Cryptosporidium species and subtypes and clinical manifestations in children, Peru

Cryptosporidium-induced acute kidney injury in a patient with acquired immunodeficiency syndrome

Cryptosporidium is a pathogen that can cause infectious enteritis especially in immunocompromised patients. Acute kidney injury, electrolyte imbalance, and acid-base disorders may occur as a result of high volumes of intestinal fluid loss, which has not been previously reported to be a common manifestation of cryptosporidiosis. Numerous antigen detection methods can be used to ensure early diagnosis of Cryptosporidium infection, which is crucial to prevent morbidities. We report a unique case of cryptosporidiosis in a 33-year-old male patient with acute kidney injury and profound hypokalemia, hyponatremia, hypocalcemia, hypophosphatemia, hypomagnesemia, and metabolic acidosis. Following the initiation of antiretroviral therapy to human immunodeficiency virus, the patient's symptoms improved and he recovered fully from kidney injury and electrolyte imbalance, highlighting the importance of early antiretroviral therapy.

Cultivation, cryopreservation, and transcriptomic studies of host-adapted Cryptosporidium parvum and Cryptosporidium hominis using enteroids

Cryptosporidium hominis and Cryptosporidium parvum are major causes of severe diarrhea. Comparative studies of them are hampered by the lack of effective cultivation and cryopreservation methods, especially for C. hominis. Here, we describe adapted murine enteroids for the cultivation and complete development of host-adapted C. parvum and C. hominis subtypes, producing oocysts infectious to mice. Using the system, we developed a cryopreservation method for Cryptosporidium isolates. In comparative RNA-seq analyses of C. hominis cultures, the enteroid system generated significantly more host and pathogen responses than the conventional HCT-8 cell system. In particular, the infection was shown to upregulate PI3K-Akt, Ras, TNF, NF-κB, IL-17, MAPK, and innate immunity signaling pathways and downregulate host cell metabolism, and had significantly higher expression of parasite genes involved in oocyst formation. Therefore, the enteroid system provides a valuable tool for comparative studies of the biology of divergent Cryptosporidium species and isolates.

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

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

Cryptosporidium and irritable bowel syndrome

Cryptosporidium is an apicomplexan parasite that causes gastrointestinal disease in a wide variety of hosts and is associated with waterborne outbreaks. Nonetheless, the parasite is underdiagnosed. Cryptosporidium has been proposed as an etiological cause of irritable bowel syndrome (IBS) in several studies. However, the exact mechanism of pathogenesis is unknown, and no direct link has been discovered. This review will discuss several parasite-induced modifications, such as immunological, microbiome, and metabolite modifications, as well as their interactions. To summarize, Cryptosporidium causes low inflammation, dysbiosis, and unbalanced metabolism, which leads to a lack of homeostasis in the intestine in a comparable pattern to postinfectious IBS.

Zoonotic Cryptosporidium meleagridis in urban invasive monk parakeets

Zoonotic Cryptosporidium meleagridis was identified in invasive monk parakeets (Myiopsitta monachus) from Santiago metropolis in Chile. Oocysts were isolated from nestlings' faeces, and a fragment of 18S ribosomal RNA gene was amplified and sequenced. This finding emphasizes the importance of permanent pathogen monitoring in synanthropic species with wide global distribution.

Genomic Heterogeneity of Cryptosporidium parvum Isolates From Children in Bangladesh: Implications for Parasite Biology and Human Infection

Cryptosporidium species are a major cause of diarrhea and associated with growth failure. There is currently only limited knowledge of the parasite's genomic variability. We report a genomic analysis of Cryptosporidium parvum isolated from Bangladeshi infants and reanalysis of sequences from the United Kingdom. Human isolates from both locations shared 154 variants not present in the cattle-derived reference genome, suggesting host-specific adaptation of the parasite. Remarkably 34.6% of single-nucleotide polymorphisms unique to human isolates were nonsynonymous and 8.2% of these were in secreted proteins. Linkage disequilibrium decay indicated frequent recombination. The genetic diversity of C. parvum has potential implications for vaccine and therapeutic design. Clinical Trials Registration. NCT02764918.

Longitudinal follow-up reveals occurrence of successive Cryptosporidium bovis and Cryptosporidium ryanae infections by different subtype families in dairy cattle

Cryptosporidium bovis and Cryptosporidium ryanae are common species causing cryptosporidiosis in cattle. Data accumulated thus far indicate that the infection patterns of the two species could be different between areas with and without Cryptosporidium parvum. To better understand the infection dynamics of these two species, cross-sectional and longitudinal studies of Cryptosporidium spp. were conducted using genotyping and subtyping tools. In the cross-sectional survey, analysis of 634 faecal samples from two farms identified only C. bovis and C. ryanae in pre-weaned calves. Two birth cohorts of 61 and 78 calves were followed longitudinally over a 12 month period, which revealed the shedding of C. bovis oocysts started at 1-2 weeks of age and peaked initially at 6-8 weeks of age. Altogether calves experienced four infections by six subtype families of C. bovis, with each infection caused by different subtype families. In contrast, the shedding of C. ryanae oocysts started at 2-4 weeks of age, and the two infections were caused by different subtype families. The cumulative incidence of C. bovis infection was 100% (58/58, 32/32) on both farms, compared with 84.4-98.3% (27/32 and 57/58) for C. ryanae infection. Overall, the mean duration of oocyst shedding in the cohort studies was 3.8-4.0 weeks for C. bovis compared with 2.1 weeks for C. ryanae. The oocyst shedding intensity was high (mean oocysts per gram of faeces was over 105) during the first infection with each species but became significantly lower in the later infections. Cryptosporidium ryanae was associated with the occurrence of diarrhea on one farm, while C. bovis was not. The data indicate that there is an early occurrence of C. bovis and C. ryanae in pre-weaned calves with high infection intensity in the absence of C. parvum. Calves infected with the same Cryptosporidium sp. multiple times could be associated with the presence of subtype-specific immunity.

The Gut-Wrenching Effects of Cryptosporidiosis and Giardiasis in Children

Cryptosporidium species and Giardia duodenalis are infectious intestinal protozoan pathogens that cause alarming rates of morbidity and mortality worldwide. Children are more likely to have clinical symptoms due to their less developed immune systems and factors such as undernutrition, especially in low- and middle-income countries. The severity of the symptoms and clinical manifestations in children may vary from asymptomatic to life-threatening depending on the Cryptosporidium species/G. duodenalis strains and the resulting complex stepwise interactions between the parasite, the host nutritional and immunologic status, and the gut microbiome profile. Structural damages inflicted by both parasites to epithelial cells in the large and small intestines could severely impair children's gut health, including the ability to absorb nutrients, resulting in stunted growth, diminished neurocognitive development, and other long-term effects. Clinically approved cryptosporidiosis and giardiasis drugs have broad antimicrobial effects that have incomprehensible impacts on growing children's gut health.

Differences in virulence and oocyst shedding profiles in lambs experimentally infected with different isolates of Cryptosporidium parvum

A wide spectrum of disease severity associated with cryptosporidiosis has been described, ranging from asymptomatic to fatal in both human and animal hosts. The reasons for the variations in severity are likely to be multifactorial, involving environmental, host and parasite factors. This paper describes two experimental infection trials in lambs, a symptomatic host for the parasite, to investigate variation in the clinical manifestations following infection with two distinct isolates of Cryptosporidium parvum. In the first experiment, groups of naïve lambs were challenged with one of two isolates (CP1 or CP2) at ​< ​1 week of age, to test the effect of the isolates on disease outcome. In a second experiment one group of lambs challenged at < 1 week of age (CP1) was then re-challenged with the same isolate at 6 weeks of age (CP1), while a second group was challenged for the first time at 6 weeks of age (CP1). This experiment examined age-related disease symptoms, oocyst shedding and the effect of prior exposure to the parasite on a subsequent homologous challenge. The two isolates were associated with significant differences in the demeanour of the animals and in the numbers of oocysts shed in the faeces. There were also differences in the duration and severity of diarrhoea, though these were not significant. The age of the lamb, at the time of a primary challenge (<1 week or 6 weeks), also resulted in differences in clinical outcomes, with younger lambs showing more severe clinical disease than the older lambs (feeding profiles and presentation of diarrhoea), while older lambs showed virtually no signs of infection but still produced large numbers of oocysts.

