Clonality, virulence and the occurrence of genes encoding antibiotic resistance among Staphylococcus warneri isolates from bloodstream infections.

Clonality, virulence and the occurrence of genes encoding antibiotic resistance among Staphylococcus warneri isolates from bloodstream infections. J Med Microbiol. 2016 May 25; Authors: Szczuka E, Krzymińska S, Kaznowski A Abstract Coagulase-negative Staphylococcus warneri is an opportunistic pathogen capable of causing several infections especially in patients with indwelling medical devices. We evaluated the virulence-associated properties of 23 clinical isolates, recovered from blood specimens. In addition, the carriage of biofilm associated genes, as well as antibiotic resistant genes, were identified. S. warneri isolates appeared to be clonally unrelated and revealed a high degree of genetic diversity. All isolates revealed adhesion to epithelial cells and 43.5% of strains conduct invasion of the cells. Moreover, 52% of isolates formed biofilm in vitro. PCR analysis demonstrated the presence of ica operon, in two of 12 the biofilm-positive isolates. This indicated that biofilm formation, in this species, is not restricted to strains harboring icaADBC genes, encoding polysaccharide intercellular adhesion (PIA). Analysis by using confocal laser scanning microscopy revealed that biofilm-forming strains formed a three-dimensional structure, composed of mainly living cells. All strains revealed cell-contact cytotoxicity that was strongly associated with biofilm formation. Moreover, cell-free supernatants, of 95% of the isolates, exp...
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research