%). Protozoa, especially Cryptosporidium sp., represented the highest frequency of infection in artiodactyl faeces (87.1%). This zoonotic protozoon was detected in eight mammalian species, including in a wild boar. High values of structural richness and Shannon and Simpson diversity indices were observed for the parasites, especially in the faeces of C. brachyurus. Significant differences in parasite diversity were observed between wild and domestic animals, such as C. brachyurus and C. familiaris, respectively, and between taxonomically distant species, such as C. brachyurus and S. scrofa. The highest values for parasite similarity were found among the species that frequented similar areas of the park, such as C. brachyurus and L. guttulus.

Conclusions

The animals and parasite infections were identified through the combination of three techniques. High frequency parasite structures were diagnosed. Zoonotic protozoa were found and mainly occurred in samples from introduced species.

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.

A chicken embryo model for the maintenance and amplification of Cryptosporidium parvum and Cryptosporidium baileyi oocysts

Cryptosporidium is a genus of apicomplexan parasites that inhabit the respiratory and gastrointestinal tracts of vertebrates. Research of these parasites is limited by a lack of model hosts. This study aimed to determine the extent to which infection at the embryo stage can enhance the propagation of Cryptosporidium oocysts in chickens. Nine-day-old chicken embryos and one-day-old chickens were experimentally infected with different doses of Cryptosporidium baileyi and Cryptosporidium parvum oocysts. Post hatching, all chickens had demonstrable infections, and the infection dose had no effect on the course of infection. Chickens infected as embryos shed oocysts immediately after hatching and shed significantly more oocysts over the course of the infection than chickens infected as one-day-olds. In chickens infected as embryos, C. baileyi was found in all organs except the brain whereas, C. parvum was only found in the gastrointestinal tract and trachea. In chickens infected as one-day-olds, C. baileyi was only found in the gastrointestinal tract and trachea. Chickens infected as embryos with C. baileyi died within 16 days of hatching. All other chickens cleared the infection. Infection of chickens as embryos could be used as an effective and simple model for the propagation of C. baileyi and C. parvum.

The first report of Cryptosporidium testudinis in Chinese alligators (Alligator sinensis) in China

Several Cryptosporidium species that infect reptiles, especially squamates, are well described, but there is limited data about Cryptosporidium species infecting crocodilians. In this study, we assess the occurrence of intestinal parasites using traditional microscopic examination and describe the prevalence and Cryptosporidium species in the captive-bred Chinese alligators (Alligator sinensis) in eastern China using molecular methods. The results of microscopic examination showed that no intestinal parasites were detected among the 491 fecal samples examined from the Chinese alligators. The overall prevalence for Cryptosporidium was 0.41% (2/491) by PCR detection using the SSU rRNA locus. Sequence and phylogenetic analysis of the SSU rRNA, COWP, and actin genes revealed the presence of Cryptosporidium testudinis, which has been isolated primarily from chelonians. This is the first detection of the specific DNA of C. testudinis in the feces of the Chinese alligator. This study expands our knowledge of the Cryptosporidium species involved in crocodiles, and more extensive studies are necessary to confirm the validity of C. testudinis in crocodiles.

First report of detection of Toxoplasma gondii DNA in oysters (Crassostrea sp.) in the state of Maranhão

Abstract The aim of this study was to report on detection of Toxoplasma gondii DNA in oysters (Crassostrea sp.) in the state of Maranhão. To conduct this study, 200 farmed oysters were acquired in the municipality of Raposa and 100 in Paço do Lumiar; and a further 100 oysters were taken from the natural stock in the municipality of Primeira Cruz. This total of 400 specimens sampled was divided into 80 pools composed of five animals each. The gills and visceral mass of each oyster were removed for DNA extraction (per pool of oysters), using a commercial kit. The nested PCR technique (with the primer SAG-1) was then used to investigate any presence of protozoa. This molecular technique demonstrated the presence of DNA of T. gondii in 2.5% of the pools of oysters (n = 2/80): these oysters were exclusively from farms. The results from this study allow the conclusion that oysters of the genus Crassostrea that are farmed in the state of Maranhão are capable of filtering oocysts of T. gondii and maintaining them in their tissues. They are therefore potential sources of contamination for humans and other animals.