Scalable cryopreservation of infectious Cryptosporidium hominis oocysts by vitrification

Cryptosporidium hominis is a serious cause of childhood diarrhea in developing countries. The development of therapeutics is impeded by major technical roadblocks including lack of cryopreservation and simple culturing methods. This impacts the availability of optimized/standardized singular sources of infectious parasite oocysts for research and human challenge studies. The human C. hominis TU502 isolate is currently propagated in gnotobiotic piglets in only one laboratory, which limits access to oocysts. Streamlined cryopreservation could enable creation of a biobank to serve as an oocyst source for research and distribution to other investigators requiring C. hominis. Here, we report cryopreservation of C. hominis TU502 oocysts by vitrification using specially designed specimen containers scaled to 100 μL volume. Thawed oocysts exhibit ~70% viability with robust excystation and 100% infection rate in gnotobiotic piglets. The availability of optimized/standardized sources of oocysts may streamline drug and vaccine evaluation by enabling wider access to biological specimens.

Oocyst Shedding Dynamics in Children with Cryptosporidiosis: a Prospective Clinical Case Series in Ethiopia

Knowledge on the duration of Cryptosporidium oocyst shedding, and how shedding may be affected by subtypes and clinical parameters, is limited. Reduced transmission may be a secondary benefit of cryptosporidiosis treatment in high-prevalence areas. We conducted a prospective clinical case series in children of <5 years presenting with diarrhea to a health center and a hospital in Ethiopia over an 18-month period. Stool samples were collected repeatedly from children diagnosed with cryptosporidiosis for up to 60 days. Samples were examined, and Cryptosporidium shedding was quantified, using auramine phenol, immunofluorescent antibody staining, and quantitative PCR (qPCR). In addition, species determination and subtyping were used to attempt to distinguish between new infections and ongoing shedding. Duration and quantity of shedding over time were estimated by time-to-event and quantitative models (sex- and age-adjusted). We also explored how diarrheal severity, acute malnutrition, and Cryptosporidium subtypes correlated with temporal shedding patterns. From 53 confirmed cryptosporidiosis cases, a median of 4 (range 1 to 5) follow-up stool samples were collected and tested for Cryptosporidium. The median duration of oocyst shedding was 31 days (95% confidence interval [CI], 26 to 36 days) after onset of diarrhea, with similar estimates from the quantitative models (31 days, 95% CI 27 to 37 days). Genotype shift occurred in 5 cases (9%). A 10-fold drop in quantity occurred per week for the first 4 weeks. Prolonged oocyst shedding is common in a pediatric clinical population with cryptosporidiosis. We suggest that future intervention trials should evaluate both clinical efficacy and total parasite shedding duration as trial endpoints. IMPORTANCE Cryptosporidiosis is an important cause of diarrhea, malnutrition, and deaths in young children in low-income countries. The infection spreads from person to person. After infection, prolonged release of the Cryptosporidium parasite in stool (shedding) may contribute to further spread of the disease. If diagnosis and treatment are made available, diarrhea will be treated and deaths will be reduced. An added benefit may be to reduce transmission to others. However, shedding duration and its characteristics in children is not well known. We therefore investigated the duration of shedding in a group of young children who sought health care for diarrhea in a hospital and health center in Ethiopia. The study followed 53 children with cryptosporidiosis for 2 months. We found that, on average, children released the parasite for 31 days after the diarrhea episode started. Point-of-care treatment of cryptosporidiosis may therefore reduce onward spread of the Cryptosporidium parasite within communities and households.

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

Background

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

Methods

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

Results

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

Conclusions

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

Graphical Abstract

Supplementary Information

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

Molecular characterization of Cryptosporidium spp. obtained from fecal samples of immunosuppressed patients from Brazil

Background:

Cryptosporidium spp. are pathogenic protozoans that play an important role in developing diseases in the elderly, children, and immunosuppressed individuals.

Methods:

The objective of this study was to detect and genetically characterize Cryptosporidium spp. in kidney transplanted patients (n = 97 samples; group 1) and immunosuppressed individuals from an outpatient clinic suspected of having Cryptosporidium infection (n = 53 samples; group 2). All fecal samples were analyzed by parasitological stool examination, immunochromatographic test, and real-time polymerase chain reaction (real-time PCR). Cryptosporidium-positive samples were tested using nested PCR for the gp60 gene, followed by sequencing for subtype determination.

Results:

Parasitological examination was negative in all Group 1, and positive in four Group 2 samples. Real-time PCR revealed Cryptosporidium in 13 samples: four in Group 1 (three C. hominis and one C. parvum) and nine in Group 2 (seven C. hominis, one C. parvum, and one mixed C. hominis/C. parvum). The immunochromatographic test was reactive in 11 samples (four in Group 1 and seven in Group 2). All 11 C. hominis isolates were identified as subtype IbA10G2 and one C. parvum as subtype IIbA15G2R1. All C. hominis belonged to subtype IbA10G2, which is recognized as the most prevalent and pathogenic subtype.

Conclusions:

This study showed, for the first time, that the presence of Cryptosporidium subtypes is considered more virulent in Brazilian transplanted kidney patients.

Global population genomics of two subspecies of Cryptosporidium hominis during 500 years of evolution

Cryptosporidiosis is a major global health problem and a primary cause of diarrhea, particularly in young children in low- and middle-income countries (LMICs). The zoonotic Cryptosporidium parvum and anthroponotic Cryptosporidium hominis cause most human infections. Here, we present a comprehensive whole-genome study of C. hominis, comprising 114 isolates from 16 countries within five continents. We detect two lineages with distinct biology and demography, which diverged circa 500 years ago. We consider these lineages two subspecies and propose the names C. hominis hominis and C. hominis aquapotentis (gp60 subtype IbA10G2). In our study, C. h. hominis is almost exclusively represented by isolates from LMICs in Africa and Asia and appears to have undergone recent population contraction. In contrast, C. h. aquapotentis was found in high-income countries, mainly in Europe, North America, and Oceania, and appears to be expanding. Notably, C. h. aquapotentis is associated with high rates of direct human-to-human transmission, which may explain its success in countries with well-developed environmental sanitation infrastructure. Intriguingly, we detected genomic regions of introgression following secondary contact between the subspecies. This resulted in high diversity and divergence in genomic islands of putative virulence genes, including muc5 (CHUDEA2_430) and a hypothetical protein (CHUDEA6_5270). This diversity is maintained by balancing selection, suggesting a co-evolutionary arms race with the host. Finally, we find that recent gene flow from C. h. aquapotentis to C. h. hominis, likely associated with increased human migration, maybe driving the evolution of more virulent C. hominis variants.

Age and episode-associated occurrence of Cryptosporidium species and subtypes in a birth-cohort of dairy calves

The role of species-specific immunity in infection patterns of Cryptosporidium spp. in humans and farm animals is not well understood. In the present study, the dynamics of Cryptosporidium infections in a natural cryptosporidiosis model was examined using genotyping, subtyping and whole genome sequencing tools. In a cross-sectional survey of Cryptosporidium spp. in 934 dairy cattle on one farm, marked age-associated differences in the distribution of Cryptosporidium species and C. bovis subtypes were observed. In a closely followed longitudinal birth cohort study of 81 calves over a 9-month period, shedding of C. parvum oocysts started at 4 days, peaked at 2 weeks, and ended mostly by 4 weeks. In contrast, the shedding of C. bovis oocysts started at 2 weeks, peaked initially at 6 weeks, and had a second wave during 15^th to 23^rd weeks. For C. ryanae, calves had mostly only one episode of infection, with accumulative infection increasing much slower than C. parvum and C. bovis. Overall, the accumulative infection rates and mean duration of oocyst shedding for calves in the cohort were 97.4% (76/78) and 2.3 weeks, 100.0% (80/80) and 3.9 weeks, and 78.7% (63/80) and 3.2 weeks for C. parvum, C. bovis, and C. ryanae, respectively. The oocyst shedding intensity was much lower in C. bovis and C. ryanae infections compared with C. parvum infection, and in the second episode of C. bovis infection compared with the first episode. The two episodes of C. bovis infections were caused by different genome types that differed mostly in nine genes. Cryptosporidium parvum infection was associated with the occurrence of watery diarrhea. Data from the natural history study of cryptosporidiosis indicate that despite the existence of acquired immunity against homologous pathogens, neonatal animals experience waves of Cryptosporidium infections by different species and genome types. This article is protected by copyright. All rights reserved.

