Comparison of diagnostic techniques for the detection of Cryptosporidium oocysts in animal samples

Prevalence and risk factors of Cryptosporidium spp. and Giardia infestation in cattle and in broiler chickens in Algeria

Cryptosporidiosis and giardiasis are zoonotic protozoan diseases with significant public health and economic concerns. In Algeria, epidemiological data on these parasites in livestock are limited. This study aimed to estimate the prevalence of Cryptosporidium spp. and Giardia in dairy calves and broiler chickens and to identify the associated risk factors. A microscopic analysis of 200 faecal samples revealed a Cryptosporidium spp. prevalence of 56% in calves and 60% in broiler chickens, while the Giardia prevalence was 8% in calves and absent in chickens. In cattle, the data showed that age constituted a potential risk factor for both parasites (P < 0.000 1 for Cryptosporidium; P < 0.000 5 for Giardia). Interestingly, the risk of a Cryptosporidium infection decreased with age, while the Giardia infestation risk increased. The sex was not a significant factor for Cryptosporidium (P = 0.115 0), but was impactful for Giardia (P < 0.000 1), with males at higher risk. These results highlighted the distinct epidemiological characteristics of Cryptosporidium and Giardia infestations in Algerian livestock. The contrasting age-related risks and sex-specific susceptibility to Giardia underline the need for targeted, age and sex prevention strategies. This study provides valuable data to inform public health policies and to improve livestock management practices in Algeria, contributing to the wider understanding of these zoonotic parasites in North African agricultural farming.

Coproantigen detection and molecular identification of Cryptosporidium species among newborn and adult farm animals

Cryptosporidium sp. is an obligatory intracellular apicomplexan protozoan parasite that causes a disease called cryptosporidiosis with substantial veterinary and medical importance. Therefore, this study aimed to evaluate an early diagnosis of cryptosporidiosis using the anti-Cryptosporidium parvum oocyst immunoglobulin IgG polyclonal antibodies (anti-C. parvum IgG PAbs)-based sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of Cryptosporidium oocyst antigens in fecal samples of farm animals in Egypt. Further molecular identification and sequencing were performed for the detected isolates. Eight hundred and twenty fecal samples of farm animals; 102 buffalo calves, 120 cattle calves, 100 lambs and 98 goat kids, 80 buffaloes, 60 cattle, 160 sheep and 100 goats, collected from different small-scale farms and local holders were examined for cryptosporidiosis by Modified Ziehl-Neelsen (MZN) technique. The percentage of positivity was 45.1%, 50%, 20%, 18.4%, 31.25%, 38.3%, 18.8%, and 11% in buffalo calves, cattle calves, lambs, goat kids, adult buffaloes, adult cattle, sheep, and goats, respectively. Molecular identification of Cryptosporidium samples was performed based on COWP gene, revealing the isolates: GenBank: OQ121955.1, OR029973.1 and PP316107.1 which were identical to the C. parvum and GenBank: PP316108.1 and OR029972.1 which were identical to C. hominis and C. andersoni, respectively. Then, C. parvum oocysts were used for preparation of antigens and rabbit immunization. Anti-C. parvum IgG PAbs were purified and characterized by SDS-PAGE and then labeled with horseradish peroxidase (HRP). Anti-C. parvum IgG PAbs in-house sandwich ELISA was prepared, then tested this ELISA on 820 samples and compared results with MZN microscopical examination and a commercial sandwich ELISA kit. In this study, in-house sandwich ELISA scored higher sensitivity of 98%, 100% specificity, validity 99% and relative agreement 98.6% than (92%, 90%, 91% and 91.4%) of MZN and (96%, 95%, 95.5% and 95.7%) of coproantigen commercial sandwich ELISA kit, respectively. Moreover, we used PCR to evaluate the positivity of in-house sandwich ELISA results, and the total PCR positive samples were 263 out of 268 sandwich ELISA positive samples (98.13%). In conclusion, the prepared Anti-C. parvum IgG PAbs based sandwich ELISA offered a simple and accurate diagnostic method for cryptosporidiosis in the fecal samples of different species of farm animals in Egypt with high sensitivity (98%) and specificity (100%). Further studies on this Anti-C. parvum IgG PAbs may help also in the protection against cryptosporidiosis.

