The findings reveal that antibiotic-resistant strains of Salmonella Typhi bacteria can out-compete drug sensitive strains when grown in the laboratory, even in the absence of antibiotics.
Typhoid fever is transmitted by consuming food or drink that is contaminated with Salmonella Typhi bacteria and the disease is linked to poor sanitation and limited access to clean drinking water. The disease can be treated but there is widespread drug resistance to common antibiotics and resistance to the recommended, more specialised antibiotic therapy for typhoid fever is increasing.
Researchers at the Oxford University Clinical Research Unit, Wellcome Trust Vietnam Research Programme, created twelve laboratory strains of Salmonella Typhi bacteria with one or more genetic mutations that confer resistance to the recommended antibiotic therapy for typhoid fever, fluoroquinolone. Typically, when bacteria develop antibiotic resistance it comes at a cost and when the drug is absent, they are usually weaker and less able to compete for food and resources than strains that are not resistant.
Dr Maciej Boni, a Sir Henry Dale Fellow funded jointly by the Wellcome Trust and Royal Society at the Oxford University Clinical Research Unit in Vietnam, who co-led the study, said: "When we grew different strains of Salmonella Typhi in the lab, we found that half of the antibiotic resistant strains had a growth advantage over their parent strain, even in the absence of antibiotic, enabling them to predominate in the population."
Dr Stephen Baker, also a Sir Henry Dale Fellow in the Oxford University Clinical Research Unit, said: "Currently, the control of typhoid across Asia and Africa relies on treatment with fluoroquinolones but resistance is rising. Withdrawing or restricting the use of this class of antibiotics is one approach to try and combat the spread of resistance. However, the results of this study suggest that we need to think beyond this , as antibiotic resistance will likely continue to rise even if these strategies are implemented."
Dr Jimmy Whitworth, Head of International Activities at the Wellcome Trust, said: "These important findings from researchers in Vietnam are very worrying. If confirmed, one of our main strategies for controlling drug-resistance in typhoid will be ineffective. We will need to concentrate on developing more effective and affordable vaccines, and improving water supplies and sanitation, a Herculean task for low and middle income countries."
There are an estimated 21 million cases of typhoid fever around the world each year. If left untreated, it's estimated that up to one in five with the disease will die and of those who survive, some will have permanent physical or mental disabilities. According to a World Health Organization report, 90% of the world's typhoid deaths occur in Asia and the disease persists mainly in children under five years.
Typhoid infects the gut and bloodstream, causing fever that can reach temperatures of 39°-40° C and constipation or diarrhoea. The disease can be associated with other characteristics including, rose-coloured spots on the chest, confusion and perforation of the gut.
Jen Middleton | EurekAlert!
GLUT5 fluorescent probe fingerprints cancer cells
20.04.2018 | Michigan Technological University
Scientists re-create brain neurons to study obesity and personalize treatment
20.04.2018 | Cedars-Sinai Medical Center
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
24.04.2018 | Life Sciences
24.04.2018 | Materials Sciences
24.04.2018 | Trade Fair News