Cryptosporidium spp. and Giardia duodenalis in two areas of Galicia (NW Spain)

Cryptosporidium and agriculture: A review

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

Occurrence and limited zoonotic potential of Cryptosporidium spp., Giardia duodenalis, and Balantioides coli infections in free-ranging and farmed wild ungulates in Spain

Little information is currently available on the occurrence and molecular diversity of the enteric protozoan parasites Cryptosporidium spp., Giardia duodenalis, and Balantioides coli in wild ungulates and the role of these host species as potential sources of environmental contamination and consequent human infections. The presence of these three pathogens was investigated in eight wild ungulate species present in Spain (genera Ammotragus, Capra, Capreolus, Cervus, Dama, Ovis, Rupicapra, and Sus) by molecular methods. Faecal samples were retrospectively collected from free-ranging (n = 1058) and farmed (n = 324) wild ungulates from the five Spanish bioregions. Overall infection rates were 3.0% (42/1382; 95% CI: 2.1-3.9%) for Cryptosporidium spp., 5.4% (74/1382; 95% CI: 4.2-6.5%) for G. duodenalis, and 0.7% (9/1382; 95% CI: 0.3-1.2%) for B. coli. Cryptosporidium infection was detected in roe deer (7.5%), wild boar (7.0%) and red deer (1.5%), and G. duodenalis in southern chamois (12.9%), mouflon (10.0%), Iberian wild goat (9.0%), roe deer (7.5%), wild boar (5.6%), fallow deer (5.2%) and red deer (3.8%). Balantioides coli was only detected in wild boar (2.5%, 9/359). Sequence analyses revealed the presence of six distinct Cryptosporidium species: C. ryanae in red deer, roe deer, and wild boar; C. parvum in red deer and wild boar; C. ubiquitum in roe deer; C. scrofarum in wild boar; C. canis in roe deer; and C. suis in red deer. Zoonotic assemblages A and B were detected in wild boar and red deer, respectively. Ungulate-adapted assemblage E was identified in mouflon, red deer, and southern chamois. Attempts to genotype samples positive for B. coli failed. Sporadic infections by canine- or swine-adapted species may be indicative of potential cross-species transmission, although spurious infections cannot be ruled out. Molecular evidence gathered is consistent with parasite mild infections and limited environmental contamination with (oo)cysts. Free-ranging wild ungulate species would not presumably play a significant role as source of human infections by these pathogens. Wild ruminants do not seem to be susceptible hosts for B. coli.

Giardia duodenalis Styles, 1902 Prevalence in Cattle (Bos taurus Linnaeus, 1758) in Europe: A Systematic Review

Giardia duodenalis Styles, 1902 is an infectious agent which can cause enteritic disease in cattle (Bos taurus Linnaeus, 1758) worldwide. As a zoonotic protozoan, it is important to acknowledge Giardia prevalence and assemblages found in cattle and risk factors associated with the Giardia infection in herds. This systematic review aims to estimate the prevalence of G. duodenalis and its assemblages in cattle and to identify the risk factors associated with Giardia infection in cattle in Europe. A systematic review was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines to collect information from published studies in Europe. A total of 1414 studies were identified and 17 relevant studies were included in this review. Mean Giardia prevalence in cattle in Europe was 35.1%, with the highest prevalence found in neonatal animals (39.6%), but mean heard prevalence was 67.0%. Mixed infections of Giardia assemblages A and E were found most frequently (55.6%), while assemblages A and B were found more frequently in animals under 24 months old. Risk factors, such as deep litter with run-out, prolonged calf contact with the dam, and seasonality, such as winter and spring, were found to be potential risk factors for Giardia presence in the herds.

Diverse Genotypes of Cryptosporidium in Sheep in California, USA

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

Multilocus Genotyping of Giardia duodenalis in Alpine Musk Deer (Moschus chrysogaster) in China

Giardia duodenalis is the underlying cause of a significant number of outbreaks of gastrointestinal illness in humans and animals worldwide. The purpose of this study was to elucidate the prevalence and genetic diversity of G. duodenalis in captive alpine musk deer (Moschus chrysogaster) in China. A total of 202 fecal samples were collected from three farms in Gansu Province, China. Identification of G. duodenalis was conducted by nested PCR targeting the genes coding for SSU rRNA, β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi). The overall prevalence of G. duodenalis in captive alpine musk deer in surveyed area was 19.3% (39/202). Two G. duodenalis genetic assemblages were identified, namely assemblage A and E. Mixed genotype infections (A+E) were found in 15.4% (6/39) of positive samples. Multilocus genotyping (MLG) analysis of G. duodenalis isolates revealed six novel assemblage A MLGs formed by two newly-described MLG-subtypes which belonged to sub-assemblage AI. To the best of our knowledge, this is the first report on MLG of G. duodenalis isolates in captive alpine musk deer in China. The presence of zoonotic assemblages and sub-assemblages of G. duodenalis in deer species suggests that these animals may potentially act as a reservoir of this protozoan for humans.

