Zoonotic cryptosporidiosis

Prevalence and genotype analysis of Cryptosporidium and Giardia duodenalis from shelter dogs in South Korea

Cryptosporidium and Giardia duodenalis are common gastrointestinal protozoan parasites that cause diarrhea in humans and animals. Although dogs in animal shelters in South Korea can be reintroduced into human society as companions, no continuous investigations have been conducted on the prevalence and genetic characteristics of the protozoan parasites. In the present study, 345 fecal samples from dogs were obtained from animal shelters in six provinces between January and December 2022. The prevalence of Cryptosporidium and G. duodenalis were molecularly identified at the 18S rRNA gene. Cryptosporidium canis isolates were subtyped at the gp60 locus, and G. duodenalis assemblages were identified at the tpi, bg and gdh loci. Overall, 6.67% of the fecal samples tested positive for Cryptosporidium spp. and two species were identified: C. canis (5.51%) and Cryptosporidium parvum (1.16%). Significant regional differences in prevalence were identified for C. canis. Subtyping analysis of C. canis isolates revealed a predominance of the subtype families XXa and XXe over XXb, and XXc. G. duodenalis was detected in 17.68% of the samples, and significant regional differences were identified; its prevalence was also significantly highest in diarrhoeic animals. Molecular characterization of G. duodenalis reveal that most isolates belonged to the canine-specific assemblages C and D. The present results can contribute to further insights into the prevalence and genotypes of Cryptosporidium and G. duodenalis in shelter dogs in South Korea.

Enteric parasites Cyclospora cayetanensis and Cryptosporidium hominis in domestic and wildlife animals in Ghana

BACKGROUND

Enteric parasitic infections remain a major public health problem globally. Cryptosporidium spp., Cyclospora spp. and Giardia spp. are parasites that cause diarrhea in the general populations of both developed and developing countries. Information from molecular genetic studies on the speciation of these parasites and on the role of animals as vectors in disease transmission is lacking in Ghana. This study therefore investigated these diarrhea-causing parasites in humans, domestic rats and wildlife animals in Ghana using molecular tools.

METHODS

Fecal samples were collected from asymptomatic school children aged 9-12 years living around the Shai Hills Resource Reserve (tourist site), from wildlife (zebras, kobs, baboons, ostriches, bush rats and bush bucks) at the same site, from warthogs at the Mole National Park (tourist site) and from rats at the Madina Market (a popular vegetable market in Accra, Ghana. The 18S rRNA gene (18S rRNA) and 60-kDa glycoprotein gene (gp60) for Cryptosporidium spp., the glutamate dehydrogenase gene (gdh) for Giardia spp. and the 18S rDNA for Cyclospora spp. were analyzed in all samples by PCR and Sanger sequencing as markers of speciation and genetic diversity.

RESULTS

The parasite species identified in the fecal samples collected from humans and animals included the Cryptosporidium species C. hominis, C. muris, C. parvum, C. tyzzeri, C. meleagridis and C. andersoni; the Cyclopora species C. cayetanensis; and the Gardia species, G. lamblia and G. muris. For Cryptosporidium, the presence of the gp60 gene confirmed the finding of C. parvum (41%, 35/85 samples) and C. hominis (29%, 27/85 samples) in animal samples. Cyclospora cayetanensis was found in animal samples for the first time in Ghana. Only one human sample (5%, 1/20) but the majority of animal samples (58%, 51/88) had all three parasite species in the samples tested.

CONCLUSIONS

Based on these results of fecal sample testing for parasites, we conclude that animals and human share species of the three genera (Cryptosporidium, Cyclospora, Giardia), with the parasitic species mostly found in animals also found in human samples, and vice-versa. The presence of enteric parasites as mixed infections in asymptomatic humans and animal species indicates that they are reservoirs of infections. This is the first study to report the presence of C. cayetanensis and C. hominis in animals from Ghana. Our findings highlight the need for a detailed description of these parasites using high-throughput genetic tools to further understand these parasites and the neglected tropical diseases they cause in Ghana where such information is scanty.

Phylogenomic reconstruction of Cryptosporidium spp. captured directly from clinical samples reveals extensive genetic diversity

Cryptosporidium is a leading cause of severe diarrhea and mortality in young children and infants in Africa and southern Asia. More than twenty Cryptosporidium species infect humans, of which C. parvum and C. hominis are the major agents causing moderate to severe diarrhea. Relatively few genetic markers are typically applied to genotype and/or diagnose Cryptosporidium. Most infections produce limited oocysts making it difficult to perform whole genome sequencing (WGS) directly from stool samples. Hence, there is an immediate need to apply WGS strategies to 1) develop high-resolution genetic markers to genotype these parasites more precisely, 2) to investigate endemic regions and detect the prevalence of different genotypes, and the role of mixed infections in generating genetic diversity, and 3) to investigate zoonotic transmission and evolution. To understand Cryptosporidium global population genetic structure, we applied Capture Enrichment Sequencing (CES-Seq) using 74,973 RNA-based 120 nucleotide baits that cover ~92% of the genome of C. parvum. CES-Seq is sensitive and successfully sequenced Cryptosporidium genomic DNA diluted up to 0.005% in human stool DNA. It also resolved mixed strain infections and captured new species of Cryptosporidium directly from clinical/field samples to promote genome-wide phylogenomic analyses and prospective GWAS studies.

Prevalence of Cryptosporidium spp. in Sheep and Goats in Jiangsu, China

Sheep and goats serve as crucial hosts for Cryptosporidium spp. and are primarily responsible for its transmission via the fecal-oral route. This can result in symptoms such as lamb weight loss, diarrhea, and even fatalities, leading to significant economic losses. Currently, there is a lack of scholarly research investigating the prevalence of Cryptosporidium spp. infection in sheep and goats specifically within Jiangsu province. This study collected fecal samples from sheep and goats, extracted their DNA, amplified target bands using nested PCR, sequenced the DNA, constructed a phylogenetic tree, and identified the genetic genotype. In total, 3 positive samples were identified out of 398 samples. Furthermore, the gene sequences of these samples exhibited significant homology with C. xiaoi in GenBank. The phylogenetic analysis revealed that the Cryptosporidium spp. parasites under investigation are phylogenetically related to C. xiaoi. Conducting epidemiological investigations and accurately identifying the species of Cryptosporidium spp. is of utmost importance not only for the mutton sheep farming industry in Jiangsu but also for the proactive safeguarding of human health.

Cryptosporidium and agriculture: A review

Cryptosporidiosis is a significant contributor to global foodborne and waterborne disease burden. It is a widespread cause of diarrheal diseases that affect humans and animals worldwide. Agricultural environments can become a source of contamination with Cryptosporidium species through faecal material derived from humans and animals. This review aims to report the main findings of scientific research on Cryptosporidium species related to various agricultural sectors, and highlights the risks of cryptosporidiosis in agricultural production, the contamination sources, the importance of animal production in transmission, and the role of farmed animals as hosts of the parasites. Agricultural contamination sources can cause water pollution in groundwater and different surface waters used for drinking, recreational purposes, and irrigation. The application of contaminated manure, faecal sludge management, and irrigation with inadequately treated water are the main concerns associated with foodborne and waterborne cryptosporidiosis related to agricultural activities. The review emphasizes the public health implications of agriculture concerning the transmission risk of Cryptosporidium parasites and the urgent need for a new concept in the agriculture sector. Furthermore, the findings of this review provide valuable information for developing appropriate measures and monitoring strategies to minimize the risk of infection.

Development of a "Rapid-Crypto Colorimetric LAMP Test" to Detect Cryptosporidiosis in Feces of Newborns Calves

BACKGROUND

Cryptosporidiosis is a disease that causes major intestinal damage in humans and animals. The causative agents of the disease are Cryptosporidium species. In newborn calves, diarrhea can lead to death, resulting in significant economic losses for the farms. Therefore, accurate, rapid, and cost-effective diagnosis of the disease is very important.

