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1 2002

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Struktura chemiczna, swoistość antygenowa i znaczenie w chorobotwórczości lipopolisacharydu (LPS, endotoksyna) na przykładzie bakterii Proteus vulgaris

Różalski A., Torzewska A., Bartodziejska B., Babicka D., Kwil I., Perepelov A.V., Kondakova A.N., Senchenkova S.N., Knirel Y., Vinogradov Evgeny V.

Wiadomości Chemiczne

2002

[Z] 56, 7-8

585-604

Gram-negative bacteria of the genus Proteus from the family Enterobacteriaceae are opportunistic pathogens, which cause mainly wounds and urinary tract infections (UTI), the latter leading to severe complications, such as acute or chronic pyelonephrithis and formation of bladder and kidney stones. Virulence factors and properties of Proteus sp. mediating infectious process are swarming phenomenon, adherence due to the fimbriae or glycocalyx, flagella, invasiveness, urease, amino acids deaminases, proteases, hemolysins, capsular polysaccharide (CPS), and lipopolysaccharide (LPS). LPS is an integral component of cell wall of bacteria. It also represents the endotoxin which, after being released from bacterial cells, causes a broad spectrum of pathological effects leading in severe cases to the septic shock. Lipopolysaccharide consists of three parts - O- specific chain (O-antigen), core and lipid A; all of them have been studied in Proteus LPS. It has been documented that Proteus is an antigenically heterogeneous genus, principally because of structural differences in its O-specific polysaccharide chain of LPS. The serological classification of P. mirabilis and P. vulgaris shares 60 serogroups : 22 described for P. vulgaris, 33 characteristic for P. mirabilis and 5 common for both P. mirabilis and P. vulgaris. Serological classification of Proteus penneri still remains to be completed. Proteus O-antigens are branched or linear polysaccharides, built up of oligosaccharide repeating units, varying from a trisaccharide to a hexasaccharide. Acidic O-specific polysaccharides represent the majority of Proteus O-antigens; it was found that 80% of Proteus O-antigens were acidic. Uronic acids and amino sugars usually determine the serological specificity of Proteus O-antigens. Amino sugars in Proteus O-antigens are usually N-acetylated. In many O-antigens, sugars constituents carry an O-acetyl groups. Hexuronic acids either have free carboxyl group or are amidated with the a-amino group of amino acids - lysine, serine, alanine or threonine. Chemical and serological studies have been undertaken with the aim to understand on the molecular level the immunospecificity of Proteus LPS and its potential role during infection of bacteria. The O-antigens and O-antisera against Proteus with defined epitope specificity can be used for serodiagnosis and epidemiological studies. It was found that O-specific polysaccharide Proteus bacteria is involved in creation of glycocalyx which allows bacteria to grow in microcolony or in biofilm. Biofilm protects bacteria against action of antimicrobial agents and leukocytes, and it is also a organic gel-like surrounding contributing to stone formation. LPS from the S form of bacteria, containing all three regions also contributes to their resistance against bactericidal action of serum. The present review is mainly focused on the structure, specificity and biological function of Proteus vulgaris LPS.