Identification of Cryptosporidium felis in a cow by morphologic and molecular methods

Recombinant Cryptosporidium parvum GP15 based enzyme linked immunosorbent assay for detection of exposure of bovine populations to Cryptosporidium

The serodiagnostic potential of recombinant Cryptosporidium parvum glycoprotein 15 (rCpGP15) was evaluated in Enzyme Linked Immunosorbent Assay (ELISA) in the detection of exposure of bovines to Cryptosporidium species in Himachal Pradesh and Uttarakhand states of North India. The 11.13 kDa rCpGP15 was expressed in pET-32a (+) transformed E. coli BL21 cells and was purified by Ni-NTA affinity chromatography as polyhistidine tagged fusion protein of ∼ 32 kDa. Its immunogenicity was checked in western blot using rabbit antisera raised to the recombinant antigen and bovine sera naturally infected with Cryptosporidium. Two hundred and forty-six bovines were screened for Cryptosporidium spp. oocysts in faecal samples by modified-Ziehl Neelson technique and their sera were used for ELISA standardization. The rCpGP15 based indirect IgG-ELISA was standardized with 83 % sensitivity, 78.3 % specificity where ELISA cut-off and accuracy were decided using ROC curve analysis. The percent accuracy was 79.19 %, with area under the Receiver Operating Characteristic (ROC) curve value 0.827 depicting the moderate accuracy of the assay. Additionally, sera from Eimeria (n = 3), strongyles (n = 3), Babesia (n = 2), Theileria (n = 5), Trypanosoma (n = 2) and Anaplasma (n = 5) positive animals showed no seroreactivity. The diagnostic performance of rCpGP15 protein in differentiating Cryptosporidium species was predicted through in-silico B cell epitope prediction, homology modelling and structural comparison of GP15 protein from C. parvum, C. hominis, C. bovis and C. ryanae. Four linear antigenic epitopes were predicted in CpGP15 protein sequence by SVMTrip. The overall root mean square deviation (RMSD) values during homology modelling and structural comparison of CpGP15 and C. hominis, C. bovis and partial C. ryanae GP15 were 2.093 Å, 3.759 Å and 1.152 Å, respectively. The serodiagnostic assay developed in the present study has moderate accuracy and can be applied in serosurveillance of large bovine populations. It is capable of detecting asymptomatic animals with intermittent oocyst shedding which will further be helpful for better understanding the disease dynamics and for the timely control of cryptosporidiosis.

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.

Cryptosporidium infections in asymptomatic calves up to 4 months in Poland: a cross-sectional population study

Cattle cryptosporidiosis is noted worldwide with varied frequency of infection prevalence depending on geographical, environmental and husbandry factors. In this study, the prevalence of Cryptosporidium infections in cattle was determined on the basis of molecular results obtained by testing 1601 faecal samples collected from calves up to 4 months of age housed in all Polish provinces from 2014 to 2018. Detection and identification of Cryptosporidium species was performed at the 18 small subunit ribosomal RNA (18S rRNA) locus by conducting PCR-RFLP analysis of the amplified DNA fragments. The prevalence of Cryptosporidium infections in the cattle population was 45.3% (CI 95%: 42.8-47.7; 725/1601). The infected animals were housed on 233/267 (87.3%) of monitored farms with regional prevalence ranging from 27.8 to 62%. The restriction pattern of 18S rRNA amplicons for positive samples was characteristic of C. parvum, C. bovis, C. ryanae, C. andersoni, and unexpectedly also of C. baileyi and C. suis. Infections of C. bovis and C. ryanae prevailed in the studied cattle population relegating C. parvum to third in prevalence. Likewise, mixed infections caused by C. bovis and C. ryanae as well as C. parvum and C. bovis were observed. A relationship between the infecting parasite species and animal breed was found. For instance, C. parvum prevailed in Black and White lowland breed, C. ryanae in Limousine cattle and C. andersoni in dairy animals of mixed dairy breeds. Furthermore, differences in prevalence of particular parasite species between cattle breeds were also shown.

Molecular Detection and Distribution of Giardia duodenalis and Cryptosporidium spp. Infections in Wild and Domestic Animals in Portugal

Enteric protozoan parasites Giardia duodenalis, Cryptosporidium spp., and, to a lesser extent, the ciliate Balantioides coli are responsible for severe human and animal intestinal disorders globally. However, limited information is available on the occurrence and epidemiology of these parasites in domestic, but especially wild species in Portugal. To fill this gap of knowledge, we have investigated G. duodenalis, Cryptosporidium spp., and B. coli occurrence, distribution, genetic diversity, and zoonotic potential by analyzing 756 fecal samples from several wild carnivores (n = 288), wild ungulates (n = 242), and domestic species (n = 226) collected across different areas of mainland Portugal. Overall, infection rates were 16.1% (122/756; 95% CI: 13.59-18.96) for G. duodenalis and 2.7% (20/756; CI: 1.62-4.06) for Cryptosporidium spp., while no ungulate sample analyzed yielded positive results for B. coli. Giardia duodenalis was found across a wide range of hosts and sampling areas, being most prevalent in the Iberian lynx (26.7%), the Iberian wolf (24.0%), and the domestic dog (23.9%). Cryptosporidium spp. was only identified in wild boar (8.4%), red fox (3.4%), Iberian lynx (3.3%), red deer (3.1%), and Iberian wolf (2.5%). Sequence analysis of G. duodenalis determined zoonotic assemblage A (subassemblage AI) in one roe deer sample, canine-specific assemblages C and D in Iberian wolf, red fox, and domestic dog, and ungulate-specific assemblage E in wild boar, sheep, cattle, and horse. Six Cryptosporidium species were identified: C. scrofarum in wild boar, C. canis in the Iberian wolf and red fox, C. ubiquitum in red deer and wild boar, C. felis in the Iberian lynx, and both C. ryanae and C. occultus in red deer. Giardia duodenalis and Cryptosporidium spp. coinfections were observed in 0.7% (5/756) of the samples. This is the first, most comprehensive, and largest molecular-based epidemiology study of its kind carried out in Portugal, covering a wide range of wild and domestic hosts and sampling areas. The detection of zoonotic Cryptosporidium spp. and G. duodenalis subassemblage AI demonstrates the role of wild and domestic host species in the transmission of these agents while representing a potential source of environmental contamination for other animals and humans.

Subtype distribution of zoonotic pathogen Cryptosporidium felis in humans and animals in several countries

Cryptosporidium felis is the major etiologic agent of cryptosporidiosis in felines and has been reported in numerous human cryptosporidiosis cases. Sequence analysis of the 60-kDa glycoprotein (gp60) gene has been developed for subtyping C. felis recently. In this study, 66 C. felis isolates from the United States, Jamaica, Peru, Portugal, Slovakia, Nigeria, Ethiopia, Kenya, China, India and Australia were subtyped using the newly established tool. Forty-four specimens yielded gp60 sequences, generating 23 subtypes clustered in 4 subtype families (XIXa, XIXc, XIXd and XIXe) with high bootstrap support in a phylogenetic analysis of sequence data. Among them, XIXa showed high genetic diversity at the nucleotide level, with the formation of 18 subtypes from both cats and humans with different geographic distribution. In contrast, all 11 XIXd isolates derived from humans from various countries had identical sequences. Results of this study improve our understanding of the genetic diversity, host specificity and transmission dynamics of C. felis.