MATERIAL AND METHODS

In this study, a novel colorimetric loop-mediated isothermal amplification (LAMP) test named "Rapid-Crypto Colorimetric LAMP test" targeting Cryptosporidium spp. 18S rRNA gene was developed to detect cryptosporidiosis in the feces of newborn calves. The analytical sensitivity of the test was determined by plasmid controls. Clinical sensitivity was determined using the feces of 127 calves collected from farms in İzmir and Manisa provinces. All of the samples were also investigated with Real-Time PCR targeting the Cryptosporidium spp. COWP gene. Cross-reactivity was tested using the DNA of other parasites and bacteria.

RESULTS

According to the results, the analytical sensitivity of the "Rapid-Crypto Colorimetric LAMP test" was found as 1 copy plasmid/reaction. When the results were compared with the Real-Time PCR test, the sensitivity of the "Rapid-Crypto Colorimetric LAMP test" was 100% and the specificity was 97.4%. The test did not cross-react with other parasites and bacteria.   CONCLUSION: The "Rapid-Crypto Colorimetric LAMP test" developed in this study provides an advantage in the diagnosis of Cryptosporidium spp. in calf stool samples since it can be applied in basic laboratories or in the field, does not require experienced personnel, and has high sensitivity. Moreover, diagnosis can be made with the naked eye without using any device.

Prevalence, risk factors and molecular epidemiology of neonatal cryptosporidiosis in calves: The Argentine perspective

Cryptosporidium spp. are enteroparasitic protozoans that cause cryptosporidiosis in newborn calves. Clinical signs of the infection are diarrhoea and dehydration leading to decreased productivity and economic losses in cattle farms around the world. Additionally, cryptosporidiosis is a relevant zoonotic disease since the ingestion of oocysts can be fatal for children under five years of age, the elderly, and/or immunocompromised adults. This review aims to integrate existing knowledge on the epidemiological situation of calf cryptosporidiosis and associated risk factors in Argentina. In addition, the GP60 subtype diversity of the pathogen was analysed and related with the global distribution of corresponding GP60 subtypes. Depending on the study region and applied diagnostics, prevalence among calves up to 20 days of age varied between 25.2% and 42.5%, while a prevalence of 16.3-25.5% was observed at the age of 1-90 days. So far, molecular studies have determined exclusively Cryptosporidium parvum in preweaned calves. In addition, C. parvum infection was reported as the major cause of calf diarrhoea, followed by rotavirus A (RVA), while enteropathogens such as coronavirus, Escherichiacoli, and Salmonella sp. played a negligible role. Calf age of 20 days or less, incidence of diarrhoea, poorly drained soils, and large farm size were identified as risk factors for C. parvum-infection in Argentina. A total of nine GP60 subtypes (IIaAxxG1R1, xx = 16 to 24) were identified, showing a stepwise increase of the trinucleotide motif TCA, and including the zoonotic subtypes IIaA16G1R1, IIaA17G1R1, IIaA18G1R1, IIaA19G1R1, and IIaA20G1R1. We found that an increase in the A16→A24 trinucleotide repeat was accompanied by a gradual decrease in the global distribution of GP60 alleles, strongly suggesting that IIaA16G1R1 represents the primordial allelic variant of this group. Since identified GP60 alleles have a similar genetic background, we hypothesize that the continuous trinucleotide repeat array has been generated by stepwise repeat expansion of A16. The information gathered and integrated in this study contributes to an improved understanding of the epidemiological characteristics of bovine cryptosporidiosis in and beyond Argentina, which in turn can help to develop control strategies for this parasitosis of veterinary and medical relevance.

Molecular Detection and Genotyping of Cryptosporidium spp. Isolates from Bats in Colombia

PURPOSE

Cryptosporidiosis is a zoonotic infectious disease caused by the protozoan parasite Cryptosporidium spp., frequently found in several animal species, including bats. Several Cryptosporidium genotypes have been described in bats worldwide, suggesting that bats are infected by host-specific Cryptosporidium spp. To date, there are no published reports about Cryptosporidium spp. in bats from Colombia. Therefore, this study aimed to determine the presence and molecular diversity of Cryptosporidium spp. in Colombian bats.

METHODS

A total of 63 gut samples from three bat species served for molecular detection of Cryptosporidium spp. 18S rDNA gene by qPCR. The sequenced amplicons were used in subsequent phylogenetic analyses to identify them as species or genotypes.

RESULTS

Cryptosporidium spp. qPCR detection occurred in 9.5% (6/63) of bat intestines, and four sequences represented two new genotypes, called Cryptosporidium bat genotypes XIX and XX, were identified.

CONCLUSIONS

This study describes the detection of two novel Cryptosporidium bat genotypes, in two species of bats from a region of Colombia, requiring further studies to determine the relationhip between Cryptosporidium and bats in Colombia.

Follow-up investigation into Cryptosporidium prevalence and transmission in Western European dairy farms

Cryptosporidium parvum is an enteric parasite and a major contributor to acute enteritis in calves worldwide, causing an important economic burden for farmers. This parasite poses a major public health threat through transmission between livestock and humans. Our previous pilot study in Western Europe revealed a high prevalence of Cryptosporidium in calves of dairy farms. In the sequel study herein, 936 faecal samples were collected from the same 51 dairy farms across Belgium, France, and the Netherlands. Following DNA extraction, Cryptosporidium screening was carried out using nested-PCR amplification targeting the SSU rRNA gene. All positive samples were sequenced, and phylogenetic analyses were used to identify the Cryptosporidium spp. present. The 60 kDa glycoprotein (gp60) gene was also sequenced to determine the C. parvum subtypes present. Prevalence of Cryptosporidium ranged from 23.3% to 25%, across the three countries surveyed. The parasite was found in most of the farms sampled, with 90.2% testing positive. Cryptosporidium parvum, C. bovis, C. ryanae and C. andersoni were all identified, with the former being the most predominant, representing 71.4% of all infections. Cryptosporidium parvum was associated with pre-weaned calves, while other species were associated with older animals. Subtyping of gp60 gene revealed nine subtypes, eight of which have previously been reported to cause clinical disease in humans. Similarly to the first study, vertical transmission was not a major contributor to Cryptosporidium spread. Our study highlights the need for further investigation into cryptosporidiosis transmission, and future studies will require a One Health approach to reduce the impact of this disease.

Rapid Reverse Purification DNA Extraction Approaches to Identify Microbial Pathogens in Wastewater

Wastewater monitoring became a promising solution in the early detection of outbreaks. Despite the achievements in the identification of pathogens in wastewater using real-time PCR, there is still a lack of reliable rapid nucleic acid extraction protocols. Therefore, in this study, samples were subjected to alkali, proteinase K and/or bead-beating followed by reverse purification magnetic beads-based separation. Wastewater samples spiked with S. aureus, E. coli and C. parvum were used as examples for Gram-positive and -negative bacteria and protozoa, respectively. All results were compared with a spin column technology as a reference method. Proteinase K with bead beating (vortexing with 0.1 mm glass beads for three minutes) was particularly successful for bacterial DNA extraction (three- to five-fold increase). The most useful extraction protocol for protozoa was pre-treatment with proteinase K (eight-fold increase). The selected methods were sensitive as far as detecting one bacterial cell per reaction for S. aureus, ten bacterial cells for E. coli and two oocysts for C. parvum. The extraction reagents are cold chain independent and no centrifuge or other large laboratory equipment is required to perform DNA extraction. A controlled validation trial is needed to test the effectiveness at field levels.

