Table 2 Mechanisms of resistance in Enterobacteriaceae and non-fermenting Gram-negative bacilli: 10 key-points for the management of antimicrobial therapy in the intensive care unit

1.

Carboxy- and ureido-penicillins should be preferred to 3GC to treat wild-type inducible AmpC-producing Enterobacteriaceae (notably Enterobacter sp.)

2.

The use of cefepime could be considered as a carbapenem-sparing option in infections due AmpC-hyperproducing Enterobacteriaceae

3.

Carbapenems are the first-line choice for severe ESBL-PE infections

4.

The efficacy of BLBLI associations has not been adequately investigated in critically ill patients with ESBL-PE infections: piperacillin–tazobactam might be discussed as a carbapenem-sparing regimen for strains with low MICs (≤2 mg/L), using optimized administration (high doses, extended or continuous infusion, therapeutic drug monitoring) and provided that the source of infection is controlled

5.

In Pseudomonas aeruginosa, the rate of resistance emergence under therapy is notably high with imipenem, which should be used only when other beta-lactams are inactive

6.

The empirical use of colistin may be considered in ICU with high prevalence of carbapenemase-producing GNB

7.

Colistin resistance may emerge in carbapenem-resistant GNB after exposure to this drug

8.

Whether combination therapy prevents the emergence of resistance in non-fermenting GNB is not proven

9.

In spite of a strong rational, the ecological benefit of de-escalation remains to be confirmed in adequate prospective studies

10.

The long-term ecological impact of SOD/SDD must be assessed in ICUs with high prevalence of multidrug-resistant GNB