17Stephen H. Gillespie (ed.), Antibiotic Resistance Protocols, Methods in Molecular Biology, vol. 1736,
https://doi.org/10.1007/978-1-4939-7638-6_2, © Springer Science+Business Media, LLC 2018
Chapter 2
Construction and Use of Staphylococcus aureus Strains
to Study Within-Host Infection Dynamics
Gareth McVicker, Tomasz K. Prajsnar, and Simon J. Foster
Abstract
The study of the dynamics that occur during the course of a bacterial infection has been attempted using
several methods. Here we discuss the construction of a set of antibiotic-resistant, otherwise-isogenic
Staphylococcus aureus strains that can be used to observe the progress of systemic disease in a mouse model
at various time-points postinfection. The strains can likewise be used to study the progression of infection
in other animal infection models, such as the zebrafish embryo. Furthermore, the use of antibiotic resis-
tance tags provides a convenient system with which to investigate the effect of antimicrobial chemotherapy
during disease.
Key words Infection, Dynamics, Mutant, Isogenic, Animal model1 Introduction
Research into the problem of antibiotic resistance depends not
only upon biochemical, genetic and pharmacological data obtained
from bacteria, but also upon studies that investigate the interac-
tions between the pathogen and its host. Posttreatment, antimi-
crobial compounds accumulate at a range of concentrations within
different human organs [ 1 ], and bacteria themselves often display
a degree of tissue tropism [ 2 , 3 ]. Even during systemic infections,
organs such as the kidneys and liver can act as a large reservoir for
bacterial cells [ 4 ].
Quantitative attempts to study host-pathogen dynamics dur-
ing infection rely upon tagging bacterial subpopulations and
observing the change in their in vivo distribution over time. This
has previously been achieved using signature DNA tags that can be
amplified after isolation of the pathogen from the diseased host
[ 5 ]. An alternative method involves the insertion of various antibi-
otic resistance cassettes into the bacterial genome at a neutral locus,
in order to create a set of selectable, otherwise-isogenic strains [ 4 ,
6 ]. Plasmid-borne antibiotic resistance markers are attractive for