Technical specifications for a baseline survey on the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in pigs

Abstract

The European Commission requested scientific and technical assistance in the preparation of a EU-wide baseline survey protocol for a European Union (EU) coordinated monitoring programme on the prevalence of methicillin-resistant Staphylococcus Aureus (MRSA) in pigs. The objective of the survey is to estimate the MRSA prevalence in batches of fattening pigs at slaughter at both European and national levels, with a 95% level of confidence and a level of precision of 10% considering an expected prevalence of 50%. The survey protocol defines the target population, the sample size for the survey, sample collection requirements, the analytical methods (for isolation, identification, phenotypic susceptibility testing and further genotypic testing of MRSA isolates), the data reporting requirements and the plan of analysis. The samples are to be analysed according to the laboratory protocols available on the European Union Reference Laboratory (EURL-AR) website. Generalised linear models will be used to estimate proportion (with 95% confidence intervals) of batches of slaughter pigs tested positive to MRSA. The necessary data to be reported by the EU Member States to support this baseline survey are presented in three data models. The results of the survey should be reported using the EFSA data collection framework.

Keywords: antimicrobial resistance; cross‐sectional prevalence study; fattening pigs; harmonisation; methicillin‐resistant Staphylococcus aureus.

Figure 1

Distribution of batch sizes provided by a MS (Jouy et al., 2009)

Figure 2

Workflow for isolation of MRSA

Figure 3

Flowchart for confirmatory testing, typing, antimicrobial susceptibility testing and whole‐genome sequencing of MRSA

1. AST: antimicrobial susceptibility testing; MRSA: methicillin‐resistant Staphylococcus aureus; WGS: whole genome sequencing.