A1 Refereed original research article in a scientific journal

Increasing trend of antimicrobial resistance among methicillin-resistant Staphylococcus aureus strains in Southwest Finland, 2007–2016: An analysis of shifting strain dynamics and emerging risk factors




AuthorsSilvola, Jaakko; Gröndahl-Yli-Hannuksela, Kirsi; Hirvioja, Tiina; Rantakokko-Jalava, Kaisu; Kanerva, Mari; Auranen, Kari; Marttila, Harri; Junnila, Jenna; Vuopio, Jaana

PublisherElsevier BV

Publication year2025

JournalJournal of Global Antimicrobial Resistance

Journal name in sourceJournal of Global Antimicrobial Resistance

Volume40

First page 47

Last page52

ISSN2213-7165

eISSN2213-7173

DOIhttps://doi.org/10.1016/j.jgar.2024.11.015

Web address https://doi.org/10.1016/j.jgar.2024.11.015

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/477202038


Abstract

Objectives: Substantial rise in the annual incidence of methicillin-resistant Staphylococcus aureus (MRSA) was reported in Southwest Finland (12.4 to 24.9/100 000 people) between 2007-2016. To understand the implications of these changes to the management of MRSA, we sought to analyze the antimicrobial resistance (AMR) trends of MRSA in relation with patient characteristics.

Methods: Antimicrobial susceptibility was determined for ten clinically relevant antimicrobials. Strains with resistance to ≥2 antimicrobials were defined multi-resistant. The isolates were spa typed and clustered. AMR trends and risk factors were identified by associating resistant phenotypes with patient demographics.

Results: A total of 983 new MRSA cases were identified between 2007-2016. After 2011, significant increasing trends were observed in the proportion of isolates resistant to clindamycin (13.9 to 31.5%, p<0.001), erythromycin (19.4 to 35.4%, p<0.001) and tetracycline (16.7 to 32%, p<0.001). The proportion of multi-resistant isolates more than doubled from 14.8 to 39.2%. The increasing AMR trend was reflected in the increase of new strain types and the decrease of previously dominant, non-multi-resistant strains. Patient risk factors associated with (p<0.001) the acquisition of multi-resistant strains included community acquisition, livestock contact, hospital care abroad and immigrant status.

Conclusions: Notable increasing AMR trends among MRSA isolates were observed in Southwest Finland, 2007-2016. The shift in patient demographics to younger age groups and community acquisition contributed to the increase in multi-resistant strains. Immigration, contact with hospital environment abroad and contact with livestock were identified as essential risk factors of multi-resistance. The increased level of co-resistance has persisted after 2016.


Downloadable publication

This is an electronic reprint of the original article.
This reprint may differ from the original in pagination and typographic detail. Please cite the original version.




Funding information in the publication
Open access funding for this study was provided by the University of Turku. This work was also supported by the Competitive State Research Financing of the Expert Responsibility area of Turku University Hospital (M3016). Sakari Alhopuro, MD, PhD, is kindly thanked for funding this project. The Orion Research Foundation and the Finnish Medical Foundation are thanked for personal research grants to Jaakko Silvola.


Last updated on 2025-02-04 at 10:00