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.

Cryptosporidium proventriculi sp. n. (Apicomplexa: Cryptosporidiidae) in Psittaciformes birds

Cryptosporidiosis is a common parasitic infection in birds that is caused by more than 25 Cryptosporidium species and genotypes. Many of the genotypes that cause avian cryptosporidiosis are poorly characterized. The genetic and biological characteristics of avian genotype III are described here and these data support the establishment of a new species, Cryptosporidium proventriculi. Faecal samples from the orders Passeriformes and Psittaciformes were screened for the presence of Cryptosporidium by microscopy and sequencing, and infections were detected in 10 of 98 Passeriformes and in 27 of 402 Psittaciformes. Cryptosporidium baileyi was detected in both orders. Cryptosporidium galli and avian genotype I were found in Passeriformes, and C. avium and C. proventriculi were found in Psittaciformes. Cryptosporidium proventriculi was infectious for cockatiels under experimental conditions, with a prepatent period of six days post-infection (DPI), but not for budgerigars, chickens or SCID mice. Experimentally infected cockatiels shed oocysts more than 30 DPI, with an infection intensity ranging from 4,000 to 60,000 oocysts per gram (OPG). Naturally infected cockatiels shed oocysts with an infection intensity ranging from 2,000 to 30,000 OPG. Cryptosporidium proventriculi infects the proventriculus and ventriculus, and oocysts measure 7.4 × 5.8 μm. None of the birds infected C. proventriculi developed clinical signs.

Review of Cryptosporidium and Giardia in the eastern part of Europe, 2016

This paper reviews the current knowledge and understanding of Cryptosporidium spp. and Giardia spp. in humans, animals and the environment in 10 countries in the eastern part of Europe: Bosnia and Herzegovina, Croatia, Czech Republic, Estonia, Hungary, Latvia, Poland, Romania, Serbia and Slovenia. Methods: Published scientific papers and conference proceedings from the international and local literature, official national health service reports, national databases and doctoral theses in local languages were reviewed to provide an extensive overview on the epidemiology, diagnostics and research on these pathogens, as well as analyse knowledge gaps and areas for further research. Results: Cryptosporidium spp. and Giardia spp. were found to be common in eastern Europe, but the results from different countries are difficult to compare because of variations in reporting practices and detection methodologies used. Conclusion: Upgrading and making the diagnosis/detection procedures more uniform is recommended throughout the region. Public health authorities should actively work towards increasing reporting and standardising reporting practices as these prerequisites for the reported data to be valid and therefore necessary for appropriate control plans.

Limitations in the screening of potentially anti-cryptosporidial agents using laboratory rodents with gastric cryptosporidiosis

The emergence of cryptosporidiosis, a zoonotic disease of the gastrointestinal and respiratory tract caused by Cryptosporidium Tyzzer, 1907, triggered numerous screening studies of various compounds for potential anti-cryptosporidial activity, the majority of which proved ineffective. Extracts of Indonesian plants, Piper betle and Diospyros sumatrana, were tested for potential anti-cryptosporidial activity using Mastomys coucha (Smith), experimentally inoculated with Cryptosporidium proliferans Kváč, Havrdová, Hlásková, Daňková, Kanděra, Ježková, Vítovec, Sak, Ortega, Xiao, Modrý, Chelladurai, Prantlová et McEvoy, 2016. None of the plant extracts tested showed significant activity against cryptosporidia; however, the results indicate that the following issues should be addressed in similar experimental studies. The monitoring of oocyst shedding during the entire experimental trial, supplemented with histological examination of affected gastric tissue at the time of treatment termination, revealed that similar studies are generally unreliable if evaluations of drug efficacy are based exclusively on oocyst shedding. Moreover, the reduction of oocyst shedding did not guarantee the eradication of cryptosporidia in treated individuals. For treatment trials performed on experimentally inoculated laboratory rodents, only animals in the advanced phase of cryptosporidiosis should be used for the correct interpretation of pathological alterations observed in affected tissue. All the solvents used (methanol, methanol-tetrahydrofuran and dimethylsulfoxid) were shown to be suitable for these studies, i.e. they did not exhibit negative effects on the subjects. The halofuginone lactate, routinely administered in intestinal cryptosporidiosis in calves, was shown to be ineffective against gastric cryptosporidiosis in mice caused by C. proliferans. In contrast, the control application of extract Arabidopsis thaliana, from which we had expected a neutral effect, turned out to have some positive impact on affected gastric tissue.