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 species identification of Cryptosporidium spp. in the newborn dairy calves from Muang District, Khon Kaen Province, Thailand

AIM

This study aims to determine the prevalence of Cryptosporidium spp. infection and to identify the species of Cryptosporidium spp. in newborn dairy calves between December 2016 and March 2017 in Muang District, Khon Kaen Province, Thailand.

MATERIALS AND METHODS

A total of 200 fecal samples from newborn dairy calves of the ages 1 day up to 28 days were collected and the presence of Cryptosporidium oocysts was examined microscopically using the modified Kinyoun's acid-fast staining technique. Then, Cryptosporidium species were identified using nested polymerase chain reaction amplification of 18S rRNA gene and sequencing.

RESULTS

The modified Kinyoun's acid-fast staining revealed the presence of Cryptosporidium oocysts in 51% (102/200). Sequence analysis of the 18S rRNA gene identified two species, namely, Cryptosporidium bovis (n=11) and Cryptosporidium ryanae (n=11) and one isolated strain could not be identified.

CONCLUSION

This study indicated that newborn dairy calves aging up to 4 weeks were highly infected with Cryptosporidium spp., and the infection mostly occurred in diarrheic dairy calves. This is the first report of Cryptosporidium in dairy calves in Khon Kaen Province and the results provide baseline information for further studies and control of Cryptosporidium infection in dairy calves in the study area.

Molecular characterization of zoonotic Cryptosporidium spp. and Giardia duodenalis pathogens in Algerian sheep

Little is known about the presence of Cryptosporidium spp. and Giardia duodenalis in Algerian sheep, nor their potential role as zoonotic reservoirs. This study aimed to investigate the occurrence and distribution of these two protists in lambs. A total of 83 fecal samples were collected from lambs (< 40 days old) from 14 different farms. Samples were screened for Cryptosporidium spp. and Giardia duodenalis presence using immunofluorescent techniques (IF). Nested PCR of the small subunit ribosomal RNA (rRNA) gene, followed by restriction fragment length polymorphism (PCR-RFLP) and sequence analyses were used to identify Cryptosporidium species. C. parvum was further subtyped by sequencing the highly polymorphic 60 kDa glycoprotein (gp60) gene. For G. duodenalis, nested PCR of the glutamate dehydrogenase (gdh) and triose phosphate isomerase (tpi) genes was performed and then PCR-RFLP was used to identify G. duodenalis assemblages. Cryptosporidium oocysts and Giardia cysts were detected in 36/83 (43%) and 23/83 (28%) of fecal samples, respectively. Of the 21/36 (58%) Cryptosporidium samples that were positive with IF, 16/21 (76%) were identified as C. parvum, and 5/21 (24%) as C. ubiquitum. From 15C. parvum isolates, 2 subtypes were identified within the IIa subtype family, including IIaA21G2R1 (3/15) and IIaA13G2R1 (1/15), while IIdA16G1 (11/15) was the only subtype identified from the IId subtype family. Of the 16/23 (69%) G. duodenalis IF-positive samples, the most frequent assemblage was ruminant-specific assemblage E (10/16), followed by assemblage D (4/16), and A + E mixed assemblages (2/16). This study is the first to identify and genotype both Cryptosporidium spp. and Giardia duodenalis in Algerian lambs, and is also the first to describe G. duodenalis assemblage D in small ruminants. The presence of zoonotic C. parvum subtype families (IIa, IId), C. ubiquitum, as well as G. duodenalis assemblage A + E, indicates that sheep could play an important role as a potential reservoir for protists.

Use of autochthonous mesophilic lactic acid bacteria as starter cultures for making Pecorino Crotonese cheese: Effect on compositional, microbiological and biochemical attributes

The use of selected autochthonous mesophilic lactic acid bacteria as starter cultures was investigated according to the traditional protocol for making Pecorino Crotonose (PC). Leuconostoc mesenteroides subsp. mesenteroides 2A, Lactobacillus casei 23C and Lactobacillus plantarum 18C (Autochthonous Starter, AS1) and Leuc. mesenteroides subsp. mesenteroides 2A, and L. casei 25D and 16A (AS2) were isolated and identified from aged ewes' milk PC cheeses, selected based on several enzymatic activities, and used as starter cultures. As shown by the in vitro kinetic of acidification, selected starter cultures had suitable capabilities to acidify. The manufacture of PC cheeses was carried out at an industrial plant scale. A control cheese (CC) was also made, using commercial starters consisting of mesophilic and thermophilic species. Ripening lasted 105 days at 10 °C. A poly-phasic approach was used to compare cheeses during manufacture and ripening, mainly based on pyrosequencing of the 16S rRNA targeting DNA, proteolysis and volatile component analyses. Compared to CC, both autochthonous starter cultures slightly affected the gross chemical composition of PC cheese. The cell density of thermophilic starters of CC progressively decreased throughout ripening. Plate count and RAPD-PCR showed that the cell number of autochthonous lactobacilli cultures of PC cheeses, made with AS1 and AS2, was almost constant throughout ripening and abundantly higher than that observed in CC. As shown by culture-independent analysis, the OTUs found during ripening varied depending on the manufacture with or without autochthonous starter cultures. The major chemical differences among cheeses were the concentration of free amino acids and the synthesis of some key volatile components (e.g., 2-methyl-1-propanol, 2-methyl-1-butanol, isobutyric, isovaleric, and isocaproic acids). Compared to CC, the use of AS1 positively affected the overall cheese quality.

Prevalence of Cryptosporidium, Blastocystis, and other opportunistic infections in patients with primary and acquired immunodeficiency

Intestinal opportunistic infections are often caused by unicellular parasites. Individuals with decreased immunity are particularly susceptible to infection by said microorganisms, and when they are infected, diarrhea can be the main clinical manifestation. However, intestinal parasites have rarely been taken into account in intestinal disorders. In our study, an investigation was conducted to determine the prevalence of intestinal micro-pathogens, such as Cryptosporidium, Giardia, Blastocystis, and microsporidia, in hospitalized patients with different immunological statuses. The study at hand indicates that protozoan parasitic infections are rare among immunodeficient patients in Poland. The overall prevalence of micro-pathogens among participants was 4.6%; it was three times higher in adults (12.5%) than in children (2.3%). Cryptosporidium and Cyclospora species (Apicomplexa) were diagnosed as the main cause of heavy diarrhea. Accordingly, adult patients were positive mainly for Blastocystis and microsporidia, while children were more often infected with the Cryptosporidium species.

