Genotyping of Cryptosporidium spp. from free-living wild birds from Brazil

Food and Waterborne Cryptosporidiosis from a One Health Perspective: A Comprehensive Review

A sharp rise in the global population and improved lifestyles has led to questions about the quality of both food and water. Among protozoan parasites, Cryptosporidium is of great importance in this regard. Hence, Cryptosporidium's associated risk factors, its unique characteristics compared to other protozoan parasites, its zoonotic transmission, and associated economic losses in the public health and livestock sectors need to be focused on from a One Health perspective, including collaboration by experts from all three sectors. Cryptosporidium, being the fifth largest food threat, and the second largest cause of mortality in children under five years of age, is of great significance. The contamination of vegetables, fresh fruits, juices, unpasteurized raw milk, uncooked meat, and fish by Cryptosporidium oocysts occurs through infected food handlers, sewage-based contamination, agricultural effluents, infected animal manure being used as biofertilizer, etc., leading to severe foodborne outbreaks. The only Food and Drug Administration (FDA)-approved drug, Nitazoxanide (NTZ), provides inconsistent results in all groups of patients, and currently, there is no vaccine against it. The prime concerns of this review are to provide a deep insight into the Cryptosporidium's global burden, associated water- and foodborne outbreaks, and some future perspectives in an attempt to effectively manage this protozoal disease. A thorough literature search was performed to organize the most relevant, latest, and quantified data, justifying the title. The estimation of its true burden, strategies to break the transmission pathways and life cycle of Cryptosporidium, and the search for vaccine targets through genome editing technology represent some future research perspectives.

The risk of wild birds contaminating source water with zoonotic Cryptosporidium and Giardia is probably overestimated

Cryptosporidium and Giardia are important waterborne protozoan parasites that are resistant to disinfectants commonly used for drinking water. Wild birds, especially wild migratory birds, are often implicated in the contamination of source and wastewater with zoonotic diseases, due to their abundance near water and in urban areas and their ability to spread enteric pathogens over long distances. This review summarises the diversity of Cryptosporidium and Giardia in birds, with a focus on zoonotic species, particularly in wild and migratory birds, which is critical for understanding zoonotic risks. The analysis revealed that both avian-adapted and zoonotic Cryptosporidium species have been identified in birds but that avian-adapted Cryptosporidium species dominate in wild migratory birds. Few studies have examined Giardia species and assemblages in birds, but the non-zoonotic Giardia psittaci and Giardia ardeae are the most commonly reported species. The identification of zoonotic Cryptosporidium and Giardia in birds, particularly C. parvum and G. duodenalis assemblages A and B in wild migratory birds, is likely due to mechanical carriage or spillback from birds co-grazing pastures contaminated with C. parvum from livestock. Therefore, the role of wild migratory birds in the transmission of zoonotic Cryptosporidium and Giardia to source water is likely overestimated. To address knowledge gaps, it is important to conduct more extensive studies on the prevalence of Cryptosporidium and Giardia in a broader range of migratory wild birds. There is also a need to investigate the extent to which zoonotic infections with C. hominis/C. parvum and G. duodenalis assemblages A and B are mechanical and/or transient, and to assess the load and viability of zoonotic oo/cysts shed in avian faeces. Understanding the contribution of birds to zoonoses is essential for effective disease surveillance, prevention, and control.

First identification and molecular subtyping of Blastocystis in free-living wild birds from urban Xinxiang, China

Blastocystis is a common enteric protist infecting humans, domestic animals, and wildlife worldwide. However, data on the prevalence and subtype diversity of Blastocystis in free-living wild birds in urban districts are rare. In this study, a total of 138 fresh fecal samples from free-living wild birds were collected from three universities and three communities in Xinxiang, China, to explore the infection rate, Blastocystis subtypes present and zoonotic potential of this protist. Blastocystis presence was determined with nested-PCR amplification based on the partial small ribosomal subunit (SSU rRNA) gene. Presence was detected from one community (Wupu) at an overall rate of 1.5% (2/136). Further DNA sequencing and phylogenetic analyses identified two ruminant-associated subtypes, ST10 (n = 1) and ST24 (n = 1), implying a cross-species transmission of Blastocystis from ruminants. This is the first report on the infection of ST10 and ST24 in free-living wild birds in an urban area in China. As potentially zoonotic subtypes, the occurrence of ST10 and ST24 suggests that these free-living birds could play a role in spreading Blastocystis to humans in Xinxiang.

Cryptosporidium proventriculi in Captive Cockatiels (Nymphicus hollandicus)

Cockatiels (Nymphicus hollandicus) are among the most commonly sold psittacines pets. The aim of this study was to evaluate the occurrence of Cryptosporidium spp. in domestic N. hollandicus and identify risk factors for this infection. We collected fecal samples from 100 domestic cockatiels in the city of Araçatuba, São Paulo, Brazil. Feces from birds of both genders and older than two months were collected. Owners were asked to complete a questionnaire to identify how they handle and care for their birds. Based on nested PCR targeting the 18S rRNA gene, the prevalence of Cryptosporidium spp. in the cockatiels sampled was 9.00%, 6.00% based on Malachite green staining, 5.00% based on modified Kinyoun straining, and 7.00% when the Malachite green was combined with Kinyoun. Applying multivariate logistic regression to test the association between Cryptosporidium proventriculi positivity and potential predictors showed that gastrointestinal alterations was a significant predictor (p < 0.01). Amplicons from five samples were sequenced successfully and showed 100% similarity with C. proventriculi. In summary, this study demonstrates the occurrence of C. proventriculi in captive cockatiels.

