Resistance to 17 antimicrobials, surface hydrophobicity, motility, biofilm, production of N-acylhomoserine lactone signal molecules (N-butyrylhomoserine lactone and N-3-oxolauroylhomoserine lactone) and response to oxidative stress were analyzed in 47 clinical Pseudomonas aeruginosa strains. In addition to natural resistance, the strains demonstrated the greatest level of resistance to cefotaxime (91.5%). Isolates in the range of 44.7-57.4% were resistant to aminoglycosides and ciprofloxacin, of 25.5-36.2% to cephalosporins. On the other hand, 97.9% remained susceptible to meropenem, 93.6% to piperacillin + tazobactam and 87.2% to piperacillin. The majority of the strains (72.3%) manifested their hydrophilic character. Higher zones of motility showed 12 isolates (in average 54.8 mm) as compared to the others (30.2 mm). Approximately 1/3 of the strains (29.8%) produced a higher amount of biofilm quantified by measuring the absorbance of solubilized crystal violet (0.20-0.46) than the rest of isolates (0-0.19). All but two strains produced N-3-oxolauroylhomoserine lactone and in 48.9% of samples N-butyrylhomoserine lactone were detected. Only four isolates with higher biofilm production showed both types of homoserine lactone. Majority of the strains (70.2%) manifested higher resistance to H2O2 than the rest of the strains. The group of strains resistant to aminoglycosides and ciprofloxacin revealed a significantly higher number of hydrophobic strains (compared with the sensitive ones). In contrast, higher number of strains sensitive to aminoglycosides and ciprofloxacin or only to ciprofloxacin produced N-butyrylhomoserine lactone and biofilm (compared to the resistant ones). Such association was not found among the rest of the tested parameters. The results indicate that the resistance to antimicrobials in P. aeruginosa isolates was not generally associated with changes in the production of the pathogenicity factors.

• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Drug Resistance, Bacterial * MeSH
• Biofilms growth & development   MeSH
• Phenotype MeSH
• Adaptation, Physiological MeSH
• 4-Butyrolactone analogs & derivatives   biosynthesis   MeSH
• Gentian Violet metabolism   MeSH
• Hydrophobic and Hydrophilic Interactions MeSH
• Humans MeSH
• Oxidative Stress MeSH
• Oxidants pharmacology   MeSH
• Hydrogen Peroxide pharmacology   MeSH
• Movement MeSH
• Pseudomonas Infections microbiology   MeSH
• Pseudomonas aeruginosa drug effects   isolation & purification   pathogenicity   MeSH
• Virulence MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• 4-Butyrolactone MeSH
• Gentian Violet MeSH
• Oxidants MeSH
• Hydrogen Peroxide MeSH

Effect of pH on production of extracellular virulence factors of Pseudomonas aeruginosa grown on catheter in biofilm was determined. Alginate and proteinase production was higher at pH 8; in contrast, siderophores (pyochelin and pyoverdin) were synthesized more intensively at pH 5.

• MeSH
• Alginates metabolism   MeSH
• Bacterial Proteins metabolism   MeSH
• Biofilms growth & development   MeSH
• Virulence Factors biosynthesis   MeSH
• Hydrogen-Ion Concentration MeSH
• Culture Media, Conditioned chemistry   MeSH
• Glucuronic Acid metabolism   MeSH
• Hexuronic Acids metabolism   MeSH
• Humans MeSH
• Urine microbiology   MeSH
• Peptide Hydrolases metabolism   MeSH
• Pseudomonas Infections microbiology   MeSH
• Pseudomonas aeruginosa growth & development   metabolism   pathogenicity   physiology   MeSH
• Siderophores metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Alginates MeSH
• Bacterial Proteins MeSH
• Virulence Factors MeSH
• Culture Media, Conditioned MeSH
• Glucuronic Acid MeSH
• Hexuronic Acids MeSH
• Peptide Hydrolases MeSH
• Siderophores MeSH