Livestock-Associated Methicillin-Resistant Staphylococcus aureus From Animals and Animal Products in the UK.

Muna F Anjum,Francisco Marco-Jimenez,Clara Marín,Richard P Smith,Sarah J Evans,Daisy Duncan

doi:10.3389/fmicb.2019.02136

Abstract

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is an emerging problem in many parts of the world. Although animal-adapted LA-MRSA has been known for many years, recent reports suggest a possible increasing trend in the zoonotic transmission of LA-MRSA in Europe. Since its emergence in the early 2000’s, several investigations have indicated that persons in prolonged, repeated contact with affected livestock are at a higher risk of becoming colonized with LA-MRSA. LA-MRSA monitoring in livestock is voluntary under current EU legislation, and not all member states, including the UK, participate. UK LA-MRSA isolates have been detected through scanning surveillance, where samples are submitted from clinically diseased livestock for diagnostic investigation, and research studies. Surveys conducted on retail beef, pig and poultry meat on sale in the UK have also detected LA-MRSA. Taken together these results suggest that LA-MRSA is present in the UK, possibly at low prevalence level, as suggested by available evidence. In this review, we examine the data available from UK livestock and animal products, and make recommendations for future. We also review the findings from whole genome sequencing (WGS) of the possible lineage of some UK livestock isolates.

Highlights

Livestock associated MRSA (LA-MRSA) was first described in 2005 (Voss et al, 2005) where a new clone of MRSA of sequence type (ST) 398 was identified and grouped within clonal complex (CC) 3981
Several studies have speculated that CC398 MSSA originated in humans but lost human associated factors such as PantonValentine Leukocidin (PVL)-associated phages, toxic shock syndrome toxin I and exfoliative toxins, which are markers of community associated (CA)-MRSA and hospital associated (HA)-MRSA strains (Kadlec et al, 2012; Mohamed et al, 2012; Ballhausen et al, 2017), and acquired antibiotic resistance genes such as mecA and tetM as they adapted to livestock (Fitzgerald, 2012a,b; Price et al, 2012)
The eight isolates identified as MRSA belonged to a novel CC30 clone, being positive for lukM and lukF-P83 genes, a marker for virulence restricted to animal lineages which has been implicated in the pathogenesis of mastitis cattle and exudative dermatitis in squirrels (Lahuerta-Marin et al, 2016)

Summary

INTRODUCTION

Livestock associated MRSA (LA-MRSA) was first described in 2005 (Voss et al, 2005) where a new clone of MRSA of sequence type (ST) 398 was identified and grouped within clonal complex (CC) 3981. LA-MRSA (mainly MRSA CC398), has become increasingly common among pigs in several European countries (Verkade and Kluytmans, 2014); it has been reported from humans and animal products (European Food Safety Authority, and European Centre for Disease Prevention, and Control, 2015). Scanning surveillance and other studies have reported the presence in the UK of LA-MRSA CC398, CC9, CC9/CC398 hybrid, CC22, CC30, CC130, CC705, and ST425 (Table 1) These isolates have been reported from horses (Loeffler et al, 2009; Bortolami et al, 2017), dairy cattle (Garcia-Alvarez et al, 2011; Paterson et al, 2012, 2014) beef cattle (Stone, 2017), poultry and pheasant The disease surveillance and microbiological laboratories based in Northern Ireland and Scotland are involved in isolation of LAMRSA from these countries

BACKGROUND

Findings

DISCUSSION