Trends in the epidemiology and antibiotic resistance of clinical Staphylococcus strains in Italy — a review

This review analyses the current Italian problem of clinical Staphylococcus isolates and trends in their antibiotic resistance. Most information has come from two recent nationwide collaborative studies. Some data have also been derived from particular experiences in individual laboratories. S. aureus was predominant among Staphylococcus isolates from most clinical sources. S. epidermidis predominated in strains isolated from artificial devices, blood, and cerebrospinal fluid. S. saprophyticus was isolated with greater frequency from outpatients than from inpatients, predominantly from urinary specimens. In spite of marked laboratory-to-laboratory and geographical variations, greater staphylococcal resistance to methicillin and most other antibiotics was noted. Overall, among clinical Staphylococcus strains isolated in Italy, more than a third of organisms from inpatients and more than a fifth of those from outpatients currently proved to be resistant to methicillin. The incidence of methicillin resistance was generally lower in Southern Italy than in the rest of the country, occurred at a twofold higher rate in isolates from inpatients than from outpatients, and was generally higher among isolates from intensive care units than from other hospital departments. There was increasing involvement of coagulase-negative staphylococci in human infections which made up about half of all clinical Staphylococcus isolates. Coagulase-negative staphylococci were more frequent than S. aureus in specimens from intensive care and surgical wards, and also were more resistant to many antibiotics including methicillin.