Transposable gentamicin resistance in IncW plasmids from Hammersmith Hospital

Area of Science:

• Molecular biology
• Microbiology
• Genetics

Background:

• Gentamicin resistance is a growing public health concern.
• Plasmids, particularly those of the IncW group, are known vectors for antibiotic resistance genes.
• Transposons facilitate the movement and dissemination of genetic elements, including those conferring antibiotic resistance.

Purpose of the Study:

• To characterize a newly identified transposon, Tn733, associated with gentamicin resistance.
• To investigate the genetic basis of gentamicin resistance in plasmids from Hammersmith Hospital.
• To assess the implications of transposon-mediated resistance for the spread of antibiotic resistance.

Main Methods:

• Plasmid isolation and characterization.
• Molecular analysis of transposon Tn733, including restriction enzyme digestion (EcoRI).
• Identification of the gentamicin acetyltransferase gene AAC(3).

Main Results:

• Transposon Tn733, encoding AAC(3), was identified on two IncW gentamicin resistance plasmids.
• Tn733 has a molecular mass of 5.8 megadaltons.
• Digestion of Tn733 with EcoRI produced a characteristic 2.4 megadalton fragment.

Conclusions:

• The presence of gentamicin resistance on a mobile genetic element like Tn733 increases the likelihood of its dissemination.
• This finding underscores the importance of monitoring transposon-mediated antibiotic resistance.
• Further research is needed to understand the prevalence and impact of Tn733 in clinical settings.