scholarly journals Efficacy of Common Laboratory Disinfectants on the Infectivity of Cryptosporidium parvum Oocysts in Cell Culture

2002 ◽  
Vol 68 (5) ◽  
pp. 2576-2579 ◽  
Author(s):  
Susan C. Weir ◽  
Nicholas J. Pokorny ◽  
Ramon A. Carreno ◽  
Jack T. Trevors ◽  
Hung Lee
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Culture ◽  
Sodium Hypochlorite ◽  
Cryptosporidium Parvum ◽  
Ammonium Hydroxide ◽  
Cryptosporidium Parvum Oocysts ◽  
Common Laboratory

ABSTRACT Nine liquid disinfectants were tested for their ability to reduce infectivity of Cryptosporidium parvum oocysts in cell culture. A 4-min exposure to 6% hydrogen peroxide and a 13-min exposure to ammonium hydroxide-amended windshield washer fluid reduced infectivity 1,000-fold. Other disinfectants tested (70% ethanol, 37% methanol, 6% sodium hypochlorite, 70% isopropanol, and three commercial disinfectants) did not reduce the infectivity after a 33-min exposure. The results indicate that hydrogen peroxide and windshield washer fluid or ammonium hydroxide disinfectant may be suitable laboratory disinfectants against C. parvum oocysts.

Improving the Rate of Infectivity of Cryptosporidium parvum Oocysts in Cell Culture Using Centrifugation

2001 ◽  
Vol 87 (6) ◽  
pp. 1502
Author(s):  
S. C. Weir ◽  
N. J. Pokorny ◽  
R. A. Carreno ◽  
J. T. Trevors ◽  
H. Lee
Keyword(s):  
Cell Culture ◽  
Cryptosporidium Parvum ◽  
Cryptosporidium Parvum Oocysts

The fate of aflatoxin in naturally contaminated corn during the ethanol fermentation

1979 ◽  
Vol 25 (8) ◽  
pp. 911-914 ◽  
Author(s):  
E. B. Lillehoj ◽  
A. Lagoda ◽  
W. F. Maisch
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Sodium Hypochlorite ◽  
Ethanol Fermentation ◽  
Potential Problem ◽  
Animal Feed ◽  
Ammonium Hydroxide ◽  
Spent Grains ◽  
Toxin Degradation

Corn naturally contaminated with aflatoxin was used as a substrate in the ethanol fermentation. Distribution of toxin in several process and recovery fractions was identified. Although little degradation of the mycotoxin occurred during fermentation, no toxin appeared in the distilled alcohol. As accumulation of toxin in spent grains represents a potential problem in use of the material as animal feed, several decontamination procedures were tested. Sodium hydroxide, ammonium hydroxide, sodium hypochlorite, and hydrogen peroxide were identified as efficient agents of toxin degradation.

Inactivation of Cryptosporidium parvum oocysts and other microbes in water and wastewater by electrochemically generated mixed oxidants

2000 ◽  
Vol 41 (7) ◽  
pp. 127-134 ◽  
Author(s):  
M. J. Casteel ◽  
M. D. Sobsey ◽  
M. J. Arrowood
Keyword(s):  
Escherichia Coli ◽  
Cell Culture ◽  
Cryptosporidium Parvum ◽  
Propidium Iodide ◽  
Treated Wastewater ◽  
E Coli ◽  
Water And Wastewater ◽  
Cryptosporidium Parvum Oocysts ◽  
Cell Culture Assay ◽  
Escherichia Coli B

Alternative disinfectants of water and wastewater are needed because conventional chlorination is ineffective against C. parvum oocysts. Reliable indicators of disinfection efficacy against C. parvum also are needed. Mixedoxidants (MO) electrochemically generated from brine were evaluated in batch disinfection experiments for inactivation of C. parvum oocysts and Cl. perfringensspores in both oxidant demand-free (ODF) water and treated wastewater. Coliphage MS2 and Escherichia coli B were also tested under some conditions. C. parvum oocyst infectivity was quantified by cell culture assay, and the dyes DAPI (4′,6-diamidino-2-phenylindole) and propidium iodide (PI) were used to assess oocyst viability in wastewater experiments. In treated wastewater dosed with 10–13 mg/L MO, inactivation after 90 minutes was about 3 log10 for C. parvum and about 2.5 log10 for Cl. perfringens spores; MS2 and E. coli were rapidly inactivated by > 5 log10. In ODF water, a 4 mg/L dose of MO inactivated ∼3 log10 of C. parvum oocysts and ∼1.5 log10 of Cl. perfringens spores. Inactivation of C. parvum oocysts and Cl. perfringensspores was less extensive at a lower MO dose of 2 mg/L. The use of DAPI and PI to determine viability of oocysts treated with MO did not correlate with, and greatly overestimated, cell culture infectivity. At practical doses and contact times, MO disinfection of water and wastewater achieves appreciable inactivation of both C. parvum oocysts and Cl. perfringens spores. Cl. perfringens spores reliably indicated oocyst inactivation by MO, but E. coli and coliphage MS2 were inactivated much too rapidly to indicate C. parvum inactivation.

