Infection with anthroponotic Cryptosporidium parvum does not fully protect the host against a subsequent challenge with C . hominis

Pilot-scale experiments were conducted to investigate removal of Cryptosporidium parvum by contact granular filtration. The research demonstrated enhanced removal of Cryptosporidium parvum in the presence of kaolin particles. This is believed to be due electrostatic adhesion of Cryptosporidium parvum oocysts to the kaolin clay particles. The elementary physico-chemical interactions between filter granules and suspension particles will be discussed. This innovative concept was successfully implemented to reduce the ripening sequence of subsequent filtration experimental test runs by the addition of large surface area particles to slurry of kaolin and Cryptosporidium parvum in surface water.

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A Nude Mouse Model as an in vivo Infectivity Assay for Cryptospomdiosis

Water Science & Technology ◽

10.2166/wst.1993.0323 ◽

1993 ◽

Vol 27 (3-4) ◽

pp. 65-68 ◽

Cited By ~ 3

Author(s):

B. H. Kwa ◽

M. Moyad ◽

M. A. Pentella ◽

J. B. Rose

Keyword(s):

Drinking Water ◽

Mouse Model ◽

Nude Mouse ◽

Cryptosporidium Parvum ◽

Nude Mice ◽

Surface Waters ◽

Nude Mouse Model ◽

Infectivity Assay ◽

Limiting Dilution

Cryptosporidium parvum is an important patliogen of diarrlieal disease which has been implicated in several outbreaks associated with contamination of surface waters. In monitoring for C. parvum in drinking water sources, it is important to asce tain the viability, and more importantly, the infectivity of low numbers of recovered oocysts. Groups of 10 Balb/C nude (nu/nu) mice, 4-8 weeks old at time of inoculation, were infected with C. parvum oocysts from naturally infected calves and purified using Sheather's sucrose gradients. Oocysts were counted using the Merifluor IFA kit (Meridian). Each group of 10 mice were infected with 1,10,100 and 1000 oocysts respectively. Numbers of oocysts per inoculation were determined by limiting dilution, and parallel inocula were counted microscopically to ascertain the accuracy of the dilutions. Two uninfected nude mice were kept in each cage to serve as controls. Mouse stools were collected every 4 days, concentrated using the Fekal Kontrate Concentration Kit (Meridian) and oocysts were counted with a UV microscope using the Merifluor IFA Kit (Meridian). Oocyst counts were expressed in terms of number of oocyst/g feces. Mice inoculated with 1000 oocysts began to shed oocysts on day 32, mice inoculated with 100 oocysts began to shed on days 44-48, mice inoculated with 10 oocysts began to shed on days 56-60, and mice inoculated with 1 oocyst shed on days 68-88. All infected mice continued to shed oocysts intermittently and with variable oocyst counts until day 180 when the experiment was terminated. This study established that it is possible to infect nude mice with very low numbers, down to a single oocyst. We are currently in the process of correlating the nude mouse assay with other viability assays.

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Survival of giardia, cryptosporidium, poliovirus and salmonella in marine waters

Water Science & Technology ◽

10.2166/wst.1997.0744 ◽

1997 ◽

Vol 35 (11-12) ◽

pp. 261-268 ◽

Cited By ~ 30

Author(s):

D. C. Johnson ◽

C. E. Enriquez ◽

I. L. Pepper ◽

T. L. Davis ◽

C. P. Gerba ◽

...

Keyword(s):

Water Quality ◽

Salmonella Typhimurium ◽

Cryptosporidium Parvum ◽

Common Method ◽

Waterborne Pathogens ◽

Protozoan Parasites ◽

Marine Waters ◽

Untreated Sewage ◽

Cryptosporidium Parvum Oocysts ◽

Giardia Muris

Discharge of sewage into the ocean is still a common method of disposal worldwide. Both treated and untreated sewage may contain significant concentrations of waterborne pathogens, such as Giardia, Cryptosporidium, poliovirus and Salmonella. Limited studies exist on the survival of poliovirus and Salmonella in marine waters; however, almost no information exists on the survival of protozoan parasites in marine waters. This study examined the survival of Giardia muris cysts, Cryptosporidium parvum oocysts, poliovirus-1 and Salmonella typhimurium in marine waters. The survival of the microorganisms varied according to the presence of light, salinity and water quality (as determined by quantity of enterococci). All microorganisms survived longer in the dark than in sunlight, the order of survival in sunlight being: Cryptosporidium > poliovirus > Giardia > Salmonella.

