Development of new enteropathogen detection system target at IgA

2014 Fiscal Year Final Research Report

• Project/Area Number: 25670272
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Laboratory medicine
• Research Institution: Okayama University (2014); Osaka University (2013)
• Principal Investigator: GOTOH Kazuyoshi 岡山大学, 医歯(薬)学総合研究科, 助教 (20626593)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: IgA / 腸内細菌叢 / 感染症診断

Outline of Final Research Achievements

When we detect nucleic acids of enteric pathogens from diarrheal stool normal gut microbiota, a dominant in fecal DNA pools, masks the low abundance of pathogens. To solve this problem we employed IgA-coated bacterial sorting technologies. First, we examined that IgA-coated cells were separated by a cell sorter from healthy human stool. DNA was extracted from sorting fraction. However, undetectable level DNA by PCR was obtained from low sorted cell count with our equipment. Because it was difficult to find other optimal conditions, I tried magnetic beads-based separation against IgA. Analysis of 16S rDNA deep sequencing using beads bound showed that no any significant differences was revealed between total and IgA-positive fractions despite the direct observation of IgA-positive bacteria by fluorescent microscopy.
We proposed that IgA-targeted separation should be carefully validated using microscopy although that technique has been published as successful experiences.

Free Research Field

細菌学