Antimicrobial Resistance Patterns in Respiratory Pathogens Isolated in an Italian University Hospital during a Period of Eight Years: A Statistical Analysis

Abstract

The antimicrobial resistance patterns of respiratory pathogens isolated during an 8-year period (1990–1997) in an Italian hospital from patients with bronchopulmonary infections were investigated. A global variation in the resistance of Staphylococcus aureus to all relevant antibiotics was observed during the years 1990–1997. With the exception of penicillin and amoxicillin, to which Staphylococci were always resistant, and vancomycin, to which they were always susceptible, in the first period (1990–1992) the percentage of resistance to β-lactams, aminoglycosides, macrolides, fluoroquinolones and cotrimoxazole was about 15%, while in the last period (1993–1997) it was about 35%. No global variation in resistance to the antimicrobials examined during the study period was observed for gram-negative bacteria. The percentages of resistance to the more recent β-lactams, aminoglycosides and fluoroquinolones were generally less than 10% for the KES group, less than 20% for Pseudomonas aeruginosa, and less than 30% for other Pseudomonas species. A high percentage of resistance was observed for the KES group to amoxicillin + clavulanic acid (60%) and to cefoxitin (48%).