Smartphone detects blood for parasites

Blood parasite smartphone1

Blood parasite smartphone

The CellScope system films a drop of blood and an app then automatically analyses any movement in the sample to detect the parasites.

The results, published in Science Translational Medicine, showed the device was successful in small trials in Cameroon.

Experts said it marked a fundamental advance in tropical diseases.

Previous efforts to eradicate two parasitic diseases – river blindness and elephantiasis – have been suspended because the treatment can become fatal in some people.

One treatment, the drug ivermectin, is risky in people with high levels of Loa loa worm – the one that can crawl across the surface of the eye – so people need to be screened first.

Automatic

The team in the most recent research, at the University of California, Berkeley, and the US National Institutes of Health, used a modified smartphone to automate the process.

A pindrop of blood was collected and loaded into a handheld box. The phone on top then kicked in.

“With one touch of the screen, the device moves the sample, captures video and automatically analyses the images,” said one of the researchers, Prof Daniel Fletcher.

Rather than attempt to identify the shape of the worm, the software in the phone looks for the movement.

Treat or not?

The software predicts the number of Loa loa parasites in the blood and tells the healthcare workers whether they are suitable for drug treatment.

It means very little training is required, while current screening procedures require someone to be skilled in analysing blood samples by eye.

Early trials in Cameroon of the new approach have been successful and there are now plans to test it on 40,000 people.

Prof Fletcher told the BBC News website: “I’m excited, it offers a new higher-tech approach to dealing with very low-tech problems.”

“There are drugs to treat many neglected tropical diseases, these are problems that should be solved, but there is not the technology to identify people who who need the right drugs.”

It is hoped the same idea could be adapted to test for other infections such as TB, malaria and soil-transmitted parasitic worms or helminths, which include roundworm.

‘Fundamental advance’

Prof Simon Brooker from the London School of Hygiene & Tropical Medicine, commented: “I think it’s one of the most fundamental advances in neglected tropical diseases in a long time.”

“In the 21st Century we are using 20th Century technology to diagnose these infections, this brings us into the modern world.

Bacteria exploit proteins to trigger potentially lethal infections

New research by scientists at the University of York sheds light on how bacteria exploit human proteins during infections:

bacteria exploit proteins

bacteria exploit proteins

 

 

A research team led by Professor Jennifer Potts, a British Heart Foundation Senior Research Fellow in York’s Department of Biology, studied how Staphylococcus aureus, which can cause life-threatening human infections, attach to two proteins fibronectin and fibrinogen found in human blood.

The human proteins play important roles in clot formation and wound healing and the bacteria appear to exploit them during the process of infection. Scientists had earlier shown that the binding sites for fibrinogen and fibronectin on the S. aureus protein FnBPA appear to “co-operate” in causing the dangerous heart infection infective endocarditis and the latest research suggest how the process occurs. The researchers, who included Vaclav Stemberk and Dr Richard Jones at York and Dr Ruth Massey, a microbiologist at the University of Bath, used X-ray crystallography, biophysical techniques and bacterial assays to investigate the process.

In research published in the Journal of Biological Chemistry, they solved the three dimensional structure of the bacterial protein FnBPA in complex with a small part of the human protein fibrinogen. This work showed that the fibrinogen binding site on FnBPA is close to, but not overlapping with, the binding site for fibronectin.

They then studied the binding of the two human proteins simultaneously to FnBPA and found that binding of fibronectin appears to block binding of fibrinogen to the bacterial protein. It appears that regulation of binding arises due to the close proximity of the fibrinogen and fibronectin binding sites on the bacterial protein and the large size of the human proteins. While the research provides the first biophysical evidence in support of the co-operation previously observed in the infection studies, it is still not clear how these two observations are linked. The scientists are planning further studies.

Professor Potts said: “Bacteria have evolved various mechanisms to exploit human proteins to cause infection. Understanding these mechanisms might not only lead to the development of new therapeutics but can also provide important information regarding the normal role of these human proteins in the body.”

Dr Sanjay Thakrar, Research Advisor at the British Heart Foundation, which co-funded the study, said: “The bacteria studied can cause a wide range of infections including the potentially fatal heart infection known as infective endocarditis.

“This study showed how this bacterium interacts with proteins found in our blood, which may give us an insight into how these deadly heart infections occur. This is an important step towards developing new treatments, but more research is needed to fully understand this interaction.”

 

Source:   eurekalert.org