Molecular epidemiology of Cryptosporidium spp. in dairy cattle in Guangdong Province, South China

To determine the prevalence of Cryptosporidium in dairy cattle in Guangdong Province, South China, 1440 fecal samples were collected from 10 farms and screened for Cryptosporidium with PCR. The overall prevalence of Cryptosporidium was 4.38% (63/1440), and the infection rates in preweaned calves, postweaned calves, heifers and adults were 6.4% (19/297), 6.19% (33/533), 1.48% (4/271) and 2.06% (7/339), respectively. Three Cryptosporidium species, Cryptosporidium andersoni (n = 33), Cryptosporidium bovis (n = 22) and Cryptosporidium ryanae (n = 8) were detected by DNA sequence analysis of the 63 positive samples, and C. andersoni was identified as the most common species on the dairy cattle farms. In preweaned calves, C. bovis was the most prevalent species (9/19, 47.4%). In contrast, C. andersoni was the predominant species (19/33, 57.6%) in postweaned calves and the only species found in heifers and adults. The zoonotic species Cryptosporidium parvum was not detected in this study. Twenty-four C. andersoni isolates were successfully classified into three multilocus sequence typing (MLST) subtypes. MLST subtype A4,A4,A4,A1 was the predominant subtype, and MLST subtype A2,A5,A2,A1, previously found in sheep, was detected in cattle for the first time. A linkage disequilibrium analysis showed that the C. andersoni isolates had a clonal genetic population structure. However, further molecular studies are required to better understand the epidemiology of Cryptosporidium in Guangdong.

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

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

Comparison of current methods used to detect Cryptosporidium oocysts in stools

In this review all of the methods that are currently in use for the investigation of Cryptosporidium in stool material are highlighted and critically discussed. It appears that more qualifications and background knowledge in this field regarding the diagnosis of the Cryptosporidium parasite is required. Furthermore, there is no standardization for the protocols that are commonly used to either detect oocysts in faeces or to diagnose the Cryptosporidium infection. It is therefore necessary to initiate further education and research that will assist in improving the accuracy of the diagnosis of Cryptosporidium oocysts in the faecal micro-cosmos. Where ambient concentrations of oocysts are low in stool material, detection becomes a formidable task. Procedures for ring tests and the standardization of multi-laboratory testing are recommended. It is also necessary to enhance the routine surveillance capacity of cryptosporidiosis and to improve the safety against it, considering the fact that this disease is under diagnosed and under reported. This review is intended to stimulate research that could lead to future improvements and further developments in monitoring the diagnostic methodologies that will assist in harmonizing Cryptosporidium oocysts in stool diagnosis.

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in 1-2-month-old highland yaks in Qinghai Province, China

Cryptosporidium and Giardia are ubiquitous parasites that infect humans and animals. Few reports are available on the prevalence of these two protozoan parasites in yaks (Bos grunniens). In this study, 344 faecal samples were collected from yaks with diarrhoea in the Chenduo and Nangqian counties of Qinghai Province, China. Cryptosporidium spp. and Giardia duodenalis were detected by light and immunofluorescence microscopy and nested PCR (nPCR). Fifteen samples were positive (4.5%) by Kinyoun staining, 40 (11.6%) samples were positive by immunofluorescence test (IFT), and 39 (11.3%) samples were positive by nPCR for Cryptosporidium spp., Cryptosporidium bovis (11/39, 28.2%) was the most prevalent species, followed by C. ryanae (6/39, 15.4%), C. andersoni (5/39, 12.8%), C. struthionis (5/39, 12.8%), C. parvum (5/39, 12.8%), C. hominis (4/39, 10.3%) and C. canis (3/39, 7.7%). Thirteen out of 344 (3.8%) samples were positive for Giardia by simple microscopy, 20 (5.8%) by IFT and 18 samples (5.2%) yak faecal samples were Giardia positive by nPCR. Two G. duodenalis assemblages (B, E) were detected in this study. Nine positive samples for G. duodenalis assemblage E were from the towns of Xiewu (8/9, 4.9%) and Xiangda (1/9, 1.3%), and nine positive samples (9/9, 8.5%) for G. duodenalis assemblage B were from the town of Zhenqin. This report provides information about infection with Cryptosporidium species and G. duodenalis assemblages in domesticated 1-2-month-old highland yaks living in the Qinghai-Tibet Plateau region of China.

