Bielecki et al. Research Paper
Pseudomonas aeruginosa is a Gram-negative bacteria, particularly known for causing nosocomial infections (1). As a pathogen, it effectively causes disease by acquiring resistance to antibiotics that would otherwise inhibit growth (2). Reported rates of infection range from 0.6 to 32% across various clinical environments because Pseudomonas aeruginosa has gained multi-drug resistance (2). Certain strains of Pseudomonas aeruginosa treated with gamma rays can break down the hydrocarbons in crude oil and are thus useful in cleaning up oil spills (3). The genome of Pseudomonas aeruginosa is 6.3 million base pairs long, which is the largest bacterial genome to be sequenced (4). It contains about 5,570 open reading frames (4). Argyrin is a naturally synthesized antibiotic peptide extracted from myxobacteria (1). It has cytotoxic properties, suppresses the immune system, and is a highly active antibiotic used against Pseudomonas strains (1). Figure 1. Argyrin A structure.
Bielecki et al chose to isolate these resistant clones in order to observe the mechanisms by which the P. aeruoginosa acquires resistance to Argyrin A within the fusA1 gene (1). They isolated these clones by growing Pseudomonas aeruginosa strains on agar that contained Argyrin A (1). After incubation, the colonies that formed were able to grow in the presence of argyrin; these colonies were then streaked onto plates with Argyrin A again to ensure accuracy of obtaining resistant strains (1). A point mutation is an alteration of one base pair within a DNA sequence (5). The point mutations, which caused changes in the amino acid sequence within the fusA1 gene, were different among the six isolates (1). They might have conferred resistance because the mutations caused the same impact on the resulting protein (1). The gene was identified by sequencing the whole genome of Pseudomonas aeruginosa strains with the bacterial target of Argyrin A, which...
Please join StudyMode to read the full document