ECJ EUROPEAN Cleaning Journal

Biofilms are everywhere. They are highly resilient; hard to remove and implicated in a staggering 80 per cent of infections. But what exactly are they? Are cleaners aware of the dangers they pose? And should we be scared?

It is the news that none of us wanted to hear: bacteria are becoming organised. We like to think of them as unsophisticated forms of life that are easy to kill with antibacterial products. But we have now come to realise they are banding together to form colonies.

It may sound like the stuff of science fiction. But biofilms are a real threat – one that is implicated in 80 per cent of infections according to experts. But alarmingly, few of us have heard of them.

A biofilm may develop on any surface that has been exposed to both bacteria and water. Biofilms can be formed by a single bacteria species but usually consist of many different types along with fungi, algae, protozoa and debris. They are bound together in a thick, gluey substance that can adhere to a range of surfaces including metals, plastics, soil and biological tissue.

Biofilms grow inside water and sewage pipes and thrive in the moist, warm environment of the shower. Food preparation areas are likely to harbour biofilms on floors and surfaces. They grow on rocks at the bottom of rivers and adhere to boat hulls. They even form in our mouths: dental plaque is a biofilm.

Increasingly advanced microscopes have led to a new awareness of the biofilm’s impact on the environment, industry and human health. But do cleaners understand the risks they pose and the need for removing them? And are chemical companies making products that can combat them?

High risk areas

Biofilms are not a new phenomenon - but they are a major problem according to Dr Schnell Chemie’s marketing executive Franz Felbermeir. “This is particularly the case in high risk areas such as care homes and hospitals,” he said. “Biofilms are a major issue in diluting stations and spray bottles and it is not easy to remove them – particularly from surfaces made from plastic or rubber.”

He says biofilms are forming at increasing rates in hospital ICU and haematology units. “These areas are an important focus: especially when immune-suppressive people come into contact with them,” he said.

High concentration

Dr Schnell Chemie offers a range of products that can tackle biofilms. “The key is a level mixture with a high concentration of active ingredients such as enzymes, peroxides, surfactants and chlorine,” he said.

A combination of chemical, thermal and mechanical action provides the best solution for removing biofilms according to Felbermeir. “But mechanical treatment cannot be provided in all situations and while disinfectants destroy microorganisms, it is difficult for active ingredients to attack the bacteria due to the polysaccharide and protein matrix of biofilms.”

He adds that the best way of addressing the problem is to prevent biofilms from forming in the first place. “This can be done by educating people on how biofilms occur,” he said. “You need to consider the combination of water, air and temperature and what type of hazard can result from which situation. The topic of biofilms will become more prominent over the coming years and new products and materials will come on stream to remove and prevent them.”

Diversey Care’s UK and Ireland’s technical manager Pete Gilbert says biofilms have been implicated in medical devices introduced into the body such as catheters, prostheses and heart valves. However he feels they are less of a threat in general cleaning.

“For a biofilm to be formed, a series of prerequisites need to take place,” he said. “Biofilms need food and water and their development should not be disrupted. During general cleaning regimes we tend to remove those parameters from surfaces.”

He receives few inquiries about the removal of biofilms, he says. “If a customer has a problem with an identified biofilm we will recommend that they use an alkaline detergent combined with chlorine or some acid solution,” said Gilbert.

Once they are in place, he agrees with Felbermeir that they are difficult to remove. “A biofilm is formed by different layers so when you apply a disinfectant, you damage the top layer but in many cases you are not reaching the inside of the biofilm,” he said.

“Furthermore you have to ensure that you remove every single organism and that the conditions that facilitated growth have been removed. Otherwise some organisms will remain on the surface and when they find the right conditions, they will start to colonise again.”

He adds that physical energy will facilitate biofilm removal. “In order to kill bacteria you also need to follow recommended contact times when applying chemicals,” he adds. “In the case of biofilms, this should be extended since the disinfectant needs to penetrate the biofilm. The best technique is to clean first and dislodge the biofilm and then move on to the disinfection step.”

Biofilms have been on the radar for cleaning services provider OCS for some time according to head of standards and solutions cleaning Yvonne Taylor.

“They are complex and present sanitation issues and cleaning challenges,” she said. “Biofilms are resistant to removal and tolerant to disinfectants. They also have a shielding effect on the bacterial cells within them which means they might not be completely eliminated by standard cleaning and sanitising methods. They can spread easily, contaminate other areas and cause illnesses – and this is a particular problem in healthcare environments.”