Akkermansia muciniphila Associated with Improved Linear Growth among Young Children, Democratic Republic of the Congo

To investigate the association between enteric pathogens, fecal microbes, and child growth, we conducted a prospective cohort study of 236 children <5 years of age in rural eastern Democratic Republic of the Congo. We analyzed baseline fecal specimens by quantitative PCR and measured child height and weight at baseline and growth at a 6-month follow-up. At baseline, 66% (156/236) of children had >3 pathogens in their feces. We observed larger increases in height-for-age-z-scores from baseline to the 6-month follow-up among children with Akkermansia muciniphila in their feces (coefficient 0.02 [95% CI 0.0001-0.04]; p = 0.04). Children with Cryptosporidium in their feces had larger declines in weight-for-height/length z-scores from baseline to the 6-month follow-up (coefficient -0.03 [95% CI -0.05 to -0.005]; p = 0.02). Our study showed high prevalence of enteric pathogens among this pediatric cohort and suggests A. muciniphila can potentially serve as a probiotic to improve child growth.

Experimental infection of cats with Cryptosporidium felis

OBJECTIVES

The aims of this study were to experimentally inoculate cats with Cryptosporidium felis oocysts and compare fecal detection by fluorescent antibody assay (FA) and quantitative PCR (qPCR), and document clinical signs associated with infection.

METHODS

Cryptosporidium felis oocysts were concentrated from the feces of a naturally infected cat and orally inoculated into six cats that tested negative for C felis by an FA and fecal flotation (FF). Cats were observed daily for the presence of clinical signs consistent with infection. Fecal samples from all cats on days 0 and 9, and one sample per cat (days 18-21), were evaluated by all assays. On day 31, two cats negative for C felis by FF and FA were administered methylprednisolone acetate and all assays were repeated on days 34, 36 and 38. Samples from all cats were tested by FF and FA on days 41, 43, 45 and 48.

RESULTS

A total of 41 samples were tested, 25 of which were compared by FA and qPCR. Cryptosporidium felis was detected in 2/25 (8%) and in 19/25 (76%) samples by FA and by qPCR, respectively; the other 16 samples were tested by FF and FA. None of the cats was positive for C felis by FF or FA in samples collected on days 0, 9 or 18-21. One, five and six samples tested positive by qPCR on days 0, 9 and 18-21, respectively. The cats administered methylprednisolone acetate tested positive for C felis by FA on day 36 and by qPCR on days 31, 34, 36 and 38. None of the cats showed clinical signs of disease.

CONCLUSIONS AND RELEVANCE

Clinical signs were not recognized in any of the cats for the duration of the study. FA was insensitive compared with qPCR for detecting cats with subclinical C felis infection.

Detection of Blastocystis spp., Cryptosporidium spp. and Encephalitozoon spp. among wild animals from Eastern Slovakia

The aim of this study was to draw attention to the risk of transmission of Encephalitozoon, Cryptosporidium and Blastocystis infection due to high animal migration and to point out that even wild animals can be a source of many zoonotic diseases. Encephalitozoon cuniculi, Cryptosporidium spp. and Blastocystis spp. are frequent microscopic organisms that parasitise humans, domestic and wild animals. Two hundred and fifty-five faecal specimens were collected from wild boars, badgers, wolves, bears, foxes and deer from 15 locations in Slovakia. Sequencing of positive PCR products and subsequent sequence comparison with GenBank sequences identified Blastocystis spp. in five wild boars. The ST 5 (n = 4) and ST 10 (n = 1) subtypes were determined by genotyping. We identified Encephalitozoon cuniculi in five wild boars, and genotype II (n = 5) was determined on the basis of ITS repeat sequences. Cryptosporidium scrofarum was sequenced in wolves (n = 4) and wild boars (n = 1), while Cryptosporidium suis only in wild boars (n = 2). None of the wild boars had a mixed infection.

Diverse Genotypes of Cryptosporidium in Sheep in California, USA

Cryptosporidium spp. is a parasite that can infect a wide variety of vertebrate species. The parasite has been detected in sheep worldwide with diverse species and genotypes of various levels of zoonotic potential and public health concern. The purpose of this study was to determine the distribution of genotypes of Cryptosporidium in sheep in California, USA. Microscopic positive samples from individual sheep from central and northern California ranches were genotyped by sequencing a fragment of the 18S rRNA gene and BLAST analysis. Eighty-eight (63.8%) of the microscopic positive samples were genotyped, and multiple genotypes of Cryptosporidium were identified from sheep in the enrolled ranches. Approximately 89% of isolates (n = 78) were C. xiaoi or C. bovis, 10% of isolates (n = 9) were C. ubiquitum, and 1% of isolates (n = 1) were C. parvum. The C. parvum and C. ubiquitum isolates were detected only from lambs and limited to four farms. Given that the majority of Cryptosporidium species (i.e., C. xiaoi and C. bovis) were of minor zoonotic concern, the results of this study suggest that sheep are not a reservoir of major zoonotic Cryptosporidium in California ranches.

Cryptosporidium infection in young dogs from Germany

Cryptosporidium is an enteric protozoan parasite which is able to cause severe gastrointestinal disease and is distributed all over the world. Since information about the prevalence of cryptosporidiosis in German dogs is rare, the aim of this study was to examine the occurrence of Cryptosporidium spp. in dogs and the potential zoonotic risk emanating from these infected animals. In total, 349 fecal samples of 171 dogs were collected during the dogs’ first year of life. The samples were examined for Cryptosporidium spp. using PCR, targeting the small subunit ribosomal RNA gene (SSU rRNA). Further analysis of Cryptosporidium parvum and Cryptosporidium canis positive samples was accomplished using the 60 kDa glycoproteine gene (GP60). Overall, 10.0% (35/349) of the specimens were tested positive for Cryptosporidium. Cryptosporidium canis was found in 94.3% (33/35) of these samples and the zoonotic type C. pavum in 5.7% (2/35). Both C. parvum infections were subtyped as IIaA15G2R1. Sixteen of the C. canis positive samples were successfully amplified at the GP60 gene locus. These isolates were identified to belong to the subtype families XXd, XXe, or XXb; however, 2 samples could not be assigned to any of the described subtype families. Considering the close contact between pets and their owners, dogs may act as a potential source of infection for human cryptosporidiosis. The results of this study, in context with other studies from different countries, provide important further insights into the distribution of Cryptosporidium species in dogs and their zoonotic potential.

Assessment microbial risks for the presence of Cryptosporidium spp. and Giardia spp. based on the surveillance of the water supply systems in Colombia, 2014-2018

Cryptosporidium spp. and Giardia spp. cause gastrointestinal diseases of zoonotic origin as well transmitted from person to person, being various reported outbreaks associated with water. The infecting (oo)cyst forms of these parasites are highly resistant to water treatments such as chlorine disinfection and fast filtration. The objective of this study was to assess the microbial risk of infection and symptomatic illness by the ingestion of Giardia spp. and Cryptosporidium spp. in water for human consumption in Colombia, based on the results of water quality surveillance. The detection method was according to the USEPA method 1623. Concentration data of the different points of distribution were grouped according to the pathogen and type of treatment (no treatment; chlorine treatment; chlorine treatment + coagulant). Annual microbial risks of infection and symptomatic diseases were estimated using the quantitative microbial risk assessment approach that included parasite concentrations, the dose-response model, the ingestion rates of water by children and adults, and the morbidity rate of the diseases. The mean annual microbial risk of infection for Giardia spp. was 29.8% for treated water and 50.4% for untreated water, while being 6.0% and 17.7%, respectively, for Cryptosporidium spp. Microbial risk of symptomatic illness for Giardia spp, was 8.2% for treated water and 13.9% for untreated water, while being 3.6% and 10.6%, respectively, for Cryptosporidium spp. The estimated annual microbial risks of infection exceeded the acceptable value of 10^-4 (0.01%) recommended by USEPA. Results obtained in this study suggest the need to reduce the microbial risk of infection to protozoan parasites by improving the water treatment, by adopting better handling practices for livestock manure and treatment processes of human feces. PRACTITIONER POINTS: The presence of Cryptosporidium spp was identified in 28 (6.2%) samples and Giardia spp in 29 (6.4%) in water for human consumption in Colombia. The mean annual risk of symptomatic illness due to infection by Giardia spp or Cryptosporidium spp ranges from 33.6%, for treated water, to 58.1%, for untreated water. Annual risks ingestion of protozoa studying in water for human exceed of 10-4 (0.01%) recommended by USEPA.