Wastewater-based epidemiology-surveillance and early detection of waterborne pathogens with a focus on SARS-CoV-2, Cryptosporidium and Giardia

Waterborne diseases are a major global problem, resulting in high morbidity and mortality, and massive economic costs. The ability to rapidly and reliably detect and monitor the spread of waterborne diseases is vital for early intervention and preventing more widespread disease outbreaks. Pathogens are, however, difficult to detect in water and are not practicably detectable at acceptable concentrations that need to be achieved in treated drinking water (which are of the order one per million litre). Furthermore, current clinical-based surveillance methods have many limitations such as the invasive nature of the testing and the challenges in testing large numbers of people. Wastewater-based epidemiology (WBE), which is based on the analysis of wastewater to monitor the emergence and spread of infectious disease at a population level, has received renewed attention in light of the current coronavirus disease 2019 (COVID-19) pandemic. The present review will focus on the application of WBE for the detection and surveillance of pathogens with a focus on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the waterborne protozoan parasites Cryptosporidium and Giardia. The review highlights the benefits and challenges of WBE and the future of this tool for community-wide infectious disease surveillance.

High-Throughput Sequencing of Environmental DNA as a Tool for Monitoring Eukaryotic Communities and Potential Pathogens in a Coastal Upwelling Ecosystem

The marine environment includes diverse microeukaryotic organisms that play important functional roles in the ecosystem. With molecular approaches, eukaryotic taxonomy has been improved, complementing classical analysis. In this study, DNA metabarcoding was performed to describe putative pathogenic eukaryotic microorganisms in sediment and marine water fractions collected in Galicia (NW Spain) from 2016 to 2018. The composition of eukaryotic communities was distinct between sediment and water fractions. Protists were the most diverse group, with the clade TSAR (Stramenopiles, Alveolata, Rhizaria, and Telonemida) as the primary representative organisms in the environment. Harmful algae and invasive species were frequently detected. Potential pathogens, invasive pathogenic organisms as well as the causative agents of harmful phytoplanktonic blooms were identified in this marine ecosystem. Most of the identified pathogens have a crucial impact on the aquacultural sector or affect to relevant species in the marine ecosystem, such as diatoms. Moreover, pathogens with medical and veterinary importance worldwide were also found, as well as pathogens that affect diatoms. The evaluation of the health of a marine ecosystem that directly affects the aquacultural sector with a zoonotic concern was performed with the metabarcoding assay.

Zoonotic giardiasis: an update

Giardia duodenalis is a common intestinal parasite in various hosts, with the disease giardiasis being a zoonosis. The use of molecular typing tools has improved our understanding of the distribution and zoonotic potential of G. duodenalis genotypes in different animals. The present review summarizes recent data on the distribution of G. duodenalis genotypes in humans and animals in different areas. The dominance of G. duodenalis assemblages A and B in humans and common occurrence of host-adapted assemblages in most domesticated animals suggests that zoonotic giardiasis is probably less common than believed and could be attributed mainly to contact with or contamination from just a few species of animals such as nonhuman primates, equines, rabbits, guinea pigs, chinchillas, and beavers. Future studies should be directed to advanced genetic characterization of isolates from well-designed epidemiological investigations, especially comparative analyses of isolates from humans and animals living in the same household or community. This will likely lead to better understanding of zoonotic transmission of G. duodenalis in different environmental and socioeconomic settings.

The Age-Related Cryptosporidium Species Distribution in Asymptomatic Cattle from North-Western SPAIN

Simple Summary

An age-related distribution of Cryptosporidium species has been reported in cattle, with the pathogenic and zoonotic C. parvum being predominant in suckling calves, C. bovis and C. ryanae being predominant in post-weaned calves and C. andersoni being predominant in adults. However, variants to this pattern have recently been reported. Unravelling the age-related species distribution pattern in cattle from a particular region will allow determining those age classes posing a higher risk to public and animal health. Thus, fecal samples from asymptomatic cattle were collected in north-western Spain. Cryptosporidium detection and species identification was performed by molecular methods. Cryptosporidium prevalence was 16.7%; it significantly decreased with age. Cryptosporidium andersoni, C. bovis, C. occultus, C. parvum, C. ryanae and C. xiaoi were identified. Cryptosporidium parvum was predominant in calves younger than 1 month and C. bovis was predominant in the rest of the age groups. The presence of C. parvum in all age groups implies animal and public health concerns. The predominance of C. bovis in cattle older than 1 month supports the idea that the age-related pattern of Cryptosporidium species described in cattle is not fully consistent, and thus further studies are needed to identify those factors determining the species distribution.

Abstract

An age-related distribution of Cryptosporidium species has been reported in cattle, with C. parvum being predominant in suckling calves, C. bovis and C. ryanae being predominant in post-weaned calves and C. andersoni being predominant in adults. However, variants to this pattern have recently been reported. Thus, fecal samples (n = 594) from asymptomatic cattle were collected in north-western Spain. Animals were classified as <1 month (G1), 1–2 months (G2), 2–12 months (G3), 12–24 months (G4) and >2 years (G5). Cryptosporidium detection and species identification were performed by SSU rRNA PCR. Individual Cryptosporidium prevalence was 16.7%; it significantly decreased with age. Cryptosporidium parvum was predominant in G1 and C. bovis was predominant in the rest of the age classes; C. bovis and C. ryanae were especially prevalent in G2 and G3. Cryptosporidium occultus was not found in suckling calves. Finally, C. andersoni and C. xiaoi were occasionally detected in G5. The presence of C. parvum in all age classes implies significant animal and public health concerns. The predominance of C. bovis in cattle older than 1 month supports the idea that the age-related pattern of Cryptosporidium species described in cattle is not fully consistent, and thus further studies are still needed to identify those factors determining the species distribution.

