Published in:
01-12-2016 | Understanding the Disease
Understanding resistance
Published in: Intensive Care Medicine | Issue 12/2016
Login to get accessExcerpt
The ability of bacterial pathogens to develop resistance against antimicrobial drugs is a key issue when caring for infected patients, especially those admitted to the intensive care unit (ICU). Antimicrobial resistance increases the risk of inadequate empirical coverage and may dramatically complicate the management of definite therapy, which often translates into worsened outcome for the most severely ill patients (Fig. 1) [1]. Nowadays, resistance rates have reached alarming levels, notably in ICU-acquired Gram-negative bacilli (GNB), and current trends suggest that the magnitude of the problem will continue to rise [2]. In this context, understanding resistance mechanisms may serve as a prerequisite to optimize antimicrobial use in daily practice and to appraise how reducing antibiotic consumption could help control the spread of multidrug-resistant (MDR) pathogens.
Fig. 1
Contributing factors and consequences of antimicrobial resistance: a schematic view. *Selected examples: (i) resistance-encoding plasmids may also encode toxin–antitoxin systems that force their maintenance in the recipient bacteria (“resistance addiction”), independently of the selective advantage conferred in case of antibiotic exposure—this factor could contribute to the persistence and dissemination of CTX-M enzymes in community populations with a relatively low antibiotic selection pressure [14]; and (ii) in methicillin-resistant coagulase-negative staphylococci (especially Staphylococcus epidermidis) and certain clones of methicillin-resistant Staphylococcus aureus (including USA300, a successful lineage of community-acquired MRSA), the mobile genetic element (MGE) carrying mecA (namely, Staphylococcal Cassette Chromosome mec—SCCmec) may be associated with another MGE (Arginine Catabolic Mobile Element—ACME) which enhances bacterial fitness and survival on skin and mucosal surfaces [15], thereby favoring their implantation in these ecosystems
× ![]()
…