Germany - Pig MRSA(ST398) is adapting itself to humans

[Gert van der Hoek]

Germany - Pig MRSA(ST398) is adapting itself to humans

In the latest Epidemiologisches Bulletin of July 4, issued by the Robert Koch Institute, an article on MRSA in Germany. The researchers looked among others, to Community Acquired MRSA and Livestock Acquired MRSA.

They found the Pig MRSA/ST398 caused 17,4% of the total of German MRSA-patients, infected outside hospital settings.

The virulence of ST398 is increasing. This indicates a better adaptation to humans.

Not good news.


LA-MRSA = Livestock Acquired MRSA

Bedeutung von LA-MRSA für die Bevölkerung

Der anteilige Nachweis für LA-MRSA ST398 als Ursache
von Infektionen außerhalb der Krankenhäuser für die Jahre 2006 – 2010 lag bei 17,4 %. Damit tritt LA-MRSA ST398
neben CA-MRSA ST8 (anteiliger Nachweis 45,7 %) und
ST80 (anteiliger Nachweis 37 %) auch als Verursacher von
Haut-Weichgewebe-Infektionen mit gleichen klinischen
Krank heitsbildern wie CA-MRSA in Erscheinung. Ähnliche Daten sind auch aus Dänemark bekannt. (20)

Die Verbreitung derartiger Isolate bedarf sorgfältiger
Aufmerksamkeit. Dabei ist ein wichtiger Aspekt der Erwerb weiterer Virulenz eigenschaften. In den Jahren 2010/11
konnten wir erstmals bei zwei MSSA-ST398-Isolaten aus
rezidivierender Furunkulose die genetische Determinante
für PVL (lukS-lukF) nachweisen. Die Frage nach bestehenden Tierkontakten blieb in beiden Fällen offen. Für MRSA
dieser klonalen Linie sind PVL-positive Isolate aus China bekannt (21) und verschiedene Sepsisfälle sowie Endokarditis
und nekrotisieren de Fasziitis für MRSA/MSSA ST398 aus
Europa (22)

Die Ausstattung mit zusätzlichen Virulenz-assoziierten Genen deutet auf die Adaptation an den Menschen
hin, denn bisher sind PVL-positive S. aureus von Tieren sehr
selten.

Update:

To add some perspective to the German research results, a quote from a recent article. The number of people with pig MRSA seemed to be very low:

EID Journal Home > Volume 17, Number 3–March 2011


Livestock-associated Methicillin-Resistant Staphylococcus aureus in Humans, Europe

Abstract
To estimate the proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates from humans that were sequence type (ST) 398, we surveyed 24 laboratories in 17 countries in Europe in 2007. Livestock-associated MRSA ST398 accounted for only a small proportion of MRSA isolates from humans; most were from the Netherlands, Belgium, Denmark, and Austria.

Full article online - CDC

 

[Gert van der Hoek]

Re: Germany - Pig MRSA(ST398) is adapting itself to humans

A confirmation from Dutch research: the spread of pig MRSA ST398 led to an increase in both MRSA carriers and MRSA infections

Eur J Clin Microbiol Infect Dis. 2011 May 1. [Epub ahead of print]

Infection and colonization with methicillin resistant Staphylococcus aureus ST398 versus other MRSA in an area with a high density of pig farms.

Wulf MW, Verduin CM, van Nes A, Huijsdens X, Voss A.

PAMM Laboratory for Medical Microbiology, De Run 6250, 5504 DL, Veldhoven, The Netherlands, m.wulf@pamm.nl.

Abstract
The purpose of this study was to evaluate the impact of the emergence of animal related methicillin resistant Staphylococcus aureus ST398 in an area with a high density of pig farms. A retrospective analysis was performed of all MRSA isolates in the laboratory database from 2002 till 2008 including typing results and clinical data from infection control archives and patient charts.

The implementation of the screening of people in contact with pigs and veal calves for MRSA led to an increase in the average number of newly identified carriers from 16 per year between July 2002 and July 2006 to 148 between July 2006 and December 2008. This is a 925% increase of which 82% (108/132) was due to ST398.

The majority (74%) came from targeted screening but 7% was due to unexpected findings. A wide range of infections with ST398 occurred in patients with and without contact with livestock varying from post-operative wound infections to sepsis and post-trauma osteomyelitis with an overrepresentation of spa type t567 among the clinical isolates. ST398 isolates were more often multi-resistant than isolates of other spa-types.

The emergence of MRSA ST398 led to an increase in both MRSA carriers and MRSA infections.

PubMed