Cryptosporidium infections in sheep farms from Italy

Cryptosporidiosis is recognized as being a significant cause of gastrointestinal illness due to its wide range of vertebrate hosts, including humans. Infection with Cryptosporidium spp. is especially common in young domestic ruminants (calves, lambs and goat kids) and has been associated with economic losses worldwide. In contrast to cattle, to date, detailed studies on Cryptosporidium infections in sheep from Europe are still limited; thus, their importance as reservoirs of Cryptosporidium species with implications on animal and public health still needs to be clarified. This study evaluates the prevalence and zoonotic potential of Cryptosporidium spp. in sheep farms in Italy. A total of 915 individual faecal samples divided into three different animal categories were collected from 61 sheep farms. Each sample was examined by microscopy of faecal smears stained by modified Ziehl-Neelsen and by biomolecular techniques. Cryptosporidium oocysts were detected in 10.1% of the animals examined and in 34.4% of the farms. The prevalence of Cryptosporidium spp. was significantly higher (χ² = 51.854; P < 0.001) in diarrhoeic samples than in pasty or normal faeces. Genotype analyses showed the presence of two Cryptosporidium species: C. parvum and C. ubiquitum. Subtyping analysis of C. parvum isolates revealed the presence of subtypes IIa15G2R1 and IIdA20G1 and of subtype XIIa for C. ubiquitum. These findings have public health implications since both Cryptosporidium species identified are considered zoonotic, and C. parvum is the second-most common Cryptosporidium species infecting humans. Our data reveal that lambs, especially those excreting diarrhoeic faeces, may be important reservoirs of Cryptosporidium. We also highlight the need to establish adequate control and monitoring programmes for the control of this infection in sheep farms primarily through coprological monitoring.

Pre-ozonation of surface water: An effective water treatment process to reduce the risk of infection by Giardia in drinking water

Giardia is a protozoan parasite of primary concern for the drinking water industry. High contact times are required for Giardia inactivation by chlorination, while ozonation may be effective at much lower Ct products. In this study, we have assessed the occurrence of Giardia cysts in raw water, and in chlorinated or ozonated water from a drinking water treatment plant (DWTP) in Brazil, over a 16-month period. Moreover, we analyzed the effects of primary disinfection on cysts, and calculated the infection risk caused by the occurrence of Giardia cysts in raw water, chlorinated or ozonated water. Furthermore, we assessed the correlation of Giardia cysts with indicator bacteria in raw water. Data referring to concentration of Giardia cysts in raw water showed adherence to a gamma distribution at a significance level α = 0.05. The detection frequency and the mean concentration of Giardia cysts were higher in raw water (86.6%, 26 cysts∙L^-1), than in chlorinated (46.1%, 15.7 cysts·L^-1) or ozonated water (43.5%, 11.1 cysts·L^-1). Overall, Giardia non-viable cysts were detected more frequently in ozonated water (80%) than in chlorinated water (68.2%) or raw water (37.7%). Ozonation and chlorination resulted, respectively, in ≈27.5- and ≈13- fold reduction of Giardia infection risk, when compared to the risk calculated for raw water. Total coliform and Escherichia coli proved to be suitable surrogates to predict the occurrence of Giardia cysts in raw surface water, however, the indicator bacteria may not be suitable surrogates to predict the disinfection of Giardia cysts, as no correlation was found between indicator bacteria and Giardia cysts in treated water. To our knowledge, this is the first study reporting the efficacy of chlorine and ozone at Ct products actually applied at a full-scale drinking water treatment plant against Giardia cysts naturally occurring in the source water, i.e. real situation. Ozonation has proven more efficient than chlorination against Giardia cysts in surface water. Escherichia coli proved to be suitable surrogate to predict Giardia cysts in raw surface water.

The red fox (Vulpes vulpes) as a potential natural reservoir of human cryptosporidiosis by Cryptosporidium hominis in Northwest Spain

Giardia duodenalis and Cryptosporidium spp. are ubiquitous intestinal protozoa that parasitize domestic and wild animals, as well as human beings. Due to their zoonotic potential, the objective of the present study was to determine the presence of these pathogens in the fox population (Vulpes vulpes) located in Northwest Spain. A total of 197 faecal samples from legally hunted foxes were collected in the autonomous region of Galicia. The presence of G. duodenalis and Cryptosporidium spp. was investigated by PCR-based methods amplifying the small subunit ribosomal RNA (ssu rRNA) gene of the parasites. Attempts to genotype obtained positive samples were subsequently conducted at the glutamate dehydrogenase (gdh) and β-giardin (bg) genes of G. duodenalis, and the 60 kDa glycoprotein (gp60) gene of Cryptosporidium. Giardia duodenalis and Cryptosporidium spp. were identified in 19 (9.6%) and 12 (6.1%) of the investigated samples, respectively. However, five Cryptosporidium species were detected at the ssu rRNA locus: C. hominis (33.4%, 4/12), C. canis (25.0%, 3/12), C. parvum (16.7%, 2/12), C. ubiquitum (8.3%, 1/12) and C. suis (8.3%, 1/12). An additional Cryptosporidium-positive sample was identified at the genus level only. Typing and subtyping of Giardia- and Cryptosporidium-positive samples were unsuccessful. The detection of C. hominis in wild foxes indicates the probable overlapping of sylvatic and domestic cycles of this parasite in rural settings. Besides, this finding raises the question of whether red foxes may act as natural reservoirs of C. hominis. The detection of C. parvum and C. suis is suggestive of active transmission events between farm and wild animals, opening up the possibility of transmission to human beings.

