title: Antibiotic resistance mechanisms of clinically important bacteria.
abstract: Bacterial resistance to antimicrobial drugs is an increasing health and economic problem. Bacteria may be innate resistant or acquire resistance to one or few classes of antimicrobial agents. Acquired resistance arises from: (i) mutations in cell genes (chromosomal mutation) leading to cross-resistance, (ii) gene transfer from one microorganism to other by plasmids (conjugation or transformation), transposons (conjugation), integrons and bacteriophages (transduction). After a bacterium gains resistance genes to protect itself from various antimicrobial agents, bacteria can use several biochemical types of resistance mechanisms: antibiotic inactivation (interference with cell wall synthesis, e.g., β-lactams and glycopeptide), target modification (inhibition of protein synthesis, e.g., macrolides and tetracyclines; interference with nucleic acid synthesis, e.g., fluoroquinolones and rifampin), altered permeability (changes in outer membrane, e.g., aminoglycosides; new membrane transporters, e.g., chloramphenicol), and "bypass" metabolic pathway (inhibition of metabolic pathway, e.g., trimethoprim-sulfamethoxazole).
authors.affiliation: Department of Microbiology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania. agne.giedraitiene@med.kmu.lt
authors.forename: Agnė
authors.initials: A
authors.lastname: Giedraitienė
authors.forename: Astra
authors.initials: A
authors.lastname: Vitkauskienė
authors.forename: Rima
authors.initials: R
authors.lastname: Naginienė
authors.forename: Alvydas
authors.initials: A
authors.lastname: Pavilonis
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use; D001419:Bacteria / Q000145:classification / Q000187:drug effects*; D001424:Bacterial Infections / Q000188:drug therapy / Q000382:microbiology; D002463:Cell Membrane Permeability; D024881:Drug Resistance, Bacterial
chemical_list: D000900:Anti-Bacterial Agents