Related Experiment Videos
Gentic properties of an R factor carrying resistance to aminolgycoside antibiotics
Abstract:
R factor Rms 151 is an fi+ R factor and belongs to a incompatibility group FII. It carries the genes governing resistance to various aminoglycoside antibiotics, i.e., kanamycin (KM), lividomycin (LV), gentamicin C complex (GM), and 3',4'-dideoxykanamycin B (DKB), in addition to those governing to tetracycline (TC), chloramphenicol (CM), sulfanilamide (SA), and ampicillin (APC). Electron microscopy observation disclosed that the Rms151 deoxyribonucleic acid was a circular form with length of 31.2 mum. A probable circular genetic map of Rms151 was proposed by genetic and biochemical studies, the genes being in the order of -tet-tra-amp-aad-sul-aph-cml-, in which aad and aph confer resistance to KM.GM.DKB by adenylytransferase or resistance to KM.LV by phosphotransferase, respectively.
Insights
The Rms151 R factor provides resistance to multiple antibiotics, including kanamycin, gentamicin, tetracycline, and ampicillin. Genetic mapping revealed the order of resistance genes on this circular DNA molecule.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- R factors are plasmids conferring antibiotic resistance.
- Rms151 is an fi+ R factor belonging to the FII incompatibility group.
- It confers resistance to a broad spectrum of antibiotics.
Purpose of the Study:
- To characterize the Rms151 R factor.
- To determine the genetic organization of antibiotic resistance genes.
- To propose a genetic map for Rms151.
Main Methods:
- Electron microscopy was used to examine the Rms151 DNA structure.
- Genetic and biochemical studies were performed to map the resistance genes.
- Antibiotic resistance profiles were analyzed.
Main Results:
- Rms151 DNA is a circular molecule approximately 31.2 µm in length.
- Genes for resistance to kanamycin (KM), lividomycin (LV), gentamicin (GM), 3',4'-dideoxykanamycin B (DKB), tetracycline (TC), chloramphenicol (CM), sulfanilamide (SA), and ampicillin (APC) were identified.
- A probable gene order of -tet-tra-amp-aad-sul-aph-cml- was proposed, with specific genes conferring resistance via adenylylation or phosphorestation.
Conclusions:
- Rms151 possesses a complex array of antibiotic resistance genes.
- The proposed genetic map provides insights into the organization of these resistance determinants.
- Understanding R factor structure is crucial for combating antibiotic resistance.