No Changes in the Occurrence of Methicillin-Resistant Staphylococcus aureus (MRSA) in South-East Austria during the COVID-19 Pandemic

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a universal threat. Once being well established in the healthcare setting, MRSA has undergone various epidemiological changes. This includes the emergence of more aggressive community-acquired MRSA (CA-MRSA) and the occurrence of MRSA which have their origin in animal breeding, called livestock-associated MRSA (LA-MRSA). Emergence of new clones as well as changes in the occurrence of some clonal lineages also describes the fluctuating dynamic within the MRSA family. There is paucity of data describing the possible impact of the COVID-19 pandemic on the MRSA dynamics. The aim of the study was the analysis of MRSA isolates in a three-year time period, including the pre-COVID-19 years 2018 and 2019 and the first year of the pandemic 2020. The analysis includes prevalence determination, antibiotic susceptibility testing, spa typing, and detection of genes encoding the PVL toxin. The MRSA rate remained constant throughout the study period. In terms of a dynamic within the MRSA family, only a few significant changes could be observed, but all except one occurred before the start of the COVID-19 pandemic. In summary, there was no significant impact of the COVID-19 pandemic on MRSA in Austria.

Keywords: CC127; MRSA; ST398; epidemiology; spa typing.

Figure 1

Proportion of resistance rates in MRSA, isolated from 2018–2020. Only the increase in tetracycline-resistant MRSA isolates from 2018 to 2019 (p < 0.01) and the decrease of clindamycin in 2020 was significant (p = 0.027); all other changes were not significant (SXT = trimethoprim-sulfamethoxazole).

Figure 2

Proportion of MRSA types, isolated from 2018–2020 in Austria. None of the changes incidence of HA-, CA-, or LA-MRSA were significant.