Linked Life Data

11425712

Source:http://linkedlifedata.com/resource/pubmed/id/11425712

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2001-6-26
pubmed:abstractText
Cryptosporidium parvum, which is resistant to chlorine concentrations typically used in water treatment, is recognized as a significant waterborne pathogen. Recent studies have demonstrated that chlorine dioxide is a more efficient disinfectant than free chlorine against Cryptosporidium oocysts. It is not known, however, if oocysts from different suppliers are equally sensitive to chlorine dioxide. This study used both a most-probable-number-cell culture infectivity assay and in vitro excystation to evaluate chlorine dioxide inactivation kinetics in laboratory water at pH 8 and 21 degrees C. The two viability methods produced significantly different results (P < 0.05). Products of disinfectant concentration and contact time (Ct values) of 1,000 mg. min/liter were needed to inactivate approximately 0.5 log(10) and 2.0 log(10) units (99% inactivation) of C. parvum as measured by in vitro excystation and cell infectivity, respectively, suggesting that excystation is not an adequate viability assay. Purified oocysts originating from three different suppliers were evaluated and showed marked differences with respect to their resistance to inactivation when using chlorine dioxide. Ct values of 75, 550, and 1,000 mg. min/liter were required to achieve approximately 2.0 log(10) units of inactivation with oocysts from different sources. Finally, the study compared the relationship between easily measured indicators, including Bacillus subtilis (aerobic) spores and Clostridium sporogenes (anaerobic) spores, and C. parvum oocysts. The bacterial spores were found to be more sensitive to chlorine dioxide than C. parvum oocysts and therefore could not be used as direct indicators of C. parvum inactivation for this disinfectant. In conclusion, it is suggested that future studies address issues such as oocyst purification protocols and the genetic diversity of C. parvum, since these factors might affect oocyst disinfection sensitivity.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-10383227, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-10458969, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-10473398, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-10579426, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-1482175, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-2339894, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-2764564, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-3545807, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-8285711, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-8368831, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-9279581, http://linkedlifedata.com/resource/pubmed/commentcorrection/11425712-9554076
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0099-2240
pubmed:author
pubmed:issnType
Print
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2993-3001
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Chlorine dioxide inactivation of Cryptosporidium parvum oocysts and bacterial spore indicators.
pubmed:affiliation
Biological and Physical Sciences Unit, Indiana University Kokomo, Kokomo, Indiana 46904-9003, USA. cchauret@iuk.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't