Many harmful bacteria have become resistant to antibiotics. Improper use, oversubscribing, and the false notion that anti- biotics can be used for a variety of ailments, including common viruses, has led to a crisis many chemists, doctors and scientists are extremely concerned about.
The discovery of penicillin in 1928 was, and continues to be, one of the greatest medical breakthroughs ever made. It has helped treat tens of millions of sick people and saved countless lives. More antibiotics were discovered after that and they remain among the most important antidotes in the fight against bacterial infections.
Very soon after penicillin was first discovered, however, scientists noticed how some harmful bacteria were already becoming resistant to its effect. With their ever-increasing use, the problem of bacterial resistance to antibiotics has reached boiling point.
“A lot of patients who receive antibiotics don’t follow the instructions,” says Carol McCarthy, PhD candidate from the Synthesis and Solid State Pharmaceutical Centre (SPSC) at University College Cork, which is funded by Science Foundation Ireland. They either skip doses or don’t finish the prescribed course.” These are two of the biggest mistakes.
Side-effects
“People also falsely believe antibiotics can be used for the treatment of common viruses like those associated with colds, flus, diarrhoea and sore throats. They cannot. In many cases all they do, when used incorrectly, is lead to side-effects such as nausea and skin rashes. In the case of minor ailments, it’s better for patients to fight off the virus themselves, or get medicine to treat the symptoms.”
There’s a lot of misinformation surrounding the correct use of antibiotics. A culture of “stockpiling” in the medicine cabinet at home has been created under the false pretence that people can keep unused prescriptions and/or unfinished courses, to avoid a costly trip to the doctor for a new prescription the next time they get sick.
The reality is, however, for antibiotics to work, they have to be the right kind, and the right dose for the infection being treated. Taking two antibiotics (like one might take aspirin) will cause more harm than good. Still many people are somehow led to believe they are “good for everything”.
“This is not true,” says McCarthy. “And the widespread overuse is of great concern, particularly for the most vulnerable in society such as older people and young children. They may find themselves becoming at risk of developing much more serious infections that can’t be treated, such as MRSA and MR tuberculosis – two very dangerous infections.”
The big concern right now is that, over the last 30 years, no new major classes of antibiotics have been discovered while bacteria are becoming increasingly resistant to the existing options.
“This is going to cause serious problems,” says McCarthy. “Even minor surgeries will become high-risk as people frequently need antibiotics after even routine procedures to prevent infection of surgical wounds etc. We need new kinds of anti- biotics.
Research and development
“Funding for relevant research is critical,” she adds. “Here in Ireland we are at the global forefront for pharmaceutical research and we need to put more money into finding new antibiotics or figuring out ways to improve the ones we already have.
Not only that but an increased emphasis must be placed on educating healthcare professionals and the public about appropriate use.
The pharmacist also has a role to play in this by giving appropriate medicines for minor ailments, like common viruses, that control the symptoms. “It’s also worth encouraging people to get two vaccines in the wintertime, for colds and flu, so that they don’t get sick.”
This is a problem worldwide so global bodies such as the World Health Organisation (WHO) are ramping up efforts to inform the public. World Antibiotics Awareness Week takes place from November 16th to 22nd.
A new initiative to take on the problem of resistance to antibiotics was agreed upon at the 68th World Health Assembly in May 2015. The main aim now is to improve “awareness and understanding of antimicrobial resistance through effective communication, education and training.” For more see iti.ms/1Gej6dR spsc.ie
Expiry dates
While expiry dates on medicines frequently err on the side of caution, it is still important to stick by them. At best taking expired medicine won’t have the desired effect. At worst, it might make you even sicker.
Many of the medicines we take are made from the same chemical building blocks as other products. But if a drug isn’t taken before it reaches its expiry date, those same blocks can rearrange themselves, forming wholly different products that may have a very different effect on the human body.
“The change in functions of medicines past their expiry date can range from reduced efficacy to causing physiological/ psychological effects to being potentially lethal,” says Dr Anuradha Radhakrishnan Pallipurath, post-doctoral research associate at the school of chemistry at NUI Galway.
“Most over-the-counter drugs like paracetamol are safe to take up to a few months after their expiry, as the only effect is that of reduced potency due to polymorphic change.
“But drugs can also undergo chemical changes, such as oxidation, as in the classic case of a freshly cut apple going yellow. Vitamins, like many other drugs, are most prone to chemical changes due to exposure to air and moisture. These changes are more prominent in liquid formulations than in solid forms.
Medicines mutate
Medicines can also have an enantiomeric change, which can be dangerous. “Imagine the reflection of your hand,” she says. “If you place the image of the reflection of your hand on your hand, do they look the same? Possibly not. Many chemical compounds have the same number of carbons, hydrogens and oxygens, and they possibly also link up in the same fashion, but putting the reflection of one molecule over itself will not give you back the same molecule. These molecules are called enantiomers.
“While this might seem trivial, it is of prime importance as drugs work when they bind to proteins in our body. And the drugs must have a specific shape for them to fit into the site on a protein, much like a key in a lock. A well-known example is thalidomide. The active form of the drug is potent against morning sickness, but once it converts to its enantiomer, it causes birth defects.”
The ocean potential
The oceans surrounding Ireland may provide the solutions to many medical challenges, particularly in our search for new antibiotics. Researchers at the SSPC have been exploring the ocean depths to discover new medicines that may end up being game-changers.
“The marine environment is now recognised as a relatively untapped major source of organisms that produce novel biological materials (including small molecules) and unique metabolic processes with huge biotechnological and biopharmaceutical potential,” explains Prof Fergal O’Gara, director of the Biomerit BioSciences Institute at UCC.
“Our main interest is coming up with the next generation of anti-microbials,” he says. With the emergence of multiple drug-resistance, the challenge to the stakeholders involved at research and industry level is to come up with an effective anti-microbial.
“We’re searching for new bioactive compounds that will basically disrupt the armoury of pathogens.
“When micro-organisms invade the body and become established, they become chronically infecting microbiomes and take the form of proliferation structures called biofilms. The challenge with biofilms is that they become refractory: they are resistant to all clinically used antibiotics.
“So we’re now trying to develop new antibiotics to disrupt the formation of biofilms.”
O’Gara and his research team are making significant progress. They have found some promising molecules on marine sponges. “Marine invertebrates have always fascinated scientists,” he says. “Their surfaces appear to be sterile, which means there are perhaps some kind of molecules preventing the growth of micro-organisms.”
They are now attempting to take genetic information from marine sponges and express it in surrogate hosts in the lab. The results have been positive. But this is just the beginning. “There’s more research to be done,” he says. “Less than 1 per cent of organisms in the marine environment can be grown in a laboratory setting. It is the other 99 per cent of biodiversity that’s untapped in our oceans that we’re going after.”
Coastal harvest
This is also a collaborative process with the SSPC partnering with a number of other EU institutes and universities in western Australia.
“This is an area with huge economic and medical potential for Ireland. The Department of the Marine now recognises fully the possibilities that lie off our coasts in terms of biodiversity, jobs creation and medical breakthroughs.”
Science Foundation Ireland funds the SSPC Centre
