Chapter 38: Antimicrobial resistance in wild boar in Europe441
farming) on AMR prevalence in wild boar, and this is an urgent
missing link. Better investigation of these links will contribute
to our understanding of the origins and roles of antibiotic resist-
ance genes in the gut microbiota of wildlife.
Following this line, future steps should try to unveil the role
of wild boar as reservoirs and amplifiers of AMR and the likely
sources and mechanisms of persistence of AMR in this species
and how the ecological landscape modulates the prevalence and
transmission of AMR in the environment. Thus, to fully under-
stand the AMR pressures exerted on wild boar populations, it is
important to continuously monitor resistance trends at sites that
differ in exposure levels, including the impact of human activi-
ties. There is evidence of the spread of resistance genes between
different animals (domestic and wild) and people. Whereas
this process is difficult to disclose mechanistically, advances in
genetic and phylogenetic analyses, and also in whole-genome
sequencing, have facilitated the detection of AMR genes, link-
ing cases, defining exposure paths and transmission routes, ena-
bling the deduction of clonal relationships and the unfolding
of hypotheses concerning AMR amplification. For example, by
performing phylogenetic analysis, Ward et al. (2014) showed
that livestock was an important source of Staphylococcus aureus
clonal complex 398 (CC398) in humans while Mather et al.
(2011) reported that sympatric animals are improbable to be
the main cause of Salmonella typhimurium DT104 (DT104) in
humans and that other sources of infections must be relevant.
Where To Go From Here – The Ecological
Landscape of AMR
Data collection and rapid detection of AMR is essential to man-
age challenges in the human, veterinary, and environmental set-
tings, through better infection prevention and control policies,
bioremediation, and epidemiological monitoring. For the last
decades, AMR research has been mainly focused on provid-
ing prevalence reference values and identifying genetic deter-
minants. Nonetheless, the knowledge of how landscape drives
AMR in both wild and domestic hosts will largely contribute to
the understanding of the dissemination of AMR in the environ-
ment (Singer et al. 2006). In that regard, the application of an
ecological approach will be essential for the comprehension of
AMR dynamics. However, few studies have actually applied such
an ecological framework, yet, this multidisciplinary approach
is vital. Ecological tools will contribute to the enlightenment
of the origins and transmission routes of AMR in the wildlife–
livestock interface with contrasted human influence, and to
optimize the resources towards AMR research and management
at a large scale.
Wild boar have been extensively described as important spe-
cies for the maintenance and dispersion of infectious agents that
are shared between livestock and humans and several characteris-
tics of their ecology contribute to this cycle (Meng et al. 2009). This
means that to acknowledge wild boar relevance to the dynamics
of AMR, it is important to deeply understand the species’ social
structure, dispersal capability and population density. A key
aspect of this process is to understand the landscape in which
the species moves and interacts within populations of wildlife/
livestock communities. In this context, factors likely to affect wild
boar spatial dynamics such as landscape structure (composition
and configuration) and connectivity will surely affect AMR risk,
hotspots, or potential outbreaks (Ostfeld et al. 2005).
In recent decades, several analytical tools, such as spatial sta-
tistics, mechanistic modelling, contact network analysis, cluster
analysis, geographic information systems (GIS), and remote
sensing, have been developed in the field of disease ecology
(Reisen 2010). Although almost none have actually been applied
in the field of AMR, these tools have proved to be essential in
managing infectious diseases on a macroscale (e.g. Lyme bor-
reliosis and West Nile virus; Reisen 2010). Given the knowledge
gap, an ecological framework is vital to identify and characterize
transmission routes of AMR in wild boar. Within this frame,
it is essential to: (i) construct detailed distribution maps of the
wild boar, through statistical modelling, and describe the spa-
tial distribution of AMR, by including the distribution of biotic/
abiotic factors that influence wild boar distribution; (ii) evaluate
the spatial distribution and clustering of resistant bacteria in
regards to their host distribution, therefore detecting outbreaks
of non-susceptible bacteria and the associated risk factors; and
(iii) infer the current risk and predict future risk scenarios (e.g.
in the context of land use and climate changes). This integrated
framework will provide early warnings of resistance trends.
Indisputably, the knowledge of the geographical distribu-
tion of wild boar and their associated resistant bacteria is a step
forward to ensure setting the right priorities for optimal surveil-
lance, as well as control programmes. This will provide impor-
tant baseline data for the scientific community to develop and
evaluate intervention strategies aimed at managing human,
livestock and wildlife risks related to AMR. Over the last years,
detailed information has been gathered about wild boar ecology,
which now needs to be incorporated into the AMR dynamics.
Mitigation of AMR requires a holistic perspective to document
the occurrence and spread of AMR in wild boar and contribute
to raising awareness of the problem to decision makers, public
health officials, the scientific community and society.Key Message
The increasing resistance of bacteria to antibiotics and their
remarkably adaptive nature has become a major challenge to
human and animal health worldwide. Furthermore, exposure of
environmental niches to stressors, such as bacterial commensals
or pathogens harbouring MDR genes with putative ecological
advantage over other niche-adapted bacteria that exert funda-
mental functions in the ecosystems (e.g. photosynthetic), may
also have threatening downstream effects. Whereas human
health must remain a priority, it is timely to develop appropri-
ate strategies under a complete agenda of the ecology of resist-
ance in both human and animal populations (livestock and
wildlife), as well as in the wider ecological network (Karesh et al.
2012). It is certainly difficult to apply the very same mitigation
measures that are used, or being foreseen, in the clinical setting,
when studying and controlling AMR transmission in the wild
compartment.
Comprehensive studies which elucidate fundamental ques-
tions in the evolution and transmission of the complex dynam-
ics of AMR in the human–livestock–wildlife interface, under an.04013:02:28