Cryptosporidium diagnosis in different groups of children and characterization of parasite species

Background:

Microscopy and enzyme-linked immunosorbent assay (ELISA) are routinely used for Cryptosporidium diagnosis, without differentiating the parasite species.

Methods:

Children’s feces were analyzed by modified Ziehl-Neelsen (mZN) and ELISA for Cryptosporidium diagnosis and by polymerase chain reaction-restriction fragment length polymorphism for species identification.

Results:

Cryptosporidium frequency was 2.6%. The sensitivity and specificity of ELISA were 85.7% and 99.7%, respectively, with excellent concordance with mZN (kappa=0.854). Parasite species were characterized as Cryptosporidium hominis (78.3%), Cryptosporidium felis (17.4%), and Cryptosporidium parvum (4.3%).

Conclusions:

Coproantigen ELISA is as efficient as mZN for Cryptosporidium diagnosis. Cryptosporidium genotyping suggests anthroponotic and zoonotic transmission to children.

Overview on Cryptosporidium bovis and Its Effect on Calves in Some Governorates in Egypt

The present study was conducted to elucidate the prevalence of Cryptosporidium bovis in suckling and weaned cattle calves (Bubalus bubalis) from different governorates in northern, middle, and southern Egypt, such as Behera, Menofia, Qaliubiya, Assiut, and Sohag; result revealed that from the overall examined fecal samples (n = 825), the overall prevalence was 7.27%, the highest significant infection rate was in young suckling calves less than one month (8.2%), and seasonally, winter season has the highest significant level (11.24%), but sex and locality were of no significant effect on the prevalence of infection in this study. Gene sequencing and phylogenetic analysis of the 18SSU-rRNA gene of the local bovine isolate were performed, and it was found that C. bovis genotype was highly similar to human isolate, which provoke the zoonotic transmission of bovine isolate to humans and identified as a potential source for human cryptosporidiosis infection in Egypt.

A multi-epitope vaccine candidate developed from unique immunogenic epitopes against Cryptosporidium hominis by utilizing an immunoinformatics-driven approach

An immunoinformatics-based strategy is being investigated to identify prospective multi-subunit vaccine candidates against Cryptosporidium hominis (C. hominis). We used a systematic technique based on protein structure to create a competent multi-subunit vaccine candidate against C. hominis, with the likelihood of antigenicity, allergenicity, and transmembrane helices as the screening criteria. Using the suitable linkers, the best-screened epitopes such as B-cell epitopes (BCL), Helper T-lymphocytes (HTL), and cytotoxic T-lymphocytes (CTL) were linked together to intensify and develop the presentation and processing of the antigenic molecules. The greatest 3 D model of the component protein was created with the help of modeling software called Raptorax. The validation of the modeled protein was accomplished via the use of PROCHECK. Furthermore, using the ClusPro web server, the projected modeled structure was docked with known receptor TLR-4 to determine their interactions. A molecular dynamics (MD) simulation was used to investigate the stability of the multi-subunit vaccine bound with TLR-4 based on the docking score. Aside from that, the codon optimization and in silico expression demonstrate the possibility of high expression and simple purification of the vaccine product resulting from codon optimization. The overall findings indicated that the multi-subunit vaccine might be a viable vaccination candidate against C. hominis.Communicated by Ramaswamy H. Sarma.

Cryptosporidium of birds in pet markets in Wuhan city, Hubei, China

Cryptosporidium is a group of protistan parasites of a range of vertebrates including mammals and birds. Stimulated by previous work that revealed “zoonotic” Cryptosporidium meleagridis subtypes (i.e. IIIbA26G1R1b and IIIbA22G1R1c) in diarrhoeic children and domestic chickens in Wuhan city and environs in Hubei Province, China, here we explored whether zoonotic C. meleagridis subtypes might also occur in pet birds in Wuhan city. From 11 bird markets in this city, we collected 322 faecal samples from 48 species of birds (representing six taxonomic orders), isolated genomic DNA and then conducted PCR-based sequencing of genetic markers in the small subunit (SSU) of the nuclear ribosomal RNA and the 60 kDa glycoprotein (gp60) genes of Cryptosporidium. Using SSU, Cryptosporidium was detected in 55 (17%) of the 322 samples. Cryptosporidium avium, C. baileyi, C. meleagridis, C. muris and C. proventriculi were characterised in 18%, 47%, 11%, 2% and 20% of the 55 samples, respectively, and a novel Cryptosporidium galli-like taxon in one sample. Using gp60, only one subtype (IIIeA17G2R1) of C. meleagridis was identified, which had not been detected in a previous study of diarrhoeic children in Wuhan. However, IIIe subtypes have been found in both humans and birds around the world. The relatively high prevalence and genetic diversity of Cryptosporidium recorded here in pet birds raise awareness about possible reservoirs of zoonotic variants of Cryptosporidium in birds in Wuhan, and potentially, other provinces in China.

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A total of 322 faecal samples from 48 species of pet birds were tested for Cryptosporidium.

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Relatively high prevalence and genetic diversity of Cryptosporidium were found.

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A novel Cryptosporidium galli-like genotype was recorded.

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A Cryptosporidium meleagridis subtype with zoonotic potential was detected.

High Occurrence of Zoonotic Subtypes of Cryptosporidiumparvum in Cypriot Dairy Farms

Cryptosporidium parvum is one of the major causes of neonatal calf diarrhoea resulting in reduced farm productivity and compromised animal welfare worldwide. Livestock act as a major reservoir of this parasite, which can be transmitted to humans directly and/or indirectly, posing a public health risk. Research reports on the prevalence of Cryptosporidium in ruminants from east Mediterranean countries, including Cyprus, are limited. This study is the first to explore the occurrence of Cryptosporidium spp. in cattle up to 24 months old on the island of Cyprus. A total of 242 faecal samples were collected from 10 dairy cattle farms in Cyprus, all of which were screened for Cryptosporidium spp. using nested-PCR amplification targeting the small subunit of the ribosomal RNA (18S rRNA) gene. The 60 kDa glycoprotein (gp60) gene was also sequenced for the samples identified as Cryptosporidium parvum-positive to determine the subtypes present. The occurrence of Cryptosporidium was 43.8% (106/242) with at least one positive isolate in each farm sampled. Cryptosporidium bovis, Cryptosporidium ryanae and C. parvum were the only species identified, while the prevalence per farm ranged from 20–64%. Amongst these, the latter was the predominant species, representing 51.8% of all positive samples, followed by C. bovis (21.7%) and C. ryanae (31.1%). Five C. parvum subtypes were identified, four of which are zoonotic—IIaA14G1R1, IIaA15G1R1, IIaA15G2R1 and IIaA18G2R1. IIaA14G1R1 was the most abundant, representing 48.2% of all C. parvum positive samples, and was also the most widespread. This is the first report of zoonotic subtypes of C. parvum circulating in Cyprus. These results highlight the need for further research into the parasite focusing on its diversity, prevalence, host range and transmission dynamics on the island.

