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Characterization of plasmids with antimicrobial resistant genes in Pasteurella haemolytica A1
Abstract:
Two R plasmids, pYFC1 and pYFC2, from Pasteurella haemolytica A1 encoding sulfonamide, streptomycin (pYFC1), and ampicillin (pYFC2) resistances have been characterized by restriction endonuclease digestions, subcloning or DNA sequencing. pYFC1 consists of 4225 bp and is 51.9% in AT content. Physical mapping indicated a highly conserved region of restriction sites among pYFC1, RSF1010, pGS05, pFM739, pHD148 and pGS03B. pYFC1 encoded a dihydropteroate synthase (29.8 kDa), and streptomycin kinase (29.6 kDa) which is homologous in nucleotide sequences or deduced amino acid sequence to that encoded by a broad-host range IncQ plasmid RSF1010. Based on the primary structure of pYFC1, the sulfonamide and streptomycin genes are derived from the same ancestor of RSF1010. pYFC2 is similar to the plasmid from P. haemolytica LNPB51 isolated in France by partial restriction enzyme mapping. pYFC1 and pYFC2 have the same size of 4.2 kbp.
Insights
Two Pasteurella haemolytica plasmids, pYFC1 and pYFC2, were analyzed. The study found that pYFC1
Area of Science:
- Molecular Biology
- Microbiology
- Genetics
Background:
- Antimicrobial resistance in bacteria is a significant public health concern.
- Plasmids are key vectors for the spread of antibiotic resistance genes.
- Characterization of resistance plasmids aids in understanding bacterial evolution and resistance mechanisms.
Purpose of the Study:
- To characterize two R plasmids, pYFC1 and pYFC2, from Pasteurella haemolytica A1.
- To determine the genetic basis of sulfonamide, streptomycin, and ampicillin resistance encoded by these plasmids.
- To compare the genetic structure of pYFC1 and pYFC2 with other known plasmids.
Main Methods:
- Restriction endonuclease digestions
- Subcloning experiments
- DNA sequencing
- Physical mapping
- Sequence homology analysis
Main Results:
- Plasmids pYFC1 and pYFC2 are both 4.2 kbp in size.
- pYFC1 encodes sulfonamide and streptomycin resistance, with genes homologous to those on IncQ plasmid RSF1010.
- A conserved region of restriction sites was identified in pYFC1, shared with several other plasmids.
- pYFC2 exhibits similarity to a plasmid from a French isolate of P. haemolytica LNPB51.
Conclusions:
- The sulfonamide and streptomycin resistance genes on pYFC1 likely originated from the same ancestor as those on RSF1010.
- The characterization provides insights into the genetic relatedness and evolutionary origins of resistance plasmids in Pasteurella haemolytica.
- Understanding plasmid structure and origins is crucial for developing strategies to combat antimicrobial resistance.