Occurrence and characterisation of methicillin-resistant Staphylococcus aureus isolated from bovine milk in Hungary.

Ervin Albert,Rita Sipos,Péter Kovács,Imre Biksi,Szilárd Jánosi,Zsófia Noszály,Adrienn Micsinai,Árpád Kenéz

doi:10.1556/004.2020.00040

Abstract

The last surveys on methicillin-resistant Staphylococcus aureus (MRSA) isolated from bovine milk in Hungary took place in the 2000s. To elucidate the genetic variability and to estimate the burden of the pathogen, MRSA from our strain collection and prospectively collected Staphylococcus aureus (SA) isolates originating from two milk hygiene laboratories were investigated. Between 2003 and 2018, 27 MRSA strains originating from 10 dairy farms were deposited and characterised. Most strains (n = 20) belonged to ST1-t127-SCCmecIV and were recovered from three unrelated farms. From other farms, variable genotypes were identified sporadically: ST22-t032-SCCmecIV from three farms; a newly described double locus variant of ST97, ST5982-t458-SCCmecIV from two farms; and ST398-t011-SCCmecIV and ST398-t011-SCCmecV from two respective farms. The prospective screening of 626 individual SA isolates originating from 42 dairy farms resulted in four (0.48 %) MRSA strains from three (7.14 %) farms. All MRSA isolates belonged to the clonal complex 398 and a novel spa-type t19251 was also identified. Most isolates were resistant to three or more antimicrobial classes. The occurrence and significance of MRSA of dairy origin seems to be unchanged in the past decade in Hungary. However, the low host specificity and multiresistance of the identified genotypes calls for periodic revision on the role and distribution of the pathogen in the Hungarian dairy sector.

Highlights

The first livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) case was published in 1972, MRSA has been recognised as a rapidly emerging issue in livestock since the 2000s (Devriese et al, 1972; Fitzgerald, 2012)
Between 2003 and 2018, 27 MRSA strains originating from 10 dairy farms were deposited in the culture collection of the Veterinary Diagnostic Directorate (VDD)
According to the investigation of 626 individual isolates originating from 42 dairy holdings, the occurrence of methicillin-resistant strains seems to be rare among SA isolates from bovine milk

Summary

Introduction

The first livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) case was published in 1972, MRSA has been recognised as a rapidly emerging issue in livestock since the 2000s (Devriese et al, 1972; Fitzgerald, 2012). LA-MRSA may colonise humans, especially those in occupational contact with farm animals. Human infections and cases of human-to-human transmission are reported to be rare (Cuny et al, 2015). In Europe, the swine industry is proven to be the primary source of LA-MRSA contamination (European Food Safety Authority, 2009), while the role of other host species seems to be less significant (Fitzgerald, 2012), including those from the dairy sector (Ou et al, 2017).

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Conclusion