Global spread of multidrug-resistant microbes including CRE and clinical alerts

After the emergence of methicillin-resistant Staphylococcus aureus (MRSA) in the 1960s, vancomycin-resistant enterococci (VRE) and ESBL (extended-spectrum β-lactamase)-producing Gram-negative bacteria emerged in 1980s. In the 1990s, multidrug-resistant (MDR) Mycobacterium tuberculosis (MDR-TB) and MDR Pseudomonas aeruginosa (MDRP) have also become a new clinical concern. In the 2000s, bacterial species belonging to the family Enterobacteriaceae that have acquired consistent resistance to various antimicrobials including carbapenems have also emerged and spread worldwide, together with rapid dissemination of MDR Acinetobacter species, particularly A. baumannii, in the clinical institutions outside Japan. Only a few antimicrobial agents are effective for infections caused by those MDR microbes and the prognoses of patients infected with those MDR microbes are often very serious. In the EU and the US, therefore, the antimicrobial resistance issues have come to be regarded as one of the political problems and comprehensive operations have been started to cope with the clinical difficulties caused by multidrug-resistant pathogenic microbes.