Role of bacterial protease degrading secretory immunoglobulin a in Klebsiella persistence
Bondarenko, V.M.; Agapova, O.V.; Vinogradov, N.A.
Zhurnal Mikrobiologii Epidemiologii i Immunobiologii 2000(4 Suppl): 12-16
2000
ISSN/ISBN: 0372-9311 PMID: 12712505 Document Number: 524208
During the study of 186 K. pneumoniae clinical strains the presence of SIgA-protease activity was detected in 109 isolates (58.6%). The PCR test system permitting the detection of iga gene DNA in K. pneumoniae strains isolated in purulent inflammatory processes of different localization was developed. For the first time a conjugative plasmid with a mol. wt. of 100 MD was detected in K. pneumoniae clinical isolates. This plasmid controlled the capacity of inactivating SIgA, carried the markers of antibiotic resistance and was capable of expression in a wide circle of hosts belonging to the family Enterobacteriaceae. The results of in vitro experiments revealed that the strains containing plasmid SIgA were cytotoxic with respect to cells HEp-2 and more resistant to the digestive action of enzymes produced by the phagolysosomes of guinea pig peritoneal cells. As shown on the in vivo biological model with the use of the genetically linked pair of Salmonella typhimurium 274 vaccine strains, differing in SIgA-protease activity, plasmid pSigA ensured more prolonged survival of bacteria in mice in comparison with the nonplasmid variant. The study of SIgA-protease activity of K. pneumoniae strains circulating among patients with a view to the detection of clones causing the development of persistent infection was shown to have good prospects.