Molecular and phylogenetic characterization of Cryptosporidium species in the saffron finch Sicalis flaveola

BACKGROUND

Cryptosporidium is the most common protozoan that can infect a wide variety of animals, including mammals and birds. Fecal samples of six saffron finches, Sicalis flaveola, from a commercial establishment were screened for the presence of Cryptosporidium by the modified Ziehl-Neelsen technique and nested PCR of the 18S rRNA gene followed by sequencing of the amplified fragments.

RESULTS

The species Cryptosporidium galli was identified in all six saffron fiches, in addition to Cryptosporidium andersoni in one of the birds, indicating a mixed infection. Only two birds had feathers that were ruffled and dirty with feces. Concomitant infection with Isospora spp. was observed in all birds.

CONCLUSIONS

Saffron finches are a possible host of C. andersoni and this is the first report of this species in a captive bird and the third report of parasitism by C. galli in Sicalis flaveola.

Cryptosporidiosis: From Prevention to Treatment, a Narrative Review

Cryptosporidiosis is a water- and food-borne zoonotic disease caused by the protozoon parasite of the genus Cryptosporidium. C. hominis and C. parvum are the main two species causing infections in humans and animals. The disease can be transmitted by the fecal-oral route as well as the respiratory route. The infective stage (sporulated oocysts) is resistant to different disinfectants including chlorine. Currently, no effective therapeutic drugs or vaccines are available to treat and control Cryptosporidium infection. To prevent cryptosporidiosis in humans and animals, we need to understand better how the disease is spread and transmitted, and how to interrupt its transmission cycle. This review focuses on understanding cryptosporidiosis, including its infective stage, pathogenesis, life cycle, genomics, epidemiology, previous outbreaks, source of the infection, transmission dynamics, host spectrum, risk factors and high-risk groups, the disease in animals and humans, diagnosis, treatment and control, and the prospect of an effective anti-Cryptosporidium vaccine. It also focuses on the role of the One Health approach in managing cryptosporidiosis at the animal-human-environmental interface. The summarized data in this review will help to tackle future Cryptosporidium infections in humans and animals and reduce the disease occurrence.

Cryptosporidium species in non-human animal species in Latin America: Systematic review and meta-analysis

Cryptosporidiosis is an infection caused by a protozoon that inhabits the gastrointestinal tract. More than forty valid species have been described in the genus Cryptosporidium, infecting a broad range of hosts around the world, some with zoonotic transmission and others with predominant anthroponotic transmission. Prevalence studies conducted in Latin American countries have been specific, without consolidating information on species prevalences. Thus, the aim of this study was to perform a systematic review and meta-analysis addressing the prevalence of Cryptosporidium species in animals in Latin America. The estimated pooled prevalence rate for cryptosporidiosis in animals, by means of meta-analysis with a random-effects model, based on species identification, was 18.0% (95% CI 11.0%-27.0%) with high heterogeneity. The estimated overall prevalence was 20.3% (36/177) in pets, 19.9% (1309/6573) in livestock animals and 23.9% (954/3995) in exotic/captive animals. Evidence of circulation of 16 Cryptosporidium species was found in five Latin American countries: Brazil, Colombia, Chile, Argentina and Mexico. Through meta-analysis with a random-effects model, the pooled prevalence rate for Cryptosporidium parvum was 0.7% (95% CI 0.2%-2.4%). Cryptosporidium felis (8.5%) was the most prevalent species in pets, C. parvum (10.3%) in livestock animals and Cryptosporidium galli (17.6%) in exotic/captive animals. C. parvum was the species with the greatest geographical dispersion, which can be explained by its eurixenic and zoonotic potential. Few studies on cryptosporidiosis in animals in Latin America were found, which shows that there is a need for investment in and expansion of studies on this parasite. The pooled prevalence of C. parvum in Latin America and its wide circulation are similar to what has been observed in other developing regions, which reaffirms the importance of this species as the cause of a neglected, emerging and zoonotic parasitosis.

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.

•

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

•

Relatively high prevalence and genetic diversity of Cryptosporidium were found.

•

A novel Cryptosporidium galli-like genotype was recorded.

•

A Cryptosporidium meleagridis subtype with zoonotic potential was detected.

Cryptosporidium and cryptosporidiosis in wild birds: A One Health perspective

Cryptosporidium is one of the most important parasitic protozoa that can be transmitted through food and water contamination. With the increasing report of Cryptosporidium infections in wild birds, especially in herbivorous waterfowl, concerns have been raised for oocyst contamination of water and food supplies, which in turn can cause human and domestic animal infections in areas neighboring wild birds' habitats. This review discusses the epidemiology, species, and genotypes distribution of Cryptosporidium in wild birds around the world. The overall prevalence of Cryptosporidium in wild birds was calculated as 3.96% (1945/49129), with 6 Cryptosporidium species (C. andersoni, C. parvum, C. meleagridis, C. avium, C. baileyi, and C. galli) and 5 genotypes (Goose genotype I, Goose genotype II, Avian genotype I, Avian genotype III, and Avian genotype VI) reported. As wild birds mainly live in the wild, control method for the Cryptosporidium infection in wild birds is still lacking, which increases the probability of disease transmission from wild birds to humans. The main purpose of this review is to highlight the Cryptosporidium infection in wild birds and its transmission, associated risk factors, and their prevention, illustrating the necessity of multidisciplinary approaches toward screening and control of Cryptosporidium infections.

