title: uspA1 of Moraxella catarrhalis clinical isolates in Japan and its relationship with adherence to HEp-2 cells.
abstract: The surface protein, UspA1, of Moraxella catarrhalis is involved in adherence to human epithelial cells. We examined the expression of uspA1, and adherence to HEp-2 cells of clinical isolates. The uspA1 gene was detected in 204 of 208 isolates. The 4 uspA1-negative isolates belonged to the 16S rRNA type II with an A to G substitution at nucleotide 445 of 16S rRNA. In 13 isolates of the 16S rRNA type II, transcription of uspA1 was decreased or absent. A relationship between the extent of uspA1 transcription and adherence to HEp-2 cells was found in 5 isolates of the type I. In contrast, the 16S rRNA type II strains still had considerable adherence to HEp-2 cells. The type I uspA1 gene was expressed in Escherichia coli JM109 and the transformants adhered to HEp-2 cells at rates about 7 times higher than the host strain. These data indicated that the uspA1 was virtually ubiquitous in clinical isolates of M. catarrhalis and was responsible for adherence to HEp-2 cells of 16S rRNA type I isolates. However, the data also suggested that adherence of 16S rRNA type II strains to HEp-2 cells was attributed to factor(s) other than UspA1.
authors.affiliation: Department of Microbiology and Immunology, Graduate School of Health Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo. qiuhl2004@yahoo.co.jp
authors.forename: Hongli
authors.initials: H
authors.lastname: Qiu
authors.forename: Wakako
authors.initials: W
authors.lastname: Kumita
authors.forename: Kenya
authors.initials: K
authors.lastname: Sato
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nakajima
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nishiyama
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Saito
authors.forename: Etsuko
authors.initials: E
authors.lastname: Sawabe
authors.forename: Emi
authors.initials: E
authors.lastname: Ono
authors.forename: Toshio
authors.initials: T
authors.lastname: Chida
authors.forename: Noboru
authors.initials: N
authors.lastname: Okamura
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000502:physiology*; D001422:Bacterial Adhesion / Q000502:physiology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000502:physiology*; D015373:Bacterial Typing Techniques; D003001:Cloning, Molecular; D004847:Epithelial Cells / Q000502:physiology; D006801:Humans; D001936:Moraxella catarrhalis / Q000737:chemistry*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D012336:RNA, Ribosomal, 16S; C089675:UspA protein, Moraxella catarrhalis