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

Molecular characterization and zoonotic potential of Cryptosporidium spp. and Giardia duodenalis in humans and domestic animals in Heilongjiang Province, China

BACKGROUND

Cryptosporidiosis and giardiasis are significant parasitic diseases shared between humans and domestic animals. Due to the close contact between humans and domestic animals in rural areas, it is important to consider the potential transmission of zoonotic parasites from infected domestic animals to humans. This investigation aimed to determine the prevalence and molecular characteristics of Cryptosporidium spp. and Giardia duodenalis in domestic animals and villagers.

METHODS

A total of 116 fecal samples from villagers and 686 fecal samples from domestic animals in Heilongjiang Province, China, were analyzed for two parasites using nested polymerase chain reaction (PCR) targeting various genetic loci and DNA sequence analysis of the PCR products.

RESULTS

By sequence analysis of the SSU rRNA gene, the prevalence of Cryptosporidium in humans was 0.9% (1/116), with one species of C. parvum (n = 1) detected; among domestic animals, the prevalence was 2.6% (18/686), with five species identified: C. suis (n = 7) and C. scrofarum (n = 7) in pigs, C. meleagridis (n = 1) in chickens, C. andersoni (n = 1) in cattle, and C. canis (n = 2) in foxes. C. parvum and C. canis were further subtyped as IIdA19G1 and XXa4 on the basis of gp60 gene. Regarding G. duodenalis, based on the SSU rRNA, bg, gdh, and tpi genes, the prevalence in domestic animals was 5.1% (31/608), with three assemblages identified: A (n = 1) in pigs, D (n = 1) in foxes, and E (n = 27) in geese, cattle, pigs, ducks, and sheep, along with mixed infection of A + E (n = 1) in one pig and B + E (n = 1) in one sheep. No G. duodenalis was detected in humans (0/116).

CONCLUSIONS

The present results show that no overlap of subtypes between animals and villagers was found in Cryptosporidium spp. and G. duodenalis, indicating a minor role of domestic animals in infecting humans in this population. However, the presence of zoonotic protozoa in domestic animals highlights the need for special attention to high-risk individuals during close contact with domestic animals.

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.

Dominant infection of Cryptosporidium baileyi in broiler chickens in Zhejiang Province, China

Cryptosporidium is a common enteric parasite in chickens. A total of 812 fecal specimens were collected from 11 broiler farms in Zhejiang Province, China, and analyzed by nested PCR amplification based on the small subunit ribosomal RNA (SSU rRNA) gene. The overall infection rate of Cryptosporidium was 6.3% (51/812), and five of 11 farms were Cryptosporidium positive. Broilers aged > 90 days accounted for the highest infection rate of 16.1% (6/56), followed by those aged 30-60 days (10.6%, 38/358) and 60-90 days (4/378, 1.1%). Two Cryptosporidium species were identified by sequence analysis, with the predominant species being C. baileyi (96.1%, 49/51) and the minor infection being C. meleagridis (3.9%, 2/51). Based on the 60-kDa glycoprotein (gp60) gene, two C. meleagridis-positive isolates were identified as one known subtype, IIIbA24G1R1. This study indicated the common occurrence of C. baileyi in broiler chickens in this region and low zoonotic transmission potential of Cryptosporidium to humans.

First detection of Cryptosporidium proventriculi from wild birds in Cyprus

Cryptosporidium is an important intestinal zoonotic pathogen that can infect various hosts and cause diarrheal disease. There are no reports on the prevalence and molecular characterization of Cryptosporidium in wild birds in Cyprus. Therefore, the present study aimed to determine the prevalence of Cryptosporidium spp. and genotypes in wild birds found at Phassouri Reedbeds (Akrotiri Wetlands), Cyprus. Fecal samples of 75 wild birds (Eurasian coot Fulica atra, N = 48; Eurasian teal Anas crecca, N = 20; duck - Anas spp., Ν = 7) were screened for Cryptosporidium by PCR amplification and sequencing. Only one sample (1.3%) belonging to a Eurasian coot was PCR-positive for Cryptosporidium. Based on sequencing of the 18S rRNA locus, this species was identified as Cryptosporidium proventriculi. This is the first report on the molecular identification of this Cryptosporidium species in a Eurasian coot.

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.

Longitudinal surveillance of Cryptosporidium spp. in broiler chickens in Xinjiang, northwest China: genetic diversity of Cryptosporidium meleagridis subtypes

Cryptosporidium spp. are common enteric parasites in humans and animals. Herein, 175 faecal specimens were collected from a broiler farm in Xinjiang, China, including seven repeated samplings at 10-day intervals of broilers aged 10 to 70 days. Cryptosporidium was detected and identified by PCR-RFLP analysis. The overall infection rate of Cryptosporidium in broilers was 23.4% (41/175), with the highest infection rate of 48.0% (12/25) at 40 days of age, and no infection was detected at 10 days of age. Two Cryptosporidium species were confirmed, namely, C. baileyi (3.4%, 6/175) and C. meleagridis (20%, 35/175). In total, 21 of 35 C. meleagridis isolates were successfully subtyped based on the gp60 gene, and one known subtype, IIIgA22G3R1 (n = 1), and three novel subtypes, IIIbA25G1R1 (n = 10), IIIgA24G3R1 (n = 9) and IIIgA25G2R1 (n = 1), were identified. Our findings highlight the genetic diversity of C. meleagridis in Xinjiang and the potential endemic characteristics of the subtypes.

Dominance of the zoonotic pathogen Cryptosporidium meleagridis in broiler chickens in Guangdong, China, reveals evidence of cross-transmission

Background

Cryptosporidium is one of the most prevalent parasites infecting both birds and mammals. To examine the prevalence of Cryptosporidium species and evaluate the public health significance of domestic chickens in Guangdong Province, southern China, we analyzed 1001 fecal samples from 43 intensive broiler chicken farms across six distinct geographical regions.

