Diversity in the major polysaccharide antigen of Acinetobacter baumannii assessed by DNA sequencing, and development of a molecular serotyping scheme

PLoS One. 2013 Jul 29;8(7):e70329. doi: 10.1371/journal.pone.0070329. Print 2013.

Abstract

We have sequenced the gene clusters for type strains of the Acinetobacter baumannii serotyping scheme developed in the 1990s, and used the sequences to better understand diversity in surface polysaccharides of the genus. We obtained genome sequences for 27 available serovar type strains, and identified 25 polysaccharide gene cluster sequences. There are structures for 12 of these polysaccharides, and in general the genes present are appropriate to the structure where known. This greatly facilitates interpretation. We also find 53 different glycosyltransferase genes, and for 7 strains can provisionally allocate specific genes to all linkages. We identified primers that will distinguish the 25 sequence forms by PCR or microarray, or alternatively the genes can be used to determine serotype by "molecular serology". We applied the latter to 190 Acinetobacter genome-derived gene-clusters, and found 76 that have one of the 25 gene-cluster forms. We also found novel gene clusters and added 52 new gene-cluster sequence forms with different wzy genes and different gene contents. Altogether, the strains that have one of the original 25 sequence forms include 98 A. baumannii (24 from our strains) and 5 A. nosocomialis (3 from our strains), whereas 32 genomes from 12 species other than A. baumannii or A. nosocomialis, all have new sequence forms. One of the 25 serovar type sequences is found to be in European clone I (EC I), 2 are in EC II but none in EC III. The public genome strains add an additional 52 new sequence forms, and also bring the number found in EC I to 5, in EC II to 9 and in EC III to 2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter baumannii / classification*
  • Acinetobacter baumannii / genetics*
  • Acinetobacter baumannii / immunology
  • Acinetobacter baumannii / metabolism
  • Antigens, Bacterial / genetics*
  • Antigens, Bacterial / immunology
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / immunology
  • Biosynthetic Pathways
  • Gene Order
  • Genes, Bacterial
  • Genetic Linkage
  • Genetic Variation
  • Genome, Bacterial
  • Molecular Typing
  • Multigene Family
  • Phylogeny
  • Polysaccharides, Bacterial / immunology*
  • Polysaccharides, Bacterial / metabolism
  • Sequence Analysis, DNA
  • Serotyping

Substances

  • Antigens, Bacterial
  • Bacterial Proteins
  • Polysaccharides, Bacterial

Grants and funding

The project was supported by the National Key Program for Infectious Diseases of China (2013ZX10004216-001-001); the National 863 program of China (2011AA100901-2); National Natural Science Foundation of China (NSFC) Program (31030002); NSFC general program (31270003). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.