Microbial drug resistance : MDR : mechanisms, epidemiology, and disease
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Microb. Drug Resist. · Feb 2013
Characterization of PVL/ACME-positive methicillin-resistant Staphylococcus aureus (genotypes ST8-MRSA-IV and ST5-MRSA-II) isolated from a university hospital in Japan.
The ST8 methicillin-resistant Staphylococcus aureus (MRSA) with Staphylococcal cassette chromosome mec (SCCmec) type IVa, known as USA300, is a prevalent community-acquired MRSA (CA-MRSA) clone in the United States and has been spreading worldwide. The USA300 characteristically harbors Panton-Valentine Leukocidin (PVL) genes and the arginine catabolic mobile element (ACME, type I). Prevalence and molecular characteristics of PVL(+) and/or ACME(+) S. aureus were investigated in a university hospital located in northern Japan, for 1,366 S. aureus isolates, including 601 MRSA strains derived from clinical specimens collected from 2008 to 2010. ⋯ Besides the two PVL(+) MRSA strains, ACME (type-ΔII) was identified into seven MRSA strains with SCCmec II belonging to ST5, one of the three spa types (t002, t067, and t071), coagulase type II, and agr type II. These PVL(-)/ACME(+) MRSA strains showed multiple drug resistance and harbored various toxin genes as observed for ST5 PVL(-)/ACME(-) MRSA-II. The present study suggested the spread of ST8-MRSA-IV in northern Japan, and a potential significance of ACME-positive ST5-MRSA-II as an emerging MRSA clone in a hospital.
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Microb. Drug Resist. · Feb 2013
The activity of silver nanoparticles (axonnite) on clinical and environmental strains of Enterococcus spp.
The spread of bacterial antibiotic resistance among clinical strains is a growing problem nowadays. Resistance in Enterococcus spp. strains has merited special concern of late, as they have become significant nosocomial pathogens. Hence, the use of compounds such as silver nanoparticles (AgNPs), displaying various mechanisms of action, is a growing new approach against virulent, drug-resistant infections. Therefore, the activity of AgNPs obtained by a physical method (microexplosion method) was tested against 30 clinical and environmental Enterococcus spp. strains presenting diverse virulence and resistance patterns. ⋯ AgNPs obtained by this method seem to be a promising alternative to chemotherapeutics in the treatment or prevention of enterococcal infections.