Towards methods for detecting UV-induced damage in individual Cryptosporidium parvum and Cryptosporidium hominis oocysts by immunofluorescence microscopy.

Author(s):  
H. V. Smith ◽  
B. H. Al-Adhami ◽  
R. A. B. Nichols ◽  
J. R. Kusel ◽  
J. O'Grady
2006 ◽  
Vol 73 (3) ◽  
pp. 947-955 ◽  
Author(s):  
B. H. Al-Adhami ◽  
R. A. B. Nichols ◽  
J. R. Kusel ◽  
J. O'Grady ◽  
H. V. Smith

ABSTRACT 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�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 Red-labeled anti-Cryptosporidium oocyst antibodies (TR-CmAb). The use of FITC-CmAb interfered with TD detection at doses below 40 mJ�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�cm−2 of UV light. Similar results were obtained with C. hominis. C. parvum oocysts exposed to 10 to 40 mJ�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.


Parasitology ◽  
2013 ◽  
Vol 140 (14) ◽  
pp. 1735-1740 ◽  
Author(s):  
MARIANNE LEBBAD ◽  
JESSICA BESER ◽  
MONA INSULANDER ◽  
LILLEMOR KARLSSON ◽  
JENS G. MATTSSON ◽  
...  

SUMMARYMost human cases of cryptosporidiosis are caused byCryptosporidium parvumorCryptosporidium hominis, but the use of molecular diagnostic methods has revealed that several other less common species or genotypes can also be involved. Here, we describe two unusual causes of cryptosporidiosis, one being the recently described speciesCryptosporidium viatorumand the otherCryptosporidiumchipmunk genotype I. Two Swedish patients who were infected withC. viatorumhad travelled to Kenya and Guatemala, respectively, and two others had been infected withCryptosporidiumchipmunk genotype I in Sweden. None of these four patients were immunocompromised, and all four showed classical symptoms of cryptosporidiosis. We performed extensive molecular characterization, including analysis of four loci. The twoC. viatorumisolates were found to differ slightly at the 70-kDa heat shock protein locus, which may indicate a local geographical variation in this species that has previously been described exclusively on the Indian subcontinent.


Author(s):  
Z. Banda ◽  
Rosely A.B. Nichols ◽  
A.M. Grimason ◽  
H.V. Smith

Of 1 346 faecal samples from the Chikwawa and Thyolo districts of Malawi, analysed for the presence of Cryptosporidium oocysts between October 2001 and May 2003, 61.3 % were from cattle (29.8 % of these were from calves < 6 months old). Cryptosporidium oocysts were detected during all three seasons studied in Chikwawa and Thyolo. In Chikwawa, 13.6 % of adult cattle and 11.7 % of calves were infected, compared to 28.9 % of adult cattle and 36.7 % of calves in Thyolo. Dependent on season, between 7.8 % and 37.7 % (Chikwawa) and 16.7 % and 39.3 % (Thyolo) of cattle samples contained oocysts. In Chikwawa, the highest percentage of infections occurred in the cool season, whereas in Thyolo, the highest percentage of infections occurred in the dry season. Faecal samples from goats [n = 225], pigs [n = 92], sheep [n = 6]), rabbits, guinea pigs, chickens, ducks, turkeys, doves and guinea fowls were also analysed. Up to 5.6 % of goat samples contained oocysts in Chikwawa, compared to between 16.7 % and 39.3 % in Thyolo. Again, in Chikwawa, the highest percentage of infections occurred in the cool season and the lowest in the rainy season, whereas, in Thyolo, the highest percentage of infections occurred in the dry season and the lowest in the cool season. In pigs, more infections were detected in the dry season in Chikwawa, but infections in the cool season were similar (17.7 %), whereas in Thyolo, infections occurred in all three seasons (17.9 % in the rainy season, 25 % in the cool season and 60 % in the dry season). Often diarrhoeic, oocyst positive cattle faecal samples collected from Chikwawa and subjected to PCR-RFLP, four oocyst positive samples (two from heifers, one from a cow and one unknown) were amplified at an 18S rRNA and Cryptosporidium oocyst wall protein (COWP) loci. RFLP of the 18S rRNA locus indicated that Cryptosporidium parvum, Cryptosporidium hominis, Cryptosporidium bovis and / or Cryptosporidium ryanae DNA, or a mixture of them was present. Cryptosporidium parvum DNA was identified in one sample that amplified at the COWP locus, indicating the presence of the major zoonotic Cryptosporidium species in Malawi.


2021 ◽  
Author(s):  
botchiesenyo not provided

Detection of Cryptosporidium parvum and/or Cryptosporidium hominis from fecal samples by qPCR.


2008 ◽  
Vol 74 (23) ◽  
pp. 7227-7234 ◽  
Author(s):  
Sultan Tanrıverdi ◽  
Alex Grinberg ◽  
Rachel M. Chalmers ◽  
Paul R. Hunter ◽  
Zorana Petrovic ◽  
...  

ABSTRACT Cryptosporidium parvum and Cryptosporidium hominis are two related species of apicomplexan protozoa responsible for the majority of human cases of cryptosporidiosis. In spite of their considerable public health impact, little is known about the population structures of these species. In this study, a battery of C. parvum and C. hominis isolates from seven countries was genotyped using a nine-locus DNA subtyping scheme. To assess the existence of geographical partitions, the multilocus genotype data were mined using a cluster analysis based on the nearest-neighbor principle. Within each country, the population genetic structures were explored by combining diversity statistical tests, linkage disequilibrium, and eBURST analysis. For both parasite species, a quasi-complete phylogenetic segregation was observed among the countries. Cluster analysis accurately identified recently introduced isolates. Rather than conforming to a strict paradigm of either a clonal or a panmictic population structure, data are consistent with a flexible reproductive strategy characterized by the cooccurrence of both propagation patterns. The relative contribution of each pattern appears to vary between the regions, perhaps dependent on the prevailing ecological determinants of transmission.


2009 ◽  
Vol 105 (3) ◽  
pp. 689-696 ◽  
Author(s):  
Hui-Wen A. Cheng ◽  
Frances E. Lucy ◽  
Thaddeus K. Graczyk ◽  
Michael. A. Broaders ◽  
Leena Tamang ◽  
...  

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