What is biofilm and how to treat it?
Acute infections are assumed to involve planktonic bacteria, which are generally treatable with antibiotics, although successful treatment depends on accurate and fast diagnosis. However, in cases where the bacteria succeed in forming a biofilm within the human host, the infection often turns out to be untreatable and will develop into a chronic state.
What is the pathophysiology of bacterial biofilms?
Observations of microbial biofilm formation by van Leeuwenhook, Pasteur and other pioneers date back to the roots of microbiology and infectious disease research . The impact of a foreign implant on the infection process was already recognized in 1956 as the presence of a foreign material required a 7.5×10 4 lower dose of Staphylococcus aureus to cause a subcutaneous …
Can bacterial biofilm infection be eradicated?
Bacterial biofilms are resistant to antibiotics, disinfectant chemicals and to phagocytosis and other components of the innate and adaptive inflammatory defense system of the body. It is known, for example, that persistence of staphylococcal infections related to foreign bodies is due to biofilm formation.
What is the European Society for Clinical Microbiology doing to diagnose biofilm infections?
Characteristics of biofilms that can be important in infectious disease processes include a) detachment of cells or biofilm aggregates may result in bloodstream or urinary tract infections or in the production of emboli, b) cells may exchange resistance plasmids within biofilms, c) cells in biofilms have dramatically reduced susceptibility to antimicrobial agents, d) biofilm …
How can biofilms complicate treatment of infectious diseases?
Biofilms increase the chance of gene transfer by the help of virulence factors and antibiotic-resistant genes from resistant to susceptible bacterial species, which leads to antibiotic resistance [52,53].Aug 19, 2019
How could biofilm formation impact the effectiveness of an antibiotic?
Biofilms possesses many cells of stationary phase which have the decreased antibiotics susceptibility to the antibiotics. Among them at least 1% becomes tolerant to antibiotics [4, 80].May 16, 2019
What role does biofilm play in disease and treatment?
The term biofilm is used to denote a polymer-encased community of microbes which accumulates at a surface. Biofilms are responsible for a number of diseases of man and, because of the intrinsic resistance of these structures to antibiotics and host defence systems, such diseases are very difficult to treat effectively.
What is biofilm and its role in causing an infectious diseases?
In addition to the protection offered by the matrix, bacteria in biofilms can employ several survival strategies to evade the host defense systems. By staying dormant and hidden from the immune system, they may cause local tissue damage and later cause an acute infection.Feb 3, 2020
Why are biofilms difficult to treat with antibiotics?
Biofilm bacteria show much greater resistance to antibiotics than their free-living counterparts and our interest is to investigate the mechanistic basis of this phenomenon. One potential reason for this increased resistance is the penetration barrier that biofilms may present to antimicrobials.
Why biofilms are resistant to antibiotics and disinfectants?
The antibiotic resistance is supported due to the transition of the colony from exponential to slow or without growth/persisters phenomena. The Glycocalyx matrix through the efflux system and enzymes, inactivate antimicrobial agents and protect the peripheral region of the biofilm.Apr 28, 2017
How do biofilms impact human health?
Bacterial biofilm is a key reason for the contamination of medical devices and the generation of microbial and chronic infections in the body. In fact, biofilms are the source of a number of human diseases as they cause serious infections and have antimicrobial drug resistant features.Apr 16, 2021
Why are biofilms important in human health and environmental processes?
Biofilms show an increased survival and resistance to environmental and chemical stressors (e.g., antibiotics) mainly, but not only, by the protection conferred by the extracellular polysaccharide matrix (Mah and O'Toole, 2001; Stewart and Costerton, 2001; Donlan, 2002; Donlan and Costerton, 2002; Stewart, 2002; Hall- ...Oct 31, 2015
Why are biofilms important in human health?
Biofilms play a significant role in the transmission and persistence of human disease especially for diseases associated with inert surfaces, including medical devices for internal or external use.Sep 19, 2015
How are biofilm infections treated?
The primary and most effective treatment of biofilm infections is physical removal followed by inhibition of reconstitution with antibiofilm agents (ABF), antibiotics (ABX), and selective biocides.
What role do biofilms play in pathogenesis of bacterial infections?
The role of biofilms in pathogenesis One example of a positive effect includes the biofilms of commensal bacteria such as Staphylococcus epidermidis, which can impede the colonisation of potentially pathogenic bacteria through the stimulation of host-cell immune defences and the prevention of adhesion.
What are biofilms and how are they beneficial for bacteria?
Biofilm is a strong and dynamic structure that confers a broad range of advantages to its members, such as adhesion/cohesion capabilities, mechanical properties, nutritional sources, metabolite exchange platform, cellular communication, protection and resistance to drugs (e.g., antimicrobials, antiseptics, and ...Jul 26, 2018
What is a biofilm?
A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and extracellular DNA. Bac …. Bacteria survive in nature by forming biofilms on surfaces and probably most, if not all, bacteria (and fungi) are capable of forming biofilms. A biofilm is a structured consortium of ...
How do bacteria communicate in biofilms?
Bacteria in biofilms communicate by means of molecules, which activates certain genes responsible for production of virulence factors and, to some extent, biofilm structure. This phenomenon is called quorum sensing and depends upon the concentration of the quorum sensing molecules in a certain niche, which depends on the number of the bacteria.
What is a biofilm resistant to?
Bacterial biofilms are resistant to antibiotics, disinfectant chemicals and to phagocytosis and other components of the innate and adaptive inflammatory defense system of the body. It is known, for example, that persistence of staphylococcal infections related to foreign bodies is due to biofilm formation.
What is biofilm research?
