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Wang D, Jiang P, Yang X, Zhang J, Chen T, Hu M, Cacciò SM, Yin J, Zhu G. Novel strategy to quantify the viability of oocysts of Cryptosporidium parvum and C. hominis, a risk factor of the waterborne protozoan pathogens of public health concern. WATER RESEARCH 2024; 258:121788. [PMID: 38810599 DOI: 10.1016/j.watres.2024.121788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 03/30/2024] [Accepted: 05/14/2024] [Indexed: 05/31/2024]
Abstract
While waters might be contaminated by oocysts from >40 Cryptosporidium species, only viable oocysts of C. parvum and C. hominis truly pose the main health risk to the immunocompetent population. Oocyst viability is also an important but often neglected risk factor in monitoring waterborne parasites. However, commonly used methods in water monitoring and surveys cannot distinguish species (microscopic observation) or oocyst viability (PCR), as dead oocysts in water could retain gross structure and DNA content for weeks to months. Here, we report new TaqMan qRT-PCR/qPCR assays for quantitative detection of viable C. parvum and C. hominis oocysts. By targeting a hypothetical protein-encoding gene cgd6_3920 that is highly expressed in oocysts and variable between species, the qRT-PCR/qPCR assays achieve excellent analytical specificity and sensitivity (limit of quantification [LOQ] = 0.25 and 1.0 oocyst/reaction). Using calibration curves, the number and ratio of viable oocysts in specimens could be calculated. Additionally, we also establish a TaqMan-18S qPCR for cost-effective screening of pan-Cryptosporidium-positive specimens (LOQ = 0.1 oocyst/reaction). The assay feasibility is validated using field water (N = 43) and soil (79) specimens from 17 locations in Changchun, China, which detects four Cryptosporidium species from seven locations, including three gp60-subtypes (i.e., IIdA19G1, IIdA17G1 and IIdA24G2) of C. parvum oocysts showing varied viability ratios. These new TaqMan q(RT)-PCR assays supplement current methods in the survey of waters and other samples (e.g., surfaces, foods and beverages), and are applicable to assessing the efficiency of oocyst deactivation protocols.
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Affiliation(s)
- Dongqiang Wang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, China
| | - Peng Jiang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xiaoxuan Yang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, China
| | - Jifei Zhang
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, China
| | - Tao Chen
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, China
| | - Min Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Simone M Cacciò
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Jigang Yin
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, China
| | - Guan Zhu
- State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, and College of Veterinary Medicine, Jilin University, Changchun, China.
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Woolsey ID, Zeller WE, Blomstrand BM, Øines Ø, Enemark HL. Effects of selected condensed tannins on Cryptosporidium parvum growth and proliferation in HCT-8 cell cultures. Exp Parasitol 2022; 241:108353. [PMID: 35995247 DOI: 10.1016/j.exppara.2022.108353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/28/2022] [Accepted: 08/15/2022] [Indexed: 11/04/2022]
Abstract
Infections with Cryptosporidium spp. constitute a substantial public health burden and are responsible for widespread production losses in cattle herds. Reducing disease and shedding of Cryptosporidium spp. oocysts is an important One Health goal. There are very few therapeutic options available to treat cryptosporidiosis. Interest in plant bioactive compounds to mitigate the spread of anthelmintic resistance in ruminants has led to investigation of these phytocompounds against other parasitic taxa. Condensed tannins (CTs) are plant secondary metabolites that have shown potential against nematodes in vitro and in vivo but their applicability to Cryptosporidium spp. is comparatively under-explored. Cryptosporidium parvum infected human ileocecal colorectal adenocarcinoma (HCT)-8 cell cultures were treated with escalating doses of highly purified and well-characterized CTs from five plant species, big trefoil (Lotus pedunculatus), black currant (Ribes nigrum), sainfoin (Onobrychis viciifolia), white clover (Trifolium repens) and grapeseed (Vitis vinifera) for 44 h. Quantitative-PCR (qPCR) analysis revealed that none of the CTs examined demonstrated inhibitory potential against the parasite. Substantial inhibition of C. parvum by paromomycin was observed in positive controls in all assays (76.94-90.72% inhibition), proving the validity of the assay. Despite the lack of inhibition, these results represent an important step towards identifying alternative treatment options against this parasite.
