Microarray transposon tracking for the mapping of conditionally essential genes in Campylobacter jejuni

Abstract

Although whole genome approaches to the study of bacteria have grown substantially in the past decade, there is still a need for quick and easy methods for the determination of which genes are essential for the growth of these bacteria under specifi c growth conditions. There are numerous methods to accomplish this depending on the resources and equipment available, each with their own advantages and disadvantages. Here we describe a method we successfully employed to map the essential genes of Campylobacter jejuni using a microarray transposon tracking approach where we constructed a saturated transposon mutant library in the C. jejuni strain NCTC11168 and used a genomic microarray approach to identify genes lacking transposon insertions under standard laboratory growth conditions. With a fully saturated library, the absence of transposon insertions can be used as an indicator of a gene essential for the survival and growth for the conditions used for the mutant library.