The use of antibiotics and implications for antimicrobial resistance development

Abstract

Antibiotic resistance has reached pandemic proportions and the increasing incidences have alarmed medical healthcare associations world wide. Some thirty years ago it was almost all infectious diseases were conquered, but over the last decades we have witnessed the re-emergence of known contagious diseases and the emergence of new infections. This is partly due to the major increase in multi-resistant microorganisms, which have made infectious diseases more difficult to treat and have taken them back into focus of medical attention. Currently we are at severe risk of entering a post-antibiotic era with multi-drug resistant microorganisms increasing in numbers and only few new antibiotics in the pipe line of the pharmaceutical industry. This means that we must be prudent in the use of the remaining effective antimicrobial agents that are currently at our disposal. The aim of this thesis was to gain more insight in the feasibility and the effect of changes in antibiotic policy on antimicrobial resistance in a surgical ICU. This thesis has demonstrated that changes in antibiotic policies actually have a relevant effect on antimicrobial resistance levels and that the length of antibiotic treatment should continuously be weighed. Alternating antibiotic policies alone will not be effective enough. A good interplay with other factors such as good antibiotic stewardship, increased infection control measures and an active surveillance system (based on phenotypic susceptibility patterns in combination with DNA-fingerprints) will be needed to place future colonization rates with (multi-) resistant microorganisms into perspective. The potential hazard of the coming decades will be the increasing frequencies of interspecies gene transfer, with the transfer of the vanA gene from the Enterococcus spp. to Staphylococcus aureus, rendering the Staphylococcus aureus vancomycin resistant, only as the beginning.