Protocols
The culture of pathogens and generation of appropriate models is crucial to the study of antimicrobial resistance. Nature Protocols publishes peer-reviewed protocols containing recipe-style details to facilitate implementation of the latest methods.
Building a morbidostat: an automated continuous-culture device for studying bacterial drug resistance under dynamically sustained drug inhibition
Erdal Toprak, Adrian Veres, Sadik Yildiz, Juan M Pedraza, Remy Chait, Johan Paulsson & Roy Kishony
We present a protocol for building and operating an automated fluidic system for continuous culture that we call the 'morbidostat'. The morbidostat is used to follow the evolution of microbial drug resistance in real time.
In vitro and in vivo generation and characterization of Pseudomonas aeruginosa biofilm–dispersed cells via c-di-GMP manipulation
Song Lin Chua, Louise D Hultqvist, Mingjun Yuan, Morten Rybtke, Thomas E Nielsen, Michael Givskov, Tim Tolker-Nielsen & Liang Yang
Here we present in vitro and in vivo protocols for the generation and characterization of dispersed cells from Pseudomonas aeruginosa biofilms by reducing the intracellular c-di-GMP content through modulation of phosphodiesterases (PDEs). Unlike conventional protocols that demonstrate biofilm dispersal by biomass quantification, our protocols enable physiological characterization of the dispersed cells. Biomarkers of dispersed cells are identified and quantified, serving as potential targets for treating the dispersed cells. The in vitro protocol can be completed within 4 d, whereas the in vivo protocol requires 7 d.
Agar and broth dilution methods to determine the minimal inhibitory concentration (MIC) of antimicrobial substances
Irith Wiegand, Kai Hilpert & Robert E. W. Hancock
The aim of broth and agar dilution methods is to determine the lowest concentration of the assayed antimicrobial agent (minimal inhibitory concentration, MIC) that, under defined test conditions, inhibits the visible growth of the bacterium being investigated. MIC values are used to determine susceptibilities of bacteria to drugs and also to evaluate the activity of new antimicrobial agents.