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Affiliation(s)
- Ian David Woolsey
- Norwegian Veterinary Institute, Department of Animal Health and Food Safety, Elizabeth Stephansens Vei, 1433As, Norway.
| | - Wayne E Zeller
- U.S. Dairy and Forage Research Center, Agricultural Research Service, U.S. Department of Agriculture, 1925 Linden Drive, Madison, WI, 53706, USA
| | | | - Øivind Øines
- Norwegian Veterinary Institute, Department of Animal Health and Food Safety, Elizabeth Stephansens Vei, 1433As, Norway
| | - Heidi L Enemark
- Norwegian Veterinary Institute, Department of Animal Health and Food Safety, Elizabeth Stephansens Vei, 1433As, Norway
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Blomstrand BM, Enemark HL, Øines Ø, Steinshamn H, Aasen IM, Mahnert KC, Sørheim KM, Athanasiadou S, Thamsborg SM, Woolsey ID. Extracts of pine bark (Pinus sylvestris) inhibit Cryptosporidium parvum growth in cell culture. Parasitol Res 2021; 120:2919-2927. [PMID: 34269871 PMCID: PMC8370916 DOI: 10.1007/s00436-021-07220-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 06/09/2021] [Indexed: 01/23/2023]
Abstract
The widespread apicomplexan parasite Cryptosporidium parvum is responsible for severe gastrointestinal disease in humans and animals. The treatment options are limited, and the efficacy of available drugs is low. Bark contains condensed tannins (CT), which are bioactive compounds previously shown to inhibit parasite development. Here, we examined the anti-cryptosporidial properties of bark extract of Scots pine (Pinus sylvestris) against C. parvum by means of an in vitro growth inhibition test. We hypothesised that bark extracts would have dose-dependent inhibitory effects on the development of C. parvum in cell culture. Bark extracts from Scots pine extracted with acetone, methanol, and water as solvents were investigated using human colorectal adenocarcinoma cells infected with C. parvum. Oocysts were inoculated onto the cell monolayer and bark extract was added at seven different concentrations. Parasite growth inhibition was quantified by qPCR. The acetone and methanol extracts demonstrated a sigmoid dose-dependent inhibition of C. parvum. The IC50 values were 244.6 and 279.1 µg dry matter extract/mL, and 25.4 and 24.1 µg CT/mL, for acetone and methanol extracts, respectively. The IC50 for both extracts were similar, both with regard to the dry matter concentration of each extract and to CT concentrations. Given the limited treatment options available for Cryptosporidium spp., the evidence generated in our study encourages further investigation into the in vitro and in vivo effects of pine bark extracts against C. parvum.
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Affiliation(s)
| | - Heidi Larsen Enemark
- Department of Animal Health and Food Safety, Norwegian Veterinary Institute, Oslo, Norway
| | - Øivind Øines
- Department of Animal Health and Food Safety, Norwegian Veterinary Institute, Oslo, Norway
| | - Håvard Steinshamn
- Division of Food Production and Society, Grassland and Livestock, Norwegian Institute of Bioeconomy Research, Tingvoll, Norway
| | - Inga Marie Aasen
- SINTEF Industry, Biotechnology and Nanomedicine, Trondheim, Norway
| | | | | | | | - Stig Milan Thamsborg
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Ian David Woolsey
- Department of Animal Health and Food Safety, Norwegian Veterinary Institute, Oslo, Norway.
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Woolsey ID, Valente AH, Williams AR, Thamsborg SM, Simonsen HT, Enemark HL. Anti-protozoal activity of extracts from chicory (Cichorium intybus) against Cryptosporidium parvum in cell culture. Sci Rep 2019; 9:20414. [PMID: 31892721 PMCID: PMC6938481 DOI: 10.1038/s41598-019-56619-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 12/16/2019] [Indexed: 11/09/2022] Open
Abstract
Cryptosporidium spp. are responsible for severe public health problems and livestock production losses. Treatment options are limited to only one drug available for human and bovine cryptosporidiosis, respectively, and both drugs exhibit only partial efficacy. Sesquiterpene lactones (SL) are plant bioactive compounds that function as a defence mechanism against herbivores. SL have demonstrated anti-parasitic properties against a range of parasitic taxa but knowledge about their anti-Cryptosporidium efficacy is limited. The effect of SL-rich leaf and root extracts from chicory (Cichorium intybus cv. Spadona) was investigated using human colon adenocarcinoma (HCT-8) cells infected with Cryptosporidium parvum. C. parvum oocysts were inoculated onto the cell monolayer and i) incubated for 4 hours with extracts (leaf and root extracts 300, 150, 75, 37.5, 18.75 and 9.375 μg/mL) in triplicates followed by incubation in bioactive free media (sporozoite invasion assays) or ii) incubated for 4 hours in bioactive free media followed by 48-hours incubation with extracts (growth inhibition assays). Extract toxicity on HCT-8 cells was assessed via water-soluble tetrazolium (WST)-1 assay prior to quantifying parasitic growth via immunofluorescence. Both extracts demonstrated dose-dependent inhibition in the growth inhibition assays (p = < 0.0001 for both extracts) but not in the invasion assays. Anti-parasitic activity did not appear to be solely related to SL content, with the extract with lower SL content (leaf) exhibiting higher inhibition at 300 μg/ml. However, given the limited treatment options available for Cryptosporidium spp., our study encourages further investigation into the use of chicory extracts to identify novel active compound(s) inhibiting these protozoa.