Molecular Identification of Cryptosporidium spp., Enterocytozoon bieneusi, and Giardia duodenalis in Captive Pet Birds in Henan Province, Central China

Cryptosporidium spp., Enterocytozoon bieneusi, and Giardia duodenalis are common enteric pathogens that are capable of infecting humans and animals. Total of 1,005 fecal samples from captive pet birds were collected from seven locations in Henan Province, China. The results demonstrated that 9.9% (99/1,005) of the captive birds were infected with one of these three pathogens. Enterocytozoon bieneusi was the most prevalent species among the birds (45/1,005, 4.5%) followed by G. duodenalis (33/1,005, 3.3%) and Cryptosporidium spp. (21/1,005, 2.1%). Five Cryptosporidium species were identified, namely, C. baileyi (10), C. galli (5), C. meleagridis (4), C. andersoni (1), and C. parvum (1). Two known E. bieneusi genotypes were identified: Peru 6 (44) was identified in pigeons (34) and European turtle doves (10); whereas, the genotype PtEb I (1) was only identified in a pigeon. Only G. duodenalis assemblage E (33) was identified in some pet birds. To the best of our knowledge, this study is the first to undertake the molecular identification of G. duodenalis in birds in China. The identification of potentially zoonotic species/genotypes of the pathogens suggests that exposure to the excreta of these birds, either directly or via food and water, may pose a threat to human health.

Cryptosporidium cf. avium in an inland-bearded dragon (Pogona vitticeps) - A case report and review of the literature

Here, we report the first case of Cryptosporidium cf. avium from an inland bearded dragon (Pogona vitticeps) from a wildlife sanctuary in Victoria, Australia. Molecular characterisation was conducted by PCR-coupled sequencing of regions in the small subunit of nuclear RNA (SSU), actin and large subunit of nuclear RNA (LSU) genes. The sequences obtained grouped with those of C. ornithophilus and other C. avium genotypes/variants originating from reptiles or birds. We discuss this case in relation to the current state of knowledge of C. avium of birds and reptiles, considering provenance and environment (agricultural, pet industry, wildlife, zoo or wildlife park) as well as clinical context, and pathological changes associated with cryptosporidiosis in these host animals.

•

Characterisation of Cryptosporidium cf. avium from an inland bearded dragon (Pogona vitticeps).

•

Molecular differentiation of C. cf. avium from other members of the C. avium clade.

•

Pathogenicity of C. cf. avium seems higher than other members of this clade.

Description of Cryptosporidium ornithophilus n. sp. (Apicomplexa: Cryptosporidiidae) in farmed ostriches

BACKGROUND

Avian cryptosporidiosis is a common parasitic disease that is caused by five species, which are well characterised at the molecular and biological level, and more than 18 genotypes for which we have limited information. In this study, we determined the occurrence and molecular characteristics of Cryptosporidium spp. in farmed ostriches in the Czech Republic.

METHODS

The occurrence and genetic identity of Cryptosporidium spp. were analysed by microscopy and PCR/sequencing of the small subunit rRNA, actin, HSP70 and gp60 genes. Cryptosporidium avian genotype II was examined from naturally and experimentally infected hosts and measured using differential interference contrast. The localisation of the life-cycle stages was studied by electron microscopy and histologically. Infectivity of Cryptosporidium avian genotype II for cockatiels (Nymphicus hollandicus (Kerr)), chickens (Gallus gallus f. domestica (L.)), geese (Anser anser f. domestica (L.)), SCID and BALB/c mice (Mus musculus L.) was verified.

RESULTS

A total of 204 individual faecal samples were examined for Cryptosporidium spp. using differential staining and PCR/sequencing. Phylogenetic analysis of small subunit rRNA, actin, HSP70 and gp60 gene sequences showed the presence of Cryptosporidium avian genotype II (n = 7) and C. ubiquitum Fayer, Santín & Macarisin, 2010 IXa (n = 5). Only ostriches infected with Cryptosporidium avian genotype II shed oocysts that were detectable by microscopy. Oocysts were purified from a pooled sample of four birds, characterised morphometrically and used in experimental infections to determine biological characteristics. Oocysts of Cryptosporidium avian genotype II measure on average 6.13 × 5.15 μm, and are indistinguishable by size from C. baileyi Current, Upton & Haynes, 1986 and C. avium Holubová, Sak, Horčičková, Hlásková, Květoňová, Menchaca, McEvoy & Kváč, 2016. Cryptosporidium avian genotype II was experimentally infectious for geese, chickens and cockatiels, with a prepatent period of four, seven and eight days post-infection, respectively. The infection intensity ranged from 1000 to 16,000 oocysts per gram. None of the naturally or experimentally infected birds developed clinical signs in the present study.

CONCLUSIONS

The molecular and biological characteristics of Cryptosporidium avian genotype II, described here, support the establishment of a new species, Cryptosporidium ornithophilus n. sp.

