Research by Wageningen University, part of Wageningen UR, has shown that the development of bacteria with resistance against the antibiotic cefotaxime occurs more often and more predictably than was previously assumed. Bacterial populations were found to have many mutations that increase resistance and therefore have a negative effect on public health. Moreover, the effects are such that it can be predicted that the development of bacterial strains with a resistance against cefotaxime will progress in a similar way in different patients from different locations. Together with German colleagues, the Wageningen scientists developed a research approach which will allow them to predict whether, and if so how, resistant bacterial strains will develop for other antibiotics as well.
The Wageningen scientists studied the main enzyme that causes resistance against the antibiotic cefotaxime. The only function of this beta-lactamase enzyme is the breakdown of so-called beta-lactam antibiotics, which kill bacteria by preventing the production of their cell walls. Martijn Schenk and Arjan de Visser, genetic scientists at Wageningen University, were surprised by the number of mutations with a positive effect on the resistance against cefotaxime. De Visser: "Of all the mutations we found in this beta-lactamase, more than three per cent caused an increase in the resistance against the antibiotic. To top it all off, we discovered that the mutations with a strong effect also had a much greater impact than we had anticipated. Based on theoretical arguments and previous observations, we had estimated the effects on the resistance against the antibiotic to be significantly lower."