Prevalence and multilocus genotyping of Giardia duodenalis in Tan sheep (Ovis aries) in northwestern China

Giardia duodenalis is a common intestinal protozoa, which can cause the occurrence of diarrhea, weight loss, and even death in animals or human, this threatens the husbandry industry and public health. It can infect virtually humans and all domestic animals including sheep. Tan sheep is one of the most important sheep breeds, which is short-tailed indigenous sheep breed used for production of high quality meat and pelts in China. However, there are no report regarding the occurrence and multilocus genotyping of G. duodenalis in Tan sheep in northwestern China. Thus, the objective of the present study was to investigate the prevalence and multilocus genotypes of G. duodenalis in Tan sheep. 1014 fecal samples were collected from Tan sheep from Ningxia Hui Autonomous Region, and three loci (β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes) were amplified by nested PCR. The prevalence of G. duodenalis in Tan sheep was 14.5% (147/1014), two assemblages (assemblage A, n = 43; and E, n = 90) were detected, including one novel assemblage A at bg locus, one novel assemblage A at tpi locus, and 10 and 11 novel subtypes of assemblage E were detected at the bg and gdh loci, respectively. One MLGs was formed based on sequence variation among the three loci. Moreover, 9 Tan sheep were infected with two assemblages (A and E) based on the three loci. These findings expand the host range of G. duodenalis and revealed genetic diversity of G. duodenalis assemblages in Tan sheep.

First report of Giardia duodenalis genotypes in Zangxiang pigs from China

Giardia duodenalis is an important zoonotic intestinal protozoan of animals and humans. We collected 450 faecal specimens from four age groups (pre-weaned piglets, weaned piglets, juveniles, adults) of Zangxiang pigs from Shaanxi and Qinghai provinces, to investigate the prevalence and genetic diversity of G. duodenalis at the β-giardin (bg), triosephosphate isomerase (tpi) and glutamate dehydrogenase (gdh) loci using nested PCRs in the present study. A total of 28 faecal samples were positive for presence of G. duodenalis, with an overall prevalence of 6.2%. Giardia duodenalis was detected in pigs from all age groups and in both investigated provinces. Significant differences (P < 0.0001) in prevalence were observed among the four age groups with prevalence decreasing with age. Sequence analysis indicated existence of genetic diversity of G. duodenalis isolates from Zangxiang pigs, with 4, 2 and 4 haplotypes at the bg, tpi and gdh loci, respectively. Two assemblages were identified, including the zoonotic assemblage B and assemblage E, with the latter as the predominant assemblage found in both locations and all age groups except adults. The present study expanded the host range of G. duodenalis and provided fundamental data for controlling G. duodenalis infection in Zangxiang pigs.

Occurrence and multilocus genotyping of Giardia duodenalis in black-boned sheep and goats in southwestern China

BACKGROUND

Giardia duodenalis is an important intestinal protozoan infecting both humans and animals, causing significant public health concern and immeasurable economic losses to animal husbandry. Sheep and goats have been reported as common reservoirs of G. duodenalis, but only a limited amount of information is available for native breeds of these small ruminants in China. The present study investigated the prevalence and multilocus genotypes of G. duodenalis in black-boned sheep and goats, two important native breeds in Yunnan Province, southwestern China.

METHODS

Fecal samples were collected from 336 black-boned goats and 325 black-boned sheep from five counties (Meishui, Shanshu, Shilin, Yongsheng and Nanping) of Yunnan Province and the genomic DNA was extracted from these feces. The prevalence of G. duodenalis was determined by the nested PCR targeting the β-giardin (bg) gene. The assemblages and multilocus genotypes (MLGs) were investigated based on analyses of three genetic loci, i.e. bg, glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi).

RESULTS

Giardia duodenalis infection was detected in both black-boned sheep and goats, and the prevalence of G. duodenalis in black-boned sheep (21.8%, 71/325) was significantly higher (χ² = 36.63, df = 1, P < 0.001) than that in black-boned goats (4.8%, 16/336). Significant differences in prevalence were also observed in goats and sheep from different counties (χ² = 39.83, df = 4, P < 0.001) and age groups (χ² = 97.33, df = 3, P < 0.001). Zoonotic assemblage A and animal-specific assemblage E were identified in both black-boned sheep and goats with the latter as the predominant assemblage. Based on sequences obtained from the three genetic loci (bg, gdh and tpi), 16 MLGs were obtained in black-boned sheep and goats, including 15 MLGs in assemblage E and one MLG in assemblage A.

CONCLUSIONS

Our results not only extended the host range of G. duodenalis, but also revealed high genetic variations in G. duodenalis assemblages. The findings of the present study also provide baseline data for preventing and controlling G. duodenalis infection in black-boned sheep and goats in Yunnan Province.