Prevalence and Factors Associated with Cryptosporidium Infection in Calves in and around Nekemte Town, East Wollega Zone of Ethiopia

Purpose

Cryptosporidiosis, caused by a protozoan parasite of the genus Cryptosporidium, is a zoonotic disease that affects young animals and humans. The study was conducted from October 2020 to May 2021, with the objectives of estimating the prevalence of Cryptosporidium infection in calves and assessing the associated risk factors in Nekemte town, Ethiopia.

Methods

A cross-sectional study was adopted during the study period. Initially, 35 dairy farms were selected using a systematic study approach from which a total of 384 calves under the age of 12 months (75 calves from intensive, 51 from semi-intensive, and 258 from extensive dairy farms) were selected purposively for fecal sample collection. Fecal samples were collected directly from the rectum of each calf and tested for Cryptosporidium oocysts using Sheather's flotation and a modified Ziehl–Neelsen staining procedure. The data were analyzed using STATA statistical software version 13.

Results

Cryptosporidium infection was found in 53 of the 384 calves investigated, with an overall prevalence of 13.8% (95% CI = 8.1–17.6). Logistic regression analysis on the risk factors showed that types of farm, age, body condition scores, fecal consistency, types of feed, source of water, and farm hygiene were found to have a statistically significant influence on the shedding of Cryptosporidium oocysts by the calves (p < 0.05). Calves under the age of six months had a higher likelihood (OR = 2.7, 95% CI = 1.0–4.2, p < 0.001) of shedding the oocysts than the calves of 6 to 12 months of age. It was also confirmed that calves with poor body condition scores had a higher likelihood (OR = 2.6, 95% CI = 1.2–3.7, p=0.024) of shedding the Cryptosporidium oocysts than other ones. The likelihood of shedding a Cryptosporidium oocyst by the diarrheic calves was higher than by the nondiarrheic ones (OR = 3.1, p < 0.001). The infection was 2.6 times highest (16.8%, 31/185, 95% CI = 14.5–19.1, OR = 2.6, p=0.028) in calves feeding on grass alone, followed by milk and grass (15%) and milk (4.2%). Similarly, it was 2.2 times higher (18.5%, OR = 2.2, and p=0.002) in calves drinking river water than in calves drinking tap water. Moreover, calves kept under poor hygiene were more likely to shed Cryptosporidium oocysts (OR = 2.8, p=0.001) than calves kept under good hygiene.

Conclusion

In conclusion, cryptosporidiosis is one of the health problems of calves in and around Nekemte town, East Wollega zone. Our findings confirmed that risk factors such as types of farm, age, body condition scores, fecal consistency, types of feed, water source, and farm hygienic status were found to have a significant effect on the occurrence of Cryptosporidium infection in the calves. While the molecular-based study is required to be carried out aiming at species identification and the epidemiology of the parasite, particular attention should be paid to the control of the disease in the study area.

Cryptosporidium felis differs from other Cryptosporidium spp. in codon usage

Cryptosporidium spp. are important enteric pathogens in a wide range of vertebrates including humans. Previous comparative analysis revealed conservation in genome composition, gene content, and gene organization among Cryptosporidium spp., with a progressive reductive evolution in metabolic pathways and invasion-related proteins. In this study, we sequenced the genome of zoonotic pathogen Cryptosporidium felis and conducted a comparative genomic analysis. While most intestinal Cryptosporidium species have similar genomic characteristics and almost complete genome synteny, fewer protein-coding genes and some sequence inversions and translocations were found in the C. felis genome. The C. felis genome exhibits much higher GC content (39.6 %) than other Cryptosporidium species (24.3–32.9 %), especially at the third codon position (GC3) of protein-coding genes. Thus, C. felis has a different codon usage, which increases the use of less energy costly amino acids (Gly and Ala) encoded by GC-rich codons. While the tRNA usage is conserved among Cryptosporidium species, consistent with its higher GC content, C. felis uses a unique tRNA for GTG for valine instead of GTA in other Cryptosporidium species. Both mutational pressures and natural selection are associated with the evolution of the codon usage in Cryptosporidium spp., while natural selection seems to drive the codon usage in C. felis. Other unique features of the C. felis genome include the loss of the entire traditional and alternative electron transport systems and several invasion-related proteins. Thus, the preference for the use of some less energy costly amino acids in C. felis may lead to a more harmonious parasite–host interaction, and the strengthened host-adaptation is reflected by the further reductive evolution of metabolism and host invasion-related proteins.

Infection agents of Didelphidae (Didelphimorphia) of Brazil: an underestimated matter in zoonoses research

Zoonoses are diseases or infections naturally transmissible from vertebrate animals to humans, and can be bacterial, viral or parasitic. The growth of urbanization, industrialization and the advance of agriculture and livestock facilitate the spread of infectious and parasitic agents from wild animals to the human population and to their domestic animals. Among the various reservoirs of zoonotic agents, we find that didelphid species, due to their high capacity for adaptation in urban environments, as an important study case. We reviewed the literature data on the pathogens, including with zoonotic potential of marsupial species occurring in Brazil, accounted for infections by agents that we categorized into Bacteria, Viruses, Protozoa, and Helminths. Aiming identifies possible knowledge gaps, we also surveyed the origin of studied samples and the institutions leading the researches on host didelphids. Among the hosts, the genus Didelphis in the cycles of these agents stands out. Moreover, we found that the majority of reported cases are in the Southeastern Brazil, mean the data from other Brazilian localities and didelphid species could be underestimated. Most studies took place in graduate programs of public research institutions, emphasizing the importance of the funding public research for the Brazilian scientific development.

Prevalence and molecular characterization of Cryptosporidium spp. and Enterocytozoon bieneusi from large-scale cattle farms in Anhui Province, China

To investigate the prevalence of Cryptosporidium spp. and Enterocytozoon bieneusi from large-scale cattle farms in Anhui Province, 955 fecal samples were collected from 16 cattle farms from March to October 2018, which included six dairy farms (526), seven yellow cattle farms (323), and three water buffalo farms (106) in different regions of Anhui Province. PCR was conducted on all fecal samples using the 18S ribosomal RNA of Cryptosporidium spp. and internal transcribed spacer gene of E. bieneusi to detect these two pathogens, and the positive samples were sequenced and analyzed. The results showed that 23 (2.4%) and 40 (4.2%) out of the 955 samples were positive for Cryptosporidium spp. and E. bieneusi, respectively. There were 11 (2.1%), 10 (3.1%), and 2 (1.9%) positive samples of Cryptosporidium spp. and 16 (3.0%), 23 (7.1%), and 1 (0.9%) positive samples of E. bieneusi collected from dairy cattle, yellow cattle, and water buffalo, respectively, and no co-infection was identified in this study. All positive samples of Cryptosporidium spp. were C. andersoni with some variations. Ten E. bieneusi genotypes were obtained, including two known genotypes, J and CHN11, and eight new genotypes, named AHDC1 and AHYC1-7. The genotype CHN11 belonged to zoonotic Group 1, and the other nine genotypes belonged to Group 2, which is mainly documented in ruminants. These results indicated that Cryptosporidium spp. and E. bieneusi infections were present in large-scale cattle farms in Anhui Province. Therefore, attention should be paid to the development of containment strategies of these two pathogens in cattle.

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.

