Pilot-Scale Pulsed UV Light Irradiation of Experimentally Infected Raspberries Suppresses Cryptosporidium parvum Infectivity in Immunocompetent Suckling Mice

2015 ◽  
Vol 78 (12) ◽  
pp. 2247-2252 ◽  
Author(s):  
L. LE GOFF ◽  
B. HUBERT ◽  
L. FAVENNEC ◽  
I. VILLENA ◽  
J. J. BALLET ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Uv Light ◽  
Immunomagnetic Separation ◽  
Pilot Scale ◽  
Suckling Mice ◽  
Cryptosporidium Spp ◽  
Organoleptic Characteristics ◽  
Pulsed Uv Light ◽  
Foodborne Infection

Cryptosporidium spp., a significant cause of foodborne infection, have been shown to be resistant to most chemical food disinfectant agents and infective for weeks in irrigation waters and stored fresh vegetal produce. Pulsed UV light (PL) has the potential to inactivate Cryptosporidium spp. on surfaces of raw or minimally processed foods or both. The present study aimed to evaluate the efficacy of PL on viability and in vivo infectivity of Cryptosporidium parvum oocysts present on raspberries, a known source of transmission to humans of oocyst-forming apicomplexan pathogens. The skin of each of 20 raspberries was experimentally inoculated with five 10-μl spots of an oocyst suspension containing 6 × 107 oocysts per ml (Nouzilly isolate). Raspberries were irradiated by PL flashes (4 J/cm2 of total fluence). This dose did not affect colorimetric or organoleptic characteristics of fruits. After immunomagnetic separation from raspberries, oocysts were bleached and administered orally to neonatal suckling mice. Seven days after infection, mice were euthanized, and the number of oocysts in the entire small intestine was individually assessed by immunofluorescence flow cytometry. Three of 12 and 12 of 12 inoculated mice that received 10 and 100 oocysts isolated from nonirradiated raspberries, respectively, were found infected. Four of 12 and 2 of 12 inoculated mice that received 103 and 104 oocysts from irradiated raspberries, respectively, were found infected. Oocyst counts were lower in animals inoculated with 103 and 104 oocysts from irradiated raspberries (92 ± 144 and 38 ± 82, respectively) than in animals infected with 100 oocysts from nonirradiated raspberries (35,785 ± 66,221, P = 0.008). PL irradiation achieved oocyst reductions of 2 and 3 log for an inoculum of 103 and 104 oocysts, respectively. The present pilot-scale evaluation suggests that PL is an effective mode of decontamination for raspberries and prompts further applicability studies in industrial contexts.

Pulsed-UV light inactivation of Cryptosporidium parvum

2008 ◽  
Vol 102 (6) ◽  
pp. 1293-1299 ◽  
Author(s):  
Soo-Ung Lee ◽  
Migyo Joung ◽  
Dong-Jin Yang ◽  
Soon-Ho Park ◽  
Sun Huh ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Uv Light ◽  
Pulsed Uv Light

Decontamination of Whole Chicken Carcasses by Using a Pilot-Scale Pulsed UV-light System

2010 ◽  
Author(s):  
Nene Meltem Keklik ◽  
Ali Demirci ◽  
Randall Gray Bock
Keyword(s):  
Uv Light ◽  
Pilot Scale ◽  
Light System ◽  
Pulsed Uv Light

Depressed filtration ripening enhances removal of Cryptosporidium parvum

2002 ◽  
Vol 2 (3) ◽  
pp. 159-168 ◽  
Author(s):  
V. Gitis ◽  
R.C. Haught ◽  
R.M. Clark ◽  
E. Radha Krishnan
Keyword(s):  
Surface Water ◽  
Cryptosporidium Parvum ◽  
Pilot Scale ◽  
Kaolin Clay ◽  
Clay Particles ◽  
Physico Chemical ◽  
Cryptosporidium Parvum Oocysts ◽  
Granular Filtration ◽  
Electrostatic Adhesion ◽  
Innovative Concept

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.

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

1993 ◽  
Vol 27 (3-4) ◽  
pp. 65-68 ◽  
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.

scholarly journals Persistent luminescence nanoparticles for cancer theranostics application

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Nian Liu ◽  
Xiao Chen ◽  
Xia Sun ◽  
Xiaolian Sun ◽  
Junpeng Shi
Keyword(s):  
Uv Light ◽  
Combined Therapy ◽  
Tumor Therapy ◽  
High Sensitivity ◽  
Persistent Luminescence ◽  
Therapeutic Drugs ◽  
High Penetration ◽  
Recent Developments ◽  
Cancer Theranostics

AbstractPersistent luminescence nanoparticles (PLNPs) are unique optical materials that emit afterglow luminescence after ceasing excitation. They exhibit unexpected advantages for in vivo optical imaging of tumors, such as autofluorescence-free, high sensitivity, high penetration depth, and multiple excitation sources (UV light, LED, NIR laser, X-ray, and radiopharmaceuticals). Besides, by incorporating other functional molecules, such as photosensitizers, photothermal agents, or therapeutic drugs, PLNPs are also widely used in persistent luminescence (PersL) imaging-guided tumor therapy. In this review, we first summarize the recent developments in the synthesis and surface functionalization of PLNPs, as well as their toxicity studies. We then discuss the in vivo PersL imaging and multimodal imaging from different excitation sources. Furthermore, we highlight PLNPs-based cancer theranostics applications, such as fluorescence-guided surgery, photothermal therapy, photodynamic therapy, drug/gene delivery and combined therapy. Finally, future prospects and challenges of PLNPs in the research of translational medicine are also discussed.

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

Biology ◽  
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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