Methods

Individual DNA samples were subjected to nested PCR-based amplification and sequencing of the small subunit of the nuclear ribosomal RNA gene (SSU rRNA). Analysis of the 60 kDa glycoprotein gene (gp60) was performed to characterize the subtypes of C. meleagridis.

Results

The overall prevalence of Cryptosporidium was 13.2% (95% CI 11.1–15.3) (24 of 43 farms), with C. meleagridis (7.8%), C. baileyi (4.8%) and mixed infections (0.6%). Using the gp60 gene, three subtype families, IIIb, IIIe and IIIg, were identified, including six subtypes: one novel (IIIgA25G3R1a) and five previously reported (IIIbA23G1R1c, IIIbA24G1R1, IIIbA21G1R1a, IIIeA17G2R1 and IIIeA26G2R1). Within these subtypes, five known subtypes were genetically identical to those identified in humans.

Conclusions

This is the first report of C. meleagridis in chickens from Guangdong. The frequent occurrence of C. meleagridis in domestic chickens and the common C. meleagridis subtypes identified in both humans and chickens is of public health significance. Our study indicates that broiler chickens represent a potential zoonotic risk for the transmission of Cryptosporidium in this region.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05267-x.

Genetic characterization of Cryptosporidium spp. in Hotan Black Chickens in China reveals two novel subtypes of Cryptosporidium meleagridis

A total of 617 fecal specimens were collected on 18 Hotan Black chicken farms in Southern Xinjiang, China, and tested for the presence of Cryptosporidium spp. by PCR of the small subunit ribosomal RNA (SSU rRNA) gene. The overall infection rate by Cryptosporidium spp. was 11.5% (71/617), and ten of the 18 farms were positive. The infection rate by Cryptosporidium spp. was 14.5% (48/331) in the 30–60 d group, higher than chickens in the <30 d (12.0%, 15/125), 60–90 d (6.9%, 5/72), and >90 d (3.4%, 3/89) groups. Cryptosporidium meleagridis (n = 38) and C. baileyi (n = 33) were confirmed by sequencing analysis. A total of 25 of the 38 C. meleagridis-positive specimens were subtyped successfully at the gp60 gene, including one known subtype (IIIbA23G1R1, n = 1) and two novel subtypes, named IIIbA25G1R1 (n = 20) and IIIbA31G1R1 (n = 4). The results showed that infection by Cryptosporidium spp. in Hotan Black Chickens was common in this area and the distribution of C. meleagridis subtypes had regional characteristics.

A systematic review and meta-analysis on the prevalence of infectious diseases of Duck: A world perspective

The Indian poultry industry is one of the fast-growing sectors of which duck farming plays an important role. Duck population in India is 33.51 million that is concentrated towards north-east and southern parts of the country who rears mainly for eggs and meat. Duck diseases are of great concern as they badly affect the financial status of the small, landless farmers. Databases such as Google Scholar, PubMed, J gate were used to search articles between 2000 and 2019 that showed the prevalence of viral, bacterial, and parasitic duck diseases. R open source software was used to derive forest plots by statistical analysis. Pooled prevalence estimates of duck diseases worldwide was found to be 20% (95%-CI:15–26). Also, continent-wise analysis of all duck diseases has revealed highest prevalence in North America, followed by Asia, Africa, Europe,Oceania and South America. This prevalence of data would be helpful to the policymakers to develop appropriate intervention strategies to prevent and control diseases in their respective locations.

Plasma metabolites associated with physiological and biochemical indexes indicate the effect of caging stress on mallard ducks (Anas platyrhynchos)

Objective

Cage rearing has critical implications for the laying duck industry because it is convenient for feeding and management. However, caging stress is a type of chronic stress that induces maladaptation. Environmental stress responses have been extensively studied, but no detailed information is available about the comprehensive changes in plasma metabolites at different stages of caging stress in ducks. We designed this experiment to analyze the effects of caging stress on performance parameters and oxidative stress indexes in ducks.

Methods

Liquid chromatography tandem mass spectrometry (LC/MS-MS) was used to determine the changes in metabolites in duck plasma at 5 (CR5), 10 (CR10), and 15 (CR15) days after cage rearing and traditional breeding (TB). The associated pathways of differentially altered metabolites were analyzed using Kyoto encyclopedia of genes and genomes (KEGG) database.

Results

The results of this study indicate that caging stress decreased performance parameters, and the plasma total superoxide dismutase levels were increased in the CR10 group compared with the other groups. In addition, 1,431 metabolites were detected. Compared with the TB group, 134, 381, and 190 differentially produced metabolites were identified in the CR5, CR10, and CR15 groups, respectively. The results of principal component analysis (PCA) show that the selected components sufficiently distinguish the TB group and CR10 group. KEGG analysis results revealed that the differentially altered metabolites in duck plasma from the CR5 and TB groups were mainly associated with ovarian steroidogenesis, biosynthesis of unsaturated fatty acids, and phenylalanine metabolism.

Conclusion

In this study, the production performance, blood indexes, number of metabolites and PCA were compared to determine effect of the caging stress stage on ducks. We inferred from the experimental results that caging-stressed ducks were in the sensitive phase in the first 5 days after caging, caging for approximately 10 days was an important transition phase, and then the duck continually adapted.

