1. Loss of Pde1 function acts as an evolutionary gateway to penicillin resistance in Streptococcus pneumoniae .
- Author
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Kobras CM, Monteith W, Somerville S, Delaney JM, Khan I, Brimble C, Corrigan RM, Sheppard SK, and Fenton AK
- Subjects
- Humans, Penicillin-Binding Proteins metabolism, Penicillin Resistance genetics, Penicillins pharmacology, Penicillins metabolism, Bacterial Proteins metabolism, Anti-Bacterial Agents pharmacology, Microbial Sensitivity Tests, Streptococcus pneumoniae, beta-Lactam Resistance genetics
- Abstract
Streptococcus pneumoniae is a major human pathogen and rising resistance to β-lactam antibiotics, such as penicillin, is a significant threat to global public health. Mutations occurring in the penicillin-binding proteins (PBPs) can confer high-level penicillin resistance but other poorly understood genetic factors are also important. Here, we combined strictly controlled laboratory experiments and population analyses to identify a new penicillin resistance pathway that is independent of PBP modification. Initial laboratory selection experiments identified high-frequency pde1 mutations conferring S. pneumoniae penicillin resistance. The importance of variation at the pde1 locus was confirmed in natural and clinical populations in an analysis of >7,200 S. pneumoniae genomes. The pde1 mutations identified by these approaches reduce the hydrolytic activity of the Pde1 enzyme in bacterial cells and thereby elevate levels of cyclic-di-adenosine monophosphate and penicillin resistance. Our results reveal rapid de novo loss of function mutations in pde1 as an evolutionary gateway conferring low-level penicillin resistance. This relatively simple genomic change allows cells to persist in populations on an adaptive evolutionary pathway to acquire further genetic changes and high-level penicillin resistance.
- Published
- 2023
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