title: Identification of a Novel Rhizopus-specific Antigen by Screening with a Signal Sequence Trap and Evaluation as a Possible Diagnostic Marker of Mucormycosis.
abstract: Mucormycosis is the second most common mould infection, often indistinguishable from other invasive mould infections such as aspergillosis. Although an appropriate antifungal therapy is effective at an early stage of the infection, there is no reliable diagnostic method for decision making. Thus, it is necessary to develop an efficient method that can detect mucormycosis rapidly and accurately. We searched for secreted or membrane-bound proteins of Rhizopus oryzae, which is the most common pathogen of mucormycosis, using the method of a signal sequence trap by retrovirus-mediated expression (SST-REX). Among the identified proteins, a Rhizopus-specific antigen was selected as a candidate, and efficacy of this specific antigen was evaluated using R. oryzae-infected mice. Of 302 clones obtained from the SST-REX library, a hypothetical protein (23 kDa, named "protein RSA") was selected as a candidate because of its highest prevalence of clones. Protein RSA was detected at significantly higher concentrations in serum and in lung homogenates of the infected mice as compared to those of uninfected mice. Our study indicates that protein RSA may be a promising biomarker of R. oryzae infection. SST-REX may be useful for comprehensive screening of prospective eukaryotic biomarkers of intractable mould infections.
authors.affiliation: Department of Bacteriology, Osaka City University Graduate School of Medicine, Osaka, Japan.|Department of Respiratory Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Bacteriology, Osaka City University Graduate School of Medicine, Osaka, Japan.|Research Center for Infectious Disease Sciences.
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Oinuma
authors.affiliation: Department of Bacteriology, Osaka City University Graduate School of Medicine, Osaka, Japan.|Research Center for Infectious Disease Sciences.
authors.forename: Mamiko
authors.initials: M
authors.lastname: Niki
authors.affiliation: Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamagoe
authors.affiliation: Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Miyazaki
authors.affiliation: Department of Respiratory Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Asai
authors.affiliation: Research Center for Infectious Disease Sciences.|Department of Infection Control Science, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Respiratory Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Hirata
authors.affiliation: Department of Bacteriology, Osaka City University Graduate School of Medicine, Osaka, Japan.|Research Center for Infectious Disease Sciences.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Research Center for Infectious Disease Sciences.|Department of Infection Control Science, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kakeya
mesh_terms: D000818:Animals; D000946:Antigens, Fungal / Q000032:analysis* / Q000097:blood*; D001769:Blood / Q000382:microbiology; D005260:Female; D008168:Lung / Q000382:microbiology; D008813:Mice, Inbred ICR; D009091:Mucormycosis / Q000175:diagnosis* / Q000382:microbiology; D021382:Protein Sorting Signals; D012233:Rhizopus / Q000302:isolation & purification*
chemical_list: D000946:Antigens, Fungal; D021382:Protein Sorting Signals
keywords: Rhizopus oryzae; biomarker; mucormycosis; signal sequence trap