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 in fish: Implications for aquaculture and beyond

Aquaculture industries are expanding worldwide and control of Cryptosporidium is of great importance. Cryptosporidiosis is a serious waterborne/foodborne disease, responsible for infectious outbreaks globally. Current knowledge on the Cryptosporidium species in the aquatic environment and their occurrence in piscine hosts is steadily increasing since the Cryptosporidium species have been detected in marine, freshwater, cultured, captive and ornamental fish in a wide range of geographical regions. The zoonotic potential of these parasites and their pathological impact on piscine hosts have been increasingly reported and the fishborne zoonotic risk from Cryptosporidium spp. is of major importance from a public health point of view. Zoonotic subtypes in fish have been described in various studies and are probably related to water contamination from animal and human wastes. This review critically evaluated existing scientific data, related to Cryptosporidium species in piscine hosts, emphasizing transmission routes and the potential impact of piscine cryptosporidiosis in aquaculture. This knowledge will facilitate consumers, authorities and water industries such as fisheries and aquaculture, the prevention and control of waterborne and fishborne cryptosporidiosis in fish products.

Evolving Patterns of Cryptosporidiosis: Issues and Implications in the Context of Public Health in India

Cryptosporidiosis is one of the major causes of diarrhea in immune-compromised individuals and children besides causing sporadic water-borne, food-borne, and zoonotic outbreaks. In 2016, Cryptosporidium species infection was the fifth leading cause of diarrhea and acute infection causing more than 4.2 million disability-adjusted life years lost besides a decrease in childhood growth. Human cryptosporidiosis is primarily caused by two species/genotype: Cryptosporidium hominis (anthroponotic) and Cryptosporidium parvum (zoonotic) besides other six rare species/genotypes. Transmission intensity, genetic diversity, and occurrence of genetic recombination have shaped the genus Cryptosporidium population structures into palmitic, clonal, and epidemic. Genetic recombination is more in C. parvum compared with C. hominis. Furthermore, parasite–host co-evolution, host adaptation, and geographic segregation have led to the formation of “subtype- families.” Host-adapted subtype-families have distinct geographical distribution and host preferences. Genetic exchanges between subtypes played an important role throughout the evolution of the genus leading to “adaptation introgression” that led to emergence of virulent and hyper-transmissible subtypes. The population structure of C. hominis in India appears to be more complex where both transmission intensity and genetic diversity are much higher. Further, study based on “molecular strain surveillance” has resulted newer insights into the epidemiology and transmission of cryptosporidiosis in India. The identification at the species and genotype levels is essential for the assessment of infection sources in humans and the public health potential of the parasite at large. The results of the study over three decades on cryptosporidiosis in India, in the absence of a national surveillance data, were analyzed highlighting current situation on epidemiology, genetic diversity, and distribution particularly among vulnerable population. Despite creditable efforts, there are still many areas need to be explored; therefore, the intent of this article is to facilitate future research approaches for mitigating the burden associated with this disease.

High Diversity of Cryptosporidium Species and Subtypes Identified in Cryptosporidiosis Acquired in Sweden and Abroad

The intestinal protozoan parasite Cryptosporidium is an important cause of diarrheal disease worldwide. The aim of this study was to expand the knowledge on the molecular epidemiology of human cryptosporidiosis in Sweden to better understand transmission patterns and potential zoonotic sources. Cryptosporidium-positive fecal samples were collected between January 2013 and December 2014 from 12 regional clinical microbiology laboratories in Sweden. Species and subtype determination was achieved using small subunit ribosomal RNA and 60 kDa glycoprotein gene analysis. Samples were available for 398 patients, of whom 250 (63%) and 138 (35%) had acquired the infection in Sweden and abroad, respectively. Species identification was successful for 95% (379/398) of the samples, revealing 12 species/genotypes: Cryptosporidium parvum (n = 299), C. hominis (n = 49), C. meleagridis (n = 8), C. cuniculus (n = 5), Cryptosporidium chipmunk genotype I (n = 5), C. felis (n = 4), C. erinacei (n = 2), C. ubiquitum (n = 2), and one each of C. suis, C. viatorum, C. ditrichi, and Cryptosporidium horse genotype. One patient was co-infected with C. parvum and C. hominis. Subtyping was successful for all species/genotypes, except for C. ditrichi, and revealed large diversity, with 29 subtype families (including 4 novel ones: C. parvum IIr, IIs, IIt, and Cryptosporidium horse genotype Vic) and 81 different subtypes. The most common subtype families were IIa (n = 164) and IId (n = 118) for C. parvum and Ib (n = 26) and Ia (n = 12) for C. hominis. Infections caused by the zoonotic C. parvum subtype families IIa and IId dominated both in patients infected in Sweden and abroad, while most C. hominis cases were travel-related. Infections caused by non-hominis and non-parvum species were quite common (8%) and equally represented in cases infected in Sweden and abroad.

Advances in molecular epidemiology of cryptosporidiosis in dogs and cats

The use of molecular tools has led to the identification of several zoonotic Cryptosporidium spp. in dogs and cats. Among them, Cryptosporidium canis and Cryptosporidium felis are dominant species causing canine and feline cryptosporidiosis, respectively. Some Cryptosporidium parvum infections have also been identified in both groups of animals. The identification of C. canis, C. felis and C. parvum in both pets and owners suggests the possible occurrence of zoonotic transmission of Cryptosporidium spp. between humans and pets. However, few cases of such concurrent infections have been reported. Thus, the cross-species transmission of Cryptosporidium spp. between dogs or cats and humans has long been a controversial issue. Recently developed subtyping tools for C. canis and C. felis should be very useful in identification of zoonotic transmission of both Cryptosporidium spp. Data generated using these tools have confirmed the occurrence of zoonotic transmission of these two Cryptosporidium spp. between owners and their pets, but have also shown the potential presence of host-adapted subtypes. Extensive usage of these subtyping tools in epidemiological studies of human cryptosporidiosis is needed for improved understanding of the importance of zoonotic transmission of Cryptosporidium spp. from pets.

Prevalence of Select Intestinal Parasites in Alabama Backyard Poultry Flocks

Simple Summary

As biosecurity is generally low in backyard chicken flocks, infections with various pathogens are common. This puts other poultry nearby, including commercial flocks, at risk. Some chicken pathogens can also infect humans and cause disease. In this study, backyard poultry flocks were tested for parasites. Eighty-four fecal samples, 82 from chickens and two from turkeys, from 64 backyard flocks throughout the state of Alabama were collected in the summers of 2017 and 2018. The most frequently observed parasites were coccidia, unicellular parasites capable of causing diarrhea. Eggs of various roundworms were observed in 20.3–26.6% of the flocks. These parasites were usually present in low numbers only. Other detected parasites were the flagellates Histomonas meleagridis and Tetratrichomonas gallinarum in 4.7% and 18.8% of flocks. Both can cause severe disease in poultry. Detected parasites that can cause disease in humans were Cryptosporidium spp. in 18.8% of the flocks and Blastocystis spp. in 87.5% of the flocks. The results will help to provide information that can be used to design outreach programs to improve the health and wellbeing of birds in backyard flocks.

Abstract

Keeping chickens as backyard pets has become increasingly popular in the United States in recent years. However, biosecurity is generally low in backyard flocks. As a consequence, they can serve as reservoirs for various pathogens that pose a risk for commercial poultry or human health. Eighty-four fecal samples, 82 from chickens and two from turkeys, from 64 backyard flocks throughout the state of Alabama were collected in the summers of 2017 and 2018. Coccidia oocysts were seen in 64.1% of flocks with oocyst counts in most samples below 10,000 oocysts per gram. Eggs of Ascaridia spp. or Heterakis gallinarum were observed in 20.3% of the flocks, and eggs of Capillaria spp. in 26.6% of the flocks. Egg counts were low, rarely exceeding 1000 eggs per gram. DNA extracted directly from fecal samples was investigated by PCR for other relevant parasites. The results showed that 4.7% of flocks were positive for Histomonas meleagridis, 18.8% of flocks for Tetratrichomonas gallinarum, 18.8% of flocks for Cryptosporidium spp. and 87.5% of flocks for Blastocystis spp. The results will help to provide information that can be used to design outreach programs to improve health and wellbeing of birds in backyard flocks.