Epidemiology of Cryptosporidium infection in cattle in China: a review

The present review discusses the findings of cryptosporidiosis research conducted in cattle in China and highlights the currently available information on Cryptosporidium epidemiology, genetic diversity, and distribution in China, which is critical to understanding the economic and public health importance of cryptosporidiosis transmission in cattle. To date, 10 Cryptosporidium species have been detected in cattle in China, with an overall infection rate of 11.9%. The highest rate of infection (19.5%) was observed in preweaned calves, followed by that in juveniles (10.69%), postweaned juveniles (9.0%), and adult cattle (4.94%). The dominant species were C. parvum in preweaned calves and C. andersoni in postweaned, juvenile, and adult cattle. Zoonotic Cryptosporidium species (C. parvum and C. hominis) were found in cattle, indicating the possibility of transmission between humans and cattle. Different cattle breeds had significant differences in the prevalence rate and species of Cryptosporidium. This review demonstrates an age-associated, breed-associated, and geographic-related occurrence of Cryptosporidium and provides references for further understanding of the epidemiological characteristics, and for preventing and controlling the disease.

Morphological and Immunohistochemical Features of Cryptosporidium andersoni in Cattle

Light and electron microscopic features and immunohistochemical features of Cryptosporidium andersoni ( C. andersoni) and host reaction in the mucosa were studied. Although the affected cattle demonstrated no apparent clinical signs, a severe infection of C. andersoni was observed in the abomasum. C. andersoni were round in shape, measured 6-8 μm in size and were mainly observed to be freely located in the gastric pits, being attached in occasional cases to the surface of the abomasum epithelium. Frequent inflammatory cells had infiltrated the lamina propria of the affected mucosa, and frequent mitotic figures were observed in epithelial cells at the dilated isthmus. To access the cell kinetics, the number of epithelial cells infected with C. andersoni were counted and compared with noninfected cattle. The number of gastric pit cells in infected cattle was significantly higher than that in the controls. The number of proliferative cells determined by the Ki-67 antigen in C. andersoni infected cattle was also significantly higher than that in the controls. Transmission electron microscopy and scanning electron microscopy revealed that the morphology of the C. andersoni organism was common to those of other Cryptosporidium spp. immunohistochemically, several commercial antibodies against Cryptosporidium spp. showed positive reactions at the wall of these oocysts or parasitophorous vacuoles. This report is possibly the first to discuss the prominent hyperplasia of the abomasum mucosa, as well as morphologic features of C. andersoni in cattle.

Prevalence and Genetic Characterization of Cryptosporidium Species in Dairy Calves in Central Ethiopia

The burden of cryptosporidiosis due to Cryptosporidium parvum is well documented in HIV-positive patients in Ethiopia. However, the role of animals in zoonotic transmission of the disease is poorly understood. The aim of this study was to determine the prevalence and genotypes of Cryptosporidium species in dairy calves; to assess the role of cattle in zoonotic transmission in central Ethiopia. A total of 449 fecal samples were collected and screened using modified Ziehl-Neelson staining method and PCR targeting the small-subunit (SSU) rRNA gene. The prevalence of Cryptosporidium was 9.4% (42/449) and 15.8% (71/449) as detected by microscopy and nested PCR, respectively. The prevalence of infection varied significantly across the study areas with the higher prevalence being observed in Chancho 25.4% (30/118). Crossbred calves had significantly higher prevalence of Cryptosporidium than indigenous zebu. Genotyping results revealed the presence of C. andersoni (76.1%), C. bovis (19.7%) and C. ryanae (4.2%). The occurrence of these Cryptosporidium species appeared to be age-related. C. andersoni constituted 92.1% of the Cryptosporidium infection in calves older than 3 months. Sequence analysis also showed the existence of intra-species variation at SSU rRNA gene. Findings of the current study indicate that cattle may not be an important source of zoonotic cryptosporidiosis in central Ethiopia. Further molecular studies are needed to support this observation from other part of the country.

Cryptosporidiumspecies in humans and animals: current understanding and research needs

Cryptosporidiumis increasingly recognized as one of the major causes of moderate to severe diarrhoea in developing countries. With treatment options limited, control relies on knowledge of the biology and transmission of the members of the genus responsible for disease. Currently, 26 species are recognized as valid on the basis of morphological, biological and molecular data. Of the nearly 20Cryptosporidiumspecies and genotypes that have been reported in humans,Cryptosporidium hominisandCryptosporidium parvumare responsible for the majority of infections. Livestock, particularly cattle, are one of the most important reservoirs of zoonotic infections. Domesticated and wild animals can each be infected with severalCryptosporidiumspecies or genotypes that have only a narrow host range and therefore have no major public health significance. Recent advances in next-generation sequencing techniques will significantly improve our understanding of the taxonomy and transmission ofCryptosporidiumspecies, and the investigation of outbreaks and monitoring of emerging and virulent subtypes. Important research gaps remain including a lack of subtyping tools for manyCryptosporidiumspecies of public and veterinary health importance, and poor understanding of the genetic determinants of host specificity ofCryptosporidiumspecies and impact of climate change on the transmission ofCryptosporidium.

Prevalence and genetic characterization of Cryptosporidium in yaks in Qinghai Province of China

The objective of this study was to determine the prevalence, species and subtypes of Cryptosporidium infecting yaks in the Qinghai Province of Northwestern China. The prevalence of Cryptosporidium spp. was detected by microscopy and nested-PCR. A total of 586 fecal samples were collected from yaks in 6 counties, of which 142 (24.2%) samples tested positive for Cryptosporidium. The small subunit (SSU) rRNA gene of fifty-five samples were amplified and sequenced successfully and demonstrated that Cryptosporidium bovis (31/55, 56.4%) was the most common species, followed by C. parvum (16/55, 29.1%) and C. ryanae (5/55, 9.0%). Mixed infections of C. parvum and C. bovis (n = 2), C. ryanae and C. bovis (n = 1) were also detected. All three species were found in yaks ranging in age from <1 year, 1–2 years, to >2 years. Cryptosporidium was most commonly detected in spring (28.4%), followed by summer (20.9%), then winter (17.5%). Cryptosporidium parvum positive samples were subtyped using the 60 kDa glycoprotein (gp60) gene. Subtypes IIaA15G2R1 (n = 8), IIaA16G2R1 (n = 2), IIaA14G1R1 (n = 1), IIaA14G2R1 (n = 1) and IIaA16G3R1 (n = 1) were detected. All of these subtypes are zoonotic, and may pose a potential threat to human health.

Cryptosporidiosis and Cryptosporidium species in animals and humans: a thirty colour rainbow?