Occurrence and molecular characterization of Cryptosporidium oocysts in chickens from Egypt, and a meta-analysis for Cryptosporidium infections in chickens worldwide

Cryptosporidium is a leading cause of diarrhea in children and immunocompromised patients. Various animals and birds can also be infected with this protist, and Cryptosporidium zoonosis is common. A few reports have been published worldwide on Cryptosporidium infections in chickens. The present study surveyed Cryptosporidium infections in chickens from Dakahlia governorate, Egypt. Cryptosporidium oocysts were tested, using the Ziehl Neelsen modified acid-fast staining, in 884 chickens collected from various farms and live bird markets (LBMs) in Dakahlia governorate, Egypt. COWP (Cryptosporidium oocyst wall protein)-PCR testing coupled with isolate sequencing was conducted for 10 Cryptosporidium-positive samples. Intestinal contents of 58 (6.6 %) out of the surveyed chickens in Dakahlia, Egypt, had Cryptosporidium oocysts. The native breed (Balady) had a significantly higher prevalence than the commercial breeds. Oocysts of two different size ranges were detected; 4-5.5 × 4-5 μm and 6-7 × 5-6 μm. Two of the ten PCR-tested samples were successfully sequenced and identified as Cryptosporidium parvum. The present study conducted also the first meta-analysis describing the epidemiology, clinical disease, and species diversity of Cryptosporidium infecting chickens worldwide. The pooled Cryptosporidium prevalence in 18,579 chickens tested worldwide was 18.3 %, with insignificant geographical variations. The prevalence was two-fold higher (40.5 %) at the flock level. Chickens collected from LBMs (30.5 %) had significantly higher pooled prevalence than farmed chickens (14.4 %). Insignificant prevalence variations were detected according to the production type (broiler or layer), diagnostic method, or disease status. Three Cryptosporidium species common to infect birds were molecularly identified in 760 chickens tested worldwide: Cryptosporidium baileyi, Cryptosporidium meleagridis, and Cryptosporidium galli, with the former being the most frequently detected. Cryptosporidium parvum was detected in a few samples mostly from free-range chickens. In conclusion, potential C. parvum zoonosis from chickens is suggested in Egypt, where C. parvum is common among humans and various animals. Given that chicken has a substantial role in the global C. meleagridis zoonoses, and no bird-specific Cryptosporidium spp. were detected in the tested samples from Egypt, we do recommend a large-scale molecular survey to detect various species and genotypes infecting chickens throughout various Egyptian governorates.

Rapid detection of Cryptosporidium spp. in diarrheic cattle feces by isothermal recombinase polymerase amplification assays

As a zoonotic parasite, Cryptosporidium spp. could cause severe diarrhea mainly in calves and children globally. Monitoring and prevention of Cryptosporidium spp.'s prevalence is of great significance in both economy and public health aspects. In this study, specific primers and probes were designed within the conserved region of 18S rRNA gene for Cryptosporidium spp. and recombinase polymerase amplification assays based on the fluorescence monitoring (real-time RPA) as well as combined with a lateral flow strip (LFS RPA) were developed. Both of the two RPA assays allowed the exponential amplification of the target fragment within 20 min. After incubation on a metal bath at 42 °C, the LFS RPA results were displayed on the lateral flow strip within 5 min while real-time RPA allowed the real-time observation of the results in Genie III at 39 °C. The RPA assays showed high specificity for Cryptosporidium spp. without any cross-reaction with other tested pathogens causing diarrhea in cattle. With the recombinant plasmid DNA containing the 18S rRNA gene of Cryptosporidium spp. serving as a template, the limit of detection for real-time RPA and LFS RPA assays were 14.6 and 12.7 copies/reaction, respectively. Moreover, the RPA assays were validated by testing diarrheic cattle fecal samples and compared with a real-time PCR. The positive ratio of Cryptosporidium spp. was 24.04 % (44/183) and 26.23 % (48/183) in both RPA assays and real-time PCR assay, respectively, and the kappa coefficient value was 0.942. The diagnostic specificity and diagnostic sensitivity of both RPA assays were 100 % and 91.67 %, respectively. Forty-one of 48 positive samples were successfully sequenced and four Cryptosporidium species were detected, including C. parvum (n = 20), C. andersoni (n = 17), C. bovis (n = 3) and C. ryanae (n = 1). The developed RPA assays are easy to operate and faster to obtain the detection results, and they are suiting for the point-of-care detection and facilitating the prevention and control of Cryptosporidium spp. infections.

