MRSA in 40% of sampled retail pork - DVFA

03-Apr-2017 - Last updated on 04-Apr-2017 at 08:37 GMT

DVFA found LA-MRSA in 122 of 305 samples. Picture: ©iStock/gbh007

Forty per cent of fresh pork sampled was found to contain livestock associated-MRSA (LA-MRSA), according to a Danish study.

The Fødevarestyrelsen (The Danish Veterinary and Food Administration - DVFA) work found methicillin-resistant Staphylococcus Aureus (MRSA) in 122 of 305 samples taken last year from retail using whole genome sequencing.

The study was done to see if the rise in incidence of MRSA at Danish farms could be seen in pork.

In conventional Danish pork, the study found livestock-MRSA in 48% of samples and in 32% of organic meat. In the meat from abroad it was found in 28% of samples.

The qualitative study looked at presence and not the quantity of bacteria in the meat sample.

Basic hygiene and cooking meat thoroughly reduces the risk of infection from meat.

Prevalence in pork

Since the last study in 2011, the prevalence of LA-MRSA in Danish pork has risen from 10% to 48% and in the imported meat from 5% to 28%.

The increase in pork is in line with the increase of LA-MRSA in pig herds, which rose from 16% in 2011 to 68% in 2014.

The DVFA has not previously studied LA-MRSA prevalence in organic pork.

The agency said the presence of 32% in organic meat in 2016 is high, if compared with the prevalence of LA-MRSA in organic pig herds, which was only 6% in 2015.

Discovery of MRSA was mainly dominated by the type clonal complex (CC)398 while the types CC9 and CC1 are less frequent but have also been associated with farm animals.

A UK study looked at 103 (52 pork and 51 chicken) pre-packaged fresh meat products, labelled as being of UK farm origin, and found two pork samples contained MRSA in 2015.

An analysis of genetic make-up showed it belonged to a type of MRSA known as LA-MRSA CC398, which has emerged in the last few years in Europe.

DANMAP study

As part of DANMAP (Danish Integrated Antimicrobial Resistance Monitoring and Research Programme) established in 1995 pork was investigated for MRSA in 2009-2011.

Objectives include monitoring the consumption of antimicrobial agents for food animals and humans and to identify routes of transmission and areas for further research studies.

Results have been provided to the LA-MRSA expert group which is reviewing LA-MRSA initiatives such as risk assessments for MRSA in fresh meat and will include these findings in their work.

A decision on more regular follow-ups or tests on different products depends on the results of the LA-MRSA expert group.