Inactivation of <I>Cryptosporidium parvum</I> Oocysts in Copper Tubing

• SASAHARA Takeshi

  Department of Microbiology & Parasitology

• KIKUNO Ritsuko

  Kitasato University School of Medicine

• NAKAMURA Takeshi

  Department of Microbiology & Parasitology

• SEKIGUCHI Tomoko

  Department of Microbiology & Parasitology

• TAKAHASHI Akira

  Laboratory Animal Centrefor Medical Science

• SATOH Yoshinori

  Department of Microbiology & Parasitology

• TAKAYAMA Yoko

  Department of Laboratory Medicine

• OKUDA Shunji

  Kitasato University School of Medicine

• INOUE Matsuhisa

  Department of Microbiology & Parasitology Kitasato University School of Medicine

Bibliographic Information

Other Title

• 銅管による<I>Cryptosporidium parvum</I>オーシストの感染性不活化
• 銅管によるCryptosporidium parvumオーシストの感染性不活化
• ドウカン ニ ヨル Cryptosporidium parvum オーシスト ノ カンセンセイ フカツカ
• Inactivation of Cryptosporidium parvum Oocysts in Copper Tubing

Abstract

We studied whether the infectivity of Cryptosporidium parvum oocysts for suckling mice could be inactivated by copper tubing or by other types of tubing used to construct water distribution systems, including stainless steel, rigid polyvinyl chloride (PVC), PVC-lined steel, polyethylene (PE), cross-linked PE, and polybutene (PB), using glass tubing as the control. Oocysts were incubated in each tubings for 24 hours. The extent of inactivation of infectious oocysts by copper tubing was -1.303 log, which significantly inactivated of infectivity. In contrast, other types of tubing had no significant effect on some oocyst infectivity, although. PB did show a maximum inactivation of -0.313 log. 25% of oocysts showed degeneration morphologically after passing through copper tubing, while 0.3% to 1.8% showed degeneration after passing through other tubing. Significant inactivation of infectious oocysts was not caused by water in which copper tubing had been let stand for 24 hours, although it had a cupric ion (Cu²⁺) concentration of 2.4mg/L. The direct contact of oocysts with copper surface resulted in a decrease in the recovery percentage of oocysts and generation of hydrogen peroxide (0.5mg/L) after 24 h of incubation. The percentage of degenerating oocysts was 29%. Such cryptosporidicidal effects of the copper surface on oocysts were completely inhibited by overlaying the surface with a Millipore filter before adding oocysts and incubating oocysts in the presence of catalase, an antioxidant enzyme. These findings suggest that copper tubing inactivates infectious C. parvum oocysts cytotoxically which may be due to oxygen radicals generated by the interaction between Cu²⁺ and hydrogen peroxide on the tubing surface.

Journal

• Kansenshogaku Zasshi

  Kansenshogaku Zasshi 80 (4), 377-382, 2006

  The Japanese Association for Infectious Diseases

Keywords

• Cryptosporidium parvum
• oocyst
• copper tubing
• cryptosporidicidal activity

Details

• CRID: 1390001205049445248
• NII Article ID: 130004331321
• NII Article ID: 10018259810
• NII Book ID: AN00047715
• DOI: 10.11150/kansenshogakuzasshi1970.80.377
• ISSN: 1884569X
• ISSN: 03875911
• NDL BIB ID: 8005182
• PubMed: 16922480
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I8005182
• Web Site: https://search.jamas.or.jp/link/ui/2006287322
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
• Abstract License Flag: Disallowed