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Analytical challenges and perspectives of assessing viability of Giardia muris cysts and Cryptosporidium parvum oocysts by live/dead simultaneous staining

Environmental Technology ◽

10.1080/09593330.2020.1775712 ◽

2020 ◽

pp. 1-10

Author(s):

Kamila Jessie Sammarro Silva ◽

Lyda Patricia Sabogal-Paz

Keyword(s):

Cryptosporidium Parvum ◽

Cryptosporidium Parvum Oocysts ◽

Giardia Muris

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Metabolic Signatures of Cryptosporidium parvum-Infected HCT-8 Cells and Impact of Selected Metabolic Inhibitors on C. parvum Infection under Physioxia and Hyperoxia

Biology ◽

10.3390/biology10010060 ◽

2021 ◽

Vol 10 (1) ◽

pp. 60

Author(s):

Juan Vélez ◽

Zahady Velasquez ◽

Liliana M. R. Silva ◽

Ulrich Gärtner ◽

Klaus Failing ◽

...

Keyword(s):

Host Cell ◽

Cryptosporidium Parvum ◽

Cell Metabolism ◽

Lactate Production ◽

Glucose Consumption ◽

Host Cells ◽

Metabolic Inhibitors ◽

Low Oxygen ◽

Metabolic Signatures

Cryptosporidium parvum is an apicomplexan zoonotic parasite recognized as the second leading-cause of diarrhoea-induced mortality in children. In contrast to other apicomplexans, C.parvum has minimalistic metabolic capacities which are almost exclusively based on glycolysis. Consequently, C. parvum is highly dependent on its host cell metabolism. In vivo (within the intestine) infected epithelial host cells are typically exposed to low oxygen pressure (1–11% O2, termed physioxia). Here, we comparatively analyzed the metabolic signatures of C. parvum-infected HCT-8 cells cultured under both, hyperoxia (21% O2), representing the standard oxygen condition used in most experimental settings, and physioxia (5% O2), to be closer to the in vivo situation. The most pronounced effect of C. parvum infection on host cell metabolism was, on one side, an increase in glucose and glutamine uptake, and on the other side, an increase in lactate release. When cultured in a glutamine-deficient medium, C. parvum infection led to a massive increase in glucose consumption and lactate production. Together, these results point to the important role of both glycolysis and glutaminolysis during C. parvum intracellular replication. Referring to obtained metabolic signatures, we targeted glycolysis as well as glutaminolysis in C. parvum-infected host cells by using the inhibitors lonidamine [inhibitor of hexokinase, mitochondrial carrier protein (MCP) and monocarboxylate transporters (MCT) 1, 2, 4], galloflavin (lactate dehydrogenase inhibitor), syrosingopine (MCT1- and MCT4 inhibitor) and compound 968 (glutaminase inhibitor) under hyperoxic and physioxic conditions. In line with metabolic signatures, all inhibitors significantly reduced parasite replication under both oxygen conditions, thereby proving both energy-related metabolic pathways, glycolysis and glutaminolysis, but also lactate export mechanisms via MCTs as pivotal for C. parvum under in vivo physioxic conditions of mammals.

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A Single-Pass Type I Membrane Protein from the Apicomplexan Parasite Cryptosporidium parvum with Nanomolar Binding Affinity to Host Cell Surface

Microorganisms ◽

10.3390/microorganisms9051015 ◽

2021 ◽

Vol 9 (5) ◽

pp. 1015

Author(s):

Tianyu Zhang ◽

Xin Gao ◽

Dongqiang Wang ◽

Jixue Zhao ◽

Nan Zhang ◽

...

Keyword(s):

Membrane Protein ◽

Cell Surface ◽

Host Cell ◽

Binding Affinity ◽

Cryptosporidium Parvum ◽

Host Cells ◽

Watery Diarrhea ◽

Type I ◽

Single Pass ◽

Host Cell Surface

Cryptosporidium parvum is a globally recognized zoonotic parasite of medical and veterinary importance. This parasite mainly infects intestinal epithelial cells and causes mild to severe watery diarrhea that could be deadly in patients with weakened or defect immunity. However, its molecular interactions with hosts and pathogenesis, an important part in adaptation of parasitic lifestyle, remain poorly understood. Here we report the identification and characterization of a C. parvum T-cell immunomodulatory protein homolog (CpTIPH). CpTIPH is a 901-aa single-pass type I membrane protein encoded by cgd5_830 gene that also contains a short Vibrio, Colwellia, Bradyrhizobium and Shewanella (VCBS) repeat and relatively long integrin alpha (ITGA) N-terminus domain. Immunofluorescence assay confirmed the location of CpTIPH on the cell surface of C. parvum sporozoites. In congruence with the presence of VCBS repeat and ITGA domain, CpTIPH displayed high, nanomolar binding affinity to host cell surface (i.e., Kd(App) at 16.2 to 44.7 nM on fixed HCT-8 and CHO-K1 cells, respectively). The involvement of CpTIPH in the parasite invasion is partly supported by experiments showing that an anti-CpTIPH antibody could partially block the invasion of C. parvum sporozoites into host cells. These observations provide a strong basis for further investigation of the roles of CpTIPH in parasite-host cell interactions.

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