Bakteriers multiresistens og triclosan: En undersøgelse af multiresistens hos Escherichia coli ved udsættelse for triclosan||Bacterial multiresistance and triclosan||A survey of multiresistance in Escherichia coli when subjected to triclosan

Kirstine Bruun-Schmidt, Christian Bierlich, Claes Schönbeck, Amalie Thit Jensen, Julia Dahlberg Filipsen, Louise Schnegell, Anne Loft & Søren Zebitz Nielsen

Studenteropgave: Semesterprojekt

Abstrakt

Triclosan er et biocid som anvendes i mange forbrugsprodukter såsom sæber, tandpasta og husholdningsartikler. I denne rapport påvises det, at triclosan selekterer antibiotikaresistente E. coli, og i særdeleshed resistens for tetracycline. Denne resistenssammenhæng kan sandsynligvis relateres til en øget effluxpumpeaktivitet i AcrAB. Det vises at den øgede aktivitet i AcrAB, som formodentlig skyldes en overekspression af acrAB eller at en af de positive regulatorer af acrAB, soxS og marA, giver de resistente kloner selektive fordele i miljøer med subletale triclosan koncentrationer. Det vises også at resistensmekanismen nedsætter mutanternes vækstfrekvens med op til 50 % i forhold til vildtypen. Triclosan is a biocide added to many consumer products such as soap, toothpaste and household articles. In this report it is proven that triclosan selects antibiotic resistant E. coli, and resistance for tetracycline in particular. This cross-resistance can probably be related to increased efflux activity in AcrAB. It is shown how the increased activity in AcrAB, most likely caused by overexpression of acrAB or of one of the positive regulators of acrAB, soxS and marA, provides the resistant clones selective advantages in environments with sublethal concentrations of triclosan. It is also shown how the resistance mechanism decreases the mutants’ growth frequency with up to 50 % compared to the wild-type.

UddannelserBasis - Naturvidenskabelig Bacheloruddannelse, (Bachelor uddannelse) Basis
SprogDansk
Udgivelsesdato1 jan. 2005

Emneord

  • Antibiotikaresistens
  • AcrAB
  • Resistens
  • E.coli
  • Bakterier
  • Multiresistens
  • Effluxpumpe
  • Triclosan
  • Biocid
  • Antibiotika