The spread of antibiotic resistances and the appearance of multiple-antibiotic-resistant
pathogenic bacteria has been recognized by the WHO as a serious problem that
complicates medical treatment of bacterial infections. WHO has called for urgent
measures to fight against the spread of pathogenic strains that are resistant
to several antibiotics. These measures concern appropriate antibiotic therapy,
hospital hygiene, control of bacterial infections and the extension of existing
surveillance systems to an international network in order to collect epidemiological
information on antimicrobial resistance. Recent reports have also shown a marked
and worrying increase of antibiotic resistance in food-poisoning bacteria due
to non-rational and excessive
uses of antibiotics as therapeutic agent or as growth promotor in livestock.
Another aspect of the antibiotic resistance issue is the uses of antibiotic resistance genes as selection marker in genetically modified organisms (GMOs). The main safety concern relates to the escape or transfer of the antibiotic resistance genes to sensitive bacterial strains when these GMO are introduced into the environment.
In order to help regulators or applicants to carry out risk assessment of GMO containing an antibiotic resistance gene, information is provided on the genetic determinants encoding resistance and on their clinical / environmental distribution when possible. These WEB pages also gather useful links to sites monitoring antimicrobial resistances and describing the antibiotic drugs.
ANTIBIOTIC RESISTANCE MECHANISMS
Antibiotic resistance can be categorized in three types:
1. Natural or intrinsic resistance
2. Mutational resistance
3. Extrachromosomal or acquired resistance (Disseminated by plasmids or transposons)
DESCRIPTION OF THE RESISTANCE MECHANISMS TO
(other categories include: Macrolides-lincosamides-streptogramins, Glycopeptides, Chloramphenicol, Rifampicin, Quinolones, Sulfonamides, Trimethoprim, and Nalidixic acid)