Genetic characterisation of a large antibiotic resistant environmental ST131 E. coli plasmid using a long read hybrid assembly approach

Escherichia coli Strain Type 131 are a globally disseminated environmental E. coli that has been linked to the capture and spread of plasmid mediated blaCTX-M type extended spectrum beta-lactamase (ESBLs). Accurately identifying such resistance genes in their wider genetic context provides a greater understanding of the mechanisms of selection and persistence in the environment. In this study we use a novel DNA extraction and enrichment method in combination with a custom long-read scaffold hybrid-assembly and polishing pipe line to identify the genetic context of the plasmid borne blaCTX-M gene previously identified in an ST131 environmental E. coli isolate. This has allowed us to discern the complete structure of a ~100kb environmental plasmid and further resolve the blaCTX-M variant to the group 9 blaCTX-M-27 gene. The upstream IS26 insertion element associated with the global capture and dissemination of blaCTX-M-15 was also identified in proximity to blaCTX-M-27. Furthermore, the lack of conjugative machinery identified on this plasmid, in combination with a toxin-antitoxin and plasmid partitioning system, indicates a mechanism of vertical transmission to maintain persistence in a population.

Bacterial Plasmids Profile from Escherichia coli Resistant to Metronidazole and Nalidixic Acid

bacteria that cause an illness. Antibiotic treatments to a patient have a purpose to eliminate the pathogen bacteria. Bacteria resistance to antibiotic was influenced by the intensity of antibiotic treatment in a region, the uncontrolled antibiotics treatments would increase the antibiotic resistance of bacteria. Plasmids was an extrachromosomal DNA that encodes a functional protein that would eliminate the antibiotic activity. Plasmid is the determinant of bacteria sensitivity to antibiotics. In this case it would be important to find out the bacterial plasmid profile on the E.coli resistant to metronidazole and nalidixic acid antibiotics. This research was using four different sample from faces of diarrhea, ice block, waters from well, and ketchup to cultivate the E. coli. lasmid isolation method was carried out by lyses alkali method. Plasmid profile of the E. coli that resistant to metronidazole and nalidixic acid antibiotics and analyzed using electrophoresis on 1% agarose. E. coli plasmid DNA profile was observed as a fluorescent DNA band in ultraviolet rays. In result, isolated plasmids from bacteria that resistant to antibiotics metronidazole and nalidixic acid having similar size approximately 500 bp, different from bacteria that sensitive to antibiotics metronidazole and nalidixic acid has a smaller size in region of 100 bp.

Plasmid segregation: spatial awareness at the molecular level

In bacteria, low-copy number plasmids ensure their stable inheritance by partition loci (par), which actively distribute plasmid replicates to each side of the cell division plane. Using time-lapse fluorescence microscopic tracking of segregating plasmid molecules, a new study provides novel insight into the workings of the par system from Escherichia coli plasmid R1. Despite its relative simplicity, the plasmid partition spindle shares characteristics with the mitotic machinery of eukaryotic cells.