Modulation of O-antigen chain length by the wzz gene in Escherichia coli O157 influences its sensitivities to serum complement

Authors

  • Kayo Osawa,

    1. Division of Infectious Diseases, Department of International Health, Kobe University Graduate School of Health Sciences, Kobe
    2. Indonesia-Japan Collaborative Research Center for Emerging and Re-emerging Infectious Diseases, Institute of Tropical Disease
    Search for more papers by this author
  • Katsumi Shigemura,

    1. Division of Urology, Department of Organs Therapeutics, Faculty of Medicine, Kobe University Graduate School of Medicine, Kobe
    Search for more papers by this author
  • Atsushi Iguchi,

    1. Interdisciplinary Research Organization, University of Miyazaki, Miyazaki
    Search for more papers by this author
  • Hiroki Shirai,

    1. Division of Infectious Diseases, Department of International Health, Kobe University Graduate School of Health Sciences, Kobe
    Search for more papers by this author
  • Toru Imayama,

    1. Division of Infectious Diseases, Department of International Health, Kobe University Graduate School of Health Sciences, Kobe
    Search for more papers by this author
  • Kazuko Seto,

    1. Division of Bacteriology, Osaka Prefectural Institute of Public Health, Osaka
    Search for more papers by this author
  • Dadik Raharjo,

    1. Indonesia-Japan Collaborative Research Center for Emerging and Re-emerging Infectious Diseases, Institute of Tropical Disease
    2. Department of Microbiology, Faculty of Medicine, Airlangga University, Surabaya, Indonesia
    Search for more papers by this author
  • Masato Fujisawa,

    1. Division of Urology, Department of Organs Therapeutics, Faculty of Medicine, Kobe University Graduate School of Medicine, Kobe
    Search for more papers by this author
  • Ro Osawa,

    1. Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe
    2. Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
    Search for more papers by this author
  • Toshiro Shirakawa

    Corresponding author
    1. Division of Urology, Department of Organs Therapeutics, Faculty of Medicine, Kobe University Graduate School of Medicine, Kobe
    2. Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe
    3. Indonesia-Japan Collaborative Research Center for Emerging and Re-emerging Infectious Diseases, Institute of Tropical Disease
    • Division of Infectious Diseases, Department of International Health, Kobe University Graduate School of Health Sciences, Kobe
    Search for more papers by this author

Correspondence

Toshiro Shirakawa, Center for Infectious Diseases, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.

Tel: +81 78 382 5686; fax: +81 78 382 5715; email: toshiro@med.kobe-u.ac.jp

ABSTRACT

Escherichia coli O157 strains belonging to a distinct lineage and expressing different O-antigen (Oag) lengths were isolated. Although the function of wzz in E. coli has not been adequately investigated, this gene is known to be associated with regulation of Oag length. Using E. coli O157:H7 ATCC43888 (wild-type), several wzz mutants of E. coli O157, including a wzz deletion mutant, were generated and the relationship between the length of Oag modulated by the wzz gene and sensitivities to serum complement investigated. SDS–PAGE, immunoblot analyses and sensitivity tests to human serum complement were performed on these strains. The lengths of the O157-antigen could be modulated by the wzz gene mutations and were classified into long, intermediate and short groups. The short chain mutant was more serum sensitive than the wild-type strain and the other wzz mutants (P < 0.001). In conclusion, Oag chain length modulated by the wzz gene in E. coli O157 influences its sensitivities to serum complement. The present findings suggest that E. coli O157 strains with intermediate or long length Oag chains might show greater resistance to serum complement than those with short chains.

Ancillary