Detection and molecular characterization of Cryptosporidium species in wild-caught pet spiny-tailed lizards

Uromastyx is a genus of the herbivorous agamid lizards, also known as spiny-tailed lizards or mastigures, which are found in parts of Africa and the Middle East. Currently, several species of this genus are available in the international pet trade in Japan. In this study, two imported wild-caught spiny-tailed lizards (Arabian blue mastigure, Uromastyx ornata philbyi, and Sudan mastigure, Uromastyx dispar flavifasciata) were diagnosed with a Cryptosporidium (Apicomplexa: Cryptosporidiidae) infection based on the presence of the oocysts in the rectal feces using sucrose flotation and light microscopy examination at a local animal hospital in Tokyo, Japan. One of the lizards had died, and histopathological examination revealed enteritis with the Cryptosporidium parasite. Sequence analyses using the small subunit ribosomal RNA, actin, and 70-kDa heat shock protein genes indicated that the lizards had contracted a novel variant of C. avium that commonly infects avian species.

•

Two pet wild-caught spiny-tailed lizards exhibited gastrointestinal symptoms.

•

Lizards were both infected with a novel Cryptosporidium avium variant.

•

First detection of avian-associated Cryptosporidium species in the family Agamidae.

First Detection of Cryptosporidium spp. in Migratory Whooper Swans (Cygnus cygnus) in China

Cryptosporidium is an important protozoan parasite that can cause gastrointestinal diseases in humans and that also causes respiratory and gastrointestinal diseases in birds. In this study, we investigated the occurrence of Cryptosporidium species in migratory whooper swans in China. Fecal samples (n = 467) from whooper swans were collected from Sanmenxia Swan Lake National Urban Wetland Park, China. The samples were analyzed for Cryptosporidium species and genotypes with PCR along a sequence analysis of the small subunit rRNA. Cryptosporidium was detected in eight of the 467 (1.7%) samples. The analysis of the small subunit rRNA sequence data revealed two zoonotic species (Cryptosporidium parvum and Cryptosporidium andersoni) and one genotype (Cryptosporidium goose genotype II). These are the first data on the positive rate of Cryptosporidium spp. in whooper swans in China, and they suggest that whooper swans can harbor the zoonotic species C. parvum and C. andersoni in China.

Effects of recycled manure solids bedding on the spread of gastrointestinal parasites in the environment of dairies and milk

The primary aim of this work was to isolate common bovine digestive tract parasites in recycled manure bedding (RMS), as well as to determine the ability of current RMS preparation procedures to eliminate these pathogens. Other objectives were to assess whether any of the aforementioned parasites could be retrieved in bulk milk from dairies using RMS and to study whether the prevalence of these parasites differed among manure of cows housed on RMS versus on straw bedding. For the study, 27 RMS farms and 61 control farms were recruited. Samples of manure from the pre-pit and milk from the bulk tank were recovered from straw-bedding farms and RMS-based farms. In addition, samples from the manure solid fraction after liquid extraction, RMS before use, and RMS currently in use were recovered from RMS herds. Parasites were first detected by double centrifugation zinc sulfate flotation to enhance isolation of gastrointestinal protozoa, and by modified Wisconsin sugar flotation for the appraisal of gastrointestinal nematodes. Cryptosporidium parasites were confirmed by nested PCR amplification and sequencing of a portion of the gene encoding the small subunit rRNA. Results revealed a high prevalence of Cryptosporidium spp. (C. parvum, C. andersoni, and C. meleagridis, identified by PCR) and Eimeria spp. (mainly E. bovis and E. zuernii) parasites in both types of farms, with a larger proportion of manure samples from RMS-bedded farms testing positive for Cryptosporidium parasites compared with manure from straw-bedded farms. Both Cryptosporidium spp. and Eimeria spp. oocysts were found at every step of RMS preparation and transformation, showing that current RMS preparation strategies do not guarantee the destruction of protozoan parasites. Cryptosporidium parvum, a potential zoonotic risk for professionals in close contact with livestock, was found to be present in 32 out of 61 straw-bedded and 24 of 27 RMS farms. No protozoan parasites were found in any sample derived from bulk milk, neither by microscopy analysis nor by molecular methods.

Identification of Cryptosporidium bat genotypes XVI-XVIII in bats from Brazil

Cryptosporidiosis is an emergent zoonotic disease caused by the globally distributed protozoa Cryptosporidium spp. Although several Cryptosporidium studies related to humans and many animal species have been published, there are still limited studies on the epidemiology of Cryptosporidium infection in bats. The aim of this study was to determine the occurrence of Cryptosporidium spp. and to perform the molecular characterization of Cryptosporidium species and genotypes in fecal samples from bats in an urban area of the municipality of Araçatuba, state of São Paulo, Brazil. Nested PCR targeting the 18S rRNA, actin, and HSP-70 genes was performed to screen 141 fecal samples from bats and detected Cryptosporidium spp. in 16.3% (23/141) of the samples. Bidirectional sequencing identified three novel Cryptosporidium bat genotypes (XVI, XVII, and XVIII) and a new genotype (18SH) genetically similar to Cryptosporidium avium in six species of bats. This is the first report on the occurrence and molecular characterization of Cryptosporidium spp. in Brazilian bats. Zoonotic Cryptosporidium species were not found in fecal samples from bats living in an urban area in the municipality of Araçatuba, state of São Paulo, Brazil.