Advances in therapeutic and vaccine targets for Cryptosporidium: Challenges and possible mitigation strategies

Cryptosporidium is known to be the second most common diarrheal pathogen in children, causing potentially fatal diarrhea and associated with long-term growth stunting and cognitive deficits. The only Food and Drug Administration-approved treatment for cryptosporidiosis is nitazoxanide, but this drug has not shown potentially effective results in susceptible hosts. Therefore, a safe and effective drug for cryptosporidiosis is urgently needed. Cryptosporidium genome sequencing analysis may help develop an effective drug, but both in vitro and in vivo approaches to drug evaluation are not fully standardized. On the other hand, the development of partial immunity after exposure suggests the possibility of a successful and effective vaccine, but protective surrogates are not precise. In this review, we present our current perspectives on novel cryptosporidiosis therapies, vaccine targets and efficacies, as well as potential mitigation plans, recommendations and perceived challenges.

Disseminated Cryptosporidiosis in an Infant with Non-HIV Pediatric Immunodeficiency: First Case Report from Oman

Cryptosporidium is a rare but important pathogen, especially in children with immunodeficiency. Intestinal cryptosporidiosis is well described in immunocompetent and immunocompromised children, but respiratory and disseminated cryptosporidiosis in immunodeficient children is not often reported. We describe an Omani infant with disseminated cryptosporidiosis and failing pharmacological therapy in the context of severe combined immunodeficiency. Chronic diarrhea can be an initial symptom of immunodeficiency in the pediatric population. Awareness of cryptosporidiosis is critical to early detection and management for such patients. As antiparasitic agents are often ineffective, amelioration of immunosuppression in immunodeficient children should be a priority.

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

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

Cryptosporidiosis outbreak in Amazonia, French Guiana, 2018

BACKGROUND

Cryptosporidiosis outbreaks in South America are poorly documented. In March 2018, 51 cases of cryptosporidiosis were reported in Maripasoula, a village located in a remote forest area along the border between Surinam and French Guiana.

METHOD

To identify the origin of the epidemic, we performed epidemiological, microbiological, and environmental investigations. Only the cases involving diarrhoea and Cryptosporidium-positive stool were considered as bona fide, while cases involving diarrhoea and close contact with a confirmed case were classified as "possible".

RESULTS

We identified 16 confirmed cases and 35 possible ones. Confirmed cases comprised nine children (median age of 18 months, range: 6-21), one immunocompromised adult and six soldiers. One child required a hospitalisation for rehydration. All 16 Cryptosporidium stools were PCR positive, and sequencing of the gp60 gene confirmed only one Cryptosporidium hominis subtype IbA10G2. Tap water consumption was the only common risk factor identified. Contamination of the water network with Cryptosporidium parvum subtype IIdA19G2 was found.

CONCLUSION

Water quality is a major public health issue in Amazonian French Guiana, especially for population at risk (children, people with comorbidity, travelers). For them, alternative water supply or treatment should be implemented.

Commensal Cryptosporidium colonization elicits a cDC1-dependent Th1 response that promotes intestinal homeostasis and limits other infections

Cryptosporidium can cause severe diarrhea and morbidity, but many infections are asymptomatic. Here, we studied the immune response to a commensal strain of Cryptosporidium tyzzeri (Ct-STL) serendipitously discovered when conventional type 1 dendritic cell (cDC1)-deficient mice developed cryptosporidiosis. Ct-STL was vertically transmitted without negative health effects in wild-type mice. Yet, Ct-STL provoked profound changes in the intestinal immune system, including induction of an IFN-γ-producing Th1 response. TCR sequencing coupled with in vitro and in vivo analysis of common Th1 TCRs revealed that Ct-STL elicited a dominant antigen-specific Th1 response. In contrast, deficiency in cDC1s skewed the Ct-STL CD4 T cell response toward Th17 and regulatory T cells. Although Ct-STL predominantly colonized the small intestine, colon Th1 responses were enhanced and associated with protection against Citrobacter rodentium infection and exacerbation of dextran sodium sulfate and anti-IL10R-triggered colitis. Thus, Ct-STL represents a commensal pathobiont that elicits Th1-mediated intestinal homeostasis that may reflect asymptomatic human Cryptosporidium infection.

TIDE analysis of Cryptosporidium infections by gp60 typing reveals obscured mixed infections

BACKGROUND

Cryptosporidiosis is a parasitic disease associated with potentially fatal diarrhea. The most used method in Cryptosporidium subtyping is based on the glycoprotein gene gp60. Each infection can represent a parasite population, and it is important to investigate the influence on transmission and virulence, as well as any impact on public health investigations. However, an easy-to-use method for detection is lacking.

METHODS

Here we report on the use of the bioinformatic program TIDE for deconvolution of gp60 chromatograms. A combination of single oocyst analysis and cloning successfully confirmed the within-sample parasite population diversity. Retrospective sample analysis was conducted on archived chromatograms.

RESULTS

For C. parvum, 8.6% multi-strain infections (13 out of 152) obscured by currently used consensus base calling were detected. Importantly, we show that single oocysts can harbor a mixed population of sporozoites. We also identified a striking dominance of unappreciated polymerase stutter artefacts in all 218 chromatograms analyzed, challenging the uncritical use of gp60 typing.

DISCUSSION

We demonstrate the value of a new easy-to-use analytical procedure for critical characterization of C. parvum and C. hominis in epidemiological investigations, also applicable in retrospect. Our findings illuminate the hidden parasite diversity with important implications for tracing zoonotic and person-to-person transmissions.

Nonsterile immunity to cryptosporidiosis in infants is associated with mucosal IgA against the sporozoite and protection from malnutrition

We conducted a longitudinal study of cryptosporidiosis from birth to three years of age in an urban slum of Dhaka Bangladesh. Fecal DNA was extracted from monthly surveillance samples and diarrheal stool samples collected from 392 infants from birth to three years. A pan-Cryptosporidium qPCR assay was used to identify sub-clinical and symptomatic cryptosporidiosis. Anthropometric measurements were collected quarterly to assess child nutritional status. 31% (121/392) of children experienced a single and 57% (222/392) multiple infections with Cryptosporidium. Repeat infections had a lower burden of parasites in the stool (Cq slope = -1.85; p<0.0001) and were more likely to be sub-clinical (Chi square test for trend; p = 0.01). Repeat infections were associated with the development of growth faltering (Pearson correlation = -0.18; p = 0.0004). High levels of fecal IgA antibodies against the Cryptosporidium Cp23 sporozoite protein at one year of life were associated with a delay in reinfection and amelioration of growth faltering through three years of life (HAZ IgA high responders -1.323 ± 0.932 versus HAZ -1.731 ± 0.984 p = 0.0001). We concluded that nonsterile immunity to cryptosporidiosis in young children was associated with high levels of mucosal IgA anti-Cp23 and protection from diarrhea and growth faltering. Trial Registration: NCT02764918.