Parasites of the genus Cryptosporidium (Apicomplexa) cause cryptosporidiosis in humans and animals worldwide. The species names used for Cryptosporidium spp. are confusing for parasitologists and even more so for non-specialists. Here, 30 named species of the genus Cryptosporidium are reviewed and proposed as valid. Molecular and experimental evidence suggests that humans and cattle are the hosts for 14 and 13 out of 30 named species, respectively. Two, four and eight named species are considered of major, moderate and minor public health significance, respectively. There are at least nine named species that are shared between humans and cattle. The aim of this review is to outline available species information together with the most commonly used genetic markers enabling the identification of named Cryptosporidium spp. Currently, 28 of 30 named species can be identified using the complete or partial ssrRNA, serving as a retrospective 'barcode'. Currently, the ssrRNA satisfies the implicit assumption that the reference databases used for comparison are sufficiently complete and applicable across the whole genus. However, due to unreliable annotation in public DNA repositories, the reference nucleotide entries and alignment of named Cryptosporidium spp. has been compiled. Despite its known limitations, ssrRNA remains the optimal marker for species identification.

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.

Occurrence and molecular identification of Cryptosporidium species isolated from cattle in Poland

Cryptosporidiosis is a disease reported in both humans and animals and is caused by a protozoan parasite Cryptosporidium. In most cases calves are infected by different Cryptosporidium species adapted to this animal host. Most infections are subclinical; however in some cases the watery diarrhea appears. The rapid development of new molecular diagnostic tools has provided an opportunity for better recognition of Cryptosporidium species and genotypes isolated from infected hosts. The aim of this study was an assessment of the prevalence of Cryptosporidium species in cattle herds in Poland. In total, 700 cattle fecal samples were tested. The examined cattle were at the age of 1 day to 6 years old. Overall 194 farms were monitored for parasite presence. Cryptosporidium detection in animal feces was performed using only molecular methods. Species identity of oocyst-positive samples were defined on the basis of PCR-RFLP and nucleotide sequence analysis of the amplified 18 SSU rRNA and COWP gene fragments. Cryptosporidium oocysts were detected in 119 (17%) of cattle feces. Most of the positive feces 55 (19.7%) were derived from young animals at the age of 1-4 weeks. The tested samples were positive for Cryptosporidium bovis, Cryptosporidium parvum, Cryptosporidium andersoni, and Cryptosporidium ryanae. C. parvum was not the most frequently detected parasite species, but calves below the age of 1 month were the major host for this parasite. The overall prevalence of C. parvum in Polish cattle herds was estimated at 5.1%. C. andersoni was the only species occurring in adult calves. The infected animals were housed in 67 (34.5%) of the monitored homesteads. Although C. bovis and C. ryanae were previously detected in cattle populations in many countries, this is the first report describing their presence in Polish cattle. Moreover, this is the first report on the prevalence of Cryptosporidium species in Polish cattle herds.

Cryptosporidium species in Australian wildlife and domestic animals

Cryptosporidium is an important enteric parasite that is transmitted via the fecal-oral route, water and food. Humans, wildlife and domestic livestock all potentially contribute Cryptosporidium to surface waters. Most species of Cryptosporidium are morphologically indistinguishable and can only be identified using molecular tools. Over 24 species have been identified and of these, 7 Cryptosporidium species/genotypes are responsible for most human cryptosporidiosis cases. In Australia, relatively few genotyping studies have been conducted. Six Cryptosporidium species (C. hominis, C. parvum, C. meleagridis, C. fayeri, C. andersoni and C. bovis) have been identified in humans in Australia. However, little is known about the contribution of animal hosts to human pathogenic strains of Cryptosporidium in drinking water catchments. In this review, we focus on the available genotyping data for native, feral and domestic animals inhabiting drinking water catchments in Australia to provide an improved understanding of the public health implications and to identify key research gaps.

Duodenal and faecal microbiota of celiac children: molecular, phenotype and metabolome characterization

BACKGROUND

Epidemiology of celiac disease (CD) is increasing. CD mainly presents in early childhood with small intestinal villous atrophy and signs of malabsorption. Compared to healthy individuals, CD patients seemed to be characterized by higher numbers of Gram-negative bacteria and lower numbers Gram-positive bacteria.

RESULTS

This study aimed at investigating the microbiota and metabolome of 19 celiac disease children under gluten-free diet (treated celiac disease, T-CD) and 15 non-celiac children (HC). PCR-denaturing gradient gel electrophoresis (DGGE) analyses by universal and group-specific primers were carried out in duodenal biopsies and faecal samples. Based on the number of PCR-DGGE bands, the diversity of Eubacteria was the higher in duodenal biopsies of T-CD than HC children. Bifidobacteria were only found in faecal samples. With a few exceptions, PCR-DGGE profiles of faecal samples for Lactobacillus and Bifidobacteria differed between T-CD and HC. As shown by culture-dependent methods, the levels of Lactobacillus, Enterococcus and Bifidobacteria were confirmed to be significantly higher (P = 0.028; P = 0.019; and P = 0.023, respectively) in fecal samples of HC than in T-CD children. On the contrary, cell counts (CFU/ml) of presumptive Bacteroides, Staphylococcus, Salmonella, Shighella and Klebsiella were significantly higher (P = 0.014) in T-CD compared to HC children. Enterococcus faecium and Lactobacillus plantarum were the species most diffusely identified. This latter species was also found in all duodenal biopsies of T-CD and HC children. Other bacterial species were identified only in T-CD or HC faecal samples. As shown by Randomly Amplified Polymorphic DNA-PCR analysis, the percentage of strains identified as lactobacilli significantly (P = 0.011) differed between T-CD (ca. 26.5%) and HC (ca. 34.6%) groups. The metabolome of T-CD and HC children was studied using faecal and urine samples which were analyzed by gas-chromatography mass spectrometry-solid-phase microextraction and 1H-Nuclear Magnetic Resonance. As shown by Canonical Discriminant Analysis of Principal Coordinates, the levels of volatile organic compounds and free amino acids in faecal and/or urine samples were markedly affected by CD.

CONCLUSION

As shown by the parallel microbiology and metabolome approach, the gluten-free diet lasting at least two years did not completely restore the microbiota and, consequently, the metabolome of CD children. Some molecules (e.g., ethyl-acetate and octyl-acetate, some short chain fatty acids and free amino acids, and glutamine) seems to be metabolic signatures of CD.