Diagnosis and control of cryptosporidiosis in farm animals

Cryptosporidium is a pathogenic protozoan parasite infecting the gastrointestinal epithelium of human and animal hosts. In farm animals, cryptosporidiosis causes significant economic losses including deaths in newborn animals, retarded growth, increased labor involved and high cost of drugs. The detection of Cryptosporidium oocysts in fecal samples is traditionally dependent on examination of stained slides by light microscope or by advanced microscopical tools such as: electron microscopy and phase contrast microscopy. Immunological diagnosis using either antibody or antigen detection could offer high sensitivity and specificity. Examples for these tests are Enzyme Linked Immunosorbent Assay (ELISA), Immunochromatographic tests, Immunochromatographic lateral flow (ICLF), Immunofluorescence assays (IFA) and Flow cytometry coupled with cell sorting. Molecular methods could differentiate species and genotypes of Cryptosporidium and help in studying the epidemiological features of this parasite with rapid, simple and sensitive procedures. Nanotechnology-based platforms could improve the sensitivity and specificity of other detection methods like: ELISA, ICLF, IFA and polymerase chain reaction. As the available prophylactic and therapeutic drugs or natural products treatments are insufficient and no approved vaccines are available, the best approach to control this parasite is by following firm hygienic measures. Many vaccine attempts were performed using hyperimmune colostrum, live or attenuated vaccines, recombinant and Deoxyribonucleic acid vaccines. Also, Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 technology could help in Cryptosporidium genome editing to improve drug and vaccine discovery. Another approach that could be useful for assigning drug targets is metabolomics. Probiotics were also used successfully in the treatment of acute diarrhea and they proved a limiting effect on cryptosporidiosis in animal models. In addition, nanotherapy-based approaches could provide a good strategy for improving the potency of any type of drugs against Cryptosporidium and give good anti-cryptosporidial effects. In conclusion, accurate diagnosis using advanced techniques is the key to the control and prevention of cryptosporidiosis.

Performance of diagnostic assays used to detect Cryptosporidium oocysts in faecal samples of cattle in Kuwait and genotyping of Cryptosporidium species

Backgroud

Cryptosporidium species are zoonotic protozoan parasites responsible for gastroenteritis in various animals and humans. The diagnosis of Cryptosporidium presents many challenges. This research attempted to match the diagnostic efficiency of the modified Ziehl–Neelsen technique (mZN), immunochromatographic assays (IC), and enzyme-linked immunosorbent assay (ELISA) for the detection of Cryptosporidium in faecal samples of cattle in Kuwait. In addition, polymerase chain reaction (PCR) was utilised to determine the predominant species infecting cattle in Kuwait and correlating the detected species with the results of different diagnostic tests used, the presence or absence of clinical signs, and the age group of the infected cattle.

Results

Of 400 analysed faecal samples, Cryptosporidium positive samples were 23%, 15.25%, and 14% using IC, ELISA, and mZN. IC had the highest sensitivity (74.07%), and mZN had the highest specificity (98.29%) using a composite reference standard (CRS) as a gold standard. The rapid IC test results in high false-positive results of cryptosporidiosis, whereas using mZN alone is insufficient to declare a negative faecal sample. Only 74.5% (35/47) of Cryptosporidium-positive samples by the three assays could be amplified by PCR. This study was the first to genotype Cryptosporidium in Kuwait. Cryptosporidium parvum (n = 26) was the dominant species detected from cattle samples, followed by C. andersoni (n = 6), C. bovis (n = 2), and C. raynae (n = 1). The findings showed a statistically relevant relationship between diarrhoea and the detection of Cryptosporidium spp. in faecal samples of cattle (p-value = 0.0003). Pre-weaned calves were the most vulnerable age group to Cryptosporidium spp. infection (p-value = 0.0007).

Conclusion

For screening of Cryptosporidium infection in faecal samples, antigen detection or PCR methods combined with one of the microscopy techniques should be used. Cryptosporidium parvum was the prepoderant Cryptosporidium spp. recovered from cattle samples in Kuwait followed by C. andersoni. Cryptosporidium parvum is a significant risk factor for diarrhoea in pre-weaned calves. However, further study is needed as many other causes of diarrhoea in calves must be ruled out before a diagnosis of Cryptosporidium diarrhoea can be made.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03435-w.

