Adaptive Processes Change as Multiple Functions Evolve.

Adaptive Processes Change as Multiple Functions Evolve. Antimicrob Agents Chemother. 2021 Jan 19;: Authors: Mira PM, Østman B, Guzman-Cole C, Sindi S, Barlow M Abstract Epistasis influences the gene-environment interactions that shape bacterial fitness through antibiotic exposure which can ultimately affect the availability of certain resistance phenotypes to bacteria. The substitutions present within bla TEM-50 confer both cephalosporin and β-lactamase inhibitor resistance. We wanted to compare the evolution of bla TEM-50 with another variant, blaTEM -85, which differs in that blaTEM -85 contains only substitutions that contribute to cephalosporin resistance. Differences between the landscapes and epistatic interactions of these TEM variants are important for understanding their separate evolutionary responses to antibiotics. We hypothesized the substitutions within blaTEM-50 would result in more epistatic interactions than blaTEM-85. As expected, we found more epistatic interactions between the substitutions present in bla TEM-50 than in bla TEM-85 Our results suggest that selection from many cephalosporins is required to achieve the full potential resistance to cephalosporins, but that a single β-lactam and inhibitor combination will drive evolution of the full potential resistance phenotype. Surprisingly, we also found significantly positive increases in growth rates as antibiotic concentration increased for some of the strain...
Source: Antimicrobial Agents and Chemotherapy - Category: Microbiology Authors: Tags: Antimicrob Agents Chemother Source Type: research