Molecular prevalence and characterization of Cryptosporidium in domestic free-range poultry in Anhui Province, China

Free-range chickens might mediate the spread of Cryptosporidium oocysts to humans and other animals. Few studies have evaluated the prevalence of Cryptosporidium species in domestic free-range poultry in China. Here, we characterized the prevalence and distribution of species and genotypes of Cryptosporidium in domestic free-range chickens, ducks, and geese in Anhui Province, China. A total of 1910 fresh fecal samples from three poultry species were examined from 18 free-range poultry farms by nested PCR and analysis of the Cryptosporidium SSU rRNA gene. The overall prevalence of Cryptosporidium species was 2.9% (55/1910), with infection rates of 1.3% (11/829) in chickens, 7.3% (36/487) in ducks, and 1.4% (8/594) in geese. C. baileyi (0.6%), C. meleagridis (0.2%), C. galli (0.2%), and C. xiaoi-like genotype (0.2%) were identified in chickens, and only C. baileyi was identified in ducks and geese, with infection rates of 7.4% and 1.3%, respectively. C. baileyi was the most prevalent species. Sequencing of the GP60 gene revealed that the C. meleagridis isolates belonged to the IIIbA26G1R1b subtype. This is the first study to document C. galli and C. xiaoi-like genotype in domestic free-range chickens in China. These findings expand the range of avian hosts known for Cryptosporidium and highlight the need for additional studies to characterize the diversity of Cryptosporidium in avian species.

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.

Protozoan and Helminth Infections of Aviary-Reared Alectoris rufa (Galliformes: Phasianidae) before Releasing for Hunting in the Czech Republic: Infection Dynamics and Potential Risks

Age-related dynamics of protozoan and helminth infections in the red-legged partridge, Alectoris rufa, were studied in an intensive breeding aviary in the Czech Republic before releasing birds for hunting purposes. Pooled fecal samples (n = 900) were examined over 3 rearing seasons (2012-2014). A total of 4 protozoan species, Cryptosporidium baileyi, Cryptosporidium meleagridis, Eimeria kofoidi, and Eimeria legionensis, and 4 helminths, Capillaria phasianina, Eucoleus perforans, Heterakis gallinarum, and Syngamus trachea, was found. The most common parasite was S. trachea (prevalence 20-26%) in dead birds (n = 99), which represents a high risk for breeders. Co-occurrence of protozoans and helminths indicated similarities in infection dynamics throughout the 3 breeding seasons. Mixed infections of Cryptosporidium baileyi and C. meleagridis with other parasitic species are reported for the first time. Our findings provide new insights into breeding of A. rufa and may help to improve the efficacy of disease control strategies and prevention, especially with the potential for spreading of parasitic infections to wildlife through released birds into open areas.

Occurrence of Cryptosporidium and Giardia in wild birds from Qinghai Lake on the Qinghai-Tibetan Plateau, China

Cryptosporidium and Giardia are important intestinal zoonotic pathogens that can infect various hosts and cause diarrhoeal diseases. There are few reports of the epidemiological prevalence and molecular characterization of Cryptosporidium and Giardia in wild birds around Qinghai Lake and in the surrounding areas on the Qinghai-Tibetan Plateau, Northwest China. Therefore, the aim of this study was to determine the Cryptosporidium spp. and Giardia duodenalis genotypes and their epidemiological prevalence in wild birds by PCR amplification. To our knowledge, this is the first report of a variety of Cryptosporidium spp. and G. duodenalis infections in wild birds from that area, with overall prevalence rates of 8.98% (61/679) and 3.39% (23/679), respectively. Furthermore, PCR sequencing confirmed the presence of Cryptosporidium baileyi (n = 3), Cryptosporidium parvum (n = 58), and G. duodenalis assemblage B (n = 19) and E (n = 4) in wild birds from the areas around Qinghai Lake. The results of the present study demonstrated the wide distribution of Cryptosporidium and Giardia among wild birds, which has potential public health significance. Moreover, the study findings also provided useful molecular epidemiological data for monitoring and investigating the two parasitic protozoa in wild animals and surrounding environments.

Molecular characterization of Cryptosporidium spp. from migratory ducks around Tokachi subprefecture, Hokkaido, Japan

Cryptosporidium, a waterborne protozoan parasite, has a substantial veterinary and medical impact worldwide. This parasite is more often recognized during waterborne outbreaks because of its resistance to chlorine disinfection, small size making it difficult to inactivate/eliminate through filtration, and presence in many animal species including humans. Migratory waterfowl, in addition to acting as mechanical carriers of Cryptosporidium oocysts, can also serve as natural reservoirs of infection by host-specific Cryptosporidium species. For better understanding of the extent of genetic diversity and inter-relationships among avian isolates of Cryptosporidium, 200 fecal samples of migratory ducks from the Tokachi subprefecture, Hokkaido, Japan were collected and analyzed by nested PCR (N-PCR) at the 18S rRNA gene. N-PCR revealed that 11.5% (23/200) were positive for Cryptosporidium spp. Among all samples, sequence analysis identified that 10% (20/200) were 98-100% identical to Cryptosporidium avian genotype III. On the other hand, 1.5% (3/200) were 99-100% identical to C. baileyi. This is the first molecular study reporting the prevalence of Cryptosporidium in migratory ducks in Japan. Genetic diversity among Cryptosporidium isolates from humans and birds has been reported worldwide. Nevertheless, further studies are important to assess genetic variety and to elucidate the transmission dynamics of Cryptosporidium parasites.

Prevalence and Genetic Characterization of Cryptosporidium, Giardia and Enterocytozoon in Chickens From Ezhou, Hubei, China

Cryptosporidium spp., Giardia spp. and microsporidia are important intestinal protozoa responsible for diarrhea in humans and other mammals. China is a major chicken-raising country, and studies on these protozoa in chickens have important public health significance. Here, we investigated the prevalence and genetic characterization of these parasites in chickens from Ezhou City, Hubei Province, China. In total, 206 stool specimens were collected from chickens in four villages of Ezhou between July 2014 and February 2015. Genomic DNA of each specimen was tested by nested PCR based on the Cryptosporidium small subunit rRNA gene, the Giardia intestinalis triose phosphate isomerase gene, and the internal transcribed spacer of the Enterocytozoon bieneusi rRNA gene, respectively. The public health significance of G. intestinalis and E. bieneusi identified in our study was evaluated via phylogenetic analysis. The infection rates were determined to be 2.43% (5/206), 8.25% (17/206), and 1.94% (4/206) for Cryptosporidium, G. intestinalis, and E. bieneusi, respectively. One sample showed coinfection with G. intestinalis and E. bieneusi. Meanwhile, sequence analysis of the PCR-positive samples showed that the Cryptosporidium was C. baileyi, G. intestinalis was assemblage C, and E. bieneusi was genotype D and novel genotype EZ0008. This is the first report of zoonotic G. intestinalis assemblage C in chickens in the world, and the first report of zoonotic E. bieneusi genotype D in chickens in China. These findings indicate new transmission dynamics and molecular epizootiology.