Apicomplexans in Goat: Prevalence of Neospora caninum, Toxoplasma gondii, Cryptosporidium spp., Eimeria spp. and Risk Factors in Farms from Ecuador

Neospora caninum, Toxoplasma gondii, Cryptosporidium and Eimeria cause severe impacts on the productivity of goat herds. The objectives of the present study were to establish the prevalence of these apicomplexans in goat farms from Ecuador; to evaluate a rapid test for Cryptosporidium diagnosis and to identify the risk factors associated with the infections. A questionnaire was designed to obtain information from 24 goat farms from Zapotillo, Garza Real, Cazaderos, Limones and Paletillas parishes in Ecuador. Blood (n = 388) and feces (n = 391) samples were collected. Indirect ELISA and standard parasitological assays were carried out to evaluate the seroprevalence of N. caninum and T. gondii and to detect oocysts of Cryptosporidium and Eimeria. The overall prevalence values of N. caninum and T. gondii were 12.11% and 18.20%, Cryptosporidium spp. and Eimeria spp. oocysts were detected in 10.49% and 89.51% of the total samples. A low correlation value was found between the results obtained by Ziehl-Nielsen and the rapid test. The multinomial logistic regression analysis revealed that vitamin supplementation, age of diarrhea, frequency of deworming, pasture area, presence of artiodactyls, domestic fowl, administration of sulfas, age group, body condition, abortions, type of pastures and the presence of cattle were risk factors according to the parasite species.

Development and Preliminary Evaluation of a Nanoparticle-Assisted PCR Assay for the Detection of Cryptosporidium parvum in Calves

C. parvum is an important diarrheal pathogen in humans and animals, especially in young hosts. To accurately and rapidly detect C. parvum infection in calves, we established a nano-PCR assay targeting the cgd3_330 gene for the specific detection of C. parvum. This nano-PCR assay was ten times more sensitive than that of the normal PCR assay by applying the same primers and did not cross-react with C. andersoni, C. bovis, C. ryanae, Balantidium coli, Enterocytozoon bieneusi, Giardia lamblia, and Blastocystis sp. To further test the nano-PCR in clinical settings, a total of 20 faecal samples from calves were examined by using the nano-PCR, the normal PCR, and the nested PCR assays. The positive rates were 30% (6/20), 30% (6/20), and 25% (5/20) for the nano-PCR, the normal PCR, and the nested PCR assays, respectively, indicating that the nano-PCR and the normal PCR assays had the same positive rate (30%). Taken together, the present study could provide a candidate method for the specific detection of C. parvum infection in calves in clinical settings.

Population genetics of Cryptosporidium parvum subtypes in cattle in Poland: the geographical change of strain prevalence and circulation over time

Background

Cryptosporidium parvum (C. parvum) is a cosmopolitan parasite that infects various livestock animals including cattle. Microsatellite typing tools for identification of C. parvum subtypes are currently employed to better understand the species-specific epidemiology of cattle cryptosporidiosis. The aim of this study was to analyse the population genetics of C. parvum strains infecting cattle and recognise geographical distribution and time-span correlations in subtype prevalence in Poland. In total, 1601 faecal samples were collected from 2014 to 2018 from healthy cattle from dairy, meat and mixed breeds at the age of 1 week to 4 months. The 267 farms visited were randomly selected and represented all Polish provinces. PCR–RFLP based identification of C. parvum at the 18 small subunit ribosomal RNA (SSU rRNA) locus was performed, followed by strain subtyping by GP60-PCR. 

Results

The overall prevalence of C. parvum in Polish cattle was estimated at 6.2% (100/1601). Animals below the age of 1 month were the major host for this parasite. Excluding one breed, that of dairy-meat mixed, there were no significant differences observed between breed and presence of C. parvum infections (95% TPI_{All breeds}: 1.67–73.53%; POPR = 0.05—0.95). Infected animals were detected in 15 out of 16 Polish provinces, with significant regional prevalence diffrences (Kruskal–Wallis rank sum test, Kruskal–Wallis χ² = 13.46, p < 0.001). When the population genetics of C. parvum strains were analysed, 11 parasite subtypes from the IIa and IId genetic families were identified. Compared to other parasite strains, IIaA17G1R1 and IIaA17G2R1 appeared at statistically significantly higher frequency (F-test, F = 3.39; p = 0.0003). The prevalence of C. parvum subtypes in cattle was breed-related (Chi-squared test, χ² = 143.6; p < 0.001).

Conclusions

The analysis of the population genetics of C. parvum subtypes showed that strains from the IIa subtype family predominated in the tested cattle population. However, relations in changes of subtype prevalence and circulation over time were observed. They were associated with the disappearance of some strains and emergence of new variants from the same genetic family in different geographical locations.

C. parvum subtypes from the IIa allele family predominated in the tested cattle. The prevalence of C. parvum subtypes in cattle was breed-related. Dynamicity in the population C. parvum strains circulating in cattle was shown.