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

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

Cryptosporidium occultus sp. n. (Apicomplexa: Cryptosporidiidae) in rats

Cryptosporidium parvum VF383 has been reported in humans, domesticated ruminants, and wild rats worldwide and described under several names including Cryptosporidium suis-like, based on its close phylogenetic relationship to C. suis. Unlike C. suis, however, it has never been detected in pigs. In the present work, C. parvum VF383 originating from wild brown rats was not infectious for piglets or calves but was infectious for laboratory brown rats, BALB/c mice, and Mongolian gerbils. The prepatent period was 4-5 days for all rodents. The patent period was longer for rats (>30 days) than other rodents (<20 days). None of the rodents developed clinical signs of infection. In all rodents, life cycle stages were detected in the colon by histology and electron microscopy. Oocysts were morphometrically similar to those of C. parvum and smaller than those of C. suis, measuring 5.20 × 4.94 μm. Phylogenetic analyses of 18S rRNA, actin, and HSP70 gene sequences revealed C. parvum VF383 to be genetically distinct from, C. suis, and other described species of Cryptosporidium. Morphological, genetic, and biological data support the establishment of C. parvum VF383 as a new species, and we propose the name Cryptosporidium occultus sp. n.

First detection of Cryptosporidium DNA in blood and cerebrospinal fluid of HIV-infected patients

Human cryptosporidiosis is an intestinal infection caused by different species belonging to the genus Cryptosporidium in both immunocompetent and immunocompromised individuals. The life cycle of Cryptosporidium sp. when affecting the digestive system is well known but the infection of other organs is less studied. Molecular methods are necessary for species and subtypes identification. The goal of this work is to propose a new approach that contributes to the diagnosis of the extra-intestinal dissemination process of Cryptosporidium infection. Cryptosporidium sp. was detected in stool and biopsy samples of two HIV-infected patients. DNA was extracted from feces, biopsy specimens, blood, and cerebrospinal fluid (CSF). All samples were analyzed by nested PCR-RFLP of the 18S rDNA, real-time PCR, and gp60 subtyping. Cryptosporidium DNA was detected in stool and tissue samples and it was also present in blood and CSF samples. Both cases were characterized as Cryptosporidium hominis subtype IeA11G3T3. This is the first report that demonstrates the presence of Cryptosporidium DNA in blood and CSF of HIV-infected patients.

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.

Response of cell lines to actual and simulated inoculation with Cryptosporidium proliferans

The need for an effective treatment against cryptosporidiosis has triggered studies in the search for a working in vitro model. The peculiar niche of cryptosporidia at the brush border of host epithelial cells has been the subject of extensive debates. Despite extensive research on the invasion process, it remains enigmatic whether cryptosporidian host-parasite interactions result from an active invasion process or through encapsulation. We used HCT-8 and HT-29 cell lines for in vitro cultivation of the gastric parasite Cryptosporidium proliferans strain TS03. Using electron and confocal laser scanning microscopy, observations were carried out 24, 48 and 72 h after inoculation with a mixture of C. proliferans oocysts and sporozoites. Free sporozoites and putative merozoites were observed apparently searching for an appropriate infection site. Advanced stages, corresponding to trophozoites and meronts/gamonts enveloped by parasitophorous sac, and emptied sacs were detected. As our observations showed that even unexcysted oocysts became enveloped by cultured cell projections, using polystyrene microspheres, we evaluated the response of cell lines to simulated inoculation with cryptosporidian oocysts to verify innate and parasite-induced behaviour. We found that cultured cell encapsulation of oocysts is induced by parasite antigens, independent of any active invasion/motility.

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.