Molecular Prevalence of Cryptosporidium spp. among Companion Birds Kept in Pet Shops in Japan

Cryptosporidium is the most common protozoan that can infect a wide range of animals, including mammals and birds. Avian Cryptosporidium spp. can cause enteric and respiratory diseases which can be fatal in birds and some species are zoonotic. Companion birds have the potential as reservoir due to their close contact with humans. Pet shops are the major source of companion birds. However, few reports are available regarding Cryptosporidium spp. infection among companion birds kept in pet shops. The present study reports the prevalence and molecular characteristics of Cryptosporidium spp. among companion birds kept in pet shops in Japan. A total of 265 fresh fecal samples were obtained from birds kept in 4 pet shops; these birds belonged to 41 species in 3 bird orders. A nested polymerase chain reaction (PCR) assay targeting the small subunit rRNA gene was employed for the detection of Cryptosporidium spp. A total of 24 samples (9.1%) were positive, and Cryptosporidium spp. were detected from all pet shops. The prevalence of Cryptosporidium spp. in each of the bird orders was 6.5% (10/153) in Psittaciformes, 14.4% (13/90) in Passeriformes, and 4.5% (1/22) in Galliformes. Based on sequence analysis, 13 (54.2%) isolates were classified to C. galli, 8 (33.3%) were avian genotype III, and the remaining 3 (12.5%) were C. baileyi. No infection with zoonotic C. meleagridis and no coinfection with multiple Cryptosporidium spp. and/or genotypes were observed. The zoonotic potential of Cryptosporidium spp. infecting companion birds kept in pet shops in Japan is likely to be low.

Molecular characterization of Cryptosporidium spp. in poultry from Brazil

Cryptosporidiosis is an important zoonotic disease caused by Cryptosporidium. Infections in birds are mainly caused by C. meleagridis, C. baileyi, and C. galli. C. meleagridis is the third most common cause of cryptosporidiosis in humans and the only Cryptosporidium species known to infect both birds and mammals. One hundred and fifty-five fecal specimens from different poultry species (chicken, turkey, ostrich, helmeted guinea fowl, quail, pheasant, and emu) were collected at local markets in the state of Minas Gerais, Brazil. Twenty-three (14.8%) birds (20 chickens, 2 quails, and 1 turkey) were found Cryptosporidium-positive. This constitutes the first report of Cryptosporidium in turkeys from Brazil. Nucleotide sequence analysis identified C. meleagridis in chickens (15), a turkey (1), and a quail (1), C. baileyi in chickens (4) and a quail (1), and a mixed infection C. meleagridis/C. baileyi in a chicken (1). This is the first report of C. meleagridis in turkeys and quails from Brazil. Using the gp60 gene, three subtype families were identified, IIIa, IIIb and IIIg. Within subtype family IIIg, four subtypes were identified in chickens, two novel (IIIgA25G3R1 and IIIgA21G3R1) and two previously reported (IIIgA22G3R1 and IIIgA24G2R1). Within subtype family IIIb two subtypes were identified, IIIbA24G1R1 in a chicken and IIIbA23G1R1 in a quail. A novel subtype in the family IIIa was identified (IIIaA22G3R1) in a turkey. The finding of C. meleagridis subtypes previously identified in humans (IIIgA22G3R1, IIIbA24G1R1 and IIIbA23G1R1) indicates that they can be potentially zoonotic. Further subtyping studies that clarify genetic diversity of C. meleagridis are required to better understand host specificity, source of infection, and transmission dynamics of C. meleagridis.

Detection and molecular characterization of Cryptosporidium spp. in captive canaries (Serinus canaria) using different diagnostic methods

This study used several diagnostic methods to examine the occurrence of and molecularly characterize Cryptosporidium spp. in captive canaries (Serinus canaria) in southern and southeastern Brazil. A total of 498 fecal samples were purified by centrifugal-flotation using Sheather's solution. Cryptosporidium spp. diagnosis was performed using three diagnostic methods: malachite green negative staining, nested PCR targeting the 18S rRNA gene, followed by sequencing the amplified fragments, and duplex real-time PCR targeting the 18S rRNA specific to detect Cryptosporidium galli and Cryptosporidium avian genotype III. The overall positivity for Cryptosporidium spp. (total samples positive in at least one protocol) from the microscopic analysis, nested PCR and duplex real-time PCR protocol results was 13.3% (66/498). The positivity rates were 2.0% (10/498) and 4.6% (23/498) for Cryptosporidium spp. by microscopy and nested PCR, respectively. Sequencing of 20 samples amplified by nested PCR identified C. galli (3.0%; 15/498), Cryptosporidium avian genotype I (0.8%; 4/498) and Cryptosporidium avium (0.2%; 1/498). Duplex real-time PCR revealed a positivity of 7.8% (39/498) for C. galli and 2.4% (12/498) for avian genotype III. Malachite green negative staining differed significantly from nested PCR in detecting Cryptosporidium spp. Duplex real-time PCR was more sensitive than nested PCR/sequencing for detecting gastric Cryptosporidium in canaries.

