2Department of Immunobiology of Bacteria, Institute of Microbiology, Biotechnology and Immunology, University of Lodz, PL 90-237 Lodz, Poland
3TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, 300457 Tianjin, P. R. China
* To whom correspondence should be addressed.
Received January 30, 2013; Revision received February 28, 2013
The genus Providencia consists of eight species of opportunistic pathogenic enterobacteria that can cause enteric diseases and urinary tract infections. The existing combined serological classification scheme of three species, P. alcalifaciens, P. stuartii, and P. rustigianii, is based on the specificity of O-antigens (O-polysaccharides) and comprises 63 O-serogroups. Differences between serogroups are related to polymorphism at a specific genome locus, the O-antigen gene cluster, responsible for O-antigen biosynthesis. This review presents data on structures of 36 O-antigens of Providencia, many of which contain unusual monosaccharides and non-carbohydrate components. The structural data correlate with the immunospecificity of the O-antigens and enable substantiation on a molecular level of serological relationships within the genus Providencia and between strains of Providencia and bacteria of the genera Proteus, Escherichia, and Salmonella. Peculiar features of the O-antigen gene cluster organization in 10 Providencia serogroups and biosynthetic pathways of nucleotide precursors of specific monosaccharide components of the O-antigens also are discussed.
KEY WORDS: Providencia, lipopolysaccharide, O-antigen, gene cluster, biosynthesis, serological specificity