The response of Cryptosporidium parvum to UV light

Rochelle, Paul A.; Upton, Steve J.; Montelone, Beth A.; Woods, Keith M.

doi:10.1016/j.pt.2004.11.009

Cited by 58 publications

(48 citation statements)

References 42 publications

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“…TDs are common forms of CPD produced in cells when UV light is absorbed by the double bond in the thymine base in a DNA molecule, opening the bond and allowing it to react with the adjacent thymine base, forming a tight four-member ring (12). UV irradiation of C. parvum oocysts also produces CPD, and UV inactivation of C. parvum and C. hominis is irreversible, despite the presence of UV repair genes (10,16,18,19). An assay that can detect the presence of TD following UV inactivation in individual waterborne oocysts would prove beneficial to the water industry, public health professionals, and government regulators.…”

Section: Discussionmentioning

confidence: 99%

“…Oguma et al (16) conducted an endonuclease-sensitive site assay to determine the presence of UV-induced pyrimidine dimers in C. parvum genomic DNA. Using a chemiluminescence-based Western blot assay, Rochelle et al (19) demonstrated the accumulation of TD in the C. parvum genome when oocysts were exposed to various doses of UV light (3 to 104 mJ ⅐ cm Ϫ2 ). Our data demonstrate the validity and usefulness of fluorescence and immunofluorescence to detect TD in the nuclei of irradiated sporozoites contained within C. parvum and C. hominis oocysts.…”

Section: Discussionmentioning

confidence: 99%

“…The experiments reported here, using the fluorogenic vital dye assay and the maximized in vitro excystation assay, do not provide supportive evidence for the inactivation of C. parvum oocysts following exposure to 10, 20, and 40 mJ ⅐ cm Ϫ2 doses of UV irradiation. There is agreement in the literature that in vitro viability assays can overestimate oocyst viability compared with animal infectivity (19). We compared results of anti-TDmAb immunofluorescence localization and the neonatal mouse infectivity assay, using C. parvum oocysts irradiated with either 10 or 20 mJ ⅐ cm Ϫ2 .…”

Section: -Mj ⅐ CMmentioning

confidence: 97%

“…However, UV inactivation of Cryptosporidium oocysts is irreversible, despite the presence of these UV repair genes (18). Rochelle et al (19) demonstrated the accumulation of cyclobutane TDs in the genome of C. parvum oocysts exposed to increasing dosages of UV light, using a chemiluminescent Western blot assay.…”

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confidence: 99%

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Detection of UV-Induced Thymine Dimers in IndividualCryptosporidium parvumandCryptosporidium hominisOocysts by Immunofluorescence Microscopy

Al-Adhami

Nichols

Kusel

et al. 2007

Appl Environ Microbiol

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To investigate the effect of UV light on Cryptosporidium parvum and Cryptosporidium hominis oocysts in vitro, we exposed intact oocysts to 4-, 10-, 20-, and 40-mJ ⅐ cm ؊2 doses of UV irradiation. Thymine dimers were detected by immunofluorescence microscopy using a monoclonal antibody against cyclobutyl thymine dimers (anti-TDmAb). Dimer-specific fluorescence within sporozoite nuclei was confirmed by colocalization with the nuclear fluorogen 4,6-diamidino-2-phenylindole (DAPI). Oocyst walls were visualized using either commercial fluorescein isothiocyanate-labeled anti-Cryptosporidium oocyst antibodies (FITC-CmAb) or Texas Redlabeled anti-Cryptosporidium oocyst antibodies (TR-CmAb). The use of FITC-CmAb interfered with TD detection at doses below 40 mJ ⅐ cm ؊2 . With the combination of anti-TDmAb, TR-CmAb, and DAPI, dimer-specific fluorescence was detected in sporozoite nuclei within oocysts exposed to 10 to 40 mJ ⅐ cm ؊2 of UV light. Similar results were obtained with C. hominis. C. parvum oocysts exposed to 10 to 40 mJ ⅐ cm ؊2 of UV light failed to infect neonatal mice, confirming that results of our anti-TD immunofluorescence assay paralleled the outcomes of our neonatal mouse infectivity assay. These results suggest that our immunofluorescence assay is suitable for detecting DNA damage in C. parvum and C. hominis oocysts induced following exposure to UV light.UV irradiation as a sterilization technology in the water and food industry is effective in killing contaminating organisms, such as viruses, bacteria, fungal spores, and parasites (8). The major DNA lesions caused by UV light are cyclobutyl pyrimidine dimers (CPD), which are responsible for UV-induced cytotoxicity and mutagenicity in living cells and microorganisms. UV-induced damage consists of chemical base modifications, whereby two adjacent pyrimidine residues (cytosine or thymine) form a dimer (thymine dimer [TD], cytosine dimer, or thymine-cytosine heterodimer) and 6-4 photoproducts. The formation of these lesions in genomic DNA inhibits normal replication and transcription of DNA and results in the inactivation of cells (12). However, UV-induced DNA lesions in living human epidermal cells (21) and in some unicellular microorganisms (16) can be repaired by one or more mechanisms. These mechanisms include the enzyme-dependent nucleotide excision repair, also named dark repair, and the light-dependent reaction known as photoreactivation. Dark repair and photoreactivation enable UV-inactivated microorganisms to recover, which can reduce the efficiency of UV inactivation (20).Cryptosporidium parvum oocysts have the ability to carry out photoreactivation and dark repair at the genomic level (13, 16). Also, nucleotide excision repair genes in C. parvum and Cryptosporidium hominis have been identified. However, UV inactivation of Cryptosporidium oocysts is irreversible, despite the presence of these UV repair genes (18). Rochelle et al. (19) demonstrated the accumulation of cyclobutane TDs in the genome of C. parvum oocysts exposed to increasing dosage...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: -Mj ⅐ CMmentioning