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Affiliation(s)
- Ian David Woolsey
- Norwegian Veterinary Institute, Department of Animal Health and Food Safety, Oslo, Norway.
| | - Angela H Valente
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Andrew R Williams
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Stig M Thamsborg
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Henrik T Simonsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Heidi L Enemark
- Norwegian Veterinary Institute, Department of Animal Health and Food Safety, Oslo, Norway
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Woolsey ID, Blomstrand B, Øines Ø, Enemark HL. Assessment of differences between DNA content of cell-cultured and freely suspended oocysts of Cryptosporidium parvum and their suitability as DNA standards in qPCR. Parasit Vectors 2019; 12:596. [PMID: 31856894 PMCID: PMC6923971 DOI: 10.1186/s13071-019-3851-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/11/2019] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Although more modern methods are available, quantitative PCR (qPCR) is reproducible, sensitive and specific with instruments and expertise readily available in many laboratories. As such, the use of qPCR in Cryptosporidium research is well established and still widely used by researchers globally. This method depends upon the generation of standards at different concentrations to generate standard curves subsequently used for the quantification of DNA. METHODS We assessed four types of DNA template used to generate standard curves in drug screening studies involving Cryptosporidium spp.: (i) serially diluted Cryptosporidium parvum oocysts (106-1); (ii) diluted template DNA from pure oocysts (×10-×106 dilution of 106 oocyst DNA template); (iii) oocysts incubated in human ileocecal adenocarcinoma (HCT-8) cells (105-1 and 5 × 104-50); and (iv) diluted DNA template (5 × 104) from cell culture incubated parasites (×10-×1000). RESULTS Serial dilutions of both cell culture and pure oocyst suspension DNA template yielded better linearity than cell culture derived standards, with dilutions of 106 oocysts exhibiting similar quantification cycle (Cq) values to those obtained from DNA template dilutions of 106 oocysts. In contrast, cell culture incubated oocysts demonstrated significantly higher DNA content than equivalent freely suspended oocysts and diluted DNA template from both cell culture derived and freely suspended oocysts across numerous concentrations. CONCLUSIONS For many studies involving Cryptosporidium, only relative DNA content is required and as such, the superior linearity afforded by freely suspended oocysts and diluted DNA template (from either cell culture derived standards or freely suspended oocysts) will allow for more accurate relative quantification in each assay. Parasite division in the cell culture standards likely explains the higher DNA content found. These standards, therefore, have the potential to more accurately reflect DNA content in cell culture assays, and despite more modern methods available for absolute quantification, i.e. droplet digital PCR (ddPCR), the ubiquity of qPCR for the foreseeable future encourages further investigation into the reduced linearity observed in these standards such as varying oocyst seeding density, non-linear growth rates and assay efficiency.
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Affiliation(s)
- Ian D. Woolsey
- Department of Animal Health and Food Safety, Norwegian Veterinary Institute, Ullevålsveien 68, 0454 Oslo, Norway
| | - Berit Blomstrand
- Norwegian Centre for Organic Agriculture, Gunnars veg 6, 6630 Tingvoll, Norway
| | - Øivind Øines
- Department of Animal Health and Food Safety, Norwegian Veterinary Institute, Ullevålsveien 68, 0454 Oslo, Norway
| | - Heidi L. Enemark
- Department of Animal Health and Food Safety, Norwegian Veterinary Institute, Ullevålsveien 68, 0454 Oslo, Norway
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