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.

Prevalence and molecular characterization of Cryptosporidium species in poultry in Bangladesh

Cryptosporidium is an opportunistic parasite that has been reported in >30 avian hosts worldwide, however, there is no information regarding Cryptosporidium spp. in poultry in Bangladesh. Accordingly, we investigated the prevalence of Cryptosporidium spp. in poultry at open live bird markets in Bangladesh. A total of 197 samples were randomly collected from poultry at open live bird markets in Bangladesh and screened for the detection of Cryptosporidium. Initial microscopic examination revealed Cryptosporidium spp. was observed in 19.8% (39/197) of the poultry specimens. Subsequent nested PCR targeting the 18S rRNA gene revealed that 15.7% (31/197) of the samples were Cryptosporidium positive. Of these 31 samples, 17 were Cryptosporidium baileyi (8.7%), 12 were Cryptosporidium meleagridis (6.0%), and 2 were Cryptosporidium parvum (1.0%). Nucleotide sequence analysis of the GP60 gene of the C. meleagridis revealed that two subtypes (IIIbA21G1R1 and IIIbA23G1R1), which were found in broiler, native and sonali chickens and a pigeon, matched those previously reported in humans and poultry. We identified two novel subtypes (IIIbA21G2R1 and IIIbA20G2R1) in sonali chickens, a broiler chicken and a layer chicken. We also amplified the GP60 gene of C. parvum and found two subtypes (IIaA11G2R1 and IIaA13G2R1) in a sonali and a broiler chicken that were previously reported in calf. These findings suggest that poultry can be a source of cryptosporidial infections for humans and animals in Bangladesh. This is the first molecular investigation of Cryptosporidium genotypes and subtypes in poultry at open live bird markets in Bangladesh.

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Cryptosporidium genotypes and subtypes in poultry in Bangladesh have been investigated firstly.

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Cryptosporidium baileyi, C. meleagridis and C. parvum are identified while C. baileyi is predominant species in poultry.

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Two novel subtypes (IIIbA21G2R1 and IIIbA20G2R1) of the C. meleagridis in chickens are detected.

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Cryptosporidium parasites are common among the live bird markets in Bangladesh.

First study of Cryptosporidium spp. occurrence in eared doves (Zenaida auriculata)

Cryptosporidium is a protozoan parasite with a wide range of hosts, including humans. However, only a few Cryptosporidium species have been described in birds (C. meleagridis, C. baileyi, C. galli and C. avium). The aim of this study was to investigate the occurrence of Cryptosporidium spp. in feces of eared doves (Zenaida auriculata), followed by molecular characterization of the parasite. A total of 196 animals of both sexes were trap-captured; the animals were culled and the intestinal contents were collected for DNA extraction. After extraction, a nested-PCR (nPCR), which amplifies a fragment of the 18S rRNA gene of Cryptosporidium spp., was performed. The amplicons obtained were purified and sequenced. PCR analysis revealed that 30 animals (15.3%) were positive for Cryptosporidium spp. There was no significant sex-dependent enrichment of Cryptosporidium occurrence (p > 0.05). Only 15 out of the 30 positive samples were successfully sequenced and their species determined, of which, 13 (86.7%) and 2 (13.3%) were C. meleagridis and C. galli, respectively. Herein, we present for the first time a molecular characterization of Cryptosporidium from feces of eared doves (Z. auriculata) and propose that these birds are a potential source of C. meleagridis infection in humans.

Interactions Between Parasites and the Bacterial Microbiota of Chickens

Except for the important role coccidia have as predisposing factors of necrotic enteritis, the role parasites play in the dynamics of a healthy microbiota of chickens is not well explored. This review describes the interactions of relevant intestinal parasites of chickens with bacteria. Infection with Eimeria spp. favor the growth of Clostridium perfringens and suppress the growth of many other bacteria by increasing viscosity and passage time of the ingesta, and by causing lesions to the intestinal mucosa that improve the availability of nutrients for C. perfringens. Conversely, there are indications that bacteria influence the course of disease after infections with Eimeria spp. Not much is known about intestinal cryptosporidiosis in chickens, but results in mice show that the intestinal microbiota induces some resistance against infection with Cryptosporidium parvum and that the innate immune response triggered by infections with cryptosporidia might have an effect on other intestinal microbes. Histomonas meleagridis depend on bacteria in vitro, and in vivo it will cause lesions in chickens only in the presence of bacteria. Blastocystis spp. are very common in chickens, but there is no information about interactions with bacteria. In humans, there is evidence of the correlation of the detection of Blastocystis and changes in the intestinal microbiota. There are indications of interactions between Ascaridia galli and various bacteria in chickens and Ascaridia spp. of mammals are known to produce various types of antimicrobial molecules. However, often the underlying mechanisms of these interactions between parasites and bacteria remain unknown and only correlations but not causation can be established.

