How ostrich eggs can help beat superbugs
Ostrich eggs could be key to tackling a deadly hospital infection that kills 1,600 people a year in the UK. the eggs are used to produce a drug that contains infection-fighting cells — antibodies — designed to destroy clostridium difficile (c. difficile).
this is an infection typically contracted in hospital by sick, frail patients whose defences have been weakened by illnesses such as cancer or diabetes.
scientists have turned to ostriches as they are one of the oldest-known birds on Earth. A reason for their survival is they have one of the toughest immune systems in the animal kingdom.
Female ostriches are able rapidly to produce antibodies to an enormous range of bacteria and viruses. these antibodies can be harvested in huge quantities from their giant eggs.
Unlike similar cells produced by other animals, they are tough enough to survive the highly acidic environment of the human stomach. this means they can pass through safely and hunt down harmful bacteria.
c. difficile, a tough bug that lives in the intestines, poses little threat in a healthy person.
however, when the normal balance of gut bacteria becomes disturbed, it can cause diarrhoea, bleeding, fever and stomach cramps. this can occur as a result of antibiotic treatment.
c. difficile can affect patients who have a weakened immune system, too — for example, as a result of chemotherapy.
in the worst cases, it can trigger potentially deadly peritonitis — a dangerous infection in the lining of the abdomen.
treatment usually involves another course of a more powerful or targeted antibiotic. however, swallowing a liquid packed with ostrich antibodies may be more effective. OstriGen, a firm based in Massachusetts in the U.s., is setting up a trial involving doctors at the Beth israel Deaconess Medical centre in Boston to test the ostrich egg therapy.
scientists have produced the antibodies needed by injecting the female birds with ‘deactivated’ traces of the c. difficile bug.
this stimulated their immune systems to produce the infectionfighting cells, without making them ill. the antibodies were then harvested from their eggs and, in the next few months, will be given to patients with suspected c. difficile infection as a one- off spoonful of medicine. Previous research shows ostrich egg antibodies are effective against other dangerous bugs.
A 2012 study in the Brazilian Journal of Microbiology showed they could stop the growth of staphylococcus aureus and E. coli — two bugs that, between them, have killed thousands of people in the UK in the past decade.
OstriGen is also looking at the same technique to produce cells that will fight flu, salmonella poisoning and even ebola.
in Mozambique, the ostrich egg medicine has been turned into a boiled sweet that can be taken by children struck down by cholera. ThE
treatment may be available in the next three to five years if the trials prove successful. Professor Mark Wilcox, a consultant microbiologist at Leeds teaching hospitals Nhs trust, says using animals such as ostriches to mass produce antibodies makes a lot of sense.
‘ these approaches are theoretically a relatively cheap way of producing antibodies to fight infection,’ he says.
MEANWhiLE, a vaccine to prevent c. difficile infection in adults has moved a step closer.
the vaccine, PF-06425090, works by neutralising disease- causing toxins released by c. difficile.
this year, tests on 854 healthy adults over 65 found it to be safe and well tolerated. Pfizer, the firm that developed the jab, say tests to check the vaccine’s effectiveness will start later this year.