COMPARATIVE INACTIVATION OF CRYPTOSPORIDIUM PARVUM OOCYSTS AND COLIPHAGE MS2 BY MONOCHROMATRIC UV RADIATION

2000 ◽  
Vol 2000 (2) ◽  
pp. 97-102 ◽  
Author(s):  
Gwy-Am Shin ◽  
Karl Linden ◽  
Mark D. Sobsey
Keyword(s):  
Uv Radiation ◽  
Cryptosporidium Parvum ◽  
Cryptosporidium Parvum Oocysts

Comparative effectiveness of UV wavelengths for the inactivation of Cryptosporidium parvum oocysts in water

2001 ◽  
Vol 43 (12) ◽  
pp. 171-174 ◽  
Author(s):  
K. G. Linden ◽  
G. Shin ◽  
M. D. Sobsey
Keyword(s):  
Uv Radiation ◽  
Cryptosporidium Parvum ◽  
Mercury Vapour ◽  
Wide Range ◽  
Mercury Vapour Lamp ◽  
A Cell ◽  
Cryptosporidium Parvum Oocysts ◽  
Cell Culture Assay ◽  
Uv Lamps ◽  
Collimated Beam

Cryptosporidium parvum oocysts in water were exposed to distinct wavelength bands of collimated beam ultraviolet (UV) radiation across the germicidal UV wavelength range (210-295 nm) that were emitted from a medium pressure (MP) mercury vapour lamp. The dose of UV radiation transmitted though each narrow bandpass filter was measured utilising potassium ferrioxalate actinometry. Oocyst infectivity was determined using a cell culture assay and titre was expressed as an MPN. The log10 inactivation for each band of radiation was determined for a dose of 2 mJ/cm2. Doses from all wavelengths between 250-275 nm resulted in approximately 2 log10 inactivation of Cryptosporidium parvum oocyst infectivity while doses with wavelengths higher and lower than this range were less effective. Because polychromatic radiation from MP UV lamps had about the same germicidal activity between the wavelengths of 250-275 nm for inactivation of oocyst infectivity, there was no unique advantage of MP UV over low pressure (LP) UV except for the simultaneous delivery of a wide range of germicidal wavelengths.

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.

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

1997 ◽  
Vol 35 (11-12) ◽  
pp. 261-268 ◽  
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.

Detection of Cryptosporidium parvum Oocysts on Fresh Vegetables and Herbs Using Antibodies Specific for a Cryptosporidium parvum Viral Antigen

2005 ◽  
Vol 68 (5) ◽  
pp. 1093-1096 ◽  
Author(s):  
K. E. KNIEL ◽  
M. C. JENKINS
Keyword(s):  
Cryptosporidium Parvum ◽  
Viral Antigen ◽  
Blot Hybridization ◽  
Surface Antigens ◽  
Food Samples ◽  
Sensitive Detection ◽  
Dot Blot ◽  
Dot Blot Hybridization ◽  
Fresh Vegetables ◽  
Cryptosporidium Parvum Oocysts

The purpose of this study was to determine if the viral symbiont of Cryptosporidium parvum (CPV) sporozoites could be used as a target for sensitive detection of the parasite in food samples. Polyclonal sera specific to the recombinant viral capsid protein (rCPV40) was used in a dot blot hybridization assay to detect oocysts recovered from green onions and cilantro. Small batches of chopped green onions and cilantro leaves were artificially contaminated with three different concentrations of oocysts: 106, 102, and 101. rCPV40 was superior in detecting oocysts compared with other antibodies directed toward total oocyst protein and oocyst surface antigens. This study provides evidence that CPV is an excellent target for sensitive detection of C. parvum oocysts in foods.

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