Modelling the fate and transport of Cryptosporidium, a zoonotic and waterborne pathogen, in the Daning River watershed of the Three Gorges Reservoir Region, China

Oospores of Cryptosporidium, a waterborne pathogen of great concern, are widely distributed in surface waters in China and pose a threat to human health. This study seeks to explore the spatio-temporal patterns of Cryptosporidium concentrations. We focus on the Daning River watershed (4166 km²) of the Three Gorges Reservoir Region (TGR) during the period 2008 to 2013 and use the SWAT (Soil and Water Assessment Tool) model to test two mitigation scenarios. Based on data on animal husbandry, population, agriculture and WWTPs (wastewater treatment plants), Cryptosporidium transport in the Daning River watershed was simulated using a calibrated hydrological and sediment transport model. Our model results showed that the average annual concentration of oocysts in the whole watershed was 9.5 oocysts/10L, but high spatial variability occurred, ranging from 0.7 to 33.4 oocysts/10L. Highest monthly mean oocysts concentrations at the outlets of the sub-basins were found at high runoff and high fertilization or at the lowest flow, while minimum monthly mean oocysts concentrations were recorded at high runoff only. A model parameter sensitivity analysis showed that the Cryptosporidium soil partitioning coefficient (BACTKDQ) and the temperature adjustment factor for Cryptosporidium die-off (THBACT) were the only two sensitive parameters among the microbial parameters. The construction of multiple WWTPs throughout the watershed and composting of 50% of the feces from rural citizens and livestock up to 56 days before its application as fertilizer could significantly reduce the concentration of oocysts. Our Cryptosporidium transport model and simulation results may assist in the establishment of better pollution control countermeasures in the Daning River and other similar watersheds.

Molecular Detection of Cryptosporidium Species in Domestic Ducks Sold for Food in Nigerian Live Bird Markets

Cryptosporidium infections has been reported in several avian species including chickens, pigeons and game birds where these infections had been identified to cause either enteric or respiratory diseases. However, little data exists on the molecular characterization of Cryptosporidium species in ducks, especially those in frequent contact with humans. The aim of this study was to detect the Cryptosporidium species infecting domestic ducks in two major live bird markets. A total of 109 fresh faecal samples were collected from all the ducks available on sale in the two markets. The detection of Cryptosporidium species was conducted by microscopy. All positive samples were confirmed by the nested PCR amplification and the nucleotide sequencing of the 18S rRNA genes. The results demonstrated that the prevalence of Cryptosporidium infection in ducks using microscopy was 11.0 % (12/109). There was a higher prevalence 14.0 % (7/50) in ducks from Ibadan compared with those 8.5 % (5/59) obtained from Oyo town. All positive samples by microscopy were also positive using the nested PCR and the DNA sequencing of the secondary PCR products from the 18S rRNA genes which revealed the presence of Cryptosporidium parvum. This study revealed that natural infections of C. parvum may occur in ducks in close contact with humans and other domestic animals and therefore suggests that cryptosporidiosis in ducks may be of public health importance.

Molecular investigation of Cryptosporidium in farmed chickens in Hubei Province, China, identifies 'zoonotic' subtypes of C. meleagridis

BACKGROUND

Cryptosporidium is a key genus of parasitic protists that infect humans and other vertebrates (mammals and birds). Birds are typically infected with C. avium, C. baileyi, C. galli and/or C. meleagridis, the latter of which is recognised as being zoonotic. Stimulated by the previous finding of C. meleagridis subtypes IIIbA21G1R1, IIIbA22G1R1 and IIIbA26G1R1 in diarrhoeic children in Wuhan city and environs in Hubei Province, China, we performed a molecular epidemiological survey to explore whether these or similar subtypes might occur in farmed chickens in this province.

METHODS

PCR-coupled sequencing analyses of regions in the small subunit (SSU) of the nuclear ribosomal RNA and 60 kDa glycoprotein (gp60) genes were utilised to characterise Cryptosporidium in faecal samples from chickens (n = 471) from 14 farms from six distinct regions in Hubei Province.

RESULTS

Cryptosporidium baileyi (33/471; 7.0%) and C. meleagridis (15/471; 3.2%) were identified in chickens on eight farms in five of the six distinct geographical regions. No significant age-associated difference in the prevalence of C. baileyi was evident, whereas the prevalence of C. meleagridis was significantly higher in younger (≤ 4 months) than in older chickens (> 4 months). For C. meleagridis, two subtype families, IIIb and IIIe, were defined; some of the subtypes (i.e. IIIbA26G1R1b and IIIbA22G1R1c) characterised here matched those identified previously in diarrhoeic children in Wuhan.

CONCLUSIONS

This is the first molecular study reporting the genetic identity and prevalence of C. baileyi and C. meleagridis in chickens in Hubei. The findings suggest that C. meleagridis subtypes IIIbA26G1R1b and IIIbA22G1R1c are cross-transmissible between chickens and humans, raising awareness about the significance of birds as potential reservoirs of zoonotic variants of Cryptosporidium. Future studies might focus on investigating the prevalence of 'zoonotic' subtypes of Cryptosporidium meleagridis in various species of wild and domesticated birds, and on comparing them with those found in humans in China and other countries.

Genome-wide analysis of differentially expressed profiles of mRNAs, lncRNAs and circRNAs during Cryptosporidium baileyi infection

Background

Cryptosporidium baileyi is the most common Cryptosporidium species in birds. However, effective prevention measures and treatment for C. baileyi infection were still not available. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) play important roles in regulating occurrence and progression of many diseases and are identified as effective biomarkers for diagnosis and prognosis of several diseases. In the present study, the expression profiles of host mRNAs, lncRNAs and circRNAs associated with C. baileyi infection were investigated for the first time.

Results

The tracheal tissues of experimental (C. baileyi infection) and control chickens were collected for deep RNA sequencing, and 545,479,934 clean reads were obtained. Of them, 1376 novel lncRNAs were identified, including 1161 long intergenic non-coding RNAs (lincRNAs) and 215 anti-sense lncRNAs. A total of 124 lncRNAs were found to be significantly differentially expressed between the experimental and control groups. Additionally, 14,698 mRNAs and 9085 circRNAs were identified, and significantly different expressions were observed for 1317 mRNAs and 104 circRNAs between two groups. Bioinformatic analyses of gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for their targets and source genes suggested that these dysregulated genes may be involved in the interaction between the host and C. baileyi.