A comparison of assays for the detection of Cryptosporidium parvum in the feces of scouring calves

Cryptosporidium parvum is a zoonotic, protozoan parasite that causes potentially life-threatening diarrhea in the host and can be transmitted via the fecal-oral route. C. parvum can infect cattle and may be detected in their feces using a variety of tests. We compared the level of agreement, ease of procedure, and cost among PCR, lateral flow immunoassay, fluorescent antibody, and Kinyoun acid-fast stain direct smear tests. Over the course of 9 mo, 74 calf fecal samples were submitted and tested for C. parvum using all 4 tests. A Fleiss kappa value of 0.813 was obtained, indicating an excellent level of agreement among tests. Overall, the best test based on cost and ease of procedure was the Kinyoun acid-fast stain direct smear.

Performance of a rapid diagnostic test for the detection of Cryptosporidium spp. in African children admitted to hospital with diarrhea

BACKGROUND

Cryptosporidium is a protozoan parasite that causes mild to severe diarrhoeal disease in humans. To date, several commercial companies have developed rapid immunoassays for the detection of Cryptosporidium infection. However, the challenge is to identify an accurate, simple and rapid diagnostic tool for the estimation of cryptosporidiosis burden. This study aims at evaluating the accuracy of CerTest Crypto, a commercialized rapid diagnostic test (RDT) for the detection of Cryptosporidium antigens in the stool of children presenting with diarrhoea.

METHODS

A cross-sectional study was conducted in four study sites in Sub-Saharan Africa (Gabon, Ghana, Madagascar, and Tanzania), from May 2017 to April 2018. Stool samples were collected from children under 5 years with diarrhoea or a history of diarrhoea within the last 24 hours. All specimens were processed and analyzed using CerTest Crypto RDT against a composite diagnostic panel involving two polymerase chain reaction (PCR) tests (qPCR and RFLP-PCR,) as the gold standard.

RESULTS

A total of 596 stool samples were collected. Evaluation of the RDT yielded a very low overall sensitivity of 49.6% (confidence interval (CI) 40.1-59.0), a specificity of 92.5% (CI 89.8-94.7), positive predictive value of 61.3% (CI 50.6-71.2), and negative predictive value of 88.5% (85.3-91.1) when compared to the composite reference standard of qPCR and RFLP-PCR for the detection of Cryptosporidium species. Moreover, the performance of this test varied across different sites.

CONCLUSION

The weak performance of the studied RDT suggests the need to carefully evaluate available commercial RDTs before their use as standard tools in clinical trials and community survey of Cryptosporidium infections in pediatric cohorts.

Molecular detection of genotypes and subtypes of Cryptosporidium infection in diarrheic calves, lambs, and goat kids from Turkey

The studies on Cryptosporidium infections of animals in Turkey mostly rely on microscopic observation. Few data are available regarding the prevalence of Cryptosporidium genotypes and subtypes infection. The aim of this study is to analyse the detection of Cryptosporidium genotypes and subtypes from young ruminants. A total of 415 diarrheic fecal specimens from young ruminants were examined for the Cryptosporidium detection by use of nested PCR of the small subunit ribosomal RNA (SSU rRNA) gene and the highly polymorphic 60 kDa glycoprotein (gp60) gene followed by sequence analyses. The results of this study revealed that 25.6% (106 of 415) of the specimens were positive for Cryptosporidium spp. infection. We identified 27.4% (91/333), 19.4% (13/67), and 13.4% (2/15) of positivity in calves, lambs and goat kids, respectively. Genotyping of the SSU rRNA indicated that almost all positive specimens were of C. parvum, except for one calf which was of C. bovis. Sequence analysis of the gp60 gene revealed the most common zoonotic subtypes (IIa and IId) of C. parvum. We detected 11 subtypes (IIaA11G2R1, IIaA11G3R1, IIaA12G3R1, IIaA13G2R1, IIaA13G4R1, IIaA14G1R1, IIaA14G3R1, IIaA15G2R1, IIdA16G1, IIdA18G1, IIdA22G1); three of them (IIaA12G3R1, IIaA11G3R1 and IIaA13G4R1) was novel subtypes found in calves and lambs. Additionally, three subtypes (IIaA11G2R1, IIaA14G3R1, and IIdA16G1) were detected in young ruminants for the first time in Turkey. These results indicate the high infection of Cryptosporidium in Turkey and propose that young ruminants are likely a major reservoir of C. parvum and a potential source of zoonotic transmission.

