Inhibition of the resuscitation from the viable but non-culturable state in Enterococcus faecalis.
The viable but non-culturable (VBNC) state is a survival strategy adopted by bacteria when exposed to environmental stresses capable of inducing cell growth inhibition and cell death. This state can be summarized as a quiescent form of life waiting for suitable conditions. This strategy has been shown to be activated by medically important bacteria either when present in natural environments or in the human body during the infection process. In this study we have evaluated the effects of antibiotics acting on peptidoglycan or protein synthesis of Enterococcus faecalis in the VBNC state. The activity of the antibiotics was determined by their ability both to inhibit resuscitation (i.e. recovery of cell division) and to bind the molecular target of action. Benzylpenicillin, piperacillin and gentamicin block cell resuscitation at the minimal inhibitory concentrations (MICs) of growing cells, while vancomycin acts only at doses 500 times higher than the MIC. This different behaviour is discussed taking into consideration the mode of action of the antibiotics.
Lleò
Maria del Mar
MM
Dipartimento di Patologia, Sezione di Microbiologia, Università di Verona, 37134 Verona, Italy.
Benedetti
Dennis
D
Tafi
Maria Carla
MC
Signoretto
Caterina
C
Canepari
Pietro
P
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D006801:Humans; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects*; D010457:Peptidoglycan / Q000187:drug effects* / Q000378:metabolism; D011500:Protein Synthesis Inhibitors
D000900:Anti-Bacterial Agents; D010457:Peptidoglycan; D011500:Protein Synthesis Inhibitors