The discovery of antibiotics more than 80 years ago has led to considerable improvements in human and animal health. Although antibiotic resistance in environmental bacteria is ancient, resistance in human pathogens is thought to be a modern phenomenon that is driven by the clinical use of antibiotics1. Here we show that particular lineages of methicillin-resistant Staphylococcus aureus—a notorious human pathogen—appeared in European hedgehogs in the pre-antibiotic era. Subsequently, these lineages spread within the local hedgehog populations and between hedgehogs and secondary hosts, including livestock and humans. We also demonstrate that the hedgehog dermatophyte Trichophyton erinacei produces two β-lactam antibiotics that provide a natural selective environment in which methicillin-resistant S. aureus isolates have an advantage over susceptible isolates. Together, these results suggest that methicillin resistance emerged in the pre-antibiotic era as a co-evolutionary adaptation of S. aureus to the colonization of dermatophyte-infected hedgehogs. The evolution of clinically relevant antibiotic-resistance genes in wild animals and the connectivity of natural, agricultural and human ecosystems demonstrate that the use of a One Health approach is critical for our understanding and management of antibiotic resistance, which is one of the biggest threats to global health, food security and development.

European hedgehog (Erinaceus europaeus) populations are widespread across diverse habitats but are declining in Western Europe. Drastic declines have been described in the UK, with the most severe declines occurring in rural areas. Hedgehogs are widely distributed in Denmark, but their status remains unknown. Fieldwork on hedgehogs has tended to focus on rural areas, leaving their ecology in suburban habitats largely unexplored, with clear implications for conservation initiatives. Here, we study the ecology of 35 juvenile hedgehogs using radio tracking during their first year of life in the suburbs of western Copenhagen. We use radio‐tracking data to estimate (a) home range sizes in autumn and spring/summer, (b) survival during their first year of life, (c) the body mass changes before, during, and after hibernation, and (d) the hibernation behavior of the juvenile hedgehogs. We show that males and females have small home ranges compared with previous studies. The 95% MCP home range sizes in autumn were 1.33 ha (95% CI = 0.88–2.00) for males and 1.40 ha (95% CI = 0.84–2.32) for females; for spring/summer they were 6.54 ha (95% CI = 3.76–11.38) for males and 1.51 ha (95% CI = 0.63–3.63) for females. The juvenile survival probabilities during the study period from September 2014 to July 2015 were .56 for females and .79 for males. All healthy individuals gained body mass during the autumn and survived hibernation with little body mass loss thus demonstrating that the juveniles in the study were capable of gaining sufficient weight in the wild to survive their first hibernation. The climate is changing, but there is a lack of knowledge on how this affects mammal ecology. The exceptionally mild autumn of 2014 caused the juvenile hedgehogs to delay hibernation for up to a month compared with previous studies in Denmark.

Objectives A recent study from Sweden showed that European hedgehogs may constitute a reservoir for methicillin-resistant Staphylococcus aureus (MRSA), but this host-parasite relationship remains to be investigated in other countries. In this study, we therefore sought to: 1) determine the dissemination of MRSA in European hedgehogs throughout Denmark; 2) investigate determinants of MRSA carriage in hedgehogs; 3) determine the potential for zoonotic transmission of MRSA from hedgehogs to humans; and 4) characterise the detected MRSA on both a phenotypic and molecular level. Methods Nasal swabs were taken from 188 dead hedgehogs collected by volunteers throughout Denmark to determine the occurrence of MRSA. Additionally, 16 hedgehog rehabilitators were tested for potential zoonotic transmission of MRSA from hedgehogs to humans. The swabs were incubated in tryptic soy broth supplemented with 6.5% NaCl, followed by spread of 10 μl on Brilliance MRSA 2 agar. One presumptive MRSA colony from each plate was subcultured on 5% blood agar. All S . aureus subcultures were verified by a PCR assay detecting mecA , mecC , lukF-PV , scn , and spa , followed by spa typing. Results A total of 114 (61%) hedgehogs carried mecC -MRSA, whereas none carried mecA -MRSA. The detected mecC -MRSA belonged to two genetic lineages CC130 ( spa -types: t528, t843, t1048, t3256, t3570, t6220, t17133) and CC1943 ( spa -types: t978, t2345, t3391, t8835, t16868), 52% of which were spa -type t843 (CC130).The detection rate of mecC -MRSA in the hedgehogs was similar regardless of cause of death, sex, region and habitat type. None of the hedgehog rehabilitators carried MRSA. Conclusions This nationwide study confirms a high occurrence of mecC -MRSA in hedgehogs, which could serve as a natural reservoir for this specific type of MRSA. Furthermore, our study did not find signs of zoonotic transmission of mecC -MRSA to hedgehog rehabilitators.