Sources and Species of Cryptosporidium Oocysts in the Wachusett Reservoir Watershed

109

Recent molecular evidence suggests that different species and/or genotypes of Cryptosporidium display strong host specificity, altering our perceptions regarding the zoonotic potential of this parasite. Molecular forensic profiling of the small-subunit rRNA gene from oocysts enumerated on microscope slides by U.S. Environmental Protection Agency method 1623 was used to identify the range and prevalence of Cryptosporidium species and genotypes in the South Nation watershed in Ontario, Canada. Fourteen sites within the watershed were monitored weekly for 10 weeks to assess the occurrence, molecular composition, and host sources of Cryptosporidium parasites impacting water within the region. Cryptosporidium andersoni, Cryptosporidium muskrat genotype II, Cryptosporidium cervine genotype, C. baileyi, C. parvum, Cryptosporidium muskrat genotype I, the Cryptosporidium fox genotype, genotype W1, and genotype W12 were detected in the watershed. The molecular composition of the Cryptosporidium parasites, supported by general land use analysis, indicated that mature cattle were likely the main source of contamination of the watershed. Deer, muskrats, voles, birds, and other wildlife species, in addition to sewage (human or agricultural) may also potentially impact water quality within the study area. Source water protection studies that use land use analysis with molecular genotyping of Cryptosporidium parasites may provide a more robust source-tracking tool to characterize fecal impacts in a watershed. Moreover, the information is vital for assessing environmental and human health risks posed by water contaminated with zoonotic and/or anthroponotic forms of Cryptosporidium.

Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Tracking Host Sources of Cryptosporidium spp. in Raw Water for Improved Health Risk Assessment

Ruecker

Braithwaite

Topp

et al. 2007

109

“…Pollution of water with pathogens has been documented worldwide (13,16,17,25,37,41). In particular, chlorine-resistant pathogens, such as pathogenic viruses (18), Cryptosporidium parvum, and so forth, have raised concerns about outbreaks of waterborne infectious diseases in our society.…”

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confidence: 99%

Virus-Binding Proteins Recovered from Bacterial Culture Derived from Activated Sludge by Affinity Chromatography Assay Using a Viral Capsid Peptide

Sano

Matsuo

Omura

2004

The contamination of water environments by pathogenic viruses has raised concerns about outbreaks of viral infectious diseases in our society. Because conventional water and wastewater treatment systems are not effective enough to inactivate or remove pathogenic viruses, a new technology for virus removal needs to be developed. In this study, the virus-binding proteins (VBPs) in a bacterial culture derived from activated sludge were successfully recovered. The recovery of VBPs was achieved by applying extracted crude proteins from a bacterial culture to an affinity column in which a custom-made peptide of capsid protein from the poliovirus type 1 (PV1) Mahoney strain (H 2 N-DNPASTTNKDKL-COOH) was immobilized as a ligand. VBPs exhibited the ability to adsorb infectious particles of PV1 Sabin 1 as determined by enzyme-linked immunosorbent assay. The evaluation of surface charges of VBPs with ion-exchange chromatography found that a majority of VBP molecules had a net negative charge under the conditions of affinity chromatography. On the other hand, a calculated isoelectric point implied that the viral peptide in the affinity column was also charged negatively. As a result, the adsorption of the VBPs to the viral peptide in the affinity column occurred with a strong attractive force that was able to overcome the electrostatic repulsive force. Two-dimensional electrophoresis revealed that the isolated VBPs include a number of proteins, and their molecular masses were widely distributed but smaller than 100 kDa. Amino acid sequences of N termini of five VBPs were determined. Homology searches for the N termini against all protein sequences in the National Center for Biotechnology Information (NCBI) database showed that the isolated VBPs in this study were newly discovered proteins. These VBPs that originated with bacteria in activated sludge might be stable, because they are existing in the environment of wastewater treatments. Therefore, a virus removal technology utilizing VBPs as viral adsorbents can be developed, since it is possible to replicate VBPs by protein cloning techniques.

“…More recently, a polyphasic approach to taxonomy has included molecular-genetic characterization as well as the traditional criteria (8). The small number of Cryptosporidium oocysts recovered from environmental samples often precludes traditional taxonomic analysis, resulting in species identification that is based solely on molecular characterization of one or more genes (13,19,28,30). Genes encoding actin (22), the 70-kDa heat shock protein (HSP70) (23), the Cryptosporidium oocyst wall protein (COWP) (29), and the 18S small-subunit rRNA (26) have all been used for molecular-genetic characterization of Cryptosporidium spp.…”

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confidence: 99%

Phylogenetic Analysis of the Hypervariable Region of the 18S rRNA Gene ofCryptosporidiumOocysts in Feces of Canada Geese (Branta canadensis): Evidence for Five Novel Genotypes

Jellison¹,

Distel

Hemond³

et al. 2004

Self Cite

To assess genetic diversity in Cryptosporidium oocysts from Canada geese, 161 fecal samples from Canada geese in the United States were analyzed. Eleven (6.8%) were positive for Cryptosporidium spp. following nested PCR amplification of the hypervariable region of the 18S rRNA gene. Nine PCR products from geese were cloned and sequenced, and all nine diverged from previously reported Cryptosporidium 18S rRNA gene sequences. Five sequences were very similar or identical to each other but genetically distinct from that of Cryptosporidium baileyi; two were most closely related to, but genetically distinct from, the first five; and two were distinct from any other sequence analyzed. One additional sequence in the hypervariable region of the 18S rRNA gene isolated from a cormorant was identical to that of C. baileyi. Phylogenetic analysis provided evidence for new genotypes of Cryptosporidium species in Canada geese. Results of this study suggest that the taxonomy of Cryptosporidium species in geese is complex and that a more complete understanding of genetic diversity among these parasites will facilitate our understanding of oocyst sources and species in the environment.