The findings will provide new targets to design a vaccine against the strain, that causes serious and untreatable infections in millions of people each year.
The landmark genomic study, by an international team of 74 scientists, including the University of Melbourne, was published today [May 11, 2015] in Nature Genetics.
The new data will also inform strategies for surveillance of the bacterium and the emergence of antimicrobial resistance, and will inform the prevention and control of typhoid through the use of effective antibiotics, introduction of vaccines, water and sanitation programs.
Typhoid affects around 30 million people each year and multidrug resistant strains of Salmonella Typhi, the bacteria that cause typhoid fever, are becoming common in many developing countries.
Kathryn Holt, senior author from the Department of Biochemistry and Molecular Biology and Bio21 Institute, University of Melbourne said there is an urgent need to develop global surveillance against the threat to public health caused by typhoid and other antimicrobial resistant pathogens.
“Multidrug resistant H58 has spread across Asia and Africa over the last 30 years, completely transforming the genetic make-up of the disease and creating a previously underappreciated and on-going epidemic through countries in eastern and southern Africa with important public health consequences,” Dr Holt said.
This latest study is the culmination of nearly 10 years of research for Dr Holt, who has received national and international awards for the typhoid work that she began during her PhD studies at the Wellcome Trust Sanger Institute in Cambridge, including a L’Oréal-UNESCO Women In Science Fellowship awarded last month in Paris.
“H58 is an example of an emerging multiple drug resistant pathogen which is rapidly spreading around the world,” says Professor Gordon Dougan, senior author from the Sanger Institute.
“In this study we have been able to provide a framework for future surveillance of this bacterium, which will enable us to understand how antimicrobial resistance emerges and spreads intercontinentally, with the aim to facilitate prevention and control of typhoid through the use of effective antimicrobials, introduction of vaccines, and water and sanitation programs.”
“Vaccination against typhoid is not currently widely used in the countries that typhoid hits hardest,” said Dr Holt.
“Instead, the disease is controlled mainly through use of antimicrobial drugs, which is why understanding the spread of resistance is so critical.”
“Our next step is to turn this knowledge towards designing effective vaccine strategies,” said Dr Holt.
That work will be supported by a £4 million strategic award from the Wellcome Trust, recently granted to Dr Holt, Prof Dougan and an international consortium of leading typhoid researchers.