Form on surfaces

She says biofilms are prone to form on surfaces that are not cleaned with sufficient frequency. “They can anchor themselves to many different surfaces and materials including medical implants and human and animal tissue,” she said.

Regular scheduled cleaning is the best way to combat biofilms, says Taylor. “This will disrupt the conditions for growth.” She adds that OCS is fully aware of the risks and works closely with suppliers to ensure they use the correct chemicals for the job.

“These include an alkaline detergent combined with chlorine, or certain acid solutions,” she said.
“We often use a 24-hour fogging process as an effective method of applying sanitiser to treat and eliminate biofilm contamination. And in high-risk healthcare environments such as operating theatres we provide dedicated cleaning equipment to remove the risk of cross-contamination.”

She says physical agitation is also required to remove biofilms. “The optimum technique is to perform routine cleaning first and then to carry out the sanitising process to dislodge the biofilm,” she said.

OCS staff are given detailed operating procedures plus bespoke work schedules based on client requirements. “Our staff receive induction training, refresher toolbox talks on correct hand washing techniques and other industry-approved training,” said Taylor. “They are also fully trained in chemical use.”

However, she believes the threat of biofilms is not currently on the increase in the professional cleaning sector. “But companies will benefit by building strong relationships with their suppliers and keeping up to date with the latest information on risks, methods, innovation and products,” she adds.

Healthcare cleaning expert Mike Rollins considers biofilms to be a significant threat in hospitals. “This is particularly the case where patients have a compromised immune system or where choice of medical treatment is restricted due to multi-drug resistant organisms,” he said.

The challenge for healthcare environments is to maintain a low bio-burden on hand contact surfaces - particularly those close to the patient, says Rollins. “Unfortunately from a preventative perspective we cannot physically see biofilm contamination,” he said. “Microbiological testing is not regularly performed and even when a patient environment is cleaned and disinfected, the process of recontamination starts again immediately.

“This is why hand hygiene remains the principal preventative measure for cross-contamination and infection prevention.”

He says environmental research has grown significantly over the last decade as a result of increasing rates of healthcare-associated infections such as MRSA, Clostridium Difficile, VRE and CRE.

“The challenge for biofilm removal is a battle against nature,” he said. “Biofilms are complex organisms that have efficient mechanisms for attachment and for survival on surfaces. And inappropriately-designed surfaces can actually aid biofilm formation.”

As an example he cites a particular no-touch tap product promoted for use in healthcare. “In principle the concept was sound but we found that the tap mechanism harboured a reservoir that enabled biofilm formation,” said Rollins. “The subsequent water flow was contaminated and as a result it transferred viable bacteria on to healthcare workers’ hands. “This in turn provided the potential for cross-contamination on surfaces - including the patient.”

He says some surfaces are more prone to biofilm colonisation than others. “Textured plastics commonly found in patients’ beds provide an ideal surface for adhesion,” he said. “The standard cleaning process may remove some top surface soil but will not be effective on this three-dimensional surface profile.

"As a result, residue may be left behind in the ‘valleys’. And if any moisture or nutrient remains in place, this will have the potential to ‘feed’ the bacteria which will lead to the biofilm quickly reestablishing itself on the surface.”

He agrees with other experts that it is easier to prevent the formation of biofilms than to remove them once formed. “Design, preventative maintenance and the use of antimicrobial devices can all help to achieve this,” he said. “These can include ultra-violet light, surface treatments with biostatic or biocidal properties, and nano surface coatings that inhibit biofilm attachment.”

When removing biofilms he says that traditional mop, bucket and wipe-clean methods are ineffective. “Superior performance has been demonstrated using cleaning methods such as microfibre textiles and dry steam vapour machines,” he said. “Meanwhile, new forms of disinfectants based on accelerated hydrogen peroxide, chlorine dioxide, peracetic acid and Quaternary Ammonium Compounds have emerged.”

Research needed

He believes that many FM companies understand the risks associated with biofilms, but feels cleaning companies are unlikely to come under the same scrutiny. “Identifiable issues such as mould can be reported, but biofilm contamination is not readily identified during cleaning activity.

“In high risk environments such as healthcare, cleaning standards are documented and staff are trained towards those standards. But in times of austerity, these standards become the minimum and may not take into account the growing challenge of bacterial resistance, environmental contamination and the risk to patient safety.

“More environmental research is therefore needed and cleaning staff need to be trained in methods of removing surface decontamination. Cleaning is Job One, but competence in surface disinfection is an area which - in my opinion - requires further investment in the training of specialist ‘technicians’.”