RESUMO
Antibiotics disrupt the intestinal microbiota, rendering patients vulnerable to colonization by exogenous pathogens. Intermicrobial interactions may attenuate this effect. Incubation with ceftriaxone-resistant, ccrA-positive, ß-lactamase-producing Bacteroides strains raised the minimum bactericidal concentration of ceftriaxone required to kill a susceptible Escherichia coli strain (mean change, <0.25 to 29 mg/liter; P = 0.009); incubation with ceftriaxone-resistant but non-ß-lactamase-producing Bacteroides strains had no effect. The production of ß-lactamase by common members of the intestinal microbiota (Bacteroides) can protect susceptible fellow commensals from ß-lactams.
Assuntos
Proteínas de Bactérias/biossíntese , Bacteroides/efeitos dos fármacos , Bacteroides/fisiologia , Microbiota/efeitos dos fármacos , Resistência beta-Lactâmica/efeitos dos fármacos , beta-Lactamases/biossíntese , Bacteroides fragilis/efeitos dos fármacos , Ceftriaxona/farmacologia , Escherichia coli/efeitos dos fármacos , Trato Gastrointestinal/microbiologia , Humanos , Testes de Sensibilidade MicrobianaRESUMO
In a study of 40 methicillin-resistant Staphylococcus aureus (MRSA) carriers, hand contamination was equally likely after contact with commonly examined skin sites and commonly touched environmental surfaces in patient rooms (40% vs 45%). These findings suggest that contaminated surfaces may be an important source of MRSA transmission.