Conclusions

The present study revealed the expression profiles of mRNAs, lncRNAs and circRNAs during C. baileyi infection for the first time, and sheds lights on the roles of lncRNAs and circRNAs underlying the pathogenesis of Cryptosporidium infection.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4754-2) contains supplementary material, which is available to authorized users.

Occurrence and molecular characterization of Giardia duodenalis cysts and Cryptosporidium oocysts in raw water samples from the Rímac River, Peru

Giardia and Cryptosporidium are potentially pathogenic protozoa which are ubiquitous in ambient surface water. The present study included 60 samples of surface water from three sampling sites from the Rímac River, Lima and Callao, Peru, to detect the occurrence of Giardia spp. and Cryptosporidium spp. and to perform molecular characterization of specimens found. Water samples were concentrated using the membrane filtration technique, and following elution, cysts and oocysts were visualized by direct immunofluorescence assay (IFA). For molecular characterization, tpi and bg gene fragments and 18S rRNA were amplified by nested PCR for Giardia and Cryptosporidium, respectively, followed by sequencing and phylogenetic analysis. Giardia cysts were found in 93.3% of the analyzed samples, whereas Cryptosporidium oocysts were detected in 15%. The positivity of the Giardia cysts was 86.6% (n = 26) in 2014, while Cryptosporidium oocysts were not detected. In 2015, both protozoa were found in raw water samples, with all 30 samples collected positive for Giardia cysts (100.0%) and 9 positive for Cryptosporidium oocysts (30.0%). Oocysts were detected in 20.0% of water samples from sites 1 (mean 5.25 oocysts/L) and 2 (mean 52.3 oocysts/L), while at site 3, oocysts were detected in 50.0% of raw water samples (mean 193.6 oocysts/L). The presence of Giardia duodenalis assemblage A was confirmed in several samples by the phylogenetic positioning of the bg and tpi genes, and the sub-assemblage AII was predominant (8/9). Sequencing for Cryptosporidium resulted in profiles compatible with Cryptosporidium hominis, Cryptosporidium meleagridis, and Cryptosporidium baileyi. This is the first time that the presence of G. duodenalis assemblage A/sub-assemblage AII and Cryptosporidium species has been reported in surface water samples in Peru. These Cryptosporidium species and the Giardia duodenalis assemblage are associated with human disease which highlights the potential risk to public health and the need to increase environmental monitoring measures to protect this water body.

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.

Presence and molecular characterization of Cryptosporidium and Giardia in recreational lake water in Tianjin, China: a preliminary study

Little is known about the occurrence of Cryptosporidium and Giardia in recreational water in China. A total of 52 samples were collected from recreational lakes in Tianjin during a high-occurrence season (June-October) for the waterborne cryptosporidiosis and giardiasis, and the occurrence and genotypes of Cryptosporidium and Giardia were investigated. The results showed that 82.7% (43) and 98.1% (51) of samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively. The mean concentration of parasites was 3.65 oocysts/10 L and 12.58 cysts/10 L, respectively. Molecular characterization revealed that the presence of Cryptosporidium parvum, C. andersoni, C. hominis, C. meleagridis, C. fragile, C. ubiquitum, and Giardia lamblia assemblage A, B and D. The protozoan contamination in the studied lakes may originate from animal feces on ground, which was washed into the lake by stormwater runoff. Nevertheless, there is a potential risk of infection during recreational activities in the lake because the dominant detected protozoan genotypes are common human pathogens. Moreover, microbial indicators analysis does not adequately indicate the protozoan contamination in recreational water. The information from this study will be valuable for future protozoan source tracking, and any further control interventions against Cryptosporidium and/or Giardia infection associated with recreational water.

Prevalence and Genetic Characterization of Cryptosporidium Infection in Java Sparrows (Lonchura oryzivora) in Northern China

Cryptosporidiosis is a cosmopolitan parasitosis that affects a wide range of hosts including birds. As information concerning Cryptosporidium in birds is limited, the present study examined the prevalence and genotypes of Cryptosporidium in Java sparrows in Beijing and Shangqiu, northern China. Three hundred and fifty fecal samples were collected from Java sparrows (Lonchura oryzivora, 225 white Java sparrows and 125 gray Java sparrows) in Beijing and Shangqiu in October 2015, and the samples were examined by PCR amplification of the small subunit ribosomal RNA (SSU rRNA) gene. The overall Cryptosporidium prevalence is 13.42% (47/350), with 16.44% (37/225) in white Java sparrows and 8.00% (10/125) in gray Java sparrows. Cryptosporidium prevalence was 9.82% (16/163) in Java sparrows from Beijing and 16.58% (31/187) in Java sparrows from Shangqiu. The prevalence of Cryptosporidium in females and males was 40.63% (26/64) and 7.34% (21/286), respectively. The Cryptosporidium prevalence in Java sparrows of different ages varied from 10.47% to 16.33%. Sequence analysis of the SSU rRNA gene revealed that all the samples represented C. baileyi. This is the first report of Cryptosporidium in gray Java sparrows in China, which extend the host range for C. baileyi. These results provide baseline information for further studies of molecular epidemiology and control of Cryptosporidium infection in poultry in China.