Sheep as a Potential Source of Zoonotic Cryptosporidiosis in China

In this study, we assessed the prevalence and genetic characteristics of Cryptosporidium in sheep from 10 provinces in China. Fecal samples from 1,035 sheep originating from 16 farms were collected, and 295 (28.5%) were found to be Cryptosporidium positive by nested PCR. Cryptosporidium was detected at all farms, with infection rates between 5.7% and 50.0%. Three Cryptosporidium species were identified, including Cryptosporidium xiaoi (73.2%, 216/295), Cryptosporidium ubiquitum (21.7%, 64/295), and Cryptosporidium parvum (5.1%, 15/295). The distribution of Cryptosporidium species differed by province and by farm. All three species were detected in lambs and adult sheep but the highest infection rate was found in postweaned lambs. All three species were detected in all four seasons, with the highest prevalence found in autumn. Four C. parvum subtypes (IIaA15G2R1, IIaA17G2R1, IIdA18G1, and IIdA19G1) and one C. ubiquitum subtype (XIIa) were identified. For most provinces in this study, we are not aware of a previously published description or molecular characterization of Cryptosporidium infections in sheep. This information will improve our knowledge and understanding of the epidemiology of cryptosporidiosis in China.IMPORTANCECryptosporidium is an important zoonotic parasite that causes diarrhea in humans and animals worldwide. Previous studies suggested geographic differences in the distribution of Cryptosporidium species in sheep. However, molecular characterization studies of Cryptosporidium species in sheep have been carried out in only a few provinces in China, and the limited data available do not reflect the real situation. In this study, five districts, covering most areas where sheep are bred in China, were selected for examination of Cryptosporidium species, and Cryptosporidium infections were detected at all farms assessed, suggesting that Cryptosporidium is widespread in sheep in China. We also found geographic differences in the distribution of Cryptosporidium species but did not detect any differences between sheep age groups or seasons. Subtyping analyses showed that all of the subtypes identified in this study have been reported in humans, suggesting that sheep may be a potential source of zoonotic cryptosporidiosis.

Molecular characterisation and risk factor analysis of Cryptosporidium spp. in calves from Italy

To provide up-to-date information on the occurrence of Cryptosporidium in pre-weaned calves from Sardinia (Italy), the species implicated and their zoonotic potential, 147 faecal samples from 22 cattle herds were microscopically examined for Cryptosporidium oocysts; positive isolates were molecularly characterised. A questionnaire was developed to identify risk factors for Cryptosporidium infection. Overall, the percentage of positive calves and farms was 38.8 and 68.2%, respectively. The SSU rRNA-based PCR identified two Cryptosporidium species, Cryptosporidium parvum (95.8%) and C. bovis (4.2%). Sequence analyses of the glycoprotein (gp60) gene revealed that all C. parvum isolates belonged to the subtype family IIa (IIaA15G2R1 and IIaA16G3R1), with the exception of three isolates that belonged to the subtype family IId (IIdA20G1b and IIdA20). Mixed logistic regression results indicated that calves aged 15-21 days were more likely to be Cryptosporidium-positive. The risk of being positive was also significantly higher in herds from Central Sardinia and in farms using non-slatted flooring. In addition, the application of disinfectants and milk replacers was significantly associated with higher Cryptosporidium prevalence. In contrast, the risk of being positive was significantly reduced in halofuginone-treated calves. Our results reveal that a significant percentage of suckling calves are carriers of zoonotic subtypes of C. parvum. Thus, both healthy and diarrhoeic calves younger than 1 month may represent a risk for the transmission of cryptosporidiosis in humans and animals.

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in deer in Henan and Jilin, China

Background

Little is known about the prevalence and zoonotic potential of Cryptosporidium spp. and Giardia duodenalis in deer in China. In this study, 662 fecal samples were collected from 11 farms in Henan and Jilin Provinces between July 2013 and August 2014, and were screened for the presence of Cryptosporidium and G. duodenalis with genotyping and subtyping methods.

Results

Cryptosporidium spp. and G. duodenalis were detected in 6.80% (45/662) and 1.21% (5/662) of samples, respectively. Six Cryptosporidium species/genotypes were identified based on the small subunit ribosomal ribonucleic acid (SSU rRNA) gene: C. parvum (n = 11); C. andersoni (n = 5); C. ubiquitum (n = 3); C. muris (n = 1); C. suis-like (n = 1); and Cryptosporidium deer genotype (n = 24). When five of the 11 C. parvum isolates were subtyped by sequencing the 60 kDa glycoprotein (gp60) gene, zoonotic subtypes IIaA15G2R2 (n = 4) and IIdA19G1 (n = 1) were found. According to a subtype analysis, three C. ubiquitum isolates belonged to XIIa subtype 2. In contrast, only assemblage E was detected in the five Giardia-positive samples with small subunit ribosomal ribonucleic acid (SSU rRNA) gene sequencing.

Conclusions

To our knowledge, this is the first study to report C. andersoni, as well as C. parvum zoonotic subtypes IIaA15G2R2 and IIdA19G1 in cervids. These data, though limited, suggest that cervids may be a source of zoonotic Cryptosporidium and Giardia. Cervids in the present study are likely to be of low zoonotic potential to humans, and more molecular epidemiological studies are required to clarify the prevalence and public health significance of Cryptosporidium and G. duodenalis in cervids throughout China.

