Selfish bacterial cells that act in their own interests and do not cooperate with their infection-causing colleagues can actually reduce the severity of infection.
The selfish behaviour of these uncooperative bacteria could be exploited to treat …
For antibiotics, the best way to beat bacterial defenses may be to avoid them altogether. Researchers at University of Pennsylvania School of Medicine have discovered that Cecropin A, a member of a family of antibiotic proteins produced by insects, may kill bacteria and avoid resistance by entering bacterial cells and taking control of their genetic machinery.
While most antibiotics kill bacteria by attacking critical enzyme systems, Cecropin A somehow slips inside the bacteria and turns specific genes on and off. The findings challenge conventional thinking on how these antibiotics function, and may aid in turning antimicrobial peptides like Cecropin A into therapeutic agents.
Scientists have discovered a promising new drug lead that works by inhibiting the sophisticated bacterial communication system called quorum sensing. The new compound is active against Pseudomonas aeruginosa, the gram-negative infection that strikes — and usually kills — cystic fibrosis patients and many others whose immune systems are compromised. The bacteria, like many others that have been routinely treated by antibiotics, have developed strains that are antibiotic-resistant.
A highly sensitive, inexpensive “lab-on-a-chip” that provides warning within seconds of even trace amounts of toxic chemicals in water was designed and demonstrated recently by National Institute of Standards and Technology (NIST) scientists and collaborators. The prototype sensor system monitors the natural response of bacterial cells bound within the microscopic channels of a plastic microfluidics device — a miniaturized chemical and biochemical analysis system. In the presence of certain chemicals, the cells eject large amounts of potassium, which is detected with an optical sensor that changes color. The prototype was demonstrated as part of an early warning system for industrial pollutants that interfere with sewage treatment, but it also has potential homeland security applications.
The prospect of using bacteria to manufacture complex human proteins for use in therapeutic drugs is a step closer thanks to new research published today in Science. Researchers from Switzerland and the UK report they have engineered the bacterium Escherichia coli to carry a vital piece of cell machinery that adds sugar molecules to newly synthesized proteins by a process known as glycosylation. The finding opens up the possibility of producing complex human proteins such as Factor VIII and the hormone erythropoietin, which stimulates the production of red blood cells by stem cells in bone marrow. Both these proteins, which require the addition of sugar molecules to function properly, are currently produced by culturing mammalian cells, which can be a costly and technically difficult process.
Within the smoothly operating factory that is the cell, tiny molecular machines carry out their tasks with order and certainty. Or at least that’s what many scientists once believed. In a recent issue of Science, researchers report the first demonstration that bacterial cells intrinsically possess a significant degree of randomness or “noise.” More precisely, they show that key “gene-reading” machines may operate unpredictably, resulting in randomly fluctuating amounts of individual proteins.