Scanning electron micrograph of methicillin-resistant Staphylococcus aureus and a dead human neutrophil.

Sequencing bacteria

Knowing the genetic sequence of an organism can help us trace how it spreads

In the future we may see the whole-genome sequencing of bacteria such as MRSA (methicillin-resistant Staphylococcus aureus) become commonplace. In a paper published in the ‘Lancet’ in 2013, researchers described how they sequenced the genomes of MRSA samples from babies in a hospital baby care unit, patients elsewhere in the hospital and people outside in the community during a suspected outbreak in 2011.

The results showed the paths of infection between babies, mothers on a postnatal ward and the community. The researchers found that a strain of MRSA responsible for an outbreak was a new sequence type that had originally been transmitted unknowingly by a member of hospital staff.

The method showed great promise as a tool to rapidly and accurately identify the potential source and people involved in an outbreak of MRSA – information that could be used when deciding how to control infections.

During the same year, US scientists used whole-genome sequencing to compare drug-resistant strains of Klebsiella pneumoniae bacteria, which can cause deadly blood and urinary infections. The researchers were able to show that several apparently unlinked cases all stemmed from one patient. That patient passed on the infection via ‘carriers’, who transmitted the bacteria but never showed any symptoms.

Lead image:

Scanning electron micrograph of methicillin-resistant Staphylococcus aureus (MRSA) and a dead human neutrophil.



About this resource

This resource was first published in ‘Genes, Genomes and Health’ in January 2010 and reviewed and updated in December 2014.

Microbiology, Genetics and genomics, Health, infection and disease, Medicine
Genes, Genomes and Health
Education levels:
16–19, Continuing professional development