[Fosfomycin--its significance for treatment of diseases due to multidrug-resistant bacteria].

Fosfomycin is a bactericidal phosphonic acid derivative, which engages by inhibiting pyruvyltransferase at an early stage in the peptidoglycan synthesis. It shows a broad spectrum of activity that includes many multidrug-resistant gram-negative and gram-positive bacteria. Fosfomycin is active against most strains of Pseudomonas aeruginosa and several multidrug-resistant Enterobacteriaceae, e.g., Escherichia coli strains expressing extended spectrum beta-lactamases (ESBL) and Klebsiella pneumoniae strains with decreased susceptibilities to carbapenems. Most methicillin-resistant Staphylococcus aureus (MRSA) strains as well as enterococci with and without vancomycin resistance are also sensitive to fosfomycin. During the last decade, a variety of studies showed that fosfomycin is not only suitable for treating uncomplicated urinary tract diseases, but also for the treatment of many other diseases caused by bacterial pathogens with and without multidrug resistance. However, large controlled studies demonstrating the efficacy of the drug to treat diseases caused by multidrug-resistant bacteria are still missing. Considering the low number of antibacterial agents with good activity against multidrug-resistant bacteria, fosfomycin should be evaluated as an important antibiotic for the treatment of several severe illnesses due to these pathogens. However, because some multidrug-resistant bacteria are also resistant to fosfomycin, this agent should only be applied if the pathogen is sensitive to this drug. In addition, because rapid development of resistance cannot be excluded if fosfomycin will be applied alone, this drug should only be given in combination with other effective drugs for the treatment of serious systemic diseases due to multidrug-resistant bacterial pathogens.