Use of a bioinformatic-assisted primer design strategy to establish a new nested PCR-based method for Cryptosporidium

BACKGROUND

The accurate tracking of Cryptosporidium in faecal, water and/or soil samples in water catchment areas is central to developing strategies to manage the potential risk of cryptosporidiosis transmission to humans. Various PCR assays are used for this purpose. Although some assays achieve specific amplification from Cryptosporidium DNA in animal faecal samples, some do not. Indeed, we have observed non-specificity of some oligonucleotide primers in the small subunit of nuclear ribosomal RNA gene (SSU), which has presented an obstacle to the identification and classification of Cryptosporidium species and genotypes (taxa) from faecal samples.

RESULTS

Using a novel bioinformatic approach, we explored all available Cryptosporidium genome sequences for new and diagnostically-informative, multi-copy regions to specifically design oligonucleotide primers in the large subunit of nuclear ribosomal RNA gene (LSU) as a basis for an effective nested PCR-based sequencing method for the identification and/or classification of Cryptosporidium taxa.

CONCLUSION

This newly established PCR, which has high analytical specificity and sensitivity, is now in routine use in our laboratory, together with other assays developed by various colleagues. Although the present bioinformatic workflow used here was for the specific design of primers in nuclear DNA of Cryptosporidium, this approach should be broadly applicable to many other microorganisms.

Prevalence, transmission, and host specificity of Cryptosporidium spp. in various animal groups from two French zoos

Cryptosporidium represents a major cause of gastrointestinal illness in humans and animals including domestic, wild, and in captivity animals, and more than 30 validated species of Cryptosporidium are recognized as infectious to different hosts such as mammals, birds, reptiles, amphibians, and fish. Therefore, numerous investigations have been conducted worldwide in order to shed light on the epidemiology of this parasite and to explore its potential reservoirs. Few surveys, targeting humans and animals have been carried out regarding the epidemiology of Cryptosporidium spp. in France and no data are available about the circulation of this parasite in French zoological gardens. Herein, we determined the prevalence of Cryptosporidium in animals housed in two French zoos. A total of 307 fecal samples belonging to 161 species were screened by nested PCR. Overall, Cryptosporidium DNA was detected in 1.9% of the 161 species and 1% of the total number of fecal samples tested. Additionally, three Cryptosporidium species were identified: C. galli, C. andersoni, and C. tyzzeri. To our knowledge, this is the first molecular study focused on Cryptosporidium infection in captivity animals in France. This study is of interest considering the exposure of a large number of humans and animals to this waterborne protozoan, found ubiquitously in the environment.

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

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

Cryptosporidium infecting wild cricetid rodents from the subfamilies Arvicolinae and Neotominae

We undertook a study on Cryptosporidium spp. in wild cricetid rodents. Fecal samples were collected from meadow voles (Microtus pennsylvanicus), southern red-backed voles (Myodes gapperi), woodland voles (Microtus pinetorum), muskrats (Ondatra zibethicus) and Peromyscus spp. mice in North America, and from bank voles (Myodes glareolus) and common voles (Microtus arvalis) in Europe. Isolates were characterized by sequence and phylogenetic analyses of the small subunit ribosomal RNA (SSU) and actin genes. Overall, 33·2% (362/1089) of cricetids tested positive for Cryptosporidium, with a greater prevalence in cricetids from North America (50·7%; 302/596) than Europe (12·1%; 60/493). Principal Coordinate analysis separated SSU sequences into three major groups (G1-G3), each represented by sequences from North American and European cricetids. A maximum likelihood tree of SSU sequences had low bootstrap support and showed G1 to be more heterogeneous than G2 or G3. Actin and concatenated actin-SSU trees, which were better resolved and had higher bootstrap support than the SSU phylogeny, showed that closely related cricetid hosts in Europe and North America are infected with closely related Cryptosporidium genotypes. Cricetids were not major reservoirs of human pathogenic Cryptosporidium spp.