Evaluation of Immunomagnetic Separation for Recovery of Infectious Cryptosporidium parvum Oocysts from Environmental Samples

1999 ◽  
Vol 65 (2) ◽  
pp. 841-845 ◽  
Author(s):  
Paul A. Rochelle ◽  
Ricardo De Leon ◽  
Anne Johnson ◽  
Mic H. Stewart ◽  
Roy L. Wolfe
Keyword(s):  
Cell Culture ◽  
Reverse Transcriptase ◽  
Cryptosporidium Parvum ◽  
Environmental Samples ◽  
Environmental Water ◽  
Immunomagnetic Separation ◽  
In Vitro Cell Culture ◽  
Magnetic Capture ◽  
Cryptosporidium Parvum Oocysts

ABSTRACT Two commercial immunomagnetic separation (IMS) kits forCryptosporidium were compared for recovery of oocysts from environmental samples. Oocyst recovery efficiencies with the Dynal and Crypto-Scan kits ranged from 62 to 100% and 34 to 74%, respectively, for seeded environmental water concentrates (turbidity of 210 to 11,480 nephelometric turbidity units). Recovery efficiencies were dependent on the mechanism of agitation during the magnetic capture procedure. An assay combining in vitro cell culture and reverse transcriptase PCR demonstrated that oocysts recovered by IMS retained their infectivity.

Effect of Organic Acids and Hydrogen Peroxide on Cryptosporidium parvum Viability in Fruit Juices

2003 ◽  
Vol 66 (9) ◽  
pp. 1650-1657 ◽  
Author(s):  
KALMIA E. KNIEL ◽  
SUSAN S. SUMNER ◽  
DAVID S. LINDSAY ◽  
CAMERON R. HACKNEY ◽  
MERLE D. PIERSON ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Culture ◽  
Organic Acids ◽  
Cryptosporidium Parvum ◽  
Most Probable Number ◽  
Oocyst Wall ◽  
Probable Number ◽  
Apple Cider ◽  
Infectivity Assay

Cryptosporidium parvum has historically been associated with waterborne outbreaks of diarrheal illness. Foodborne cryptosporidiosis has been associated with unpasteurized apple cider. Infectious oocysts are shed in the feces of common ruminants like cattle and deer in and near orchards. In this study, the ability of organic acids and hydrogen peroxide (H2O2) added to fruit juice to inhibit the survival of C. parvum was analyzed. Oocyst viability was analyzed by a cell culture infectivity assay with the use of a human ileocecal cell line (HCT-8) whose infectivity pattern is similar to that for human oral infectivity. Cell monolayers were infected with 106 treated oocysts or a series of 10-fold dilutions. Parasitic life stages were visualized through immunohistochemistry with 100 microscope fields per monolayer being counted. In vitro excystation assays were also used to evaluate these treatments. Organic acids and H2O2 were added to apple cider, orange juice, and grape juices on a weight/volume basis. Malic, citric, and tartaric acids at concentrations of 1 to 5% inhibited C. parvum's infectivity of HCT-8 cells by up to 88%. Concentrations ranging from 0.025 to 3% H2O2 were evaluated. The addition of 0.025% H2O2 to each juice resulted in a >5-log reduction of C. parvum infectivity as determined with a most-probable-number–based cell culture infectivity assay. As observed with differential interference contrast and scanning electron microscopy, reduced infectivity may be mediated through effects on the oocyst wall that are caused by the action of H2O2 or related oxygen radicals. The addition of low concentrations of H2O2 can represent a valuable alternative to pasteurization.

scholarly journals Infectious Cryptosporidium parvum Oocysts in Final Reclaimed Effluent

2003 ◽  
Vol 69 (8) ◽  
pp. 4983-4984 ◽  
Author(s):  
Angela L. Gennaccaro ◽  
Molly R. McLaughlin ◽  
Walter Quintero-Betancourt ◽  
Debra E. Huffman ◽  
Joan B. Rose
Keyword(s):  
Cell Culture ◽  
Cryptosporidium Parvum ◽  
Detection Method ◽  
Reclaimed Water ◽  
Culture Technique ◽  
Most Probable Number ◽  
Probable Number ◽  
Cryptosporidium Parvum Oocysts ◽  
Focus Detection ◽  
Cell Culture Technique

ABSTRACT Water samples collected throughout several reclamation facilities were analyzed for the presence of infectious Cryptosporidium parvum by the focus detection method-most-probable-number cell culture technique. Results revealed the presence of infectious C. parvum oocysts in 40% of the final disinfected effluent samples. Sampled effluent contained on average seven infectious oocysts per 100 liters. Thus, reclaimed water is not pathogen free but contains infectious C. parvum.

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