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.

Members of the genus Borrelia are among the most common infectious agents causing tick-borne disease in humans worldwide. Here, we developed a Light Upon eXtension (LUX) real-time PCR assay that can detect and quantify Borrelia species in ticks that have fed on humans, and we applied the assay to 399 such ticks. Borrelia PCR-positive ticks were identified to species level by sequencing the products of conventional PCR performed using Borrelia group-specific primers. There was a 19% prevalence of Borrelia spp. in the detached ticks, and the number of spirochetes per Borrelia PCR-positive tick ranged from 2.0 ؋ 10 2 to 4.9 ؋ 10 5 , with a median of 7.8 ؋ 10 3 spirochetes. Adult ticks had a significantly larger number of spirochetes, with a median of 8.4 ؋ 10 4 compared to the median of nymphs of 4.4 ؋ 10 4 . Adult ticks also exhibited a higher prevalence of Borrelia (33%) than nymphs (14%). Among the identified species, Borrelia afzelii was found to predominate (61%) and was followed by B. garinii (23%), B. valaisiana (13%), B. burgdorferi sensu stricto (1%), B. lusitaniae (1%), and B. miyamotoi-like (1%). Also, 3% of the ticks were coinfected with multiple strains of B. afzelii. Notably, this is the first report of B. lusitaniae being detected in ticks in Sweden. Our LUX real-time PCR assay proved to be more sensitive than a corresponding TaqMan assay. In conclusion, the novel LUX real-time PCR method is a rapid and sensitive tool for detection and quantification of Borrelia spp. in ticks.Lyme borreliosis (LB) is the most common tick-borne disease in humans in Europe (26), and it is caused by spirochetes belonging to the Borrelia burgdorferi sensu lato complex. That group comprises the species B. burgdorferi sensu stricto, B. afzelii, and B. garinii, which are usually transmitted by the vector Ixodes ricinus. Furthermore, there have been reports of B. valaisiana, B. lusitaniae, and B. spielmanii being detected in samples of human skin and cerebrospinal fluid (5, 7, 30), which suggests that those three species can also give rise to LB. It is often hard to distinguish the clinical symptoms of LB from those of other diseases (10), and hence, it can be difficult to establish a correct diagnosis, especially if the patient is unable to recall having a tick bite.Today, diagnosis is based mainly on serological tests, although some PCR-based approaches, such as the TaqMan real-time PCR assay (3, 12), have been developed to detect Borrelia species in clinical samples. Even if real-time PCR is not yet considered to be a routine method in clinical practice, it can nonetheless provide valuable information about Borrelia infections, with regard to species type and the number of spirochetes present. Additional major advantages of PCR in this context are its simplicity, sensitivity, robustness, and speed.Other assays besides the TaqMan assay include a method based on SYBR green dye chemistry (37) and another using Light Upon eXtension (LUX) (Invitrogen Corporation). Compared to the SYBR green real-time PCR assay, the LUX assay o...

The purpose of this study was to investigate whether S. pseudintermedius is misdiagnosed as S. aureus by clinical laboratories when isolated from humans with dog bite wounds. In addition, we attempted to determine whether S. pseudintermedius isolates related to dog bite wounds share phenotypic and genotypic traits. S. pseudintermedius was identified by PCR targeting the nuc gene. Isolates were tested for antibiotic susceptibility using VetMIC GP-mo microdilution panels. The occurrence of genes encoding leukocidins, exfoliatins, pyrogenic toxin superantigens and enterotoxins was determined by PCR. The relatedness of S. pseudintermedius isolates was investigated using Multi Locus Sequence Typing (MLST). Out of 101 isolates defined as S. aureus by human clinical microbiology laboratories, 13 isolates were re-identified as S. pseudintermedius and one isolate was confirmed to carry the mecA gene, i.e. methicillin-resistant (MRSP). The MRSP isolate was also defined as multi-resistant. Two methicillin-susceptible S. pseudintermedius isolates were also multi-resistant and five were susceptible to all antibiotics tested. With the exception of three S. pseudintermedius isolates belonging to multi locus sequence type (MLST) 158, all the isolates belonged to unique STs. All isolates contained lukS/F-I, siet and se-int, and expA were identified in two isolates and expB and sec canine-sel in one isolate respectively. S. pseudintermedius is frequently misdiagnosed as S. aureus from humans with dog bite wounds showing that it can act as an opportunistic pathogen in humans. No common phenotypic and genotypic traits shared by the S. pseudintermedius isolates could be identified.

Escherichia coli ST58 has recently emerged as a globally disseminated uropathogen that often progresses to sepsis. Unlike most pandemic extra-intestinal pathogenic E. coli (ExPEC), which belong to pathogenic phylogroup B2, ST58 belongs to the environmental/commensal phylogroup B1. Here, we present a pan-genomic analysis of a global collection of 752 ST58 isolates from diverse sources. We identify a large ST58 sub-lineage characterized by near ubiquitous carriage of ColV plasmids, which carry genes encoding virulence factors, and by a distinct accessory genome including genes typical of the Yersiniabactin High Pathogenicity Island. This sub-lineage includes three-quarters of all ExPEC sequences in our study and has a broad host range, although poultry and porcine sources predominate. By contrast, strains isolated from cattle often lack ColV plasmids. Our data indicate that ColV plasmid acquisition contributed to the divergence of the major ST58 sub-lineage, and different sub-lineages inhabit poultry, swine and cattle.