Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-28T00:18:29.294Z Has data issue: false hasContentIssue false
  • English
  • Français

Analysis of genomic diversity within the Xr-region of the protein A gene in clinical isolates of Staphylococcus aureus

Published online by Cambridge University Press:  01 April 1999

N. KOBAYASHI ,
S. URASAWA ,
N. UEHARA  and
N. WATANABE
N. KOBAYASHI
Affiliation:
Department of Hygiene, Sapporo Medical University School of Medicine, S-1 W-17, Chuo-ku, Sapporo, 060, Japan
S. URASAWA
Affiliation:
Department of Hygiene, Sapporo Medical University School of Medicine, S-1 W-17, Chuo-ku, Sapporo, 060, Japan
N. UEHARA
Affiliation:
Department of Laboratory Diagnosis, Sapporo Medical University School of Medicine, S-1 W-16, Chuo-ku, Sapporo, 060, Japan
N. WATANABE
Affiliation:
Department of Laboratory Diagnosis, Sapporo Medical University School of Medicine, S-1 W-16, Chuo-ku, Sapporo, 060, Japan
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Protein A of Staphylococcus aureus contains a polymorphic Xr-region characterized by a tandem repeat of eight amino acid units. In this study, the diversity of genes encoding the repeat regions and their relatedness among S. aureus strains was analyzed. Ten different protein-A types characterized by repeat numbers 4–13 were identified in a total of 293 clinical isolates. The protein-A type with 10 repeat units (10 repeats) in the Xr-region was most frequently detected in methicillin-resistant S. aureus, whereas the majority of methicillin- susceptible strains were distributed almost evenly into protein-A types with 7–11 repeats. Strains that belonged to a single coagulase type were classified into multiple protein-A types, e.g. strains with the common coagulase types II and VII were differentiated into 7 and 8 protein-A types, respectively.

Nucleotide sequence analysis of the Xr-region of 42 representative strains revealed the presence of 37 different genotypes (spa types), which were constituted by a combination of several of 24 different repeat unit genotypes. Based on the similarity in arrangement of repeat unit genotypes, 34 strains with different repeat numbers were classified into 5 genetic clusters (C1–C5). The clusters C1, C2 and C3 consisted exclusively of strains with identical coagulase types II, III, and IV, respectively. These findings suggested that the protein-A gene of S. aureus has evolved from a common ancestral clone in individual clusters independently.

Type
Research Article
Information
Epidemiology & Infection , Volume 122 , Issue 2 , April 1999 , pp. 241 - 249
Copyright
© 1999 Cambridge University Press