title: Characterization and evaluation of a novel immunochromatographic assay for pharyngeal Mycoplasmapneumoniae ribosomal protein L7/L12 antigens.
abstract: Point-of-care testing for Mycoplasma pneumoniae infection may be ideal and useful because significant numbers of the cases will be seen as outpatients. Recently, a new immunochromatographic method (ICM) targeting M. pneumoniae ribosomal protein L7/L12 (RP-L7/L12) in pharyngeal swabs became available in Japan, although clinical data and basic information regarding efficacy and characterization of this ICM are limited. The present study examined the fate of M. pneumoniae RP-L7/L12 during in vitro growth and the correlation between M. pneumoniae concentration in clinical specimens and the sensitivity of the ICM test. The usefulness of the ICM was investigated in patients suspected of having M. pneumoniae pneumonia and upper respiratory tract infection (137 children and 39 adults). The limit of detection for the ICM test was 1.1×104 c.f.u. ml-1 of M. pneumoniae. Bacterial production of RP-L7/L12 correlated positively with the viable M. pneumoniae concentration in vitro; antigen was then degraded in culture broth, with an in vitro half-life of approximately 2 days. Five other Mycoplasma spp. and 14 representative respiratory pathogens were ICM assay negative at bacterial concentrations of 106 c.f.u. ml-1. The clinical sensitivity and specificity of the ICM assay were 57.1 % (20/35) and 92.2 % (130/141), respectively, in comparison with bacterial culture. Clinical specimens containing ≥106 c.f.u. ml-1 of M. pneumoniae burden were ICM positive in 13 of 18 cases (72.2 %). The ICM is a poorly sensitive but reasonably specific means for detecting M. pneumoniae infections.
authors.affiliation: Department of Respiratory Medicine, Toho University Omori Medical Center, Tokyo 143-8540, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Sano
authors.affiliation: Yamanobe Pediatric Clinic, Yamagata, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Itagaki
authors.affiliation: Department of Pediatrics, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Naruhiko
authors.initials: N
authors.lastname: Ishiwada
authors.affiliation: Department of Pediatrics, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Matsubara
authors.affiliation: Department of Pediatrics, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iwata
authors.affiliation: Department of Respiratory Diseases, Mishuku Hospital, Tokyo, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Nakamori
authors.affiliation: Healthcare R&D Center, Asahi Kasei Corporation, Shizuoka, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsuyama
authors.affiliation: R&D Group, Diagnostics Department, Asahi Kasei Pharma Corporation, Shizuoka, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Microbiology and Infectious Disease, Toho University School of Medicine, Tokyo 143-8540, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ishii
authors.affiliation: Department of Respiratory Medicine, Toho University Omori Medical Center, Tokyo 143-8540, Japan.
authors.forename: Sakae
authors.initials: S
authors.lastname: Homma
authors.affiliation: Department of Microbiology and Infectious Disease, Toho University School of Medicine, Tokyo 143-8540, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tateda
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D002846:Chromatography, Affinity / Q000379:methods*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D051379:Mice; D008875:Middle Aged; D009174:Mycoplasma / Q000737:chemistry / Q000302:isolation & purification*; D010614:Pharynx / Q000382:microbiology*; D011019:Pneumonia, Mycoplasma / Q000175:diagnosis*; D019095:Point-of-Care Systems; D012269:Ribosomal Proteins / Q000032:analysis*; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D012269:Ribosomal Proteins; C016700:ribosomal protein L7-L12