Resistance to Antibiotics and Inorganic Ions in Virulent Bacterial Strains from a Hospital

Summary

Virulent strains of Staphylococcus aureus, S. epidermidis, Escherichia coli and Pseudomonas aeruginosa were studied for their resistance to antibiotics and inorganic ions, the correlation with their clinical use and the usefulness as an epidemioliogical tool. Multiresistance was common, the antibiotypes were similar to those previously reported, but characteristic resistotypes endemic of our county were found. A correlation between resistance and metal ion consumption was not detected. Staphylococci strains were susceptible to vancomycin, cephalothin and mercury chloride; S. epidermidis showed higher rates of resistance to antibiotics and lower to cadmium chloride and potassium iodine than S. aureus. E. coli strains were susceptible to new β-lactamans; resistance to cephalothin, gentamicin, tobramycin and amikacin was < 10%. P. aeruginosa was the species with the most multiresistance and antibiotype diversity, only ceftazidime, amikacin and imipenem had a resistance rate < 11%. In both E. coli and P. aeruginosa resistance to all tested metals (except silver nitrate) was found although with different percentages.

Key Words::

• Antibiotic resistance
• metal resistance
• inorganic ion resistance
• resistance patterns
• resistotype
• Staphylococcus aureus
• Staphylococcus epidermidis
• Escherichia coli
• Pseudomonas aeruginosa