A major genetic research project has identified 621 strains of Streptococcus pneumoniae, it was announced last night.
The findings help explain how the bacteria survive vaccination, researchers say.
The project, led by the Wellcome Trust Sanger Institute in the UK, involved sequencing the DNA of more than 20,000 samples from patients in 51 countries.
The researchers say that the levels of vaccine-resistant bacteria increased after the introduction of the pneumococcal conjugate vaccine, suggesting the evolution of resistant strains.
The findings were reported in The Lancet Infectious Diseases and in EBioMedicine and were also led by Emory University in Atlanta, Georgia, USA, and the US Centres for Disease Control and Prevention.
Researcher Professor Stephen Bentley, from the Wellcome Sanger Institute, said: "Pneumonia is a huge threat to health worldwide. We now have an unprecedented view of the global population of S. pneumoniae bacteria, the usual cause of bacterial pneumonia, and can see evolutionary changes that lead to vaccine evasion.
"This will give crucial information for future vaccine strategy worldwide and help save lives."
Fellow researcher Dr Rebecca Gladstone said: "Our study gives the first genomic description of the S. pneumoniae population of the world. This has never been possible before, as previously only samples from individual populations had been studied."
Professor Keith Klugman, from the Bill & Melinda Gates Foundation, which financed the work, said: "We must continue to immunise children around the world because vaccination is the single best way of reducing the risk of pneumonia, as it prevents children passing S. pneumoniae between them and adults. However, we are fighting a battle against evolution of bacterial strains.
"This research shows the importance of ongoing global genomic surveillance to understand which strains are likely to cause a threat, to help reformulate the next generation of vaccines."
Stephanie Lo & Rebecca Gladstone et al. Pneumococcal Lineages Associated with Serotype Replacement and Antibiotic Resistance in Childhood Invasive Pneumococcal Disease in the Post-PCV13 Era: An international whole genome sequencing study. The Lancet Infectious Diseases 10 June 2019
http://www.thelancet.com/journals/laninf/article/PIIS1473-3099(19)30297-X/fulltext
Rebecca Gladstone & Stephanie Lo et al. International Genomic Definition of Pneumococcal Lineages to Contextualise Disease, Antibiotic Resistance and Vaccine Impact: A Whole Genome Bacterial Sequencing Study. EBioMedicine 10 June 2019; doi: 10.1016/j.ebiom.2019.04.021
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