Molecular diagnosis and characterization of Cryptosporidium spp. in turkeys and chickens in Germany reveals evidence for previously undetected parasite species

A total of 256 fecal specimens were randomly collected from farmed poultry in Germany and screened for the presence of Cryptosporidium spp. by PCR and further characterized by direct automated DNA sequencing. Using a nested PCR amplifying approximately 830 bp 18S rDNA fragment, 7.03% (n = 18) of the samples were Cryptosporidium-positive. In detail, Cryptosporidium was detected in 9.3% (8/86) of turkeys, 5.7% (9/158) of broilers and 8.3% (1/12) of layers. After DNA sequencing, Cryptosporidium parvum the most frequently observed species was identified in 5.1% (13/256) of all poultry species, including 8.1% (7/86) of turkeys, 3.2% (5/158) of broilers and 8.3% (1/12) of layers. Cryptosporidium baileyi was detected in 1.3% (2/256) of the broilers only. Three novel unclassified Cryptosporidium spp. were detected in 1.2% (1/86) of turkeys and 1.3% (2/158) of broilers. The infection rate was high in 13-20 week old turkeys, 1-6 weeks old broilers and >20 weeks old layers but differences between age groups were not significant. This is the first study in Germany uses molecular methods for the detection of Cryptosporidium in poultry. The results indicate that Cryptosporidium parasites are common among broilers and turkeys in Germany. Considering the large size of the poultry industry, the large amount of poultry meat that is consumed and the fact that C. parvum is also the most common Cryptosporidium parasite in humans, poultry might also be a source of human infections.

Prevalence and risk factors for cryptosporidiosis: a global, emerging, neglected zoonosis

Background

Cryptosporidiosis is a zoonotic disease caused by the important parasitic diarrheal agent Cryptosporidium spp. Cryptosporidiosis occurs in all classes of animals and man with a rapidly expanding host range and increased importance since the occurrence of human immunodeficiency virus/acquired immunodeficiency syndrome in man.

Objectives

To review the global picture of cryptosporidiosis in man and animals with emphasis on prevalence and risk factors.

Methods

Current relevant literature on cryptosporidiosis was reviewed.

Results

Cryptosporidiosis is widely distributed and the risk factors vary from one region to another with hygiene and immune status as important risk factors.

Conclusions

Cryptosporidium spp. associated mortality has not only been reported in immune-compromised patients, but also in immune-competent patients. Yet in many countries not much attention is paid to the control and prevention of this infection in animals and man. The neglect of this disease despite the serious threat it poses to animals, their husbandry, and humans, has led the World Health Organization to list it among globally neglected diseases. To control and prevent this infection more effort needs to be directed at controlling the risk factors of the infection in man and animals.

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.

Molecular characterization of Cryptosporidium spp. in domestic pigeons (Columba livia domestica) in Guangdong Province, Southern China

To investigate the prevalence and assess the zoonotic transmission burden of Cryptosporidium species in domestic pigeons in Guangdong Province, Southern China, 244 fecal samples were collected from four pigeon breeding farms between June 2012 and March 2013. Cryptosporidium oocysts were purified by Sheather's sugar flotation technique and characterized by DNA sequencing of small subunit ribosomal RNA (SSU rRNA) gene. Cryptosporidium species were determined by comparison of sequences with corresponding Cryptosporidium sequences in GenBank and phylogenetic analysis using neighbor-joining (NJ) in MEGA5.2. The overall prevalence of Cryptosporidium infection in domestic pigeons in Guangdong Province was 0.82% (2/244). Two Cryptosporidium species, namely Cryptosporidium baileyi and Cryptosporidium meleagridis, were identified in Huizhou and Chaozhou farm, respectively. These findings confirmed the existence of C. meleagridis infection in domestic pigeons in China for the first time and provided base-line information for further studies to evaluate the public health risk from pigeon to human.

Cryptosporidium andersoni as a novel predominant Cryptosporidium species in outpatients with diarrhea in Jiangsu Province, China

Background

Cryptosporidium hominis and C. parvum are usually considered to be the major pathogens responsible for human cryptosporidiosis. However, there have been few studies regarding the molecular epidemiology of Cryptosporidium in human infections in China. Here we investigated Cryptosporidium infection in patients with diarrhea, in Danyang Hospital of Jiangsu Province, China, at the genotype level.

Methods

A total of 232 stool specimens were collected from outpatients with diarrhea in Danyang Hospital of Jiangsu Province, China, from February 2012 to January 2013. Each specimen was stained from direct fecal smears and examined for Cryptosporidium using modified acid fast staining and microscopy. Moreover, genomic DNA of each fecal sample was screened for the presence of Cryptosporidium with nested PCR, which was genotyped by analyzing the DNA sequences of small subunit rRNA (SSU rRNA).

Results

The average infection rate of Cryptosporidium was 1.3% (3/232) by microscopy and subjected to PCR amplification of the SSU rRNA gene of Cryptosporidium, with 9.91% (23/232) being positive for Cryptosporidium with a significant peak in autumn. Based on the SSU rRNA gene, two Cryptosporidium spp. were identified, including C. andersoni (n =21) and C. hominis (n =2). Two types of C. andersoni, designated as A₃₇₀⁺ and A₃₇₀^- , were found in the SSU rRNA gene in our present study, which was 100% homologous to C. andersoni infections derived from dairy calves and goats, respectively. The clinical questionnaires showed no significant difference in age, gender and frequency of diarrhea, but duration of diarrhea was shorter for C. andersoni than that of C. hominis (mean, 2 vs. 4 days; p <0.01).

Conclusions

C. andersoni is the dominant species in Danyang City of Jiangsu Province. The fact that SSU rRNA sequences of C. andersoni obtained from human stools exhibited 100% homologous to those derived from dairy calves and goats supported that C. andersoni infection might be attributable to animal origin. The difference in the duration of diarrhea of C. andersoni and C. hominis indicated that different Cryptosporidium species might cause different clinical manifestations.

Cryptosporidiosis in broiler chickens in Zhejiang Province, China: molecular characterization of oocysts detected in fecal samples

Cryptosporidium is one of the most important parasites in poultry, and this pathogen can infect more than 30 avian species. The present study investigated the infection rate of Cryptosporidium among broiler chicken flocks. A total of 385 fecal samples from broiler chickens in 7 regions of Zhejiang Province collected from November 2010 to January 2012 were examined by microscopy. Thirty-eight (10%) samples were positive for Cryptosporidium infection, and 3 genotypes (Cryptosporidium baileyi, Cryptosporidium meleagridis, and avian genotype II) were identified by PCR and sequencing. A phylogenetic tree of the isolates was analyzed. These results suggest that cryptosporidiosis is widespread in poultry in Zhejiang Province, and is a potential threat to public health as well as the economy. This is the first report about the infection rate and molecular characterization of Cryptosporidium in broiler chickens in Zhejiang.

