Abstract: Disclosed is a process for producing a mutant bacterium which exhibits improved survival and/or growth under a selected growth condition, the process comprising the steps of: (a) generating a pool of mutant bacteria by transposon mutagenesis with an activating transposon (TnA), wherein the TnA comprises an outward-facing promoter (TnAP) capable of increasing transcription of a gene at or near its insertion site in the DNA of said bacterium; (b) growing bacteria from the mutant pool under the selected growth condition and under one or more reference conditions to produce two or more test cultures; and (c) sequencing mRNA transcripts produced by TnAP in each of said test cultures to produce an mRNA transcript profile for each of the test cultures; and (d) comparing the mRNA transcript profiles of the test cultures to identify a first class of genes which are disadvantageous for growth and/or survival under the selected growth condition and a second class of genes which are advantageous for growth and/or surviva

Abstract: Disclosed is a method for characterizing the effect of an antibiotic on a bacterium, the method comprising the steps of: (a) generating a pool of mutant bacteria by transposon mutagenesis of a culture of said bacterium with an activating transposon (TnA) which comprises an outward-facing promoter (TnAP) capable of increasing transcription of a gene at or near its insertion site in the DNA of said bacterium; (b) growing bacteria from the mutant pool in the presence of different amounts of said antibiotic to produce two or more test cultures; (c) sequencing mRNA transcripts produced by TnAP in each of said test cultures to produce an mRNA transcript profile for each of the test cultures; and (d) comparing the mRNA transcript profiles of the test cultures.