Occurrence and molecular genotyping of Giardia duodenalis and Cryptosporidium spp. in wild mesocarnivores in Spain

There is a surprisingly scarce amount of epidemiological and molecular data on the prevalence, frequency, and diversity of the intestinal protozoan parasites Giardia duodenalis and Cryptosporidium spp. in wildlife in general and mesocarnivore species in particular. Consequently, the extent of the cyst/oocyst environmental contamination attributable to these wild host species and their potential implications for public veterinary health remain largely unknown. In this molecular epidemiological survey a total of 193 individual faecal samples from badgers (Meles meles, n=70), ferrets (Mustela putorius furo, n=2), genets (Genetta genetta, n=6), Iberian lynxes (Lynx pardinus, n=6), beech martens (Martes foina, n=8), mongooses (Herpestes ichneumon, n=2), otters (Lutra lutra, n=2), polecats (Mustela putorius, n=2), red foxes (Vulpes vulpes, n=87), wildcats (Felis silvestris, n=2), and wolves (Canis lupus, n=6) were obtained from road-killed, hunted, and accidentally found carcasses, and from camera-trap surveys or animals entering rescue shelters, during the period December 2003-April 2016. Investigated specimens were collected in five Spanish autonomous regions including Andalusia (n=1), Asturias (n=69), Basque Country (n=49), Castile-La Mancha (n=38), and Extremadura (n=36). The presence of cysts/oocysts was confirmed by PCR-based methods targeting the small subunit (ssu) ribosomal RNA gene of these parasite species. Genotyping of the obtained isolates were attempted at appropriate markers including the glutamate dehydrogenase (G. duodenalis) and the 60-kDa glycoprotein (C. parvum and C. ubiquitum) loci. Overall, G. duodenalis was detected in 8% (7/87) of red foxes, a single beech marten, and a single wolf, respectively. Cryptosporidium was identified in 3% (2/70) of badgers, 8% (7/87) of red foxes, a single genet, and a single mongoose, respectively. None of the nine G. duodenalis isolates generated could be genotyped at the assemblage/sub-assemblage level. Out of the nine Cryptosporidium isolates successfully characterized, three were identified as C. canis (one in a mongoose and two in red foxes), and three as C. parvum (one in a badger and three in red foxes). The remaining three isolates were assigned to C. felis (in a red fox), C. hominis (in a badger), and C. ubiquitum (in a red fox), respectively. Two additional Cryptosporidium isolates infecting a badger and a genet, respectively, were untypable. The red fox was confirmed as a suitable host of potentially zoonotic Cryptosporidium species, mainly C. parvum and C. ubiquitum. The high mobility and wide home range of red foxes, together with their increasing presence in urban and peri-urban settings, may led to the overlapping of sylvatic and domestic cycles of the parasite, and consequently, to an increased risk of cryptosporidiosis in production animals and humans. The detection of C. hominis oocysts in a badger raises the question of whether this finding represents a true infection or a sporadic event of mechanical passage of C. hominis oocyst of anthroponotic origin.

Contribution of environmental media to cryptosporidiosis and giardiasis prevalence in Tehran: a focus on surface waters

The occurrences of Cryptosporidium and Giardia in surface sources of drinking water in Tehran were monitored, using US EPA method 1623.1. The prevalence ratios (PR) of positive samples among other media (animal's stools, vegetables, and human's stools) were also estimated from literature data. The density of Giardia and Cryptosporidium in water samples were 0.129 ± 0.069 cysts/L and 0.005 ± 0.002 oocysts/L, respectively. Estimated PR in vegetables, animal stools, surface waters, and human stools were 6.65, 20.42, 21.05, and 4.28 % for Cryptosporidium and 6.46, 17.13, 73.68, and 15.65 % for Giardia, respectively. These reveal the importance of surface waters' and animal stools' roles in the prevalence of cryptosporidiosis and giardiasis in Tehran's population. Giardia's prevalence in untreated surface waters in Tehran was found 3.5 times as much as Cryptosporidium while this found 2.3 times on a global scale. Moreover, the prevalence of giardiasis to cryptosporidiosis infections in Tehran's human population was 3.65. These values could be a clue to attribute the infections to the occurrence of parasites in surface waters. Significant (p < 0.05) associations were observed between rainfalls and presence of Giardia (r = 0.62) and Cryptosporidium (r = 0.60) in surface waters. In autumn, rainfalls can increase the parasites occurrences in surface waters. Significant (p < 0.05) difference on the density of parasites was found between some seasons using Kruskal-Wallis and multiple comparison tests. A significant correlation (r = 0.86) between Giardia and Cryptosporidium densities also confirms the common sources of pollution in surface waters. Findings suggest that untreated surface waters in Tehran may be a potential route of human exposure to protozoan parasites.