The expression dynamics of IL-17 and Th17 response relative cytokines in the trachea and spleen of chickens after infection with Cryptosporidium baileyi

BACKGROUND

Cryptosporidium baileyi is the dominant Cryptosporidium species in birds causing emerging health problems in the poultry industry, and is also a model to study the biology of Cryptosporidium spp.. IL-17 (also called IL-17A) is a hallmark pro-inflammatory cytokine of Th17 cells that plays an important role in several human autoimmune diseases and microbial infection disease of many animals, and it may play a role in Cryptosporidium infection.

METHODS

The present study examined the mRNA level of IL-17 and Th17 response relative cytokines in the trachea and spleen of C. baileyi-infected chickens at different time points using real-time quantitative PCR (qPCR).

RESULTS

All examined cytokines in the trachea were up-regulated in the infected chickens compared with the uninfected control during C. baileyi infection. Significant increased IL-17 mRNA level in the trachea was observed as early as 12 h post infection (pi), peaking at 24 h pi and 10 d pi, and declining thereafter. The transcription levels of IL-17 and Th17 response relative cytokines in spleen were also significantly increased at different time points during the infection.

CONCLUSIONS

IL-17 was indicated to participate in the induction of inflammation during infection of some intracellular protozoan parasites. The results in the present study suggest that IL-17 may play a role in immunity against Cryptosporidium infection, and provide basic information for determining the role of Th17 cell in Cryptosporidium infection.

Cryptosporidiosis in Farmed Animals

Cryptosporidiosis was first identified as a disease of veterinary, rather than human medical, importance, and infection of farmed animals with different species of Cryptosporidium continues to be of veterinary clinical concern. This chapter provides insights into Cryptosporidium infection in a range of farmed animals – cattle, sheep, goats, pigs, cervids, camelids, rabbits, water buffalo and poultry – presenting not only an updated overview of the infection in these animals, but also information on clinical disease, infection dynamics and zoonotic potential. Although extensive data have been accrued on, for example, Cryptosporidium parvum infection in calves, and calf cryptosporidiosis continues to be a major veterinary concern especially in temperate regions, there remains a paucity of data for other farmed animals, despite Cryptosporidium infection causing significant clinical disease and also, for some species, with the potential for transmission of infection to people, either directly or indirectly.

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.

Distribution and genetic characterizations of Cryptosporidium spp. in pre-weaned dairy calves in Northeastern China's Heilongjiang Province

Background

Cryptosporidium spp. are common parasites of humans and animals. Farm animals, especially pre-weaned calves, are considered to be one of main animal reservoir hosts of Cryptosporidium in the transmission of human cryptosporidiosis. The aim of this study was to determine the distribution and genotypes of Cryptosporidium spp. in pre-weaned calves using molecular tools and to assess zoonotic transmission and elucidate the public health significance in northeastern China.

Methodology/Principal Findings

A total of 151 fecal specimens from pre-weaned calves were collected in Heilongjiang Province and were screened for Cryptosporidium by PCR. The average prevalence of Cryptosporidium was 47.68% (72/151). Cryptosporidium spp. were characterized by DNA sequencing of the small subunit (SSU) rRNA gene and the 60-kDa glycoprotein (gp60) gene. Based on the SSU rRNA gene, five Cryptosporidium spp. were identified, including C. bovis (n = 34), C. andersoni (n = 26), C. ryanae (n = 5), C. meleagridis (n = 5) and C. parvum (n = 2). The SSU rRNA nucleotide sequences were identical to each other, respectively, within C. ryanae, C. parvum, C. meleagridis and C. andersoni. Four types of C. bovis were found in the SSU rRNA gene, with two novel types. The gp60 gene was successfully sequenced in one C. parvum isolate and three C. meleagridis isolates, with IIdA19G1 for C. parvum and IIIeA22G2R1 for C. meleagridis.

Conclusion/Significance

Molecular analysis indicates that Cryptosporidium spp. are endemic in pre-weaned calves in Heilongjiang Province. The findings of C. parvum and C. meleagridis suggested the possibility of zoonotic transmission and public health significance. The transmission dynamics of C. parvum and C. meleagridis needed to be clarified by further molecular epidemiologic studies from humans and animals. Whether calves could act as the natural reservoirs of C. meleagridis needed to be confirmed by more systematic experimental infection studies.

Fecal contamination and diarrheal pathogens on surfaces and in soils among Tanzanian households with and without improved sanitation

Little is known about the extent or pattern of environmental fecal contamination among households using low-cost, on-site sanitation facilities, or what role environmental contamination plays in the transmission of diarrheal disease. A microbial survey of fecal contamination and selected diarrheal pathogens in soil (n = 200), surface (n = 120), and produce samples (n = 24) was conducted in peri-urban Bagamoyo, Tanzania, among 20 households using private pit latrines. All samples were analyzed for E. coli and enterococci. A subset was analyzed for enterovirus, rotavirus, norovirus GI, norovirus GII, diarrheagenic E. coli, and general and human-specific Bacteroidales fecal markers using molecular methods. Soil collected from the house floor had significantly higher concentrations of E. coli and enterococci than soil collected from the latrine floor. There was no significant difference in fecal indicator bacteria levels between households using pit latrines with a concrete slab (improved sanitation) versus those without a slab. These findings imply that the presence of a concrete slab does not affect the level of fecal contamination in the household environment in this setting. Human Bacteroidales, pathogenic E. coli, enterovirus, and rotavirus genes were detected in soil samples, suggesting that soil should be given more attention as a transmission pathway of diarrheal illness in low-income countries.