Molecular characterization of Cryptosporidium spp. in native breeds of cattle in Kaduna State, Nigeria

Despite numerous molecular epidemiologic studies of cryptosporidiosis in dairy cattle in industrialized countries, there are very few studies on the diversity and public health significance of Cryptosporidium species in native cattle in developing countries. In this study, a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis of the small-subunit (SSU) rRNA gene was used to detect and identify Cryptosporidium spp. in 194 fecal specimens from 2 to 365 days old calves in 20 White Fulani and Sokoto Gudali herds in Nigeria. Thirty one (16.0%) of the specimens were positive for Cryptosporidium. Restriction digestion of the PCR products showed the presence of Cryptosporidium bovis (7.2%), Cryptosporidium ryanae (4.1%), Cryptosporidium andersoni (2.5%), and concurrent occurrence of C. bovis and C. ryanae (1.5%), and C. bovis and C. andersoni (0.5%). There were no significant differences (p>0.05) in Cryptosporidium infection rates by sex, herd location, management system, breed of calves, or fecal consistency. However, calves 180 days or younger had a higher infection rate of Cryptosporidium than older calves (p=0.034). Likewise, younger calves also had higher occurrence of C. bovis and C. ryanae (p=0.022). The absence of zoonotic Cryptosporidium parvum in the calves studied suggests that native breeds of cattle may not be important in the transmission of human cryptosporidiosis in Kaduna State, Nigeria.

Prevalence and genetic characterization of Giardia and Cryptosporidium in cats from Italy

One hundred and eighty one cats living in central Italy were tested for the presence of Giardia and Cryptosporidium infection by IFAT test and specific PCRs. Overall eight (4.4%) samples were IFAT-positive for Giardia. All the IFAT-positive samples for Giardia scored positive for the PCRs, and three more samples IFAT-negative generated PCR products leading to a total 6.1% molecular positivity rate for Giardia. All the examined samples were negative for Cryptosporidium. Sequencing of samples molecularly positive to Giardia indicated that three cats harbored the zoonotic Giardia duodenalis Assemblage A, whereas all other positive animals were infected with the feline-specific G. duodenalis Assemblage F. Phylogenetic analysis carried out on the sequences obtained supported the clustering of the isolates within Assemblages A and F. The results here presented provide data on the occurrence of Giardia genotypes in cats living in close contact with humans highlighting the potential importance of this protozoan disease for the public health.

Cryptosporidium andersoni is the predominant species in post-weaned and adult dairy cattle in China

Dairy industry plays an important role in the agricultural economy of China. To estimate the prevalence and public health significance of cryptosporidiosis in post-weaned and adult dairy cattle in China, during four consecutive years (from 2006 to 2009), a total of 1315 fecal samples from 22 dairy cattle farms in ten prefectures in Henan Province were examined for the presence of Cryptosporidium oocysts. The overall prevalence of Cryptosporidium was 7.9%, with the highest infection rate (11.3%) in 3 to 11-month-old calves and the lowest infection rate (1.0%) in >2-year-old cows (p<0.01). Cryptosporidium-positive samples (n=104) were analyzed by PCR-restriction fragment length polymorphism (RFLP) analysis of the small subunit (SSU) rRNA gene, and 25 representative samples were further analyzed by DNA sequencing of the PCR products. Cryptosporidium bovis and Cryptosporidium andersoni were identified. C. andersoni (84/104) was the predominant species and was found in all age groups, whereas C. bovis (20/104) was only detected in 3 to 11-month-old calves. Thus, C. andersoni appears to be the dominant species in weaned dairy calves and heifers in China, in contrast with its common occurrence in adult cattle in other parts of the world.

Robustness of Lactobacillus plantarum starters during daily propagation of wheat flour sourdough type I

This study aimed at investigating the robustness of selected sourdough strains of Lactobacillus plantarum. Seven strains were singly used as sourdough type I starters under daily back-slopping propagation (ten days) using wheat flour. Cell numbers of presumptive lactic acid bacteria varied slightly (median values of 9.13-9.46 log cfu g(-1)) between and within started sourdoughs, as well as the acidifying activity (median values of 1.24-1.33). After three days also the control sourdough (unstarted) had the same values. As shown by RAPD-PCR analysis, five (DB200, 3DM, G10C3, 12H1 and LP20) out of seven strains maintained elevated cell numbers (ca. 9 log cfu g(-1)) throughout ten days. The other two strains progressively decreased to less than 5 log cfu g(-1). As identified by partial sequencing of 16S rRNA and recA genes, L. plantarum (11 isolates), pediococci (7), Lactobacillus casei (3) and Lactobacillus rossiae (2) dominated the flour microbiota. Monitoring of lactic acid bacteria during sourdough propagation was carried out by culture dependent approach and using PCR-DGGE (Denaturing Gradient Gel Electrophoresis). Except for the sourdough started with L. plantarum LP20, in all other sourdoughs at least one autochthonous strain of L. plantarum emerged. All emerging strains of L. plantarum showed different RAPD-PCR profiles. L. rossiae and Pediococcus pentosaceus were only found in the control and sourdough started with strain 12H1. The characterization of the catabolic profiles of sourdoughs (Biolog System) showed that sourdoughs containing persistent starters behaved similarly and their profiles were clearly differentiated from the others. One persistent strain (DB200) of L. plantarum and Lactobacillus sanfranciscensis LS44, previously shown to be persistent (Siragusa et al., 2009), were used as the mixed starter to produce a wheat flour sourdough. Both strains cohabited and dominated during ten days of propagation.

A multiplex polymerase chain reaction assay to simultaneously distinguish Cryptosporidium species of veterinary and public health concern in cattle

Four species of Cryptosporidium are routinely found in cattle: Cryptosporidium parvum, Cryptosporidium bovis, Cryptosporidium ryanae, and Cryptosporidium andersoni. It is important to determine the species of Cryptosporidium in infected cattle because C. parvum is the only serious pathogen for humans as well as cattle. Identification of Cryptosporidium species and genotypes currently relies on molecular methods such as polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) or gene sequencing. Incorporation of these techniques in a routine veterinary diagnostic laboratory is cost prohibitive. As such, their applications are limited primarily to research and a few public health laboratories. To overcome this problem, a multiplex PCR assay was developed for simultaneously detecting the 4 species of Cryptosporidium that commonly infect cattle. This assay specifically identifies Cryptosporidium oocysts present in cattle feces, improves the detection of mixed infections, reduces the time and cost relative to current sequencing methods, and further demonstrates the shortcomings of sequencing as the definitive method for identification when analyzing samples containing mixed infections.

Genetic polymorphism in Cryptosporidium species: an update

Cryptosporidia, widely distributed protozoan parasites of vertebrates, have attracted increasing interest due to several serious waterborne outbreaks, the life-threatening nature of infection in immunocompromised patients, and the realization of economic losses caused by these pathogens in livestock. Genetic polymorphism within Cryptosporidium species is being detected at a continuously growing rate, owing to the widespread use of modern molecular techniques. The aim of this paper is to review the current status of taxonomy, genotyping and molecular phylogeny of Cryptosporidium species. To this date, 20 Cryptosporidium species have been recognized. Two named species of Cryptosporidium have been found in fish, 1 in amphibians, 2 in reptiles, 3 in birds, and 12 in mammals. Nearly 61 Cryptosporidium genotypes with uncertain species status have been found based on SSUrRNA sequences. The gp-60 gene showed a high degree of sequence polymorphism among isolates of Cryptosporidium species and several subtype groups and subgenotypes have been identified, of which the Cryptosporidium parvum IIa and IId subtype groups were found to be zoonotic. This review describes considerable progress in the identification, genetic characterization, and strain differentiation of Cryptosporidium over the last 20 years. All the valid species, genotypes and zoonotic subtypes of Cryptosporidium reported in the international literature are included in this paper with respect to the taxonomy, epidemiology, transmission and morphologic-genetic information for each species.