A novel genotyping method for Cryptosporidium hominis

Cryptosporidiosis remains the leading protozoan induced cause of diarrhoea-associated mortality worldwide. Cryptosporidium hominis, the anthroponotically transmitted species within the Cryptosporidium genus, contributes significantly to the global burden of infection, accounting for the majority of clinical cases in many countries. This study applied high resolution melting analysis, a post-real-time PCR application, to the differentiation of six globally prevalent C. hominisgp60-subtypes. This novel method targeted three microsatellite, tandem repeat containing genetic markers, gp60, the genetic marker upon which current Cryptosporidium subtype nomenclature is based, MSB, and MSE, by which to differentiate between C. hominis isolates. This multi-locus approach successfully differentiated between all six C. hominisgp60-subtypes studied, some of which, such as IbA10G2, are known to exhibit global ubiquity. Thus, this method has the potential to be universally employed as a sensitive, cost effective and highly reproducible means to rapidly differentiate between C. hominisgp60-subtypes. Such a method would be of particular utility in epidemiological studies and outbreak scenarios, providing cost effective, clinically accessible alternative to DNA sequencing. The success of this preliminary study also supports further analysis of an expanded C. hominisgp60-subtype range and the potential expansion of the multi-locus panel in order to improve the discriminatory power of this approach.

Evolving Patterns of Cryptosporidiosis: Issues and Implications in the Context of Public Health in India

Cryptosporidiosis is one of the major causes of diarrhea in immune-compromised individuals and children besides causing sporadic water-borne, food-borne, and zoonotic outbreaks. In 2016, Cryptosporidium species infection was the fifth leading cause of diarrhea and acute infection causing more than 4.2 million disability-adjusted life years lost besides a decrease in childhood growth. Human cryptosporidiosis is primarily caused by two species/genotype: Cryptosporidium hominis (anthroponotic) and Cryptosporidium parvum (zoonotic) besides other six rare species/genotypes. Transmission intensity, genetic diversity, and occurrence of genetic recombination have shaped the genus Cryptosporidium population structures into palmitic, clonal, and epidemic. Genetic recombination is more in C. parvum compared with C. hominis. Furthermore, parasite–host co-evolution, host adaptation, and geographic segregation have led to the formation of “subtype- families.” Host-adapted subtype-families have distinct geographical distribution and host preferences. Genetic exchanges between subtypes played an important role throughout the evolution of the genus leading to “adaptation introgression” that led to emergence of virulent and hyper-transmissible subtypes. The population structure of C. hominis in India appears to be more complex where both transmission intensity and genetic diversity are much higher. Further, study based on “molecular strain surveillance” has resulted newer insights into the epidemiology and transmission of cryptosporidiosis in India. The identification at the species and genotype levels is essential for the assessment of infection sources in humans and the public health potential of the parasite at large. The results of the study over three decades on cryptosporidiosis in India, in the absence of a national surveillance data, were analyzed highlighting current situation on epidemiology, genetic diversity, and distribution particularly among vulnerable population. Despite creditable efforts, there are still many areas need to be explored; therefore, the intent of this article is to facilitate future research approaches for mitigating the burden associated with this disease.

Cryptosporidiosis - A Plausible Cause for Relapse of Guillain-Barré Syndrome

A 25-year-old female presented on the acute medical take with rapidly evolving ascending weakness, sensory loss, and areflexia after a prodromal diarrhoeal illness, ultimately critical care admission, tracheostomy, and intravenous immunoglobulin (IVIG) therapy. The patient had been diagnosed with Guillain-Barré Syndrome (GBS) six years previously, treated with intravenous Immunoglobulin, and discharged after a five-day in-patient stay without mechanical ventilation. On this occasion, a diagnosis of recurrent GBS was made, supported by cytoalbuminological dissociation in the cerebrospinal fluid (CSF). Investigations for infective precipitants were negative aside from a stool culture, positive for Cryptosporidium spp. DNA (deoxyribonucleic acid) two weeks earlier. There are no previously reported cases of GBS due to cryptosporidiosis on PubMed. The patient was treated with a course of IVIG and discharged from critical care after 66 days, requiring ongoing neurorehabilitation, which is likely to be prolonged.

Analysis of Cryptosporidium spp. from clinical samples by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry

AIM

To purify Cryptosporidium spp. oocysts from clinical stool samples and evaluate using an up-to-date mass spectrometry protocol producing high-quality reference spectra.

METHODS AND RESULTS

A refined purification protocol was developed for oocysts from stools, involving salt flotation and potassium bromide density centrifugation. Purified oocysts were prepared for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) by formic acid extraction, and the extracts analysed using the Bruker MALDI Biotyper system. Individual spectral markers were identified by their specific mass peaks. Cryptosporidium parvum oocysts (Iowa strain) propagated in vivo, and C.  parvum (n = 2) and Cryptosporidium hominis (n = 1) oocysts from clinical stool samples produced distinct spectra that were considered specific to Cryptosporidium spp. with no evidence of contamination.

CONCLUSIONS

The production of distinct spectra demonstrated the utility of the purification method for oocysts from clinical stool samples and provided reference spectra.

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of MALDI-TOF MS and other mass spectrometry techniques has been limited previously to C.  parvum oocysts propagated in vivo. Appropriate purification of oocysts can achieve sufficient biomass, enabling analysis by MALDI-TOF MS and potentially other mass spectrometry platforms, facilitating peptide and protein discovery and identification of biomarkers from a much wider range of Cryptosporidium spp. from natural infections.

First Molecular Characterization of Cryptosporidium spp. in Patients Living with HIV in Honduras

Cryptosporidiosis is one of the most important causes of gastroenteritis in the world, especially in low- and middle-income countries. It is caused by the Apicomplexan parasite Cryptosporidium spp., and mainly affects children and immunocompromised people, in whom it can pose a serious threat to their health, or even be life threatening. In Honduras, there are no data on parasite species or on molecular diversity or Cryptosporidium subtypes. Therefore, a cross-sectional study was conducted between September 2019 and March 2020 for the molecular identification of Cryptosporidium spp. in 102 patients living with HIV who attended a national hospital in Tegucigalpa. Stool samples were analyzed by direct microscopy, acid-fast stained smears, and a rapid lateral flow immunochromatographic test. All samples that tested positive were molecularly analyzed to identify the species and subtype of the parasite using three different markers: gp60, cowp, and 18Sr. PCR products were also sequenced. Four out of 102 samples (3.92%) were positive for Cryptosporidiumparvum, and all were assigned to subtype IIa. These findings suggest a possible zoonotic transmission in this population.

Megasphaera in the stool microbiota is negatively associated with diarrheal cryptosporidiosis

BACKGROUND

The protozoan parasites in the Cryptosporidium genus cause both acute diarrheal disease and subclinical (i.e. non-diarrheal) disease. It is unclear if the microbiota can influence the manifestation of diarrhea during a Cryptosporidium infection.

METHODS

To characterize the role of the gut microbiota in diarrheal cryptosporidiosis, the microbiome composition of both diarrheal and surveillance Cryptosporidium-positive fecal samples from 72 infants was evaluated using 16S rRNA gene sequencing. Additionally, the microbiome composition prior to infection was examined to test whether a preexisting microbiome profile could influence the Cryptosporidium infection phenotype.

RESULTS

Fecal microbiome composition was associated with diarrheal symptoms at two timepoints. Megasphaera was significantly less abundant in diarrheal samples when compared to subclinical samples at the time of Cryptosporidium detection (log2(fold change) = -4.3, p=10 -10) and prior to infection (log2(fold change) = -2.0, p=10 -4); this assigned sequence variant was detected in 8 children who had diarrhea and 30 children without diarrhea. Random forest classification also identified Megasphaera abundance in the pre- and post-exposure microbiota as predictive of a subclinical infection.

CONCLUSIONS

Microbiome composition broadly, and specifically low Megasphaera abundance, was associated with diarrheal symptoms prior to and at the time of Cryptosporidium detection. This observation suggests that the gut microenvironment may play a role in determining the severity of a Cryptosporidium infection.