A pathological study of Leishmania infantum natural infection in European rabbits (Oryctolagus cuniculus) and Iberian hares (Lepus granatensis)

In this study, we describe the pathology of Leishmania infantum infection in naturally infected wild Leporidae and compare diagnosis of infection using histopathology, direct fluorescent antibody (DFA) assay, immunofluorescence antibody test (IFAT) and quantitative real-time PCR (qPCR). Tissues were analysed from 52 European rabbits (Oryctolagus cuniculus) and 7 Iberian hares (Lepus granatensis) from the Community of Madrid (Spain). Our results show that L. infantum infection is associated with only minimal histopathological lesions and that L. infantum amastigotes can be detected by DFA assay in all tissues types tested, including skin. These results were confirmed by qPCR on fresh frozen tissues in 13% of rabbits and 100% of hares. However, L. infantum DNA could not be detected by qPCR on paraffin-embedded tissue obtained by laser capture microdissection. Using the DFA assay to diagnose L. infantum, infection may provide further insights into this disease in wild animals and may allow the precise tissue localization of L. infantum, thereby guiding follow-up tests with more accurate qPCR.

New insights into the detection and molecular characterization of Cryptosporidium with emphasis in Brazilian studies: a review

Cryptosporidium spp. is a pathogenic protozoan present in the gastrointestinal tract of several hosts. This protozoan was originally classified as within the Coccidia Class and has recently been reclassified to gregarine based on studies that observed the evolutionary phases from the process of excision and sequencing of the 18S rRNA gene. Molecular biology techniques have become diagnostic tools and have also been used to understand the epidemiology of Cryptosporidium spp., since several species of this genus are very similar morphologically and morphometrically. Molecular techniques have been used in the identification of parasites, at the species and subtypes levels and to study disease transmission. The laboratory diagnosis of human cryptosporidiosis can be made by parasite detection methods, such as optical microscopy, antigens or genetic material detection, as well as serum antibodies raised to Cryptosporidium spp. Molecular methods were developed and allowed, not only an extensive revision of the taxonomy, but also an improvement in the laboratory diagnosis. In Brazil, there are few reports of Cryptosporidium spp. outbreaks in humans and all of them took place in nurseries. A few epidemiological studies developed in Brazil have used molecular methods for the detection of Cryptosporidium spp., as well as genotyping studies of their species and subtypes. The use of real-time PCR, together with microscopy and immunochromatography techniques, would result in a more precise diagnosis of cryptosporidiosis. The analysis of genotypes, subtypes and clonality of Cryptosporidium could be useful to understand and define the prognosis and severity of infections.

Comparison of current methods used to detect Cryptosporidium oocysts in stools

In this review all of the methods that are currently in use for the investigation of Cryptosporidium in stool material are highlighted and critically discussed. It appears that more qualifications and background knowledge in this field regarding the diagnosis of the Cryptosporidium parasite is required. Furthermore, there is no standardization for the protocols that are commonly used to either detect oocysts in faeces or to diagnose the Cryptosporidium infection. It is therefore necessary to initiate further education and research that will assist in improving the accuracy of the diagnosis of Cryptosporidium oocysts in the faecal micro-cosmos. Where ambient concentrations of oocysts are low in stool material, detection becomes a formidable task. Procedures for ring tests and the standardization of multi-laboratory testing are recommended. It is also necessary to enhance the routine surveillance capacity of cryptosporidiosis and to improve the safety against it, considering the fact that this disease is under diagnosed and under reported. This review is intended to stimulate research that could lead to future improvements and further developments in monitoring the diagnostic methodologies that will assist in harmonizing Cryptosporidium oocysts in stool diagnosis.

