Although much of today's media focuses on multidrug-resistant gram-positive bacteria such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, resistance within gram-negative bacilli continues to rise, occasionally creating situations in which few or no antibiotics that retain activity are available. Extended-spectrum beta-lactamase (ESBL)-producing Escherichia ...

Polymyxins are often last-line therapeutic agents used to treat infections caused by multidrug-resistant A. baumannii. Recent reports of polymyxin-resistant A. baumannii highlight the urgent need for research into mechanisms of polymyxin resistance. This study employed genomic and transcriptomic analyses to investigate the mechanisms of polymyxin resistance in A. baumannii AB307-0294 using an i...

Multidrug resistance in Pseudomonas aeruginosa is increasingly becoming a threat for human health. Indeed, some strains are resistant to almost all currently available antibiotics, leaving very limited choices for antimicrobial therapy. In many such cases, polymyxins are the only available option, although as their utilization increases so does the isolation of resistant strains. In this study,...

Polymyxins are old antimicrobials, discontinued for many years because of nephrotoxicity and neurotoxicity reports and reintroduced recently due to the increasing frequency of multiresistant Gram-negative bacterial infections. There are very few data related to toxicity and efficacy from transplanted patients, the major subjects of this study. All solid-organ-transplanted patients from our inst...

OBJECTIVES To characterize a five gene cluster, macRS-macABCsm, in Stenotrophomonas maltophilia. METHODS The presence of macABCsm operon was verified by RT-PCR. The substrate spectrum of the MacABCsm efflux pump was investigated by mutant construction and susceptibility testing. The physiological role of MacABCsm was assessed by comparing the growth of wild-type and macABCsm mutant under diff...

Enterobacteriaceae species are important human pathogens while increasing number of antibiotic resistant strains are detected worldwide. The most common antibiotic resistance in Enterobacteriaceae is observed against beta-lactams, fluoroquinolones, aminoglycosides while recently resistance to polymyxins has also appeared. Beta-lactam resistance is mainly conferred by beta-lactamases, capable to...