Globally, around 700,000 people die every year as a result of drug-resistant infections, including tuberculosis, HIV and malaria. And the Guardian reports that this figure will rise to 10 million a year by 2050 if we do not act now.

Making matters worse, Public Health England (PHE) revealed that around a fifth of antibiotic prescriptions are unnecessary.

But, as head of drug-resistant infections programme at the Wellcome Trust, Dr Timothy Jinks, questions in a recent BBC article, why is it so difficult for scientists to discover new drugs?

Alexander Fleming is heralded as the man who, accidentally, discovered the antibiotic penicillin when he returned from holiday to find it on Petri dishes he had left in his basement laboratory at St Mary's Hospital in London almost 90 years ago.

Jump to the 1950s, which became known as the golden age of antibiotic discovery, and an array of new medicines were found.

But what about today?

Scientists are searching for a new breakthrough. As well as developing new, synthetic drugs created in laboratories, scientists are testing microbes in soil, caves, and even in Komodo dragon blood.

While researchers continue to look for the next big thing, the world is running out of effective antibiotics.

Deadly bacteria are becoming resistant to penicillin and over 100 different antibiotics. These drugs are vital in fighting infection and are key in everything from treating food poisoning to organ transplants.

While Fleming's discovery of penicillin might be well documented, what might not be so well known is that Fleming himself warned about bacteria and their ability to become resistant to drugs.

Microorganisms evolve to ensure those that develop defences against antibiotics will survive. This means that the more antibiotics we use, the faster bacteria develop resistance.

With misuse and overuse in human and animal health, we are facing a race to stay ahead of superbugs.

Dr Jinks believes that part of the difficulty in discovering new drugs lies in the time it takes to test potential candidates.

He notes that it can be easy to find chemicals that kill bacteria, but that it's harder to find and develop substances that aren't also toxic to humans.

The journey from discovery to clinical approval is a long one. First scientists start with basic research to identify any potential substances, which itself can take years.

When a candidate is found, it is tested on known infectious bacteria. If this is successful, it is tested to see if it is toxic to humans and then the years of clinical trials begin. It can take around 10 to 20 years from the moment of discovery to medicines being available.

As of May this year, 51 antibiotics were reported to be in the clinical pipeline. But it may take years for them to appear on shelves.

But Dr Jinks argues that new drugs are only part of the solution. We also need more accurate diagnosis of infections to help doctors know the best treatment course, a better understanding of how and where drug-resistant infections are spreading, and exploration of vaccines to help protect against infection in the first place.

To stop infection spreading, there also needs to be a global improvement in the hygiene of hospitals, clinics and communities.

But it seems steps may already be underway to help our understanding. The University of Bristol is leading two studies that aim to identify what makes bacteria resistant to antibiotics and how this process can be reversed.

Speaking to ITV News, Dr Matthew Avison, reader in molecular bacteriology at Bristol University, explained: "By understanding the biology of antibiotic resistance, understanding the mechanisms that bacteria use to resist antibiotics, you can pick apart the machinery of resistance and develop chemicals that can get into those machines and actually block them and inhibit resistance.

"The idea is that you give the inhibitor, or the blocker, with the antibiotics, and the antibiotic can work again."

While the blockers will be reserved for the most seriously ill patients, these new resistance blockers could be in hospitals in the next two to three years.