Cryptosporidium-associated diarrhoea in neonatal calves in Algeria

Neonatal calf diarrhoea triggered by the enteric protozoan parasite Cryptosporidium is a leading cause of morbidity and mortality in calves aged 1-month-old or younger globally. Infected cattle in general and calves in particular have also been demonstrated as major contributors of zoonotic C. parvum oocysts in the environment and have been linked to a number of waterborne outbreaks of human cryptosporidiosis. Little is known on the occurrence, geographical distribution, and molecular diversity of Cryptosporidium infections affecting bovine populations in Algeria. In this study faecal specimens were randomly collected from 460 cattle aged between two days and 18 months on 10 farms located in the provinces of Aïn Defla, Blida, Sétif, and Tizi Ouzou between the autumn of 2015 and the spring of 2016. Faecal samples were microscopically examined using the modified Ziehl-Neelsen acid-fast technique as screening method. Microscopy-positive samples were confirmed by a commercial coproantigen enzyme-linked immunosorbent assay (Bio-X Diagnostics). The identification of Cryptosporidium species and sub-genotypes in confirmed samples was conducted by PCR and sequence analyses of the small subunit ribosomal RNA (ssu rRNA) and the 60 kDa glycoprotein (gp60) genes of the parasite. Overall, 52.2% (240/460) of the investigated cattle tested positive to Cryptosporidium by microscopy. The infection was widespread in all 10 farms surveyed, but was significantly more prevalent in those from Blida in the central part of the country. Bovine cryptosporidiosis affected cattle of all age groups but with different outcomes. Pre-weaned (up to one month old) calves typically presented with diarrhoea, whereas older animals mostly harboured sub-clinical infections. The commercial ELISA used only detected 15.8% (38/240) of the samples that previously tested positive by microscopy, demonstrating a poor performance in field epidemiological surveys. Sequence analysis of the 29 isolates generated at the ssu rRNA loci confirmed the presence of four Cryptosporidium species including C. parvum (72.4%), C. bovis (13.8%), C. andersoni, (3.4%), and C. ryanae (3.4%). Two additional isolates (7.0%) could only be identified at the genus level. Eight out of the 21 isolates assigned to C. parvum were identified as sub-genotype IIaA16G2R1 at the gp60 locus. C. parvum was almost exclusively found infecting pre-weaned calves, whereas C. ryanae and C. andersoni were only detected in asymptomatic animals. Bovine cryptosporidiosis is highly endemic in the surveyed area and represents a veterinary public health concern that should be adequately tackled by Algerian veterinary health authorities and policy makers.

Detection and characterization of Cryptosporidium species and genotypes in three chicken production systems in Brazil using different molecular diagnosis protocols

The objective of this study was to determine the occurrence of Cryptosporidium spp. in domestic chickens raised in different chicken production systems in Brazil using three nested PCR protocols. The purification and concentration of oocysts present in 190 fecal samples from chickens raised in extensive, semi-intensive and intensive production systems were accomplished by centrifugal flotation in Sheather's solution and were followed by the extraction of genomic DNA. The detection and molecular characterization of Cryptosporidium species and genotypes were performed using three nested polymerase chain reaction (nested PCR) protocols targeting the 18S rRNA gene followed by sequencing of the amplified fragments. Subgenotyping of C. meleagridis was performed using a nested PCR reaction targeting the gp60 gene. Sample identified as Cryptosporidium sp. genetically similar to Cryptosporidium xiaoi and Cryptosporidium bovis by 18S rRNA gene sequencing were further analyzed by nested PCR targeting the actin gene and subsequent sequencing of the amplified fragment. Positive amplification for Cryptosporidium spp. was observed in 12.6% (24/190) of the samples, including C. baileyi (9.8%; 18/190), C. meleagridis (0.5%, 1/190), C. parvum (2.1%; 4/190) and Cryptosporidium sp. (0.5%; 1/190). Subgenotyping of C. meleagridis revealed the presence of the zoonotic subtype IIIgA23G3R1. Sequencing of the 18S rRNA gene and the actin gene fragments revealed a Cryptosporidium genotype in an extensive poultry system genetically related to C. xiaoi and C. bovis. There was no significant difference in the frequency of positive results obtained by the three nested PCR protocols (p > 0.05); additionally, the agreement obtained by Kappa index ranged from substantial (0.70) to almost perfect (0.9).

Identification of pig-specific Cryptosporidium species in mixed infections using Illumina sequencing technology

Nowadays molecular methods are widely used in epidemiological studies of Cryptosporidium infections in humans and animals. However to gain better understanding of parasite species or genotypes, especially when mixed infections are noticed, highly sensitive tools with adequate resolution power need to be employed. In this article, we report an application of the next generation sequencing method (NGS) for detection and characterisation of Cryptosporidium species concurrently present in pig faeces. A mixture of Cryptosporidium DNA obtained from two faecal samples was amplified at the 18 SSU rRNA gene locus and the resulting amplicons were subsequently used for MiSeq sequencing. Although initial molecular analyses indicated the possible presence of another Cryptosporidium species other than Cryptosporidium scrofarum and Cryptosporidium suis, deep sequencing only confirmed the presence of pig-specific Cryptosporidium.

Cryptosporidium infection in children with cancer undergoing chemotherapy: how important is the prevention of opportunistic parasitic infections in patients with malignancies?

