Detecting MRSA outbreaks

German researchers have proposed an automated DNA sequence-based early warning system to detect methicillin-resistant Staphylococcus aureus (MRSA) outbreaks in hospitals, which they say could replace traditional slower techniques.

Outbreaks are usually identified manually from laboratory test results and patients’ charts, which is time consuming. Established outbreaks are tracked by molecular typing. To improve the speed and reproducibility of this process, DNA sequence-based approaches are used but are usually still too expensive for routine use.

However, just typing a single locus -- the S. aureus protein A (spa) gene -- is fast and cost effective. In this month’s PLoS Medicine, Dag Harmsen and colleagues from the Universities of Münster and Hamburg investigated the combination of spa typing with a novel software program that automatically analyzes the spa sequences, links them to a database integrated with epidemiological information, and triggers an alarm if an outbreak is suspected. This approach was more sensitive at identifying outbreaks than classical surveillance techniques.

The combination of medical informatics and molecular laboratory techniques could help clinicians prevent limited clusters of MRSA expanding into large-scale outbreaks.

The rising global incidence of MRSA outbreaks in hospitals is a major concern because of the high mortality rate and the stringent hygiene requirements needed for patients who become infected.

Citation: Mellmann A, Friedrich AW, Rosenkötter N, Rothgänger J, Karch H, et al. (2006) Automated DNA sequence-based early warning system for the detection of methicillin-resistant Staphylococcus aureus outbreaks. PLoS Med (3)3: e33.

http://dx.doi.org/10.1371/journal.pmed.0030033