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[Transmissible formaldehyde resistance in Serratia marcescens]
Abstract:
It was possible to isolate a strain of Serratia marcescens from fresh clinical bacterial isolates which was 4-6 times more resistant against formaldehyde than other strains. It was shown that the strain harbours two plasmids with molecular sizes of 58- and 90 Mdal. It was demonstrated by conjugation-, transformation- and plasmid-curing experiments that the formaldehyderesistance is plasmid mediated and transferable to E. coli. It was shown by labelling with 14C-formaldehyde that the resistant strains bind much more formaldehyde than the sensible strains.
Insights
A resistant Serratia marcescens strain was identified. Formaldehyde resistance in this strain is plasmid-mediated and transferable, with resistant bacteria binding more formaldehyde.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Formaldehyde is a potent biocide used for disinfection.
- Bacterial resistance mechanisms to biocides are of clinical and industrial importance.
- Limited information exists on formaldehyde resistance in Serratia marcescens.
Purpose of the Study:
- To investigate the mechanism of formaldehyde resistance in a clinical isolate of Serratia marcescens.
- To determine if formaldehyde resistance is transferable.
- To elucidate the role of plasmids in formaldehyde resistance.
Main Methods:
- Isolation and characterization of a formaldehyde-resistant Serratia marcescens strain.
- Plasmid analysis (size determination).
- Conjugation, transformation, and plasmid-curing experiments.
- Radiolabeling with 14C-formaldehyde to quantify formaldehyde binding.
Main Results:
- A Serratia marcescens strain exhibiting 4-6 fold higher formaldehyde resistance was isolated.
- The resistant strain harbored two plasmids (58 Mdal and 90 Mdal).
- Formaldehyde resistance was demonstrated to be plasmid-mediated and transferable to E. coli.
- Resistant strains showed significantly higher binding of 14C-formaldehyde compared to sensitive strains.
Conclusions:
- Plasmids confer significant formaldehyde resistance in Serratia marcescens.
- The identified plasmids are responsible for the observed resistance phenotype.
- Understanding these resistance mechanisms is crucial for effective disinfection strategies.