Cryptosporidiosis is a relatively uncommon disease in healthy individuals but could be potentially worrisome in immunocompromised patients. This study aimed to evaluate Cryptosporidium infection in children with cancer undergoing chemotherapy. A case-control study was conducted in 132 children with cancer undergoing chemotherapy and 132 non-cancer controls. The modified Ziehl-Neelsen (MZN) staining and polymerase chain reaction methods were used for the detection of Cryptosporidium parasite. All positive isolates were sequenced for phylogenetic analysis. Statistical analysis was performed using the SPSS version 16 and Fisher exact test. The rate of cryptosporidiosis in children with cancer undergoing chemotherapy was 3.8%, which was higher than that of the control group. Other intestinal parasites detected in patients with cancer included Giardia lamblia (3%), Entamoeba coli (1.5%), and Chilomastix mesnili (0.8%). In the control group, only two (1.5%) cases were positive for G. lamblia. No significant difference was observed between the gender, age, residency, contact with domestic animals, stool appearance, neutropenia, chemotherapy period, and type of malignancy with regard to cryptosporidiosis. Phylogenetic analysis revealed that Cryptosporidium parvum isolates in this study relied on a branch that represents similar sequences from Iran and other countries. Although the rate of Cryptosporidium infection was relatively higher in children with cancer undergoing chemotherapy compared to the control group, any statistically significant difference has not been found between them. These findings should not be contrary to the need for healthcare to prevent opportunistic parasitic infections in malignant and immunocompromised patients.

Multilocus typing of Cryptosporidium spp. in young calves with diarrhea in Korea

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Cryptosporidium spp. were detected using PCR and ELISA in diarrheal feces from calves.

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PCR and ELISA data showed good agreement in detecting C. parvum.

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Multilocus typing with 18S rRNA, gp60, and hsp70 genes of C. parvum was performed.

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Subtyping of C. parvum gp60 gene first revealed IIaA18G3R1 and IIaA16G3R1 in Asia.

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PCR and sequencing of hsp70 gene clearly differentiated C. bovis and C. ryanae.

We assessed the prevalence and performed molecular analysis of Cryptosporidium spp. in diarrheal feces of calves in Korea. Diarrheal fecal samples were collected from 951 young calves (<3 months) on 425 farms. Cryptosporidium prevalence was assessed by PCR and ELISA, and molecular characterization was performed by targeting the 18S rRNA, heat-shock protein 70 (hsp70), and glycoprotein 60 (gp60) genes. Data were analyzed according to the sex, type of cattle, region, season, and type of diarrhea. PCR analysis revealed Cryptosporidium spp. in 9.9% (94/951) of diarrheal fecal samples. C. parvum and C. bovis/ryanae were present in 6.1% (58/951) and 4.1% (39/951) of diarrheal fecal samples, respectively. In addition, ELISA showed positive results for C. parvum in 9.7% (92/951) samples. Statistical analysis of the PCR and ELISA results revealed a lower prevalence of C. parvum in the hemorrhagic diarrheal samples (P < 0.05). For C. bovis/ryanae, seasonality and high prevalence in hemorrhagic diarrhea were observed (P < 0.05). Of the 951 samples tested for C. parvum, 903 samples showed agreement with a κ value of 0.65, indicating good agreement between the two tests. Although C. bovis and C. ryanae share highly similar 18S rRNA sequences, PCR based on hsp70 successfully distinguished C. bovis from C. ryanae. Sequence analysis of gp60 revealed that C. parvum belonged to the IIa families and was further subtyped as IIaA18G3R1 and IIaA16G3R1, which have not been previously reported in Asia. These findings indicate that Cryptosporidium spp. play an important role in diarrhea in young calves in Korea. Considering the zoonotic significance of C. parvum IIa subtype and dense rearing system of cattle in Korea, prevention and continuous monitoring of Cryptosporidium are required.

Molecular epidemiology of Cryptosporidium species in livestock in Ireland

Cryptosporidium is a protozoan that can cause gastro-intestinal illness with diarrhoea in a wide range of hosts. In fact some species of Cryptosporidium can infect the broad range of hosts. The current paper is focused to investigate monthly prevalence and diversity of Cryptosporidium spp. during the spring and early summer (March-June) in 2009 and 2010 in farms with no history of cryptosporidiosis. Animal samples were analyzed to elucidate the prevalence of Cryptosporidium in two regions, West and the East catchments in Ireland. Our investigation demonstrates the prevalence ranges from 14% to 26% an early summer peak (June) was observed. Based on the findings of this study Cryptosporidium ryanae (in cattle, horses), and Cryptosporidium bovis/xiaoi followed by Cryptosporidium parvum (in sheep) were found to be the predominant species in asymptomatic cases. The circulation of other Cryptosporidium species such as C. parvum, C. bovis, C. ubiquitum, C. andersoni and Cryptosporidium horse and pig genotypes in livestock was investigated.