Captive-bred neotropical birds diagnosed with Cryptosporidium Avian genotype III

Currently, there are only three valid species of Cryptosporidium infecting avian hosts, namely, Cryptosporidium meleagridis, Cryptosporidium baileyi, Cryptosporidium galli and Cryptosporidium avium in addition to 12 genotypes of unknown species status. The objectives of this study were to microscopically diagnose the presence of Cryptosporidium in birds from a commercial aviary located in Rio de Janeiro, Brazil; genotypically characterize species and/or genotypes of genus Cryptosporidum; and conduct sequencing and phylogenetic analyses to compare the obtained DNA sequences with those deposited in GenBank. A total of 85 fecal samples were collected from wild captive-bred birds: 48 of family Psittacidae and 37 of family Ramphastidae. Initially, a search for the presence of Cryptosporidium sp. oocysts was conducted using the centrifugal-flotation in saturated sugar solution technique, after that, the collected samples were analyzed microscopically. Cryptosporidium infections were only detected in 24.32% of samples belonging to the family Ramphastidae. DNA was extracted from positive samples and molecular diagnostics was applied targeting the 18S rRNA gene, followed by sequencing and phylogenetic analysis. The Cryptosporidium Avian genotype III was diagnosed in this study more closely related to the gastric species. This is the first record of Cryptosporidium Avian genotype III in order Piciformes and family Ramphastidae, where three host species (Ramphastus toco, Ramphastus tucanus, and Pteroglossus bailloni) were positive for the etiologic agent. Based on the molecular data obtained, these wild birds raised in captivity do not represent a source of human cryptosporidiosis, considering that Cryptosporidium Avian genotype III does not constitute a zoonosis.

Cryptosporidium baileyi in wild captive psittacines in Brazil

Cryptosporidiosis in birds manifests as an acute or chronic disease of the respiratory or digestive tracts. The objective of our study was to perform the molecular characterization of Cryptosporidium spp. in wild psittacines kept in captivity at the Araçatuba Municipal Zoo, São Paulo, Brazil. A total of 47 fecal samples were collected from Amazona aestiva, Psittacara leucophthalma, and Ara ararauna. All samples were collected at the time the birds defecated. DNA extraction was performed using the ZR Fecal DNA MiniPrep™ kit (Zymo Research). Screening for Cryptosporidium spp. was accomplished using nested PCR targeting the 18S RNA gene and sequencing of amplified fragments. Positivity for Cryptosporidium spp. (10.64%; 5/47) was found in A. ararauna (4) and P. leucophthalma (1) samples. The amplified fragments were sequenced and showed 100% genetic similarity with Cryptosporidium baileyi.

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.

Molecular identification of Enterocytozoon bieneusi, Cryptosporidium, and Giardia in Brazilian captive birds

A total of 85 fecal samples from captive birds collected from October 2013 to September 2014 in Uberlândia and Belo Horizonte in the state of Minas Gerais (Brazil) were evaluated for the presence of Enterocytozoon bieneusi, Cryptosporidium, and Giardia by PCR. Of these, three birds were found positive for E. bieneusi (3.5%), two for Cryptosporidium (2.3%), and one for Giardia (1.2%). Two genotypes of E. bieneusi were detected by nucleotide sequence analysis of the ITS region, genotypes D and Peru 6 in a swan goose and in two rock pigeons, respectively. For Cryptosporidium and Giardia, nucleotide sequence analysis of the SSU rRNA identified Cryptosporidium baileyi and Duck genotype in a swan goose and a mandarin duck, respectively, and Giardia duodenalis assemblage A in a toco toucon. Our results demonstrate that human-pathogenic E. bieneusi genotypes D and Peru6 and G. duodenalis assemblage A are present in captive birds in Brazil, corroborating their potential role as a source of human infection and environmental contamination.

The Prevalence of Cryptosporidium Oocysts in Birds in Zaria, Nigeria

A study was conducted to elucidate the prevalence of Cryptosporidium oocysts in birds in Zaria, Nigeria. A total of 890 faecal samples comprising 132, 305 and 453 from wild, local and exotic birds respectively from different parts of Zaria were examined using the formol-ether concentration technique with safranin–methylene blue stain and auramine phenol stain using light microscopy and fluorescent microscopy respectively. The total prevalence rate was 7.4%. However, Samaru had the highest prevalence rate of 20.6% and Tudun Wada the lowest rate of 2.8%. The difference in the prevalence rates between the different localities of Zaria was found to be statistically significant (P<0.001). Among the different birds sampled, local birds had the highest prevalence rate of 9.5% followed by exotic birds 6.6% and the wild ones with 5.3%. The difference was not statistically significant (P>0.05). In Tudun Wada, where the different sexes were noted, there was no significant statistical difference (P>0.05) in the prevalence rate between male and female birds and none between the different species of wild birds sampled (P>0.05). This study confirms the presence of avian Cryptosporidium in Zaria, Nigeria and indicates that whereas location may influence infection, breed, sex and species of birds may not be significant factors in the epidemiology of the infection.

Public health significance of zoonotic Cryptosporidium species in wildlife: Critical insights into better drinking water management

Cryptosporidium is an enteric parasite that is transmitted via the faecal-oral route, water and food. Humans, wildlife and domestic livestock all potentially contribute Cryptosporidium to surface waters. Human encroachment into natural ecosystems has led to an increase in interactions between humans, domestic animals and wildlife populations. Increasing numbers of zoonotic diseases and spill over/back of zoonotic pathogens is a consequence of this anthropogenic disturbance. Drinking water catchments and water reservoir areas have been at the front line of this conflict as they can be easily contaminated by zoonotic waterborne pathogens. Therefore, the epidemiology of zoonotic species of Cryptosporidium in free-ranging and captive wildlife is of increasing importance. This review focuses on zoonotic Cryptosporidium species reported in global wildlife populations to date, and highlights their significance for public health and the water industry.