Development of a Subtyping Tool for Zoonotic Pathogen Cryptosporidium canis

Cryptosporidium canis is an important cause of cryptosporidiosis in canines and humans. Studies of the transmission characteristics of C. canis are currently hampered by the lack of suitable subtyping tools. In this study, we conducted a genomic survey of the pathogen and developed a subtyping tool targeting the partial 60-kDa glycoprotein gene (gp60). Seventy-six isolates previously identified as C. canis were analyzed using the new subtyping tool. Amplicons of the expected size were obtained from 49 isolates, and phylogenetic analysis identified 10 subtypes clustered into five distinct groups (XXa to XXe). The largest group, XXa, contained 43 isolates from four subtypes that differed slightly from each other at the nucleotide level, while groups XXb to XXe contain one to three isolates each. The similar distributions of subtypes in humans and canines suggest that zoonotic transmission might play an important role in the epidemiology of C. canis In addition, suspected zoonotic transmission of C. canis between dogs and humans in a household was confirmed using the subtyping tool. The subtyping tool and data generated in this study might improve our understanding of the transmission of this zoonotic pathogen.

A review of Cryptosporidium spp. and their detection in water

Cryptosporidium spp. are one of the most important waterborne pathogens worldwide and a leading cause of mortality from waterborne gastrointestinal diseases. Detection of Cryptosporidium spp. in water can be very challenging due to their low numbers and the complexity of the water matrix. This review describes the biology of Cryptosporidium spp. and current methods used in their detection with a focus on C. parvum and C. hominis. Among the methods discussed and compared are microscopy, immunology-based methods using monoclonal antibodies, molecular methods including PCR (polymerase chain reaction)-based assays, and emerging aptamer-based methods. These methods have different capabilities and limitations, but one common challenge is the need for better sensitivity and specificity, particularly in the presence of contaminants. The application of DNA aptamers in the detection of Cryptosporidium spp. oocysts shows promise in overcoming these challenges, and there will likely be significant developments in aptamer-based sensors in the near future.

Epidemiology of Cryptosporidiosis in France from 2017 to 2019

Cryptosporidiosis is currently recognized worldwide as a leading cause of moderate to severe diarrhea. In Europe, large water- and foodborne outbreaks have been reported, highlighting the widespread distribution of the parasite and its important health impact. Surveillance networks have been progressively set up and the aim of this study was to present recent epidemiological data obtained in France from 2017 to 2019 by the National Reference Center-Expert Laboratory of cryptosporidiosis (Centre National de Référence-Laboratoire Expert cryptosporidioses CNR-LE). Data were obtained from online reports of volunteer network participants and stools were sent to the CNR-LE for species identification and GP60 genotyping. During this period, data from 750 online reports were available. Cryptosporidiosis occurred predominantly in young children (<5 years old) and in young adults, especially during late summer. Most patients were immunocompetent (60%), and deaths were reported only in immunocompromised patients. Cryptosporidium parvum was largely predominant (72% of cases) over C. hominis (24%) and some other uncommon species. C. parvum GP60 subtypes IIa and IId were the most represented, which suggests frequent zoonotic transmission. For C. hominis, subtypes IbA10G2 and IaA22R2 were predominant.

Comparative genetic diversity of Cryptosporidium species causing human infections

Parasites sometimes expand their host range and cause new disease aetiologies. Genetic changes can then occur due to host-specific adaptive alterations, particularly when parasites cross between evolutionarily distant hosts. Characterizing genetic variation in Cryptosporidium from humans and other animals may have important implications for understanding disease dynamics and transmission. We analyse sequences from four loci (gp60, HSP-70, COWP and actin) representing multiple Cryptosporidium species reported in humans. We predicted low genetic diversity in species that present unusual human infections due to founder events and bottlenecks. High genetic diversity was observed in isolates from humans of Cryptosporidium meleagridis, Cryptosporidium cuniculus, Cryptosporidium hominis and Cryptosporidium parvum. A deviation of expected values of neutrality using Tajima's D was observed in C. cuniculus and C. meleagridis. The high genetic diversity in C. meleagridis and C. cuniculus did not match our expectations but deviations from neutrality indicate a recent decrease in genetic variability through a population bottleneck after an expansion event. Cryptosporidium hominis was also found with a significant Tajima's D positive value likely caused by recent population expansion of unusual genotypes in humans. These insights indicate that changes in genetic diversity can help us to understand host-parasite adaptation and evolution.

Use of Veterinary Vaccines for Livestock as a Strategy to Control Foodborne Parasitic Diseases

Foodborne diseases (FBDs) are a major concern worldwide since they are associated with high mortality and morbidity in the human population. Among the causative agents of FBDs, Taenia solium, Echinococcus granulosus, Toxoplasma gondii, Cryptosporidium spp., and Trichinella spiralis are listed in the top global risk ranking of foodborne parasites. One common feature between them is that they affect domestic livestock, encompassing an enormous risk to global food production and human health from farm to fork, infecting animals, and people either directly or indirectly. Several approaches have been employed to control FBDs caused by parasites, including veterinary vaccines for livestock. Veterinary vaccines against foodborne parasites not only improve the animal health by controlling animal infections but also contribute to increase public health by controlling an important source of FBDs. In the present review, we discuss the advances in the development of veterinary vaccines for domestic livestock as a strategy to control foodborne parasitic diseases.

Cryptosporidium species and cryptosporidiosis in Japan: a literature review and insights into the role played by animals in its transmission

Cryptosporidium species infect domestic animals, livestock, and humans. These protozoan parasites are frequently reported as major environmental contaminants in many countries despite their differing climatic, socioeconomic, and demographic factors. This review focuses on the research findings that relate to Cryptosporidium epidemiology, genetic diversity, and associated risk factors relating to animals, contaminated water sources, and humans in Japan. Adequate knowledge of these factors is essential for understanding the economic and public health importance of cryptosporidiosis in Japan so that effective control strategies against it are implemented. Cryptosporidium infections are highly prevalent in animals in Japan. Among the different animal species, cattle infections stand out because of their economic importance and zoonotic potential. Living circumstances in Japan restrain Cryptosporidium transmission between humans, but there is evidence to suggest that animals, especially those in close contact with humans, can be potential sources of human infections. Water sampling studies have provided clues about how environmental contamination with Cryptosporidium oocysts can cause infections in livestock and wild animals. There is some evidence of person-to-person transmission of cryptosporidiosis, but only occasionally and under certain circumstances. By identifying the major role played by animals in Cryptosporidium transmission to people in Japan, we highlight the urgent need for disease control against this pathogen.

Species and genotypes causing human cryptosporidiosis in New Zealand

Cryptosporidium is one of the most common causes of diarrhoea around the world. Successful management and prevention of this infectious disease requires knowledge of the diversity of species and subtypes causing human disease. We use sequence data from 2598 human faecal samples collected during an 11-year period (2009-2019) to better understand the impact of different species and subtypes on public health and to gain insights into the variation of human cryptosporidiosis in New Zealand. Human cryptosporidiosis in New Zealand is caused by a high diversity of species and subtypes. Six species cause human disease in New Zealand: C. hominis, C. parvum, C. cuniculus, C. erinacei, C. meleagridis and C. tyzzeri. Sequence analysis of the gp60 gene identified 16 subtype families and 101 subtypes. Cryptosporidium hominis IbA10G2 and C. parvum IIaA18G3R1 were the most frequent causes of human cryptosporidiosis with 27% and 29% of infections, respectively. Cryptosporidium hominis presented a peak of notified human cases during autumn (March-May) whereas most cases of human cryptosporidiosis caused by C. parvum are found during the calving and lambing season in spring (September-November). We also reported some subtypes that have been rarely detected in other countries such as IbA20G2 and IIoA13G1 and a low prevalence of the hypertransmissible and virulent IIaA15G2R1. This study provides insight into the variability of cryptosporidiosis in New Zealand essential for disease management and surveillance to prevent the introduction or spread of new species and subtypes in the country.