Cryptosporidium and Giardia in Africa: current and future challenges

Cryptosporidium and Giardia are important causes of diarrhoeal illness. Adequate knowledge of the molecular diversity and geographical distribution of these parasites and the environmental and climatic variables that influence their prevalence is important for effective control of infection in at-risk populations, yet relatively little is known about the epidemiology of these parasites in Africa. Cryptosporidium is associated with moderate to severe diarrhoea and increased mortality in African countries and both parasites negatively affect child growth and development. Malnutrition and HIV status are also important contributors to the prevalence of Cryptosporidium and Giardia in African countries. Molecular typing of both parasites in humans, domestic animals and wildlife to date indicates a complex picture of both anthroponotic, zoonotic and spill-back transmission cycles that requires further investigation. For Cryptosporidium, the only available drug (nitazoxanide) is ineffective in HIV and malnourished individuals and therefore more effective drugs are a high priority. Several classes of drugs with good efficacy exist for Giardia, but dosing regimens are suboptimal and emerging resistance threatens clinical utility. Climate change and population growth are also predicted to increase both malnutrition and the prevalence of these parasites in water sources. Dedicated and co-ordinated commitments from African governments involving "One Health" initiatives with multidisciplinary teams of veterinarians, medical workers, relevant government authorities, and public health specialists working together are essential to control and prevent the burden of disease caused by these parasites.

Limiting swimming pool outbreaks of cryptosporidiosis - the roles of regulations, staff, patrons and research

Cryptosporidium is the leading cause of swimming pool outbreaks of gastroenteritis. Transmission occurs through the ingestion of oocysts that are passed in the faeces of an infected person or animal when an accidental faecal release event occurs. Cryptosporidium parasites present specific challenges for infection control as oocysts are highly resistant to chlorine levels used for pool disinfection, infected individuals can shed large numbers of oocysts, there is a long incubation period and shedding of oocysts occurs even after symptom resolution. The purposes of this review are to identify key barriers to limiting swimming pool-associated outbreaks of cryptosporidiosis and to outline needs for research and collaboration to advance co-ordinated management practices. We reviewed swimming pool-associated cryptosporidiosis outbreaks, disinfection teachniques, current regulations and the role of staff and patrons. Key barriers to limiting swimming pool-associated outbreaks of cryptosporidiosis are a lack of uniform national and international standards, poor adherence and understanding of regulations governing staff and patron behaviour, and low levels of public knowledge and awareness.

Zoonotic Cryptosporidium Species in Animals Inhabiting Sydney Water Catchments

Cryptosporidium is one of the most common zoonotic waterborne parasitic diseases worldwide and represents a major public health concern of water utilities in developed nations. As animals in catchments can shed human-infectious Cryptosporidium oocysts, determining the potential role of animals in dissemination of zoonotic Cryptosporidium to drinking water sources is crucial. In the present study, a total of 952 animal faecal samples from four dominant species (kangaroos, rabbits, cattle and sheep) inhabiting Sydney's drinking water catchments were screened for the presence of Cryptosporidium using a quantitative PCR (qPCR) and positives sequenced at multiple loci. Cryptosporidium species were detected in 3.6% (21/576) of kangaroos, 7.0% (10/142) of cattle, 2.3% (3/128) of sheep and 13.2% (14/106) of rabbit samples screened. Sequence analysis of a region of the 18S rRNA locus identified C. macropodum and C. hominis in 4 and 17 isolates from kangaroos respectively, C. hominis and C. parvum in 6 and 4 isolates respectively each from cattle, C. ubiquitum in 3 isolates from sheep and C. cuniculus in 14 isolates from rabbits. All the Cryptosporidium species identified were zoonotic species with the exception of C. macropodum. Subtyping using the 5' half of gp60 identified C. hominis IbA10G2 (n = 12) and IdA15G1 (n = 2) in kangaroo faecal samples; C. hominis IbA10G2 (n = 4) and C. parvum IIaA18G3R1 (n = 4) in cattle faecal samples, C. ubiquitum subtype XIIa (n = 1) in sheep and C. cuniculus VbA23 (n = 9) in rabbits. Additional analysis of a subset of samples using primers targeting conserved regions of the MIC1 gene and the 3' end of gp60 suggests that the C. hominis detected in these animals represent substantial variants that failed to amplify as expected. The significance of this finding requires further investigation but might be reflective of the ability of this C. hominis variant to infect animals. The finding of zoonotic Cryptosporidium species in these animals may have important implications for the management of drinking water catchments to minimize risk to public health.