Different fecal microbiotas and volatile organic compounds in treated and untreated children with celiac disease

This study aimed at investigating the fecal microbiotas of children with celiac disease (CD) before (U-CD) and after (T-CD) they were fed a gluten-free diet and of healthy children (HC). Brothers or sisters of T-CD were enrolled as HC. Each group consisted of seven children. PCR-denaturing gradient gel electrophoresis (DGGE) analysis with V3 universal primers revealed a unique profile for each fecal sample. PCR-DGGE analysis with group- or genus-specific 16S rRNA gene primers showed that the Lactobacillus community of U-CD changed significantly, while the diversity of the Lactobacillus community of T-CD was quite comparable to that of HC. Compared to HC, the ratio of cultivable lactic acid bacteria and Bifidobacterium to Bacteroides and enterobacteria was lower in T-CD and even lower in U-CD. The percentages of strains identified as lactobacilli differed as follows: HC (ca. 38%) > T-CD (ca. 17%) > U-CD (ca. 10%). Lactobacillus brevis, Lactobacillus rossiae, and Lactobacillus pentosus were identified only in fecal samples from T-CD and HC. Lactobacillus fermentum, Lactobacillus delbrueckii subsp. bulgaricus, and Lactobacillus gasseri were identified only in several fecal samples from HC. Compared to HC, the composition of Bifidobacterium species of T-CD varied, and it varied even more for U-CD. Forty-seven volatile organic compounds (VOCs) belonging to different chemical classes were identified using gas-chromatography mass spectrometry-solid-phase microextraction analysis. The median concentrations varied markedly for HC, T-CD, and U-CD. Overall, the r(2) values for VOC data for brothers and sisters were equal to or lower than those for unrelated HC and T-CD. This study shows the effect of CD pathology on the fecal microbiotas of children.

Prevalence and distribution of Cryptosporidium spp. in dairy cattle in Heilongjiang Province, China

Few data are available on the molecular characterization of Cryptosporidium spp. in cattle in China. In the present study, a total of 507 fecal specimens from six dairy farms in Heilongjiang Province were examined for Cryptosporidium spp. by light microscopy of concentrates from the formalin-ethyl acetate sedimentation method (for less than 2-month-old calves) or Sheather's floatation method (more than 3-month-old dairy cattle). Twenty-seven post-weaned calves on five farms were positive for Cryptosporidium oocysts. PCR and DNA sequence analysis of the 18S rRNA, actin, and 70 kDa heat shock protein genes identified Cryptosporidium andersoni and Cryptosporidium ryanae, with C. andersoni as the dominant species (26 out of 27). In comparison with other regions of the world, the distribution of Cryptosporidium species in the areas appears to be unique.

Taxonomy and species delimitation in Cryptosporidium

Amphibians, reptiles, birds and mammals serve as hosts for 19 species of Cryptosporidium. All 19 species have been confirmed by morphological, biological, and molecular data. Fish serve as hosts for three additional species, all of which lack supporting molecular data. In addition to the named species, gene sequence data from more than 40 isolates from various vertebrate hosts are reported in the scientific literature or are listed in GenBank. These isolates lack taxonomic status and are referred to as genotypes based on the host of origin. Undoubtedly, some will eventually be recognized as species. For them to receive taxonomic status sufficient morphological, biological, and molecular data are required and names must comply with the rules of the International Code for Zoological Nomenclature (ICZN). Because the ICZN rules may be interpreted differently by persons proposing names, original names might be improperly assigned, original literature might be overlooked, or new scientific methods might be applicable to determining taxonomic status, the names of species and higher taxa are not immutable. The rapidly evolving taxonomic status of Cryptosporidium sp. reflects these considerations.

A longitudinal study of cryptosporidiosis in dairy cattle from birth to 2 years of age

Fecal specimens were collected from 30 calves from birth to 24 months of age at a dairy farm in Maryland to determine the prevalence and age distribution of Cryptosporidium species/genotypes. After centrifugation to remove debris and concentrate oocysts, specimens were examined by immunofluorescence microscopy and polymerase chain reaction (PCR). Fragments of the SSU-rDNA gene amplified by PCR were purified and PCR products were sequenced. All 30 calves shed Cryptosporidium oocysts at some time during the 24 months of the study. Of 990 specimens, 190 were Cryptosporidium-positive (19.2%). The highest prevalence of infection was at 2 weeks of age when 29 of the 30 calves were excreting oocysts. Prevalence was higher in pre-weaned calves (1-8 weeks of age) (45.8%) than in post-weaned calves (3-12 months of age) (18.5%) and heifers (12-24 months of age) (2.2%). Sequence data for 190 PCR-positive specimens identified: C. parvum, C. bovis, the Cryptosporidium deer-like genotype and C. andersoni, with cumulative prevalences of 100, 80, 60, and 3.3%, respectively. C. parvum constituted 97% of infections in pre-weaned calves but only 4% and 0% of infections in post-weaned calves and heifers, respectively. All C. parvum GP60 nucleotide sequences were subtype IIaA15G2R1.

Genotypic characterization and phylogenetic analysis of Cryptosporidium sp. from domestic animals in Brazil

The purpose of the present study was the genetic characterization, sequencing and phylogenetic analysis of 18S rDNA sequences of Cryptosporidium isolates obtained from different animal hosts in Brazil. Fecal samples containing Cryptosporidium oocysts were obtained from chickens, ducks, quails, guinea pigs, dairy calves, dogs and cats. For amplification of 18S rDNA sequences the Secondary-PCR product of the extracted DNA from fecal suspension of each studied animal was utilized. The primary genetic characterization of Cryptosporidium sp. was performed using RFLP with the enzymes SspI and VspI. DNA samples were sequenced and subjected to phylogenetic analysis. The results showed C. baileyi infecting two ducks and one quail and C. melagridis infecting one chicken. The sequences obtained from Cryptosporidium sp. infecting guinea pigs were not identified within groups of known Cryptosporidium species. The isolates found parasitizing cats and one dog were diagnosed as C. felis and C. canis, respectively. One isolate of calf origin was identified as C. parvum. The phylogenetic analysis showed clear distribution of isolates between two Cryptosporidium sp. groups according to their gastric or intestinal parasitism. A great genetic distance was observed between C. felis and C. canis from Brazil when compared to the reference sequences obtained from GenBank. The results obtained during this study constitute the first report of rDNA sequences from C. baileyi, C. meleagridis, C. felis, C. canis and C. parvum isolated in Brazil.