A retrospective epidemiological analysis of human Cryptosporidium infection in China during the past three decades (1987-2018)

Background

Cryptosporidiosis is an emerging infectious disease of public health significance worldwide. The burden of disease caused by Cryptosporidium varies between and within countries/areas. To have a comprehensive understanding of epidemiological status and characteristics of human Cryptosporidium infection in China since the first report in 1987, a retrospective epidemiological analysis was conducted by presenting differences in the prevalence of Cryptosporidium by province, year, population, living environment and season and possible transmission routes and risk factors as well as genetic characteristics of Cryptosporidium in humans.

Methodology/Principal findings

A systematic search was conducted to obtain epidemiological papers of human Cryptosporidium infection/cryptosporidiosis from PubMed and Chinese databases. Finally, 164 papers were included in our analysis. At least 200,054 people from 27 provinces were involved in investigational studies of Cryptosporidium, with an average prevalence of 2.97%. The prevalence changed slightly over time. Variable prevalences were observed: 0.65–11.15% by province, 1.89–47.79% by population, 1.77–12.87% and 0–3.70% in rural and urban areas, respectively. The prevalence peak occurred in summer or autumn. Indirect person-to-person transmission was documented in one outbreak of cryptosporidiosis in a pediatric hospital. 263 Cryptosporidium isolates were obtained, and seven Cryptosporidium species were identified: C. hominis (48.3%), C. andersoni (22.43%), C. parvum (16.7%), C. meleagridis (8.36%), C. felis (3.04%), C. canis (0.76%) and C. suis (0.38%).

Conclusions/Significances

This systematic review reflects current epidemiological status and characteristics of Cryptosporidium in humans in China. These data will be helpful to develop efficient control strategies to intervene with and prevent occurrence of human Cryptosporidium infection/cryptosporidiosis in China as well as have a reference effect to other countries. Further studies should focus on addressing a high frequency of C. andersoni in humans and a new challenge with respect to cryptosporidiosis with an increasing population of elderly people and patients with immunosuppressive diseases.

Cryptosporidium is a major cause of diarrheal disease in humans globally. Due to the lack of effective drug treatment and vaccine prevention against cryptosporidiosis, it is particularly important to develop efficient control strategies to intervene with and prevent Cryptosporidium infection in humans. The present review presented and analyzed epidemiological status and characteristics of Cryptosporidium infection in humans in China since the first report in 1987. To date, epidemiological investigations of Cryptosporidium infecion have been carried out in different populations in 27 provinces, autonomous regions, and municipalities. Average prevalence of Cryptosporidium was 2.97% (5,933/200,054). Like other infectious disease, due to poor sanitation conditions in rural areas, people living in rural areas had a significantly higher prevalence of Cryptosporidium (1.77–12.87%) than those living in urban areas (0–3.70%). Seven Cryptosporidium species were identified, including C. hominis, C. andersoni, C. parvum, C. meleagridis, C. felis, C. canis and C. suis. This retrospective epidemiological analysis indicates wide geographical distribution of human Cryptosporidium infection/cryptosporidiosis in China.

Molecular study and genotyping of Cryptosporidium baileyi and Cryptosporidium parvum from free-range and commercial broiler chickens in Guilan province, Iran

Cryptosporidiosis acutely impacts the digestive and/or respiratory tract of the birds in many species of various orders. More importantly, it is also well known as a significant zoonotic disease, which can lead to diarrhea in humans and livestock. Regarding increasing demand for free-range products and increasing the number of free-range poultry farms, the present paper evaluated histopathological and molecular detection of Cryptosporidium baileyi and Cryptosporidium parvum in free-range and commercial broiler chickens in the north part of Iran. For this purpose, 100 fecal and tissue samples of the chickens in Guilan province were collected. After microscopic examination using Ziehl-Neelsen staining, molecular analyses of the fecal samples were processed by Nested-PCR targeting the 18S rRNA gene followed by sequencing of the amplicons and phylogenetic analyses. Eventually, the tissue samples were studied for histological lesions. Findings demonstrated the presence of Cryptosporidium baileyi and Cryptosporidium parvum in 6 % and 2 % of fecal samples, respectively. This is the first identification of C.parvum in avian hosts in Iran, and for the first time, C.baileyi and C.parvum are shown in native free-range chickens in Iran. All of the PCR positive birds with clinical symptoms showed gross lesions of respiratory infections. There was no significant difference between infection rate in free-range and commercial broiler chickens; however, the infection rate was significantly higher in chickens <25 days old. To conclude, we present here a notable Cryptosporidium infection rate in the free-range chicks in Iran, which notify the role of this host as a reservoir and should be more noted due to the economic and zoonotic importance.

Biological HRPs in wastewater

Biological high-risk pollutants (HRPs) have become a serious threat to human health worldwide, and wastewater is one of the major sources of them in a natural environment. Despite the long history of wastewater research, comprehensive understanding of the role and behavior of HRPs during wastewater treatment is still limited owing to the complexity of the community. In recent decades, the rapid development of molecular tools, especially the wide application of next generation sequencing technologies, helps to unravel the community composition, structure, and dynamic variation in wastewater. Overall, this chapter mainly focuses on biological HRPs, including bacteria, viruses, protozoa, helminth, biotoxins, antibiotic resistance genes and antibiotic resistant bacteria in wastewater. The characteristics, classification, fates, functions, and health implications of these HRPs are introduced in detail. Moreover, the biogeography of HRPs is a research hotspot in recent years, and available information is also summarized in this chapter. Finally, we also propose the future research needs of HRPs in wastewater after the comprehensive summary of the existing research reports. This chapter is wished to be helpful for beginners to quickly understand the biological HRPs in wastewater.

Prevalence and genotyping identification of Cryptosporidium in adult ruminants in central Iran

Background

Apicomplexan parasites of the genus Cryptosporidium infect a wide range of animal species as well as humans. Cryptosporidium spp. can cause life threatening diarrhea especially in young animals, children, immunocompromised patients and malnourished individuals. Asymptomatic cryptosporidial infections in animals can also occur, making these animals potential reservoirs of infection.

Methods

In the present study, a molecular survey of Cryptosporidium spp. in ruminants that were slaughtered for human consumption in Yazd Province, located in central Iran was conducted. Faeces were collected per-rectum from 484 animals including 192 cattle, 192 sheep and 100 goats. DNA was extracted from all samples and screened for Cryptosporidium by PCR amplification of the 18S rRNA gene. Positives were Sanger sequenced and further subtyped by sequence analysis of the 60 kDa glycoprotein (gp60) locus.

Results

In total, Cryptosporidium spp. were detected in 22 animals: C. andersoni and C. bovis in seven and two cattle faecal samples, respectively, C. ubiquitum in five sheep, and C. xiaoi in six sheep and two goat samples, respectively. To our knowledge, this study provides for the first time, molecular information concerning Cryptosporidium species infecting goats in Iran, and is also the first report of C. ubiquitum and C. xiaoi from ruminants in Iran.

Conclusion

The presence of potentially zoonotic species of Cryptosporidium in ruminants in this region may suggest that livestock could potentially contribute to human cryptosporidiosis, in particular among farmers and slaughterhouse workers, in the area. Further molecular studies on local human populations are required to more accurately understand the epidemiology and transmission dynamics of Cryptosporidium spp. in this region.