TY - JOUR

T1 - An ecological approach to assessing the epidemiology of antimicrobial resistance in animal and human populations

AU - Mather, Alison E

AU - Matthews, Louise

AU - Mellor, Dominic J

AU - Reeve, Richard

AU - Denwood, Matt

AU - Boerlin, Patrick

AU - Reid-Smith, Richard J

AU - Brown, Derek J

AU - Coia, John E

AU - Browning, Lynda M

AU - Haydon, Daniel T

AU - Reid, Stuart W J

PY - 2012/4/22

Y1 - 2012/4/22

N2 - We examined long-term surveillance data on antimicrobial resistance (AMR) in Salmonella Typhimurium DT104 (DT104) isolates from concurrently sampled and sympatric human and animal populations in Scotland. Using novel ecological and epidemiological approaches to examine diversity, and phenotypic and temporal relatedness of the resistance profiles, we assessed the more probable source of resistance of these two populations. The ecological diversity of AMR phenotypes was significantly greater in human isolates than in animal isolates, at the resolution of both sample and population. Of 5200 isolates, there were 65 resistance phenotypes, 13 unique to animals, 30 unique to humans and 22 were common to both. Of these 22, 11 were identified first in the human isolates, whereas only five were identified first in the animal isolates. We conclude that, while ecologically connected, animals and humans have distinguishable DT104 communities, differing in prevalence, linkage and diversity. Furthermore, we infer that the sympatric animal population is unlikely to be the major source of resistance diversity for humans. This suggests that current policy emphasis on restricting antimicrobial use in domestic animals may be overly simplistic. While these conclusions pertain to DT104 in Scotland, this approach could be applied to AMR in other bacteria-host ecosystems.

AB - We examined long-term surveillance data on antimicrobial resistance (AMR) in Salmonella Typhimurium DT104 (DT104) isolates from concurrently sampled and sympatric human and animal populations in Scotland. Using novel ecological and epidemiological approaches to examine diversity, and phenotypic and temporal relatedness of the resistance profiles, we assessed the more probable source of resistance of these two populations. The ecological diversity of AMR phenotypes was significantly greater in human isolates than in animal isolates, at the resolution of both sample and population. Of 5200 isolates, there were 65 resistance phenotypes, 13 unique to animals, 30 unique to humans and 22 were common to both. Of these 22, 11 were identified first in the human isolates, whereas only five were identified first in the animal isolates. We conclude that, while ecologically connected, animals and humans have distinguishable DT104 communities, differing in prevalence, linkage and diversity. Furthermore, we infer that the sympatric animal population is unlikely to be the major source of resistance diversity for humans. This suggests that current policy emphasis on restricting antimicrobial use in domestic animals may be overly simplistic. While these conclusions pertain to DT104 in Scotland, this approach could be applied to AMR in other bacteria-host ecosystems.

KW - Animals

KW - Anti-Infective Agents

KW - Drug Resistance, Bacterial

KW - Humans

KW - Microbial Sensitivity Tests

KW - Phenotype

KW - Salmonella typhimurium

KW - Scotland

U2 - 10.1098/rspb.2011.1975

DO - 10.1098/rspb.2011.1975

M3 - Journal article

C2 - 22090389

VL - 279

SP - 1630

EP - 1639

JO - Proceedings of the Royal Society B: Biological Sciences

JF - Proceedings of the Royal Society B: Biological Sciences

SN - 0962-8452

IS - 1733

ER -