Genomic diversity and antimicrobial resistance in Salmonella isolates recovered from diverse sources in Nigeria
type: CreativeWork
description: Antimicrobial Resistance (AMR) jeopardises the gains of modern medicine and is therefore considered a global public health threat. It has been predicted to cause up to 10 million deaths by 2050 if no serious actions are taken. AMR threatens people's lives worldwide but with a significantly higher burden in low and middle-income countries (LMICs), where it is challenging to determine the exact burden of bacterial AMR due to gaps in surveillance. Salmonella is an important zoonotic gram-negative pathogen that may be categorised into serovars and sequence types (STs) based on seven housekeeping genes. The Salmonella isolates that cause problems vary for geographical regions and have different antimicrobial susceptibility patterns. This is likely to be driven by the antimicrobials that are in use in these regions. Fluoroquinolone and cephalosporins are important antimicrobials for treating salmonellosis, but due to growing resistance, the World Health Organisation now considers fluoroquinolone-resistant (FQR) Salmonella a critically important pathogen. The central hypothesis of this thesis is that a better understanding of the genetic diversity, and sources, of antibiotic resistant Salmonella spp in Nigeria, and of markers of emergent antibiotic resistance will inform and encourage the development of integrated interventions to reduce the impact of Salmonella in this country. Whole-genome sequences of the sampled dataset combined with publicly available Nontyphoidal Salmonella (NTS) genomes (Nigeria NTS collection) recovered from various sources revealed the diversity of NTS in Nigeria. One hundred and twenty-one unique serovars belonging to 167 STs were identified within the dataset, with some serovars having more than one ST. An eBURST diagram confirmed that the majority of the Nigeria NTS collection were not closely related. S. enterica Kentucky (ST198) was the most common strain in poultry, while S. enterica Enteritidis (ST11) was the most common human serovar. Phen…
abstract: Antimicrobial Resistance (AMR) jeopardises the gains of modern medicine and is therefore considered a global public health threat. It has been predicted to cause up to 10 million deaths by 2050 if no serious actions are taken. AMR threatens people's lives worldwide but with a significantly higher burden in low and middle-income countries (LMICs), where it is challenging to determine the exact burden of bacterial AMR due to gaps in surveillance. Salmonella is an important zoonotic gram-negative pathogen that may be categorised into serovars and sequence types (STs) based on seven housekeeping genes. The Salmonella isolates that cause problems vary for geographical regions and have different antimicrobial susceptibility patterns. This is likely to be driven by the antimicrobials that are in use in these regions. Fluoroquinolone and cephalosporins are important antimicrobials for treating salmonellosis, but due to growing resistance, the World Health Organisation now considers fluoroquinolone-resistant (FQR) Salmonella a critically important pathogen. The central hypothesis of this thesis is that a better understanding of the genetic diversity, and sources, of antibiotic resistant Salmonella spp in Nigeria, and of markers of emergent antibiotic resistance will inform and encourage the development of integrated interventions to reduce the impact of Salmonella in this country. Whole-genome sequences of the sampled dataset combined with publicly available Nontyphoidal Salmonella (NTS) genomes (Nigeria NTS collection) recovered from various sources revealed the diversity of NTS in Nigeria. One hundred and twenty-one unique serovars belonging to 167 STs were identified within the dataset, with some serovars having more than one ST. An eBURST diagram confirmed that the majority of the Nigeria NTS collection were not closely related. S. enterica Kentucky (ST198) was the most common strain in poultry, while S. enterica Enteritidis (ST11) was the most common human serovar. Phen…
author: Achi, Chioma
language: eng
keywords: Antimicrobial Resistance, Salmonella, Nigeria, Genomic diversity
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2021-11-23
date modified: 2026-07-22T22:23:59Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.88840