Molecular Epidemiology of Human Cryptosporidiosis in Low- and Middle-Income Countries

Cryptosporidiosis is one of the most important causes of moderate to severe diarrhea and diarrhea-related mortality in children under 2 years of age in low- and middle-income countries. In recent decades, genotyping and subtyping tools have been used in epidemiological studies of human cryptosporidiosis. Results of these studies suggest that higher genetic diversity of Cryptosporidium spp. is present in humans in these countries at both species and subtype levels and that anthroponotic transmission plays a major role in human cryptosporidiosis. Cryptosporidium hominis is the most common Cryptosporidium species in humans in almost all the low- and middle-income countries examined, with five subtype families (namely, Ia, Ib, Id, Ie, and If) being commonly found in most regions. In addition, most Cryptosporidium parvum infections in these areas are caused by the anthroponotic IIc subtype family rather than the zoonotic IIa subtype family. There is geographic segregation in Cryptosporidium hominis subtypes, as revealed by multilocus subtyping. Concurrent and sequential infections with different Cryptosporidium species and subtypes are common, as immunity against reinfection and cross protection against different Cryptosporidium species are partial. Differences in clinical presentations have been observed among Cryptosporidium species and C. hominis subtypes. These observations suggest that WASH (water, sanitation, and hygiene)-based interventions should be implemented to prevent and control human cryptosporidiosis in low- and middle-income countries.

Development of a Subtyping Tool for Zoonotic Pathogen Cryptosporidium canis

Cryptosporidium canis is an important cause of cryptosporidiosis in canines and humans. Studies of the transmission characteristics of C. canis are currently hampered by the lack of suitable subtyping tools. In this study, we conducted a genomic survey of the pathogen and developed a subtyping tool targeting the partial 60-kDa glycoprotein gene (gp60). Seventy-six isolates previously identified as C. canis were analyzed using the new subtyping tool. Amplicons of the expected size were obtained from 49 isolates, and phylogenetic analysis identified 10 subtypes clustered into five distinct groups (XXa to XXe). The largest group, XXa, contained 43 isolates from four subtypes that differed slightly from each other at the nucleotide level, while groups XXb to XXe contain one to three isolates each. The similar distributions of subtypes in humans and canines suggest that zoonotic transmission might play an important role in the epidemiology of C. canis In addition, suspected zoonotic transmission of C. canis between dogs and humans in a household was confirmed using the subtyping tool. The subtyping tool and data generated in this study might improve our understanding of the transmission of this zoonotic pathogen.

Performance of formalin ethyl acetate, percoll sedimentation and ELISA for the detection of Cryptosporidium infection in asymptomatic children

This study aimed to assess the performance of formalin ethyl acetate (FEA)/modified Ziehl-Neelsen (MZN), and percoll technique/MZN for the diagnosis of cryptosporidiosis among asymptomatic children compared to ELISA coproantigen. The study was conducted on 100 children in a rural area in Kafr El-Sheikh governorate. Stool samples were collected and examined by the three techniques. Microscopic examination revealed the presence of acid-fast stained oocysts and non-acid fast ghost oocysts. The overall prevalence rate was 7% with an infection intensity of 1-5 oocysts/oil immersion field. FEA/MZN technique showed the highest diagnostic performance (5%) with 71.4% sensitivity and 98% negative predictive value (NPV) compared to the other techniques. ELISA revealed 3% prevalence, 42.9% sensitivity and 96% NPV. Percoll/MZN gave the lowest prevalence, sensitivity and NPV (1%, 14.29% and 93.9% respectively). Agreement fluctuated between moderate and poor regarding FEA/MZN versus ELISA and percoll/MZN versus both techniques. In conclusion, FEA/MZN gave the top diagnostic performance, yet it missed some positive cases. Its combination with ELISA coproantigen might prove beneficial for Cryptosporidium diagnosis. Percoll technique needs more validation by modifying the density gradient, speed of centrifugation, and staining methods.

Subtype Characterization and Zoonotic Potential of Cryptosporidium felis in Cats in Guangdong and Shanghai, China

Cryptosporidiumfelis is an important cause of feline and human cryptosporidiosis. However, the transmission of this pathogen between humans and cats remains controversial, partially due to a lack of genetic characterization of isolates from cats. The present study was conducted to examine the genetic diversity of C. felis in cats in China and to assess their potential zoonotic transmission. A newly developed subtyping tool based on a sequence analysis of the 60-kDa glycoprotein (gp60) gene was employed to identify the subtypes of 30 cat-derived C. felis isolates from Guangdong and Shanghai. Altogether, 20 C. felis isolates were successfully subtyped. The results of the sequence alignment showed a high genetic diversity, with 13 novel subtypes and 2 known subtypes of the XIXa subtype family being identified. The known subtypes were previously detected in humans, while some of the subtypes formed well-supported subclusters with human-derived subtypes from other countries in a phylogenetic analysis of the gp60 sequences. The results of this study confirmed the high genetic diversity of the XIXa subtype family of C. felis. The common occurrence of this subtype family in both humans and cats suggests that there could be cross-species transmission of C. felis.

Comparative genomic analysis of the principal Cryptosporidium species that infect humans

Cryptosporidium parasites are ubiquitous and can infect a broad range of vertebrates and are considered the most frequent protozoa associated with waterborne parasitic outbreaks. The intestine is the target of three of the species most frequently found in humans: C. hominis, C. parvum, and. C. meleagridis. Despite the recent advance in genome sequencing projects for this apicomplexan, a broad genomic comparison including the three species most prevalent in humans have not been published so far. In this work, we downloaded raw NGS data, assembled it under normalized conditions, and compared 23 publicly available genomes of C. hominis, C. parvum, and C. meleagridis. Although few genomes showed highly fragmented assemblies, most of them had less than 500 scaffolds and mean coverage that ranged between 35X and 511X. Synonymous single nucleotide variants were the most common in C. hominis and C. meleagridis, while in C. parvum, they accounted for around 50% of the SNV observed. Furthermore, deleterious nucleotide substitutions common to all three species were more common in genes associated with DNA repair, recombination, and chromosome-associated proteins. Indel events were observed in the 23 studied isolates that spanned up to 500 bases. The highest number of deletions was observed in C. meleagridis, followed by C. hominis, with more than 60 species-specific deletions found in some isolates of these two species. Although several genes with indel events have been partially annotated, most of them remain to encode uncharacterized proteins.

Identification of Uncommon Cryptosporidium viatorum (a Novel Subtype XVcA2G1c) and Cryptosporidium andersoni as Well as Common Giardia duodenalis Assemblages A and B in Humans in Myanmar

Cryptosporidium and Giardia are two important zoonotic intestinal protozoa responsible for diarrheal diseases in humans and animals worldwide. Feces from infected hosts, water and food contaminated by Cryptosporidium oocysts and Giardia cysts as well as predictors such as poverty have been involved in their transmission. Myanmar is one of the world’s most impoverished countries. To date, there are few epidemiological studies of Cryptosporidium and Giardia in humans. To understand the prevalence and genetic characterization of Cryptosporidium spp. and Giardia duodenalis in humans in Myanmar, a molecular epidemiological investigation of the two protozoa was conducted in four villages of Shan State. 172 fecal specimens were collected from Wa people (one each) and identified for the presence of Cryptosporidium spp. and G. duodenalis by sequence analysis of their respective small subunit ribosomal RNA genes. 1.74% of investigated people were infected with Cryptosporidium spp.—C. andersoni (n = 2) and C. viatorum (n = 1) while 11.05% infected with G. duodenalis—assemblages A (n = 6) and B (n = 13). By sequence analysis of 60-kDa glycoprotein gene, the C. viatorum isolate belonged to a novel subtype XVcA2G1c. DNA preparations positive for G. duodenalis were further subtyped. Five of them were amplified and sequenced successfully: different assemblage B sequences (n = 2) at the triosephosphate isomerase (tpi) locus; sub-assemblage AII sequence (n = 1) and identical assemblage B sequences (n = 2) at the β-giardin (bg) locus. This is the first molecular epidemiological study of Cryptosporidium spp. and G. duodenalis in humans in Myanmar at both genotype and subtype levels. Due to unclear transmission patterns and dynamics of Cryptosporidium spp. and G. duodenalis, future research effort should focus on molecular epidemiological investigations of the two parasites in humans and animals living in close contact in the investigated areas, even in whole Myanmar. These data will aid in making efficient control strategies to intervene with and prevent occurrence of both diseases.

