Antibiotics are used routinely to cure infections, without these drugs many patients would endure much suffering or die. Patients in hospitals, for example those with cancer, succumb to infection frequently. For such patients, having antibiotics to treat these infections is a medical necessity. Many bacteria have developed resistance to antibiotics, thus many of the drugs no longer work. Combatting antimicrobial resistance is thus a major public health issue. Colistin is an antibiotic which was first discovered in Japan in 1949. Colistin is often used to treat infections where the bacteria is resistant to many drugs. This drug is thus used as a last resort.
The lab in which I wish to work has identified two factors, produced by bacteria, that result in colistin resistance in Escherichia coli. This particular form of E. coli is associated with infection of the human bloodstream. The purpose of my project will be to characterise these factors in more detail. These factors are polysaccharides; these are long strings of sugar that coat the surface of bacteria. The polysaccharides may be drug targets, since inactivation of these will make the bacteria mores sensitive to colistin.