confidence: 97%

mentioning

confidence: 99%

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Detection of UV-Induced Thymine Dimers in IndividualCryptosporidium parvumandCryptosporidium hominisOocysts by Immunofluorescence Microscopy

Al-Adhami

Nichols

Kusel

et al. 2007

Appl Environ Microbiol

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“…They should take additional precautions, including avoiding contact with young pets, and avoiding swallowing water while swimming (John & Petri, 2006). The realization that Cryptosporidium oocysts are resistant to many chemical disinfectants (Tzipori & Giovanni, 2008;Rochelle et al, 2005) led to a search for methods that can inactivate oocysts without generating harmful by products. Much attention has focused on UV irradiation and ozone as alternative methods capable of inactivating waterborne oocysts (Tzipori & Giovanni, 2008;Lloyd & Drury, 2002).…”

Section: Prophylaxismentioning

confidence: 99%

Cryptosporidiosis - From Epidemiology to Treatment

Sonia¹

2011

Microbes, Viruses and Parasites in AIDS Process

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Differential expression of the two distinct replication protein A subunits from Cryptosporidium parvum

Rider

Zhu

2008

J of Cellular Biochemistry

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Apicomplexan parasites differ from their host by possessing at least two distinct types (long and short) of replication protein A large subunits (RPA1). Different roles for the long and short types of RPA1 proteins have been implied in early biochemical studies, but certain details remained to be elucidated. In the present study, we have found that the Cryptosporidium parvum short-type RPA1 (CpRPA1A) was highly expressed at S-phase in parasites during the early stage of merogony (a cell multiplication process unique to this group of parasites), but otherwise present in the cytosol at a much lower level in other cell-cycle stages. This observation indicates that CpRPA1A is probably responsible for the general DNA replication of the parasite. On the other hand, the long-type CpRPA1B protein was present in a much lower level in the early life cycle stages, but elevated at later stages involved in sexual development, indicating that CpRPA1B may play a role in DNA recombination. Additionally, CpRPA1B could be up-regulated by UV exposure, indicating that this long-type RPA1 is probably involved in DNA repair. Collectively, our data implies that the two RPA1 proteins in C. parvum are performing different roles during DNA replication, repair and recombination in this parasite.

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The response of Cryptosporidium parvum to UV light

Cited by 58 publications

References 42 publications

Detection of UV-Induced Thymine Dimers in IndividualCryptosporidium parvumandCryptosporidium hominisOocysts by Immunofluorescence Microscopy

Detection of UV-Induced Thymine Dimers in IndividualCryptosporidium parvumandCryptosporidium hominisOocysts by Immunofluorescence Microscopy

Cryptosporidiosis - From Epidemiology to Treatment

Differential expression of the two distinct replication protein A subunits from Cryptosporidium parvum

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