[An alarming problem in the therapy of infective endocarditis: the development of antibiotic-resistant strains].
We shall focus on infective endocarditis due to Enterococcus spp and Staphylococcus aureus, both able to develop resistance to antibiotics with different mechanisms. Vancomycin-resistant strains produce some of the most challenging nososocomial infections. Enterococci develop resistance practically to all classes of antibiotics. Vancomycin-resistant strains, in the '90s, passed from 2% to more than 25%. Five types of vancomycin-resistance were reported (from van A to van E), linked to the presence of certain classes of genes regulating the production of abnormal precursors of peptidoglycan which inhibit the action of vancomycin. Staphylococcus aureus is a fearful organism whose infections can reach a mortality rate of 80%. In 1943, as soon as penicillin G was introduced into therapy, Staphylococcus strains producers of beta-lactamase were identified. After beta-lactamase-resistant penicillins were introduced into therapy, methicillin-resistant Staphylococcus strains appeared in the '60s. In 1996 the first strain of methicillin-resistant and vancomycin-resistant Staphylococcus aureus was isolated. In 2001, in Japan, the first case of infective endocarditis due to Staphylococcus aureus resistant to methicillin and non-responsive to vancomycin was described. The resistance is connected to an increased synthesis of the cell wall, which thickens reducing the activity of vancomycin.
Enia
Francesco
F
U. O. di Cardiologia II, Centro di Riferimento Regionale per lEpidemiologia Clinica dell'Insufficienza Cardiaca, Azienda Ospedaliera V Cervello, Palermo. fenia@tin.it
Bella
Rosario
R
Mineo
Riccardo
R
Mizio
Gisella
G
Reina
Giuseppe
G
D024881:Drug Resistance, Bacterial; D004697:Endocarditis, Bacterial / Q000188:drug therapy*; D016983:Enterococcus; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy; D006801:Humans; D013203:Staphylococcal Infections / Q000188:drug therapy