RESUMEN
AIM: To determine the virulence genes, antibiotic resistance and plasmid profiles of 16 Enterococcus faecium and 68 Enterococcus faecalis strains isolated from various naturally fermented foods. METHODS AND RESULTS: The presence of virulence genes (agg(2) , gelE, cylM, cylB, cylA, espfs, espfm, efaAfs, efaAfm, cpd, cop, ccf, cad) and also the genes vanA and vanB were investigated by polymerase chain reaction (PCR). Antibiotic resistance of the isolates was determined by disc diffusion method. Most of the tested isolates were positive for virulence genes and resistant to some antibiotics. One of the Ent. faecalis strains isolated from a cheese sample carried the vanA gene and was intermediately resistant to vancomycin. The strains usually contained large plasmids, which might harbour acquired antibiotic resistance. CONCLUSION: The study showed that Ent. faecium and Ent. faecalis strains isolated from naturally fermented Turkish foods may be potential risk factors for consumer health in terms of virulence genes and acquired antibiotic resistance. SIGNIFICANCE AND IMPACT OF THE STUDY: The results indicate the importance of enterococcal contamination in terms of the safety of some fermented Turkish foods.
Asunto(s)
Farmacorresistencia Bacteriana , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecalis/patogenicidad , Enterococcus faecium/efectos de los fármacos , Enterococcus faecium/patogenicidad , Microbiología de Alimentos , Factores de Virulencia/genética , Proteínas Bacterianas/genética , Ligasas de Carbono-Oxígeno/genética , Queso/microbiología , Enterococcus faecalis/genética , Enterococcus faecalis/aislamiento & purificación , Enterococcus faecium/genética , Enterococcus faecium/aislamiento & purificación , Fermentación , Plásmidos/química , Turquía , Resistencia a la Vancomicina/genética , Virulencia/genéticaAsunto(s)
Apraxia Ideomotora/diagnóstico , Infarto Cerebral/diagnóstico , Lóbulo Frontal/irrigación sanguínea , Enfermedades del Nervio Oculomotor/diagnóstico , Lóbulo Parietal/irrigación sanguínea , Arteritis de Takayasu/diagnóstico , Apraxia Ideomotora/fisiopatología , Infarto Cerebral/fisiopatología , Diagnóstico Diferencial , Fijación Ocular/fisiología , Estudios de Seguimiento , Lóbulo Frontal/fisiopatología , Humanos , Aumento de la Imagen , Angiografía por Resonancia Magnética , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Enfermedades del Nervio Oculomotor/fisiopatología , Lóbulo Parietal/fisiopatología , Seguimiento Ocular Uniforme/fisiología , Arteritis de Takayasu/fisiopatologíaRESUMEN
At pH 5-6 ATP-depleted washed cell preparations of strain NC233-10b[pII4-9], in which the cytosine permease was overexpressed, absorbed cytosine, hypoxanthine or fluorocytosine stoichiometrically with, respectively, about 1, 1.4 and 5 proton equivalents. The cellular pH fell proportionately. The membrane depolarization caused by each compound was assayed in the presence of glucose with a voltage-sensitive dye and increased in the same order. Fluorocytosine significantly lowered the growth yield that a 'petite' strain of the yeast formed at limiting glucose concentrations. At pH 5.6 with extracellular [K+] below 1 mM, each of the three substrates was accumulated about 200-fold from a dilute solution at the expense of the proton gradient. This concentration ratio corresponds to a solute gradient (delta mu(s)) of 13 kJ mol-1. Raising [K+]o systematically lowered the substrate accumulation ratio and delta muH. The mean ratio delta mu(s)/delta muH was 0.82 for all three substrates. It was concluded that whereas the behaviour of cytosine approximated to that expected for a symport of unit proton stoichiometry, the absorption of protons with fluorocytosine and, to a lesser extent, hypoxanthine, was only partly conserved as useful work. A possible mechanism of this novel phenomenon is outlined.