Prevalence of cryptosporidian infection in cats in Turin and analysis of risk factors

An epidemiological study was carried out to identify factors associated with the risk of cryptosporidian infection in cats. Faecal samples from 200 domestic cats were collected in the small animal clinic at the Faculty of Veterinary Medicine in Turin (north-west Italy). The faecal samples were analysed for the presence of Cryptosporidium species oocysts using a centrifugation concentration floatation method. For each cat, age, sex, breed, indoor/outdoor status, diet, diarrhoea and presence of other enteric parasites were analysed for association with Cryptosporidium species infection. Cryptosporidia oocysts were identified in 49 cats (24.5%) aged from 2 months to 18 years. Statistical analysis revealed that four variables are significantly associated with an increased risk of infection: less than 1 year of age (chi(2)=6.5, P=0.01), feeding home-cooked diet (chi(2)=6.92, P<0.01), presence of diarrhoea (chi(2)=4.34, P<0.037), and presence of other enteric parasites (chi(2)=10.31, P<0.01). No statistical differences were found for sex (chi(2)=1.56, P=0.21), breed (chi(2)=0.78, P=0.38) and outdoor/indoor status (chi(2)=1.49, P=0.22). Cryptosporidium species was the parasite most frequently detected in the cats surveyed.

Molecular epidemiology with subtype analysis of Cryptosporidium in calves in Belgium

The prevalence of Cryptosporidium in calves younger than 10 weeks was estimated in a cross-sectional epidemiological study on 100 dairy (n=499) and 50 beef (n=333) farms in East Flanders (Belgium), using a previously evaluated immunofluorescence assay (Merifluor). The calf prevalence was 37% (95% Probability Interval (PI): 7-70%) in dairy calves and 12% (95% PI: 1-30%) in beef calves. To elucidate the genetic diversity, the Cryptosporidium 18S ribosomal DNA and the 70 kDa heat shock protein gene were targeted. In the majority of the samples C. parvum was present, although C. bovis was also identified, all but one in calves older than 1 month. The porcine-specific C. suis was identified in 1 beef calf. Subtyping of C. parvum positive isolates by sequence analysis of the 60 kDa glycoprotein gene indicated the presence of 4 allele IIa subtypes, along with 1 subtype IIdA22G1. The subtype IIaA15G2R1 was most prevalent, next to subtype IIaA13G2R1 and IIaA16G2R1, and a new subtype IIaA14G2R1. The results of the present study indicate a high prevalence of Cryptosporidium infections in calves in Belgium and confirm that these calves should be considered as a potential zoonotic reservoir for human infections.

Rapid microsphere assay for identification of cryptosporidium hominis and cryptosporidium parvum in stool and environmental samples

Cryptosporidium hominis and Cryptosporidium parvum are associated with massive disease outbreaks worldwide. Because these two species have different transmission cycles, identification of these parasites to the species level in clinical samples may provide laboratory data of crucial importance in epidemiologic investigations. To date, the most reliable way to differentiate C. hominis and C. parvum is based on DNA sequencing analysis of PCR amplicons. Although this approach is very effective for differentiation of Cryptosporidium species, it is labor-intensive and time-consuming compared with methods that do not require DNA sequencing analysis as an additional step and that have been successfully used for specific identification of a number of pathogens. In this study, we describe a novel Luminex-based assay that can differentiate C. hominis from C. parvum in a rapid and cost-effective manner. The assay was validated by testing a total of 143 DNA samples extracted from clinical specimens, environmental samples, or samples artificially spiked with Cryptosporidium oocysts. As few as 10 oocysts per 300 microl of stools could be detected with this assay. The assay format includes species-specific probes linked to carboxylated Luminex microspheres that hybridize to a Cryptosporidium microsatellite-2 region (ML-2) where C. hominis and C. parvum differ by one nucleotide substitution. The assay proved to be 100% specific when samples that had been characterized by direct fluorescent antibody test (DFA) and DNA sequencing analysis were tested. In addition, the assay was more sensitive than DFA and provided species identification, which is an advantage for epidemiologic studies.

The first finding of a natural infection of Cryptosporidium muris in a cat

Little is known about the species of Cryptosporidium infecting cats. The limited number of genetic studies conducted to date, have all identified C. felis as the species of Cryptosporidium in cats. We report a morphological and genetic description of a natural C. muris infection in a cat. Oocysts were viable and were successfully transmitted to laboratory mice. Further studies are required to determine the range and prevalence of Cryptosporidium species infecting cats.

Cryptosporidium species found in cattle: a proposal for a new species

Humans and animals are infected worldwide by apicomplexan parasites of the genus Cryptosporidium. Yet, parasitologists are continuously surprised by the expanding complexity of this genus. Over the past 20 years, cattle were identified as being a reservoir host for taxa transmitted from animals to humans. However, a remarkable assemblage of species affects cattle, including both cattle-specific, in addition to a zoonotic, species. To clarify species classification, Cryptosporidium pestis n. sp. is proposed for the species formerly recognized as the "bovine genotype" of C. parvum. The observed increasing complexity of Cryptosporidium species, along with recent advances in knowledge, should be reconsidered in the context of past records, and not vice versa. In this way, the gaps in our understanding of Cryptosporidium species can be identified and addressed in a scientific manner.

Genetic analysis of Cryptosporidium from 2414 humans with diarrhoea in England between 1985 and 2000

The characterization of Cryptosporidium using DNA extracted from whole faecal samples collected from 2414 humans with diarrhoea in England between 1985 and 2000 where cryptosporidial oocysts were detected using conventional methods is described. Characterization was achieved by PCR/RFLP and DNA sequencing of fragments of the Cryptosporidium oocyst wall protein and the 18S rDNA genes. Cryptosporidium parvum was detected in 56.1 % of cases, Cryptosporidium hominis in 41.7 % and a mixture of C. parvum and C. hominis in 0.9 %. In the remainder of cases, Cryptosporidium meleagridis (0.9 %), Cryptosporidium felis (0.2 %), Cryptosporidium andersoni (0.1 %), Cryptosporidium canis (0.04 %), Cryptosporidium suis (0.04 %) and the Cryptosporidium cervine type (0.04 %) were detected.