Development of a Quantitative Real-Time PCR Assay for Detection of Cryptosporidium spp. Infection and Threatening Caused by Cryptosporidium parvum Subtype IIdA19G1 in Diarrhea Calves from Northeastern China

Parasitic diarrheal disease is a major cause of morbidity and mortality in the developing world. Calves are highly susceptible to Cryptosporidium spp. infection that resulted in diarrhea, growth retardation, and weight loss, and was one of the most common enteropathogens. It is especially difficult for molecular detection of calves with inapparent or subclinical infections of cryptosporidiosis. In view of this, this study established a real-time quantitative PCR (RT-qPCR) detection method to clarify its epidemic characteristics, based on Cryptosporidium 18S rRNA gene with the 150 bp product length to investigate the infection of Cryptosporidium spp. in northeastern China The standard curve equation is Ct = -2.91 × lg (Cryptosporidium spp. copies) +10.18, with better sensitivity, stability, and reproducibility. A total of 148 out of 425 fecal samples (34.82%) were detected Cryptosporidium positive with RT-qPCR, including (36.11%) in Heilongjiang province (29.60%), (29.6%) in Jilin province, and (37.50%) in Liaoning province. The infection prevalence of Cryptosporidium parvum, Cryptosporidium ryanae, Cryptosporidium andersoni, and Cryptosporidium bovis from calves in order from high to low was 14.35% (95% confidence interval [CI], 11.2-18.1), 6.12 (95% CI, 4.0-8.8), 2.35 (95% CI, 1.1-4.3), and 0.47 (95% CI, 0.1-1.7), respectively, suggesting C. parvum was the predominant species in calves in northeastern China. Using 60-kDa glycoprotein gp60 gene, all of the 61 C. parvum-positive specimens were further precisely confirmed to IIdA19G1 subtype. This suggested that IIdA19G1 subtype of C. parvum could threaten to cause diarrhea calves from notheastern China (p < 0.01). The prevalence of 34.82% (148/425) using RT-qPCR had a significant difference compared with the prevalence of nested-PCR (23.29%) and microscopic examination (3.76%). The findings improved the epidemiological knowledge of calves infected with cryptosporidiosis in China, highlighting the importance of ongoing Cryptosporidium surveillance.

Diversity of Cryptosporidium spp. in wild rodents from the Canary Islands, Spain

BACKGROUND

Cryptosporidium spp. are worldwide protozoan parasites which include species that can lead to cryptosporidiosis in humans. Different animal species can serve as reservoirs and sources of dissemination of the disease, such as rodent species due their potential in transmitting zoonotic pathogens to humans and other animals. In the Canary Islands (Spain), Cryptosporidium parvum and Cryptosporidium hominis have been identified in patients with diarrhea. However, the occurrence of Cryptosporidium spp. in possible reservoirs in this archipelago remains unclear. Considering the zoonotic potential of these protozoans, the aim of the present study was to determine the presence of Cryptosporidium spp. in peridomestic wild rodents and the possible role of these mammals as a source of transmission of these protozoans in Canary Islands.

METHODS

A total of 179 rodents belonging to Rattus rattus and Mus musculus domesticus from four Canary Islands, La Palma, El Hierro, Tenerife and Lanzarote, were analyzed. Feces were screened for Cryptosporidium spp. by nested PCR of the 18S ribosomal RNA fragment and the sequences used for phylogenetic analyses.

RESULTS

Cryptosporidium spp. were found widely distributed with an overall prevalence of 12.30% in rodents (13.86% for R. rattus and 10.25% for M. m. domesticus). The overall prevalence by island was 19.60% for Tenerife, 7.14% for La Palma, 5.71% for El Hierro and 0% for Lanzarote. Cryptosporidium tyzzeri, Cryptosporidium meleagridis, Cryptosporidium muris and Cryptosporidium sp. rat genotype I and II/III were successfully identified, in addition to two unidentified Cryptosporidium genotypes.

CONCLUSIONS

This study contributes to the knowledge of the biodiversity and distribution of Cryptosporidium spp. in wild rodents from the Canary Islands, highlighting the presence of three zoonotic species, C. tyzzeri, C. meleagridis and C. muris, being the first detection of these three species in wild rodents in the Canary Islands and the first report of C. meleagridis in R. rattus. Given the results obtained in our study, future studies in non-sampled areas are required to better understand the epidemiology of these protozoans in wild rodents in the archipelago.

Increased diversity and novel subtypes among clinical Cryptosporidium parvum and Cryptosporidium hominis isolates in Southern Ireland

Reported incidence rates of cryptosporidiosis in Ireland are consistently among the highest in Europe. Despite the national prevalence of this enteric parasite and the compulsory nature of incidence surveillance and reporting, in-depth analyses seeking to genotype clinical isolates of Cryptosporidium on an intra-species level are rarely undertaken in Ireland. This molecular epidemiology study of 163 clinical Cryptosporidium isolates was conducted in Southern Ireland, from 2015 to 2018, in order to ascertain population subtype heterogeneity. Analysis was conducted via real-time PCR amplification and gp60 gene sequencing, which successfully determined the subtype designation of 149 of the 163 (91.4%) tested isolates. Overall, 12 C. parvum and five C. hominis subtypes were identified, with the incidence of the regionally predominant C. parvum species found to primarily occur during springtime months, while C. hominis incidence was largely confined to late summer and autumnal months. Additionally, one C. parvum and four C. hominis subtypes were newly reported by this study, having not been previously identified in clinical or livestock infection in Ireland. Overall, these data give insight into the diversification of the Cryptosporidium population and emergent subtypes, while also allowing comparisons to be made with clinical epidemiological profiles reported previously in Ireland and elsewhere.

Prevalence and Molecular Genotyping of Cryptosporidium Spp. in Diarrheic Patients from Bandar Abbas City, Southern Iran

Background: Cryptosporidium species are recognized as one of the most important gastrointestinal pathogens of humans and livestock. Objectives: This study aimed to determine the prevalence and sub-genotypes of Cryptosporidium spp. among diarrheic patients in Bandar Abbas City, Iran. Methods: Diarrheic fecal samples were collected from 170 patients in three hospitals of Bandar Abbas, Iran, from October 2018 to May 2019. Initial parasitological identification of Cryptosporidium spp. was performed by modified Ziehl-Neelsen (ZN) staining. For molecular analysis, the positive specimens and the suspected ones of Cryptosporidium spp. were evaluated by sequence analysis of the 60-kDa glycoprotein gene (gp60). The collected data were analyzed using SPSS software and the relationship between the variables and the presence of Cryptosporidium spp. assessed by the chi-square test. To assess the degree of agreement between PCR and ZN staining, Cohen’s kappa-index was applied. Results: Of the 170 diarrheic patients, 98 (57.6%) were male, and 72 (42.4%) were female. Prevalence of Cryptosporidium spp. by parasitological examination was 1.8% (3/170). However, using PCR, Cryptosporidium spp. was detected in 12% (6/50) of the positive microscopically samples (3 samples) and 47 suspected specimens. Sequence analysis of the gp60 gene showed that all of the positive isolates were Cryptosporidium parvum in which all subtypes belonged to allele family IId. Two distinct nucleotide sequences obtained from this study were deposited in GenBank under the accession numbers MN820453 and MN820454. Conclusions: The predominance of C. parvum (subtype family IId) in this study emphasizes the importance of zoonotic Cryptosporidium transmission in Bandar Abbas, Southern Iran.

In-silico analysis of Calcium Dependent Protein Kinase 6 of Cryptosporidium parvum through molecular modeling, docking, and dynamics simulation study

Calcium Dependent Protein Kinases are found in the Apicomplexan, algae, and plants; however, they are not reported in vertebrates and are regarded as excellent drug targets for pharmaceutical interventions. Calcium Dependent Protein Kinases of Cryptosporidium are probably involved in the regulation of invasion and egress process during the infection of the host cells. The previous study reported that after the Calcium Dependent Protein Kinase 1 gene, Calcium Dependent Protein Kinase 6 of Cryptosporidium parvum is expressed in all stages of the parasite (merozoites/schizonts as well as sexual stages) at a comparable level and makes it as a valid drug target. In this study, an attempt is made to address the similarity in sequences and phylogenetic study of Calcium Dependent Protein Kinase 6 (CDPK6) among Calcium Dependent Protein Kinases of Apicomplexans. Further, the three-dimensional structure determination of CDPK6 of C. parvum was performed through a molecular modeling approach followed by virtual screening of small-molecule inhibitors from different datasets. The best inhibitor from Tres Cantos Antimalarial Set with ID 11730 reported a binding affinity of -8.2 kcal/mol against CDPK6 of C. parvum. Furthermore, the reliability of the binding mode of the inhibitor is validated through a complex molecular dynamics simulation study for a time interval of 100 ns. The simulation study advocates that the inhibitor Tres Cantos Antimalarial Set_11730 formed a stable interaction with the predicted active site residues and can be considered for industrial pharmaceutical research in future.Communicated by Ramaswamy H. Sarma.

