Clonal dissemination of successful emerging clone mecA-MRSA t304/ST6 among humans and hedgehogs in the Helsinki metropolitan area in Finland

Johansson Venla; Al-Mustapha Ahmad; Heljanko Viivi; Lindholm Laura; Salmenlinna Saara; Sainmaa Sanna; Heikinheimo Annamari

doi:10.1016/j.onehlt.2023.100516

Clonal dissemination of successful emerging clone mecA-MRSA t304/ST6 among humans and hedgehogs in the Helsinki metropolitan area in Finland

One Health. 2023 Feb 21:16:100516. doi: 10.1016/j.onehlt.2023.100516. eCollection 2023 Jun.

Authors

Johansson Venla¹, Al-Mustapha Ahmad¹, Heljanko Viivi¹, Lindholm Laura², Salmenlinna Saara², Sainmaa Sanna³, Heikinheimo Annamari^{1

4}

Affiliations

¹ Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Agnes Sjöberginkatu 2, PO Box 66, 00790, Helsinki, Finland.
² Expert Microbiology Unit, Department of Health Security, Finnish Institute for Health and Welfare, Mannerheimintie 166, PO Box 30, 00271, Helsinki, Finland.
³ Korkeasaari Zoo, Mustikkamaanpolku 12, PO Box 1000, 0081 Helsinki, Finland.
⁴ Microbiology Unit, Finnish Food Authority, Mustialankatu 3, PO Box 200, 00790 Helsinki, Finland.

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) carrying mecC gene (mecC-MRSA) is frequently reported among European hedgehogs (Europeaus erineaus) due to co-evolutionary adaptation to dermatophyte infection in European hedgehogs. The occurrence of MRSA in European hedgehogs in Finland is unknown. Consequently, we investigated the occurrence of MRSA in wild hedgehogs from urban Helsinki metropolitan area in 2020-2021 and applied whole genome sequencing (WGS) to further characterize the studied isolates and compared them with human clinical MRSA isolates. Altogether 115 dead hedgehogs were screened for MRSA using selective cultivation methods. Presumptive MRSA isolates were tested for antimicrobial susceptibility and confirmed MRSA isolates were further characterized by spa-typing and WGS. Hedgehog derived MRSA isolates were compared with clinical human MRSA isolates using core genome multilocus sequence typing (cgMLST). In total MRSA was recovered from 11 out of 115 (10%) hedgehogs. Among these four different spa types (t304; n = 4, t8835; n = 4, t5133; n = 2 and t622; n = 1) and three different sequence types (STs) (ST6; n = 6, ST7663; n = 4 and ST2840; n = 1) were identified. From the studied MRSA isolates seven harboured the mecA gene (mecA-MRSA) and four were identified as mecC-MRSA. All mecA-MRSA isolates carried immune evasion cluster genes, and one isolate was positive for Panton-Valentine leukocidin. cgMLST comparison revealed close genetic relatedness among three hedgehog and two human mecA-MRSA isolates all belonging to t304/ST6. Our results suggest a clonal dissemination of a successful MRSA clone among humans and hedgehogs. Further studies are warranted to investigate the sources and dissemination of such clone in urban environments. We observed a relatively low occurrence of mecC-MRSA in Finnish hedgehogs.

Keywords: Antimicrobial resistance; Hedgehog; Human–wildlife interface; Methicillin-resistant Staphylococcus aureus; Wild animals; t304.