Acambis Research Limited

Discuva Limited

Bactevo Ltd.

Arthur Keith Turner

David Hugh Williams

Judith Greenwood

Juliet Claire Beavis

Michael James Darsley

Jonathan Clive Stephens

John Richard Wain

Disclosed are methods related to identifying an essential gene which serves as an antibiotic target in a bacterium.

Method for identifying antibiotic targets

Provided are methods for identifying differentially represented genes, the method comprising the steps of generating a pool of mutant bacteria by transposon mutagenesis with an activating transposon (Tn), wherein the Tncomprises a promoter such that transposon insertion into bacterial DNA increases the transcription of a gene at or near the insertion site; growing bacteria from the mutant pool in the presence of different amounts of said antibiotic to produce two or more test cultures; and comparing the distribution of Tninsertions between test cultures.

Provided herein are methods, and related compositions for identifying a putative essential gene which serves as an antibiotic target in a bacterium, the method, in some embodiments, comprising (a) generating an antibiotic resistant mutant of the bacterium by a method comprising the step of selecting for growth in the presence of an antibiotic to produce an antibiotic resistant mutant clone (Abmutant); (b) transforming the Abmutant with one or more essential genes of the bacterium and a transposon which insertionally inactivates bacterial DNA to produce a pool of transposon mutants which are merodiploid for the one or more essential genes; (c) growing bacteria from the merodiploid pool in the presence of different amounts of the antibiotic to produce two or more test cultures; and (d) comparing the distribution of transposon insertions between the test cultures to identify a putative essential gene serving as a target of the antibiotic in the bacterium.

Method for identifying antibiotic targets by complemented sequencing

The invention provides strains of bacteria, especially enterotoxigenic, attenuated by mutations in the genes encoding enterotoxins (LT, ST, EAST1) and optionally further attenuated by deletion of additional chromosomal genes. In addition the invention provides strains of attenuated bacteria expressing immunogenic but non-toxic variants of one or more of these enterotoxins. These bacteria are useful as a vaccine against diarrhoeal disease.

Attenuated bacteria useful in vaccines

A bacterial cell which expresses three or more coli surface (CS) antigens and methods of making such a cell. The cell is useful in making vaccines against diarrhea.

Growing community of inventors

Cambridge, United Kingdom

Arthur Keith Turner