Antimicrobial agents and chemotherapy
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Antimicrob. Agents Chemother. · Jun 2008
Increasing incidence of linezolid-intermediate or -resistant, vancomycin-resistant Enterococcus faecium strains parallels increasing linezolid consumption.
Clinical enterococcal resistance to linezolid is defined by the presence of the G2576T mutation. We evaluated the incidence of genetically proven linezolid resistance among vancomycin-resistant Enterococcus faecium strains and linezolid consumption for a possible association. A relationship was found (r(2) = 0.73, P = 0.03) and predicts increasing resistance with current trends of linezolid use.
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Antimicrob. Agents Chemother. · Jun 2008
Comparative StudyDifferential antibiotic susceptibility of Mycobacterium abscessus variants in biofilms and macrophages compared to that of planktonic bacteria.
Mycobacterium abscessus causes refractory pulmonary infections requiring surgery for cure. It exists as a smooth biofilm-forming phenotype which is noninvasive and a rough, non-biofilm-forming phenotype which can invade macrophages and cause persistent pulmonary infection in mice. We have postulated that the dissociation of the smooth phenotype to the rough phenotype may lead to invasive lung disease following initial colonization of the airways. ⋯ In human macrophages, all three antibiotics were only bacteriostatic for M. abscessus variants at 10 times their MICs. These results suggest why treatment failure with antibiotics alone is common in the clinical setting of M. abscessus pulmonary infection. Determination of the efficacies of new antibiotics should include an assessment of their activities against the smooth and rough M. abscessus morphotypes in biofilms and macrophages.