Common occurrence of Cryptosporidium hominis in children attending day-care centers in Medellin, Colombia

Cryptosporidium spp. are apicomplexan protozoa associated with chronic diarrhea in AIDS and other immunocompromised patients, and one of the commonest causes of childhood diarrhea and malnutrition, particularly in low-income settings. In Colombia, there are few molecular epidemiological studies on Cryptosporidium spp.; thereby, the transmission dynamics of this parasite in the country is poorly known. This study evaluated the diversity of Cryptosporidium at species, subtype family, and subtype level in children attending various day-care centers in Medellin, Colombia. Two hundred and ninety stool samples from children < 5 years of age were collected from April to November of 2015. All samples were processed by PCR and sequence analysis of the ssu RNA gene and the gp60 gene. An infection rate of 2.4% was observed, with only two Cryptosporidium species identified: C. hominis (6/7) and C. meleagridis (1/7). Cryptosporidium hominis isolates belonged to the subtypes IbA10G2, IaA13R6 and IaA13R7; IIIbA26G1R1 C. meleagridis subtype was also detected. There is a C. hominis predominance in the children evaluated, suggesting an important role of the anthroponotic transmission cycle in the day-care centers analyzed. Further investigation is required to determine infection sources and susceptible hosts in order to define appropriate management of cryptosporidiosis.

First report of Cryptosporidium spp. infection and risk factors in black-boned goats and black-boned sheep in China

Cryptosporidium is an opportunistic protozoan parasite that can inhabit in the gastrointestinal tract of various hosts. Cryptosporidium infection in black-boned goats and black-boned sheep may pose a threat to the survival and productivity, causing considerable economic losses to the livestock industry. However, it is yet to know whether black-boned goats and black-boned sheep in China are infected with Cryptosporidium. Thus, the objective of the present study was to investigate the prevalence and associated risk factors of Cryptosporidium infection in black-boned goats and black-boned sheep in Yunnan province, China. A total of 590 fecal samples were obtained from black-boned goats and black-boned sheep from five counties in Yunnan province, and the prevalence and species distribution of Cryptosporidium were determined by amplification of the 18S rDNA fragment using the nested PCR. The overall Cryptosporidium prevalence was 13.2% (78/590), with 18.0% (55/305) in black-boned goats and 8.1% (23/285) in black-boned sheep. The age and sampling site were identified as main factors that result in significant differences in Cryptosporidium prevalence. Three species, namely C. muris, C. xiaoi, and C. ubiquitum, were identified in black-boned goats and black-boned sheep in the present study, with C. muris (46/78) as the predominant species. This is the first report of Cryptosporidium infection in black-boned goats and black-boned sheep in China, and the findings will facilitate better understanding, prevention, and control of Cryptosporidium infection in black-boned goats and black-boned sheep in China.

A retrospective epidemiological analysis of human Cryptosporidium infection in China during the past three decades (1987-2018)

Background

Cryptosporidiosis is an emerging infectious disease of public health significance worldwide. The burden of disease caused by Cryptosporidium varies between and within countries/areas. To have a comprehensive understanding of epidemiological status and characteristics of human Cryptosporidium infection in China since the first report in 1987, a retrospective epidemiological analysis was conducted by presenting differences in the prevalence of Cryptosporidium by province, year, population, living environment and season and possible transmission routes and risk factors as well as genetic characteristics of Cryptosporidium in humans.

Methodology/Principal findings

A systematic search was conducted to obtain epidemiological papers of human Cryptosporidium infection/cryptosporidiosis from PubMed and Chinese databases. Finally, 164 papers were included in our analysis. At least 200,054 people from 27 provinces were involved in investigational studies of Cryptosporidium, with an average prevalence of 2.97%. The prevalence changed slightly over time. Variable prevalences were observed: 0.65–11.15% by province, 1.89–47.79% by population, 1.77–12.87% and 0–3.70% in rural and urban areas, respectively. The prevalence peak occurred in summer or autumn. Indirect person-to-person transmission was documented in one outbreak of cryptosporidiosis in a pediatric hospital. 263 Cryptosporidium isolates were obtained, and seven Cryptosporidium species were identified: C. hominis (48.3%), C. andersoni (22.43%), C. parvum (16.7%), C. meleagridis (8.36%), C. felis (3.04%), C. canis (0.76%) and C. suis (0.38%).

Conclusions/Significances

This systematic review reflects current epidemiological status and characteristics of Cryptosporidium in humans in China. These data will be helpful to develop efficient control strategies to intervene with and prevent occurrence of human Cryptosporidium infection/cryptosporidiosis in China as well as have a reference effect to other countries. Further studies should focus on addressing a high frequency of C. andersoni in humans and a new challenge with respect to cryptosporidiosis with an increasing population of elderly people and patients with immunosuppressive diseases.

Cryptosporidium is a major cause of diarrheal disease in humans globally. Due to the lack of effective drug treatment and vaccine prevention against cryptosporidiosis, it is particularly important to develop efficient control strategies to intervene with and prevent Cryptosporidium infection in humans. The present review presented and analyzed epidemiological status and characteristics of Cryptosporidium infection in humans in China since the first report in 1987. To date, epidemiological investigations of Cryptosporidium infecion have been carried out in different populations in 27 provinces, autonomous regions, and municipalities. Average prevalence of Cryptosporidium was 2.97% (5,933/200,054). Like other infectious disease, due to poor sanitation conditions in rural areas, people living in rural areas had a significantly higher prevalence of Cryptosporidium (1.77–12.87%) than those living in urban areas (0–3.70%). Seven Cryptosporidium species were identified, including C. hominis, C. andersoni, C. parvum, C. meleagridis, C. felis, C. canis and C. suis. This retrospective epidemiological analysis indicates wide geographical distribution of human Cryptosporidium infection/cryptosporidiosis in China.

Factors Associated With Cryptosporidium Infection Among Adult HIV Positive Population in Contact With Livestock in Namwala District, Zambia

Cryptosporidium spp. is one of the leading causes of diarrhoeal disease globally. In Zambia, the burden of Cryptosporidium infection in the general human population is unknown and factors associated with it are unclear. A study was conducted to determine the prevalence of Cryptosporidium spp. and identify factors associated with its infection among Human Immunodeficiency Virus (HIV) positive individuals in contact with livestock in Namwala district of Zambia. Three hundred and twenty six stool samples were collected from HIV infected individuals presenting at local health centers in Namwala district of Zambia between August 2015 and June 2016. The Meriflour Cryptosporidium/Giardia test kit was used to test for presence of oocysts. Demographic information such as age and sex and information on hypothesized risk factors was collected using a structured questionnaire. Overall prevalence of Cryptosporidium infection was 9.5% (95% CI = 6.7–13.2%); 13.3% and 7.1% among male and female participants, respectively. Males were 2.5 times more likely to be infected than females whereas the divorced had higher odds of being infected (OR = 14.8). Participants who kept animals had a higher prevalence (11.4%) than those that did not (7.0%). Those that shared water with neighbors were 5.7 times more likely to be infected than those who did not. We conclude that Cryptosporidium infection is prevalent among HIV positive adults in Namwala district and infection is associated with sex, marital status and sharing water sources among neighbors. Community sensitization is required to create awareness and reduce human exposure to Cryptosporidium infection.

