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Characteristics of Pseudomonas aeruginosa strains isolated from urinary tract infections
H Puzová1, L Siegfried, M Kmetová
1Institute of Medical Microbiology, Faculty of Medicine, Safárik University, Kosice, Slovakia.
Abstract:
Thirty-three uropathogenic strains of Pseudomonas aeruginosa were investigated for hemolytic activity in both bacterial broth culture filtrates and isolate lyzates, resistance to bactericidal activity of fresh human serum, resistance to six antibiotics and plasmid DNA profile. Twenty-four of the 33 (73%) bacterial filtrates showed lysis of rabbit erythrocytes, as did the three after guinea-pig erythrocyte treatment. Twelve of 33 isolate lysates showed in parallel lysis of both types of erythrocytes used. Serum resistance was found in 17 (52%) isolates, intermediate resistance in 15 (45 %) isolates and only one isolate showed serum sensitivity. Resistance to antibiotics was detected as follows (in %): tetracycline 94, kanamycin 79, chloramphenicol 76, septrin 73, ampicillin 64, streptomycin 45, gentamicin 18. None of the isolates investigated showed resistance to colistine. With the exception of one isolate, plasmid DNA was detected in all P. aeruginosa strains.
Insights
Most Pseudomonas aeruginosa strains exhibit hemolytic activity and resistance to human serum and common antibiotics. Plasmid DNA is prevalent in these uropathogenic bacteria, influencing their virulence factors.
Area of Science:
- Microbiology
- Bacteriology
- Molecular Biology
Background:
- Uropathogenic Pseudomonas aeruginosa is a significant cause of urinary tract infections.
- Understanding the virulence factors and resistance mechanisms of P. aeruginosa is crucial for effective treatment.
Purpose of the Study:
- To investigate the hemolytic activity, serum resistance, antibiotic resistance, and plasmid DNA profiles of uropathogenic Pseudomonas aeruginosa strains.
Main Methods:
- Bacterial broth culture filtrates and isolate lysates were used to assess hemolytic activity against rabbit and guinea-pig erythrocytes.
- Resistance to human serum was evaluated.
- Antibiotic resistance to six common antibiotics was tested.
- Plasmid DNA profiles were analyzed.
Main Results:
- 73% of bacterial filtrates showed hemolytic activity. 52% of isolates were resistant to human serum, with 45% showing intermediate resistance.
- High rates of antibiotic resistance were observed for tetracycline (94%), kanamycin (79%), and chloramphenicol (76%). No resistance to colistin was detected.
- Plasmid DNA was present in all but one isolate.
Conclusions:
- Uropathogenic Pseudomonas aeruginosa strains frequently possess hemolytic activity and significant resistance to human serum and multiple antibiotics.
- The high prevalence of plasmid DNA suggests its role in the dissemination of resistance and virulence traits.