Cryptosporidium infections in birds - a review

Cryptosporidiosis is one of the main protozoan infections in birds. It manifests as either a respiratory or a digestive illness, and it affects a very large number of avian species across several continents. The aim of this review is to report on the main results of studies on cryptosporidiosis among birds and the importance of these results to veterinary medicine and public health.

Prevalence and Genotyping of Cryptosporidium Infection in Pet Parrots in North China

Cryptosporidiosis is a worldwide zoonosis caused by Cryptosporidium spp., sometimes leading to severe diarrhea in humans and animals. In the present study, 311 parrots, belonging to four species, namely, Budgerigars (Melopsittacus undulatus), Lovebirds (Agapornis sp.), Alexandrine parakeets (Psittacula eupatria), and Cockatiel (Nymphicus hollandicus), from Beijing and Weifang cities, were examined for Cryptosporidium spp. infection. Blood samples of each bird were examined using enzyme linked immunosorbent assay (ELISA) and fecal samples were examined by Sheather's sugar flotation technique. Prevalence of Cryptosporidium infection were 3.22% (10/311) and 0.64% (2/311) by ELISA and Sheather's sugar flotation technique, respectively. Seroprevalence of Cryptosporidium infection in different breeds varied from 0 to 15.39%. Sequencing analysis showed that both positive samples from fecal samples belonged to Cryptosporidium avian genotype V. This is the first report of Cryptosporidium avian genotype V in Budgerigars. The results of the present study provided foundation-data for prevention and control of cryptosporidiosis in pet birds in China.

Highly divergent 18S rRNA gene paralogs in a Cryptosporidium genotype from eastern chipmunks (Tamias striatus)

Cryptosporidium is an apicomplexan parasite that causes the disease cryptosporidiosis in humans, livestock, and other vertebrates. Much of the knowledge on Cryptosporidium diversity is derived from 18S rRNA gene (18S rDNA) phylogenies. Eukaryote genomes generally have multiple 18S rDNA copies that evolve in concert, which is necessary for the accurate inference of phylogenetic relationships. However, 18S rDNA copies in some genomes evolve by a birth-and-death process that can result in sequence divergence among copies. Most notably, divergent 18S rDNA paralogs in the apicomplexan Plasmodium share only 89-95% sequence similarity, encode structurally distinct rRNA molecules, and are expressed at different life cycle stages. In the present study, Cryptosporidium 18S rDNA was amplified from 28/72 (38.9%) eastern chipmunks (Tamias striatus). Phylogenetic analyses showed the co-occurrence of two 18S rDNA types, Type A and Type B, in 26 chipmunks, and Type B clustered with a sequence previously identified as Cryptosporidium chipmunk genotype II. Types A and B had a sister group relationship but shared less than 93% sequence similarity. In contrast, actin and heat shock protein 70 gene sequences were homogeneous in samples with both Types A and B present. It was therefore concluded that Types A and B are divergent 18S rDNA paralogs in Cryptosporidium chipmunk genotype II. Substitution patterns in Types A and B were consistent with functionally constrained evolution; however, Type B evolved more rapidly than Type A and had a higher G+C content (46.3% versus 41.0%). Oocysts of Cryptosporidium chipmunk genotype II measured 4.17 μm (3.73-5.04 μm) × 3.94 μm (3.50-4.98 μm) with a length-to-width ratio of 1.06 ± 0.06 μm, and infection occurred naturally in the jejunum, cecum, and colon of eastern chipmunks. The findings of this study have implications for the use of 18S rDNA sequences to infer phylogenetic relationships.

Occurrence of Giardia and Cryptosporidium in wild birds in Galicia (Northwest Spain)

Faecal samples were obtained from 433 wild birds being treated in wildlife recovery centres in Galicia (Northwest Spain), between February 2007 and September 2009. The birds belonged to 64 species representing 17 different orders. Giardia cysts and Cryptosporidium oocysts were detected by an immunofluorescence antibody test and identified at the molecular level by established PCR-sequencing methods. The overall prevalence of Giardia was 2·1% and that of Cryptosporidium, 8·3%. To our knowledge, this is the first description of Giardia sp. in Tyto alba and Caprimulgus europaeus; and of Cryptosporidium sp. in Apus apus, Athene noctua, C. europaeus, Falco tinnunculus, Morus bassanus, Parabuteo unicinctus and Strix aluco. Furthermore, the first PCR-sequence confirmed detection of Giardia duodenalis assemblage B in, Buteo buteo, Coturnix coturnix and Pica pica; G. duodenalis assemblage D in Garrulus glandarius; and G. duodenalis assemblage F in Anas platyrhynchos; Cryptosporidium parvum in Accipiter nisus, B. buteo, Milvus migrans, Pernis apivorus and P. pica; and Cryptosporidium meleagridis in Streptopelia turtur. The study findings demonstrate the wide spread of Giardia and Cryptosporidium between wild birds.

