The evolution of resistance to pesticides

Published on December 31, 2019   35 min

A selection of talks on Plant & Animal Sciences

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I'm Nichola Hawkins from Rothamsted Research, and I'm going to be talking about the evolution of pesticide resistance in crop protection. My own research focuses on fungicide resistance in plant pathogens, but there are a lot of common themes across pesticide groups.
I'll start by introducing the problem of resistance, then talk about research, monitoring resistance, identifying the molecular mechanisms of resistance, and investigating the underlying evolutionary biology leading to resistance.
This is growing public awareness now of the threat posed to human health by antibiotic resistance in medicine. The superbug MRSA has a death rate of two-thirds higher than drug-sensitive staphylococcus infections. Drug-resistant E. coli has double the death rates of sensitive types, and nearly half a million cases of drug-resistant TB have been reported globally within one year.
Resistance evolves when genetic variation in a population of microbes includes differences in antibiotic sensitivity. When an antibiotic is used, the most sensitive bacteria will kill at a higher rate than the resistant bacteria. Then, when the surviving bacteria reproduce, more of them will pass on the resistance genes to their offspring. So, an increasing proportion of the population will be resistant. The resistance threat extends beyond antibiotics. We see a similar situation for other biocidal drugs: antivirals and antiretrovirals, antifungals, and antiparasitics. We see malarial parasites resistant to antimalarials, but also mosquitoes resistance to the insecticides used in vector control; also, the evolution of anticancer drug resistance where resistant mutants are selected at the cellular level.