title: In vivo Distribution and Clearance of Purified Capsular Polysaccharide from Burkholderia pseudomallei in a Murine Model.
abstract: Burkholderia pseudomallei is the causative agent of melioidosis, a severe infection prominent in northern Australia and Southeast Asia. The "gold standard" for melioidosis diagnosis is bacterial isolation, which takes several days to complete. The resulting delay in diagnosis leads to delayed treatments, which could result in death. In an attempt to develop better methods for early diagnosis of melioidosis, B. pseudomallei capsular polysaccharide (CPS) was identified as an important diagnostic biomarker. A rapid lateral flow immunoassay utilizing CPS-specific monoclonal antibody was developed and tested in endemic regions worldwide. However, the in vivo fate and clearance of CPS has never been thoroughly investigated. Here, we injected mice with purified CPS intravenously and determined CPS concentrations in serum, urine, and major organs at various intervals. The results indicate that CPS is predominantly eliminated through urine and no CPS accumulation occurs in the major organs. Immunoblot analysis demonstrated that intact CPS was excreted through urine. To understand how a large molecule like CPS was eliminated without degradation, a 3-dimenational structure of CPS was modeled. The predicted CPS structure has a rod-like shape with a small diameter that could allow it to flow through the glomerulus of the kidney. CPS clearance was determined using exponential decay models and the corrected Akaike Information Criterion. The results show that CPS has a relatively short serum half-life of 2.9 to 4.4 hours. Therefore, the presence of CPS in the serum and/or urine suggests active melioidosis infection and provides a marker to monitor treatment of melioidosis.
authors.affiliation: Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, Nevada, United States of America.
authors.forename: Teerapat
authors.initials: T
authors.lastname: Nualnoi
authors.affiliation: Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, Nevada, United States of America.
authors.forename: Adam
authors.initials: A
authors.lastname: Kirosingh
authors.affiliation: Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, Nevada, United States of America.
authors.forename: Sujata G
authors.initials: SG
authors.lastname: Pandit
authors.affiliation: Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, Nevada, United States of America.
authors.forename: Peter
authors.initials: P
authors.lastname: Thorkildson
authors.affiliation: Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, United States of America.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Brett
authors.affiliation: Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, United States of America.
authors.forename: Mary N
authors.initials: MN
authors.lastname: Burtnick
authors.affiliation: Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, Nevada, United States of America.
authors.forename: David P
authors.initials: DP
authors.lastname: AuCoin
mesh_terms: D061605:Administration, Intravenous; D000818:Animals; D001315:Australia; D016667:Bacterial Capsules / Q000737:chemistry*; D016957:Burkholderia pseudomallei / Q000737:chemistry*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006207:Half-Life; D015151:Immunoblotting; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008554:Melioidosis / Q000175:diagnosis / Q000382:microbiology; D051379:Mice; D011135:Polysaccharides, Bacterial / Q000097:blood / Q000737:chemistry* / Q000493:pharmacokinetics* / Q000652:urine
chemical_list: D011135:Polysaccharides, Bacterial