Prevalence of Cryptosporidium and Giardia in the water resources of the Kuang River catchment, Northern Thailand

A catchment-scale investigation of the prevalence of Cryptosporidium and Giardia in the Kuang River Basin was carried out during the dry and rainy seasons. Water samples were collected from the Kuang River and its tributaries as well as a major irrigation canal at the study site. We also investigated the prevalence of gastrointestinal parasitic infection among dairy and beef cattle hosts. Cryptosporidium and/or Giardia were detected in all the rivers considered for this study, reflecting their ubiquity within the Kuang River Basin. The high prevalence of Cryptosporidium/Giardia in the upper Kuang River and Lai River is of a particular concern as both drain into the Mae Kuang Reservoir, a vital source of drinking-water to many local towns and villages at the research area. We did not, however, detected neither Cryptosporidium nor Giardia were in the irrigation canal. The frequency of Cryptosporidium/Giardia detection nearly doubled during the rainy season compared to the dry season, highlighting the importance of water as an agent of transport. In addition to the overland transport of these protozoa from their land sources (e.g. cattle manure, cess pits), Cryptosporidium/Giardia may also be re-suspended from the streambeds (a potentially important repository) into the water column of rivers during storm events. Faecal samples from dairy and beef cattle showed high infection rates from various intestinal parasites - 97% and 94%, respectively. However, Cryptosporidium and Giardia were only detected in beef cattle. The difference in management style between beef (freeranging) and dairy cattle (confined) may account for this disparity. Finally, phylogenetic analyses revealed that the Cryptosporidium/Giardia-positive samples contained C. ryanae (non-zoonotic) as well as Giardia intestinalis assemblages B (zoonotic) and E (non-zoonotic). With only basic water treatment facilities afforded to them, the communities of the rural area relying on these water supplies are highly at risk to Cryptosporidium/Giardia infections.

Prevalence of Giardia spp. in young dogs using a combination of two diagnostic methods

In this study, prevalence of the protozoan parasites from the genus Giardia spp, with zoonotic potential and worldwide dissemination, was accessed in young dogs, which are reported as having higher prevalence rates. With that purpose, 49 animals from the Grupo de Intervenção Cinotécnico of the Guarda Nacional Republicana (Portuguese Gendarmerie Canine Unit) were chosen. They were housed individually in areas with a high number of kennels (up to 100), with ages ragging from newborns to 10 years old. Dogs were divided in four groups, according their age: under 6 months (n = 16), 6-12 months (n = 6), 12-18 months (n = 13) and 18-24 months (n = 14), comprising 22 females and 27 males. Fecal samples were collected from every animal and all were submitted to two different diagnostic tests, a passive flotation technique with a ZnSO4 solution and a detection of fecal antigen using a commercially available ELISA test (Witness® Giardia - Zoetis). From the 49 samples, 5 (10.2%) were considered positive with ZnSO4 flotation technique and 6 (12.24%) with the Witness® Giardia test. When considering the combination of both tests, 5 animals (10.2%) were considered positive. Of these, 3 (60%) were from the group under 6 months old, 1 (20%) from the 6-12 months and 1 from the 18-24 (20%) months. Within each group, in the under 6 months group 18.75% (n = 16) were considered positive, 16.67% in the 6-12 month group (n = 6), 0% in the 12-18 month group (n=13) and 7.14% in 18-24 month group (n = 14). None of the animals had clinical signs and no significant differences were found when comparing prevalence according to age, breed or gender. A combination of fecal flotation and antigen ELISA tests have good sensitivity and are easy to perform in practice and, therefore, could be a good choice to perform a diagnostic and small animal veterinarians should have this possible diagnostic in mind when in the present of clinical signs, particularly in young dogs.

Epidemiological Observations on Cryptosporidiosis in Diarrheic Goat Kids in Greece

This study aimed at investigating the occurrence of Cryptosporidium spp. in diarrheic goat kids in Greece and the risk factors associated with cryptosporidiosis. Altogether, 292 diarrheic 4–15-day-old goat kids from 54 dairy goat herds of Northern Greece were examined. Oocysts of Cryptosporidium spp. were detected in 223 of 292 (76.4%) goat kids and the intensity of infection was scored as “high” in 142 samples, “moderate” in 45 samples, and “low” in 36 samples. Larger herds (>200 animals) had higher infection rates than smaller ones, although this difference was not statistically significant. Significantly higher infection rates were observed in herds during late kidding season (1 January to 30 April) compared to the early one (1 September to 31 December). These results suggest that cryptosporidiosis is very common in diarrheic goat kids in Greece, especially in large herds during the late parturition season.

Distribution of Cryptosporidium species in Tibetan sheep and yaks in Qinghai, China

Few data are available on the distribution of Cryptosporidium species in Tibetan sheep and yaks, which are free-range animals living in a cold, low oxygen, and high ultraviolet radiation habitat. In this study, 904 fecal specimens were collected from 350 Tibetan sheep and 554 yaks in six counties. Cryptosporidium spp. were detected and differentiated by PCR and sequence analyses. Altogether, 43 (12.3%) Tibetan sheep and 158 (28.5%) yaks were positive for Cryptosporidium spp. In Tibetan sheep, Cryptosporidium xiaoi (39/43, 90.7%) was the dominant species, with the remaining cases (4/43, 9.3%) by Cryptosporidium ubiquitum. All C. ubiquitum specimens belonged to the subtype family XIIa. In contrast, Cryptosporidium andersoni (72/158, 45.6%), Cryptosporidium bovis (47/158, 29.7%), Cryptosporidium ryanae cattle type (35/158, 22.2%), C. ryanae buffalo type (2/158, 1.3%), and Cryptosporidium suis-like (2/158, 1.3%) were identified in yaks. Contradictory to previous observations, C. andersoni was one of the dominant Cryptosporidium species in yaks in this study. Despite sharing habitats, Tibetan sheep and yaks are evidently infected with different Cryptosporidium species.

