Antibiotic-resistant bacteria thriving in Galway’s sewers
Scientists at NUIG have discovered high levels of bacteria resistant to all antibiotics in urban sewage – but they insist that risk can be reduced greatly by an effective wastewater treatment.
Researchers at the School of Medicine – together with colleagues in UCD – carried out the study on whether antibiotics and antibiotic resistant bacteria are present in hospital sewage and city sewage generally.
The research, published by the EPA, sought to address how antibiotics seep into the environment and to examine possible effects on human health.
The NUIG scientists claimed that antibiotic resistance was one of the greatest threats to public health. They revealed a worldwide epidemic whereby bacterium was becoming resistant to antibiotics and as a result infections becoming increasingly difficult to treat.
High levels of resistant bacteria existed in hospital sewage where – on average – one in three patients are on antibiotics. Bacteria in hospital sewage also proved resistance to a number of “newer” antibiotics.
But the study also showed resistant bacteria was reduced greatly by effective wastewater treatment. However they maintain that it did not eliminate them completely some antibiotic resistant bacteria survive and are discharged to seawater.
“This study highlights a part of the problem of antibiotic resistance that does not receive very much attention,” explained Dr. Dearbháile Morris, a bacteriologist from the School of Medicine at NUI Galway.
“Our work shows that there is a risk related to antibiotics and antibiotic resistant bacteria in sewage but that a high standard of sewage treatment goes a long way to reduce that risk.
“This is one more reason why the discharge of untreated or inadequately treated sewage to the environment in Ireland or indeed anywhere in Europe or the wider world is an unacceptable risk to our health,” she added.
Resistant bacteria have emerged in humans due to overconsumption and improper use of antibiotic medicines. Bodies do not distil all of the antibiotics we ingest and as a result many active agents find their way into the natural environment.
Once exposed to the environment, expelled antibiotics mingle with bacteria in the water and cause existing microorganisms to develop resistant genes thus increasing the number of antibiotic resistant bacteria.
Urban waste water and sewage treatment is vitally important in combating the global phenomenon of antibiotic and antimicrobial resistance. Untreated sewage has a long term ecological impact on the environment.
The latest EPA report on Urban Waste Water Treatment reveals that untreated sewage was discharged from 45 areas, 27 of which were located in counties Cork, Donegal and Galway.
The report also shows just 24% of waste water discharged into sensitive areas from large towns and cities complied with mandatory European Union nutrient quality standards.
But Dr Morris acknowledged that the old hypothesis which suggests an occasional pinch of dirt can actually benefit the immune system by keeping it tuned and strong, could well hold some weight.
She admitted that “we have possibly become over concerned with hygiene” – to the detriment of our own health.
“Antibiotics are fantastic drugs” she insisted, adding “we have to protect them”. When antibiotics first came to use, they were made using naturally occurring ingredients like medicinal fungi – penicillin.
Since then, antibiotic resistance has forced pharmaceutical providers to create a new selection of drugs to fight infection.
Synthetic antibiotics like fluoroquinolones have increased in popularity as they do not biologically occur in nature, making them more robust. However, lately scientists are discovering increased resistance against synthetic drugs.
Reports last November emerged of the so called ‘Apocalypse Pig’, a swine which showed resistance to a 50-year-old and unexposed antibiotic, known as the ‘last-resort antibiotic’ - colistin.
The ECDC (European Centre for Disease Control) together with the WHO (World Health Organisation) have since called for global awareness on the issue.
Dr. Morris, echoing the sentiments of global health authorities, calls for more considered use of antibiotics in tackling the antimicrobial resistance epidemic.
Considered use means only taking antibiotics when they are genuinely needed as antibiotic use is a key driver for antimicrobial resistance. The modern lax approach to pharmaceuticals is one that ought to be curtailed according to Dr. Morris.
‘Dr. Google’ is also mentioned as responsible for spawning a nation of self-diagnosing hypochondriacs – pro ne to self-medication and exaggeration in order to obtain prescription.
Dr. Morris also warned against the unnecessary and futile use of antibiotics for treatment of viral infections.
The common cold and flu are two such examples – both strains of the influenza virus. It is said taking antibiotics for treatment of a virus may do the body – and the environment – more harm than good.