[Impact of antibiotic prophylaxis on microbial ecology]

This review of the literature analysed the impact of prophylactic antibiotics on patients, nurses, the ecosystem of the wards, the hospital and the general environment. After prophylactic antibiotics a qualitative and quantitative modification of the cutaneous and digestive flora of the patient can occur, as well as modification of susceptibility to antibiotics. Several factors may modulate their action on the bacterial flora: the breadth of the spectrum, the administered dose, the duration of treatment, the form of development of resistance and the type of antibiotics. Numerous studies have demonstrated the role of the nursing staff as a reservoir of multi-resistant micro-organisms. Staff of intensive care units is apparently the most affected. Prophylactic antibiotics can also induce changes in the quantitative and qualitative features both in the ward and hospital flora. An increase in the bacterial resistance to antibiotics in the general environment can occur; a long duration of oral prophylactic antibiotic administration is undoubtedly associated with this phenomenon. Thus, the benefit associated with prophylactic antibiotic in the prevention of postoperative infections, unquestionable in some indications, must be balanced with the possible selection of resistant micro-organisms and their consequences on the environment.