Researchers have pinpointed mutations encoding antibiotic resistance in bacteria that cause pneumonia, borrowing a technique more often used to hunt for gene variations linked to common human diseases.

Streptococcus pneumoniae is a leading killer of children under five worldwide. The bacterium is prone to develop antibiotic resistance, but pinning down the mutations responsible has proved difficult.

A team led by Stephen Bentley and Julian Parkhill, at the Wellcome Trust Sanger Institute in Hinxton, UK, analysed the genomes of 3,701 samples of S. pneumoniae collected from carriers in a refugee camp in Thailand and from patients in Massachusetts clinics.

The authors searched for regions of the genome that differed between bacteria resistant to β-lactam antibiotics (such as penicillin) and those still susceptible to them. They found 301 DNA variations in 51 regions linked to drug resistance, including novel genes as well as those involved in building the cell wall, the target of the β-lactams.

PLoS Genet. 10, e1004547 (2014)