Occurrence and molecular characterization of Giardia duodenalis and Cryptosporidium spp. in sheep and goats reared under dairy husbandry systems in Greece

Giardia duodenalis and Cryptosporidium spp. are gastro-intestinal protozoa known to infect small ruminants. Both protozoa are also considered as a potential public health concern. The objective of this study was to determine their prevalence in lambs and goat kids kept under common Mediterranean dairy husbandry systems and to identify the species and genotypes infecting these small ruminants. In total, 684 faecal samples (429 from lambs and 255 from goat kids) were collected on 21 farms in Greece and examined using a quantitative immunofluorescence assay. G. duodenalis was detected in 37.3% of the lambs and 40.4% of the goat kids. On all but one of the farms G. duodenalis was detected. Most samples were typed as a mono-infection with G. duodenalis assemblage E, both on the β-giardin gene and the triose phosphate isomerase gene. Only 10% of samples were typed as mixed assemblage A and E infections. The prevalence of Cryptosporidium spp. was 5.1% in lambs and 7.1% in goat kids. In total, 8 out of the 14 farms with a sheep flock and 7 out of the 14 farms with a goat flock were positive. Cryptosporidium parvum (subtype IId), C. ubiquitum and C. xiaoi were identified, the latter especially in goat kids. In conclusion, the results of the present study illustrate that G. duodenalis and Cryptosporidium spp. occur frequently on both sheep and goats farms. The prevalence of zoonotic genotypes or species was low, indicating a limited but existing risk for zoonotic infections.

Enterocytozoon bieneusi, giardia, and Cryptosporidium infecting white-tailed deer

Despite a white-tailed deer (WTD) population in the United States of approximately 32 million animals extremely little is known of the prevalence and species of the protists that infect these animals. This study was undertaken to determine the presence of potential human protist pathogens in culled WTD in central Maryland. Feces from fawns to adults were examined by molecular methods. The prevalence of Enterocytozoon bieneusi, Cryptosporidium, and Giardia was determined by PCR. All PCR-positive specimens were sequenced to determine the species and genotype(s). Of specimens from 80 WTD, 26 (32.5%) contained 17 genotypes of E. bieneusi. Four genotypes were previously reported (I, J, WL4, LW1) and 13 novel genotypes were identified and named DeerEb1-DeerEb13. Genotypes I, J, and LW1 are known to infect humans. Ten (12.5%) specimens contained the Cryptosporidium deer genotype, and one (1.25%) contained Giardia duodenalis Assemblage A. The identification zoonotic G. duodenalis Assemblage A as well as four E. bieneusi genotypes previously identified in humans suggest that WTD could play a role in the transmission of those parasites to humans.

A year-long study of Cryptosporidium species and subtypes in recreational, drinking and wastewater from the central area of Spain

A year-long longitudinal study was undertaken to evaluate the presence of Cryptosporidium spp. in drinking water treatment plants (DWTPs), wastewater treatment plants (WWTPs) and freshwater bathing beaches (FBBs) from the central area of Spain. Water samples were collected according to USEPA Method 1623, and concentrated by the IDEXX Filta-Max® system. Cryptosporidium species were detected based on PCR-restriction fragment length polymorphism and sequence analyses of the ssuRNA gene. C. hominis and/or C. parvum isolates were subtyped by DNA sequencing of the Gp60 gene. Among 150 samples, 23 (15.3%) were positive by IFAT and 40 (26.7%) by PCR. Cryptosporidium spp. was more frequent in WWTPs (26.2 and 50.8%) and FBBs (12.5 and 17.5%) by IFAT and PCR respectively. Effluent waters from DWTPs were negative for this parasite suggesting that they are suitable for public use. Tertiary treatment in the WWTPs demonstrated a high removal efficiency of Cryptosporidium in the samples evaluated. Cryptosporidium species identified included C. hominis, C. parvum, C. ubiquitum, C. andersoni and C. muris. Subtyping analysis revealed C. hominis IbA10G2 and IeA11G3T3 alleles, which is the first report of the latter in water samples. Cryptosporidium highest frequency was observed in winter and spring. Our data provide information about the occurrence and diversity of Cryptosporidium in water of human use from the central area of Spain.

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.

Zoonotic potential of Giardia

Giardia duodenalis (syn. Giardia lamblia and Giardia intestinalis) is a common intestinal parasite of humans and mammals worldwide. Assessing the zoonotic transmission of the infection requires molecular characterization as there is considerable genetic variation within G. duodenalis. To date eight major genetic groups (assemblages) have been identified, two of which (A and B) are found in both humans and animals, whereas the remaining six (C to H) are host-specific and do not infect humans. Sequence-based surveys of single loci have identified a number of genetic variants (genotypes) within assemblages A and B in animal species, some of which may have zoonotic potential. Multi-locus typing data, however, has shown that in most cases, animals do not share identical multi-locus types with humans. Furthermore, interpretation of genotyping data is complicated by the presence of multiple alleles that generate "double peaks" in sequencing files from PCR products, and by the potential exchange of genetic material among isolates, which may account for the non-concordance in the assignment of isolates to specific assemblages. Therefore, a better understanding of the genetics of this parasite is required to allow the design of more sensitive and variable subtyping tools, that in turn may help unravel the complex epidemiology of this infection.