Biological HRPs in wastewater

Biological high-risk pollutants (HRPs) have become a serious threat to human health worldwide, and wastewater is one of the major sources of them in a natural environment. Despite the long history of wastewater research, comprehensive understanding of the role and behavior of HRPs during wastewater treatment is still limited owing to the complexity of the community. In recent decades, the rapid development of molecular tools, especially the wide application of next generation sequencing technologies, helps to unravel the community composition, structure, and dynamic variation in wastewater. Overall, this chapter mainly focuses on biological HRPs, including bacteria, viruses, protozoa, helminth, biotoxins, antibiotic resistance genes and antibiotic resistant bacteria in wastewater. The characteristics, classification, fates, functions, and health implications of these HRPs are introduced in detail. Moreover, the biogeography of HRPs is a research hotspot in recent years, and available information is also summarized in this chapter. Finally, we also propose the future research needs of HRPs in wastewater after the comprehensive summary of the existing research reports. This chapter is wished to be helpful for beginners to quickly understand the biological HRPs in wastewater.

Epidemiology and Risk Factors for Cryptosporidiosis in Children From 8 Low-income Sites: Results From the MAL-ED Study

Background

Cryptosporidium species are enteric protozoa that cause significant morbidity and mortality in children worldwide. We characterized the epidemiology of Cryptosporidium in children from 8 resource-limited sites in Africa, Asia, and South America.

Methods

Children were enrolled within 17 days of birth and followed twice weekly for 24 months. Diarrheal and monthly surveillance stool samples were tested for Cryptosporidium by enzyme-linked immunosorbent assay. Socioeconomic data were collected by survey, and anthropometry was measured monthly.

Results

Sixty-five percent (962/1486) of children had a Cryptosporidium infection and 54% (802/1486) had at least 1 Cryptosporidium-associated diarrheal episode. Cryptosporidium diarrhea was more likely to be associated with dehydration (16.5% vs 8.3%, P < .01). Rates of Cryptosporidium diarrhea were highest in the Peru (10.9%) and Pakistan (9.2%) sites. In multivariable regression analysis, overcrowding at home was a significant risk factor for infection in the Bangladesh site (odds ratio, 2.3 [95% confidence interval {CI}, 1.2-4.6]). Multiple linear regression demonstrated a decreased length-for-age z score at 24 months in Cryptosporidium-positive children in the India (β = -.26 [95% CI, -.51 to -.01]) and Bangladesh (β = -.20 [95% CI, -.44 to .05]) sites.

Conclusions

This multicountry cohort study confirmed the association of Cryptosporidium infection with stunting in 2 South Asian sites, highlighting the significance of cryptosporidiosis as a risk factor for poor growth. We observed that the rate, age of onset, and number of repeat infections varied per site; future interventions should be targeted per region to maximize success.

Morbidity, mortality, and long-term consequences associated with diarrhoea from Cryptosporidium infection in children younger than 5 years: a meta-analyses study

Background

The protozoan Cryptosporidium is a leading cause of diarrhoea morbidity and mortality in children younger than 5 years. However, the true global burden of Cryptosporidium infection in children younger than 5 years might have been underestimated in previous quantifications because it only took account of the acute effects of diarrhoea. We aimed to demonstrate whether there is a causal relation between Cryptosporidium and childhood growth and, if so, to quantify the associated additional burden.

Methods

The Global Burden of Diseases, Injuries, and Risk Factors study (GBD) 2016 was a systematic and scientific effort to quantify the morbidity and mortality associated with more than 300 causes of death and disability, including diarrhoea caused by Cryptosporidium infection. We supplemented estimates on the burden of Cryptosporidium in GBD 2016 with findings from a systematic review of published and unpublished cohort studies and a meta-analysis of the effect of childhood diarrhoea caused by Cryptosporidium infection on physical growth.

Findings

In 2016, Cryptosporidium infection was the fifth leading diarrhoeal aetiology in children younger than 5 years, and acute infection caused more than 48 000 deaths (95% uncertainty interval [UI] 24 600–81 900) and more than 4·2 million disability-adjusted life-years lost (95% UI 2·2 million–7·2 million). We identified seven data sources from the scientific literature and six individual-level data sources describing the relation between Cryptosporidium and childhood growth. Each episode of diarrhoea caused by Cryptosporidium infection was associated with a decrease in height-for-age Z score (0·049, 95% CI 0·014–0·080), weight-for-age Z score (0·095, 0·055–0·134), and weight-for-height Z score (0·126, 0·057–0·194). We estimated that diarrhoea from Cryptosporidium infection caused an additional 7·85 million disability-adjusted life-years (95% UI 5·42 million–10·11 million) after we accounted for its effect on growth faltering—153% more than that estimated from acute effects alone.

Interpretation

Our findings show that the substantial short-term burden of diarrhoea from Cryptosporidium infection on childhood growth and wellbeing is an underestimate of the true burden. Interventions designed to prevent and effectively treat infection in children younger than 5 years will have enormous public health and social development impacts.

Funding

The Bill & Melinda Gates Foundation.

A retrospective molecular study of Cryptosporidium species and genotypes in HIV-infected patients from Thailand

Background

Opportunistic infections represent a serious health problem for HIV-infected people. Among enteric infections, cryptosporidiosis, a severe and life-threatening diarrheal disease, is of particular importance in low economic settings where access to anti-retroviral therapy is limited. Understanding transmission routes is crucial in establishing preventive measures, and requires the use of informative genotyping methods. In this study, we performed a retrospective analysis of Cryptosporidium species in 166 stool samples collected from 155 HIV-infected patients during 1999–2004 at the Siriraj Hospital in Bangkok, Thailand.

Results

Microscopic examination of stools identified 104 of the 155 patients as positive for Cryptosporidium. Other common pathogens identified were microsporidia, Isospora, Giardia, Strongyloides and Opisthorchis. All samples were tested by amplification of a fragment of the 18S rDNA locus, and sequencing showed the presence of Cryptosporidium hominis (n = 42), C. meleagridis (n = 20), C. canis (n = 12), C. felis (n = 7), C. suis (n = 6) and C. parvum (n = 5). Genotyping at the glycoprotein 60 (gp60) locus revealed substantial variability in isolates of C. hominis and C. meleagridis. Among C. hominis isolates, subtype IeA11G3T3 was the most prevalent, but allelic family Id was the more diverse with four subtypes described, two of which were identified for the first time. Among C. meleagridis isolates, seven subtypes, two of which were new, were found in the allelic family IIIb, along with new subtypes in allelic families IIIe and IIIg. In the four C. parvum isolates, subtype IIoA16G1, a rare subtype previously reported in a Swedish patient who had traveled to Thailand, was identified.

Conclusions

This study confirms the high susceptibility of HIV-infected individuals to infection with different Cryptosporidium species and subtypes, and further stresses the importance of surveillance for opportunistic intestinal protozoans.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3348-4) contains supplementary material, which is available to authorized users.

The First Evidence of Cryptosporidium meleagridis Infection in a Colon Adenocarcinoma From an Immunocompetent Patient

Objectives: The potential linkage between Cryptosporidium spp. infection and colorectal human cancer was suggested by limited reports showing higher prevalence of C. parvum and C. hominis in patients with colon cancer. Here we conducted research concerning presence of Cryptosporidium spp. in malignant tissue collected from patients with colorectal cancer.

Methods: Cancerous colon tissue samples collected from 145 non-HIV infected patients with colorectal cancer were screened for Cryptosporidium spp. by immunofluorescence antibody test and genus-specific nested polymerase chain reaction followed by sequencing.

Results: Screened pathogen was found in cancerous tissue originating from immunocompetent man with colon adenocarcinoma. Genotyping revealed presence of Cryptosporidium meleagridis. The presence of Cryptosporidium life cycle stages (oocysts and endogenous stages) in colon carcinoma tissue was confirmed by genus-specific FITC-labeling.

Conclusions: Herein, we report on a C. meleagridis infection of a colon adenocarcinoma in an immunocompetent patient. This is the first report of C. meleagridis infection in the human colon and first evidence of active development of this species in cancer tissue.