Effects of different inoculation routes on the parasitic sites of Cryptosporidium baileyi infection in chickens

Cryptosporidiosis is prevalent in domesticated, caged, and wild birds. Cryptosporidium baileyi, an ascendant species of avian Cryptosporidium, is an important pathogen. It causes respiratory disease in chickens, especially chickens younger than 50 days. In this study, SEM, histological, semi-quantitative PCR, and nested PCR techniques were used to explore the impact of different inoculation routes on sites of C. baileyi infection in chickens. Results showed that inoculation with sporozoites or oocysts via the rectum was an effective means of causing infection. This may provide an important reference for the development of the transfection system of C. baileyi in chickens. Numerous endogenous stages of C. baileyi were observed in the bursas of Fabricius (BF) and cloacas of chickens inoculated with sporozoites or oocysts via the rectum, but no parasite was seen in the tracheas of any of these chickens. In chickens infected with oocysts via the crop, the number of parasites in the BF was approximately 23-fold more than in the trachea. All blood samples collected after inoculation were negative for C. baileyi. These data show that C. baileyi was not transferred by blood circulation between the BF and respiratory tract. Different routes of inoculation were here found to distinctly affect sites of parasitism in chickens. These findings may facilitate further understanding of the biology of C. baileyi and efforts to control avian cryptosporidiosis.

A new set of primers directed to 18S rRNA gene for molecular identification of Cryptosporidium spp. and their performance in the detection and differentiation of oocysts shed by synanthropic rodents

Cryptosporidium spp. are cosmopolitan protozoa that infect fishes, reptiles, amphibians, birds and mammals. More than 20 species are recognized within this genus. Rodents are a group of abundant and ubiquitous organisms that have been considered reservoirs of Cryptosporidium for humans and livestock. The aim of this study was to design specific primers for the gene encoding 18S rRNA, potentially capable of amplifying any species or genotype of Cryptosporidium spp. and evaluate the diagnostic attributes of the nested-PCR based on such probes. The primers were designed to amplify the shortest segment as possible to maximize the sensitivity of the test, but preserving the discriminatory potential of the amplified sequences for phylogenetic inferences. The nested-PCR standardized in this study (nPCR-SH) was compared in terms of sensitivity with another similar assay (nPCR-XIAO) that has been largely used for the detection and identification of Cryptosporidium spp. worldwide. We also aimed to molecularly characterize samples of Cryptosporidum spp. isolated from synanthropic rodents using these probes. Forty-five rodents were captured in urban areas of the municipality of Umuarama, Paraná State, Brazil. Fecal samples were submitted to three molecular tests (nested-PCRs), two of them targeted to the 18S rDNA gene (nPCR-SH and nPCR-XIAO) and the third targeted to the gene encoding actin (nPCR-actin). The nPCR-SH was tested positive on samples of Cryptosporidum parvum, Cryptosporidum andersoni, Cryptosporidum meleagridis, Cryptosporidum hominis, Cryptosporidum canis, and Cryptosporidum serpentis. Sixteen samples of rodents were positive by nPCR-SH, six by nPCR-XIAO and five by nPCR-actin. Sequencing of amplified fragments allowed the identification of Cryptosporidum muris in three samples of Rattus rattus, and two genotypes of Cryptosporidium, the genotypes mouse II and III. Cryptosporidium genotype mouse II was found in one sample of Mus musculus and genotype mouse III, in twelve samples, being five from R. rattus and seven from M. musculus. The results of this study demonstrated that the primers designed for detection of Cryptosporidium spp. were more efficient than those used in the nPCR-XIAO. Genotypes or species of Cryptosporidium that can be usually transmitted for human beings and livestock were not found in synanthropic rodents, suggesting that the importance of these animals in zoonotic transmission of cryptosporidiosis should be revisited.

Common occurrence of zoonotic pathogen Cryptosporidium meleagridis in broiler chickens and turkeys in Algeria

Only a small number of birds have been identified by molecular techniques as having Cryptosporidium meleagridis, the third most important species for human cryptosporidiosis. In this study, using PCR-RFLP analysis of the small subunit (SSU) rRNA gene, we examined the ileum of 90 dead chickens from 23 farms and 57 dead turkeys from 16 farms in Algeria for Cryptosporidium spp. C. meleagridis-positive specimens were subtyped by sequence analysis of the 60 kDa glycoprotein gene. Cryptosporidium infection rates were 34% and 44% in chickens and turkeys, respectively, with all positive turkeys (25) and most positive chickens (26/31) having C. meleagridis. All C. meleagridis specimens belonged to a new subtype family. The frequent occurrence of C. meleagridis in chickens and turkeys illustrates the potential for zoonotic transmission of cryptosporidiosis in Algeria.

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

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

Cryptosporidium spp. parasitize exotic birds that are commercialized in markets, commercial aviaries, and pet shops

The purpose of this study was to genetically characterize and phylogenetically analyze the Cryptosporidium spp. isolated from exotic birds commercialized in popular markets, commercial aviaries, and pet shops located in Rio de Janeiro, Brazil. Fecal samples from individually housed birds were collected and subjected to centrifuge-flotation technique using saturated sugar solution. DNA was isolated from Cryptosporidium positive samples, and 18S subunit rDNA was amplified and processed using nested-polymerase chain reaction (PCR). To identify the protozoan species, the PCR amplicons were used for restriction fragment length polymorphism and sequencing analyses. Of the 103 analyzed fecal samples, seven (6.8%) were positive for Cryptosporidium oocysts. Sequencing and further phylogenetic analyses allowed us to identify the following species: Cryptosporidium parvum in Bengalese finch (Lonchura striata domestica) and avian genotype III in Java sparrow (Padda oryzivora) and cockatiel (Nymphicus hollandicus). The sequences of the Cryptosporidium spp. isolated from canaries (Serinus canarius) were not identifiable within the groups of known species, but they presented a higher genetic similarity with C. parvum. This is the first report in Brazil showing that C. parvum parasitizes Bengalese finches and that avian genotype III parasitizes Java sparrows.