A rapid method for extracting oocyst DNA from Cryptosporidium-positive human faeces for outbreak investigations

We describe a rapid method for extracting and concentrating Cryptosporidium oocysts from human faecal samples with subsequent DNA preparation for mainstream PCR applications. This method consists of extracting faecal lipids using a modified water-ether treatment and releasing DNA from semi-purified oocysts by freeze thawing in lysis buffer. Following immunomagnetisable separation (IMS), recovery rates of 29.5%, 43.2% and 49.8% were obtained from oocyst-negative solid, semi-solid and liquid faeces, respectively, seeded with 100 +/- 2 C. parvum oocysts, which were enumerated by flow cytometry. A retrospective analysis was conducted on 92 positive human faecal samples including 78 oocyst-positive cases from 2 UK cryptosporidiosis outbreaks (outbreak A = 34 samples, outbreak B = 44 samples) and 14 oocyst-positive, sporadic cases. We used primers targeting the Cryptosporidium oocyst wall protein gene (COWP; STN-COWP), the 18S rRNA (direct PCR) and the dihydrofolate reductase gene (dhfr, MAS-PCR) fragments to evaluate extracted DNA by PCR. PCR inhibitors were present in 20 samples when template was co-amplified with the 18S rRNA gene primers and an internal control. Template dilution (1/5) in polyvinylpyrrolidone (10 mg ml(-1), pH 8.0) transformed four PCR-negative samples to PCR-positive and increased amplicon intensity in previously positive samples. Eighteen of 20 PCR-negative samples produced visible amplicons when Taq polymerase concentration in the STN-COWP PCR was increased from 2.5 to 5 U. The STN-COWP PCR assay amplified 90 of 92 samples (97.8%) and the MAS-PCR assay amplified 70 of 92 samples (76.1%) tested. In the absence of inhibitors, DNA equivalent to 3 C. parvum oocysts was amplified.

Detection of Cryptosporidium felis and Giardia duodenalis Assemblage F in a cat colony

Eighteen cats, 3-6 months of age, bred and housed in a closed colony, were transferred from that colony and placed in separate stainless steel cages in a building designed for housing animals. At daily intervals, feces were collected from the litter pans in each cage, pans and cages were cleaned, and fresh food and water were provided. Beginning 4 weeks after the transfer, oocysts of Cryptosporidium were detected in the feces of two cats by brightfield microscopy. For the following 21 days, with minor exceptions, feces from each cat were collected daily and examined by immunofluorescence microscopy and by molecular methods that included DNA extraction, 18S rDNA gene amplification, and DNA sequence analysis. Within those 22 days, every cat was found to be infected with Cryptosporidium felis and excreted oocysts for 6-18 days. Eight of these 18 cats also excreted cysts of Giardia duodenalis Assemblage F, a genotype found only in cats. Six Giardia infections were concurrent during part of the patency with C. felis infections. Neither diarrhea nor other signs of illness were observed in any of the cats during this time. Because C. felis is zoonotic these findings suggest that care should be taken by veterinary health care providers and others in close contact with cats, even when cats appear healthy and asymptomatic.

Multilocus genotyping of Cryptosporidium hominis associated with diarrhea outbreak in a day care unit in São Paulo

A number of species of Cryptosporidium are associated with diarrhea worldwide. Little data exists regarding the genotypes and species of Cryptosporidium associated with cases of infections in Brazil.

PURPOSE

In the present study, we ascertained by molecular methods the species and the genotype of Cryptosporidium sp from a diarrhea outbreak diagnosed in a day care at the Hospital Clínicas, São Paulo University Medical School.

MATERIALS AND METHODS

Specific identification and typing of the isolates associated with the outbreak was done by DNA sequencing analysis of fragments amplified by polymerase chain reaction (PCR) from 3 different Cryptosporidium loci: the SSUrRNA coding region, the Cryptosporidium oocyst wall protein (COWP) gene, and the microsatellite locus 1 (ML1), a tandem GAG-trinucleotide repeat containing substitutions that differentiate the genotypes of Cryptosporidium parvum and Cryptosporidium hominis.

RESULTS

A total of 29 positive samples from the outbreak were studied by the molecular methods described. Our study revealed the presence of a single genotype of Cryptosporidium hominis in all samples.

CONCLUSION

The molecular analysis reinforced the hypothesis that the transmission of Cryptosporidium hominis during the period the samples were collected occurred in an outbreak pattern, possibly by person-to-person contact through the fecal-oral route. As far as we know, this is the first time that molecular tools have been used to identify the species and the genotype of isolates showing the presence of the ML1 genotype in samples from Brazilian patients.

Prevalence of species and genotypes of Cryptosporidium found in 1–2-year-old dairy cattle in the eastern United States

The prevalence of Cryptosporidium species in 1-2-year-old heifers was determined for 571 animals on 14 dairy farms in seven states on the East Coast of the United States. A fecal specimen collected directly from each heifer was processed to concentrate oocysts that were then examined by polymerase chain reaction (PCR). For every PCR-positive specimen the 18S rRNA gene of Cryptosporidium was sequenced. Cryptosporidium was identified by PCR from heifers on 13 of 14 farms. On all except four farms groups of heifers were housed in a barn or in large covered pens. Others were pastured. From many of the same farms an earlier study reported that 41% of 393 pre-weaned calves and 26.2% of 447 post-weaned calves were infected. In the present study, 11.9% of 571 heifers were infected with Cryptosporidium, 0.7% with Cryptosporidium parvum, the zoonotic species. Of 68 PCR-positive specimens characterized by gene sequencing 1, 4, 10, 24, and 29 calves were infected with Cryptosporidium suis, Cryptosporidium parvum, Cryptosporidium deer-like genotype, Cryptosporidium bovis, and Cryptosporidium andersoni, respectively. These findings demonstrate a lower prevalence of infection in 1-2-year-old dairy cattle than in younger cattle as well as a change in the diversity of species present. Consequently, the risk of humans acquiring infection with C. parvum from exposure to feces from yearling and older cattle appears much lower than from exposure to pre-weaned calves.

Development of procedures for direct extraction of Cryptosporidium DNA from water concentrates and for relief of PCR inhibitors

Extraction of high-quality DNA is a key step in PCR detection of Cryptosporidium and other pathogens in environmental samples. Currently, Cryptosporidium oocysts in water samples have to be purified from water concentrates before DNA is extracted. This study compared the effectiveness of six DNA extraction methods (DNA extraction with the QIAamp DNA minikit after oocyst purification with immunomagnetic separation and direct DNA extraction methods using the FastDNA SPIN kit for soil, QIAamp DNA stool minikit, UltraClean soil kit, or QIAamp DNA minikit and the traditional phenol-chloroform technique) for the detection of Cryptosporidium with oocyst-seeded samples, DNA-spiked samples, and field water samples. The study also evaluated the effects of different PCR facilitators (nonacetylated bovine serum albumin, the T4 gene 32 protein, and polyvinylpyrrolidone) and treatments (the use of GeneReleaser or ultrafiltration) for the relief from or removal of inhibitors of PCR amplification. The results of seeding and spiking studies showed that PCR inhibitors were presented in all DNA solutions extracted by the six methods. However, the effect of PCR inhibitors could be relieved significantly by the addition of 400 ng of bovine serum albumin/mul or 25 ng of T4 gene 32 protein/mul to the PCR mixture. With the inclusion of bovine serum albumin in the PCR mixture, DNA extracted with the FastDNA SPIN kit for soil without oocyst isolation resulted in PCR performance similar to that produced by the QIAamp DNA minikit after oocysts were purified by immunomagnetic separation.