Exploring the essential genome of Klebsiella pneumoniae

Gray, Jessica (2022). Exploring the essential genome of Klebsiella pneumoniae. University of Birmingham. Ph.D.

Gray2022PhD.pdf
Text - Accepted Version
Restricted to Repository staff only until 12 February 2027.
Available under License All rights reserved.
Download (13MB) | Request a copy

Abstract

Klebsiella pneumoniae is a key nosocomial pathogen associated with increasing resistance to first-line antibiotics. The identification of novel targets for the treatment of these infections is vital. Proteins encoded by genes that are essential for the survival of a pathogen represent good targets. Transposon Directed Insertion-site Sequencing (TraDIS) was used to generate a highly-saturated mutant library of Klebsiella pneumoniae ECL8. The library consists of 554,834 unique transposon insertion sites and is the most densely saturated library generated in K. pneumoniae. A total of 266 genes were identified as essential, present in 175 diverse Klebsiella isolates and lacked a human homolog. Among these genes were three involved in the sulfur-relay system required for a thiomodification of transfer RNA (tRNA). These genes were non-essential in other members of the Enterobacteriacae. Subsequently, this library was used to identify genes which, when mutated, confer reduced fitness for growth in urine and survival in serum. Eleven genes were identified for growth in urine, five encode proteins required for TonB-dependent transport of substances such as siderophores. Transposon insertions within 144 genes conferred increased sensitivity to serum, these include genes not previously implicated in sensitivity to serum in K. pneumoniae, such as those involved in enterobacterial common antigen biosynthesis. Four genes (ompA, sodA, exbB and exbD) were identified as conferring reduced fitness in both urine and serum and thus are good targets for treatment of K. pneumoniae in different body sites. The results presented provide targets for the design of antimicrobial compounds to treat K. pneumoniae infections and a greater knowledge of genes required for K. pneumoniae survival within different host niches.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):