Research on microbial biofilms is proceeding on many fronts, with particular emphasis on elucidation of the genes specifically expressed by biofilm-associated organisms, evaluation of various control strategies (including medical devices treated with antimicrobial agents and antimicrobial locks) for either preventing or remediating biofilm colonization of medical devices, and development of new methods for assessing the efficacy of these treatments. Research should also focus on the role of biofilms in antimicrobial resistance, biofilms as a reservoir for pathogenic organisms, and the role of biofilms in chronic diseases. The field of microbiology has come to accept the universality of the biofilm phenotype. Researchers in the fields of clinical, food and water, and environmental microbiology have begun to investigate microbiologic processes from a biofilm perspective. As the pharmaceutical and health-care industries embrace this approach, novel strategies for biofilm prevention and control will undoubtedly emerge. The key to success may hinge upon a more complete understanding of what makes the biofilm phenotype so different from the planktonic phenotype.
How do biofilms work?
Microorganisms attach to surfaces and develop biofilms. Biofilm-associated cells can be differentiated from their suspended counterparts by generation of an extracellular polymeric substance (EPS) matrix, reduced growth rates, and the up- and down- regulation of specific genes. Attachment is a complex process regulated by diverse characteristics of the growth medium, substratum, and cell surface. An established biofilm structure comprises microbial cells and EPS, has a defined architecture, and provides an optimal environment for the exchange of genetic material between cells. Cells may also communicate via quorum sensing, which may in turn affect biofilm processes such as detachment. Biofilms have great importance for public health because of their role in certain infectious diseases and importance in a variety of device-related infections. A greater understanding of biofilm processes should lead to novel, effective control strategies for biofilm control and a resulting improvement in patient management.
What is the role of biofilms in microbiology?
Research should also focus on the role of biofilms in antimicrobial resistance, biofilms as a reservoir for pathogenic organisms , and the role of biofilms in chronic diseases. The field of microbiology has come to accept the universality of the biofilm phenotype.
What is attachment in biology?
Attachment is a complex process regulated by diverse characteristics of the growth medium, substratum, and cell surface. An established biofilm structure comprises microbial cells and EPS, has a defined architecture, and provides an optimal environment for the exchange of genetic material between cells.
How are biofilm cells dispersed?
Biofilm cells may be dispersed either by shedding of daughter cells from actively growing cells, detachment as a result of nutrient levels or quorum sensing, or shearing of biofilm aggregates (continuous removal of small portions of the biofilm) because of flow effects.
What is a biofilm?
A Historical Basis. A biofilm is an assemblage of surface-associated microbial cells that is enclosed in an extracellular polymeric substance matrix. Van Leeuwenhoek, using his simple microscopes, first observed microorganisms on tooth surfaces and can be credited with the discovery of microbial biofilms.
Is a biofilm a monolayer?
The term biofilm is in some ways a misnomer, since biofilms are not a continuous monolayer surface deposit. Rather, biofilms are very heterogeneous, containing microcolonies of bacterial cells encased in an EPS matrix and separated from other microcolonies by interstitial voids (water channels) ( 44 ).
What is biofilm in biology?
Formation of biofilm is a survival strategy for bacteria and fungi to adapt to their living environment, especially in the hostile environment. Under the protection of biofilm, microbial cells in biofilm become tolerant and resistant to antibiotics and the immune responses, which increases the difficulties for the clinical treatment ...
Where is biofilm found?
Bacterial biofilm formation is widely found in natural environments with water, and also in human diseases, especially in the patients with indwelling devices for the purpose of medical treatments.2,7With the progress of medical sciences, more and more medical devices and/or artificial organs are applied in the treatment of human diseases.
What are the amyloids in bacteria?
Beside of the focus on QS and c-di-GMP, bacterial amyloids have become another popular topic. Amyloids has been identified in both bacteria and fungi, since many types of bacterial species relay on amyloids to stick to each other or further to host surfaces resulting in the creation of biofilms.
Can antibiotics eradicate biofilm?
According to the biofilm characters of antibiotic resistance, it is currently difficult to eradicate biofilm infections by conventional antibiotic treatments. Therefore, the removal of a foreign body becomes an important prerequisite for the eradication of such biofilm infections.
Is an abscess a biofilm?
Abscesses are not biofilm, but they have some kinds of connections with biofilm.45When an abscess is formed, it becomes difficult for antibiotic to penetrate through the wall of abscess into the focus. Therefore empty of abscess is necessary. Early and aggressive antibiotic treatments against biofilm infections.
Can infection cause acidosis?
It is well known that infection could lead to inflammation, which results in faster metabolism and significant consumption of oxygen locally or systemically. If oxygen supply could not meet the demand, glycolysis will be activated leading to acidosis, and the effects of antibiotics could be affected by pH values.
Is biofilm a chronic infection?
According to the features of biofilm development, mature biofilms are significantly resistant to antibiotic chemotherapies and they will intermittently disperse planktonic bacterial cells to the environments. Hence, a typical biofilm infection is usually a chronic infection ...
How does biofilm develop?
When an indwelling medical device is contaminated with microorganisms , several variables determine whether a biofilm develops. First the microorganisms must adhere to the exposed surfaces of the device long enough to become irreversibly attached. The rate of cell attachment depends on the number and types of cells in the liquid to which the device is exposed, the flow rate of liquid through the device, and the physicochemical characteristics of the surface. Components in the liquid may alter the surface properties and also affect rate of attachment. Once these cells irreversibly attach and produce extracellular polysaccharides to develop a biofilm, rate of growth is influenced by flow rate, nutrient composition of the medium, antimicrobial-drug concentration, and ambient temperature. These factors can be illustrated by examining what is known about biofilms on three types of indwelling medical devices: central venous catheters, mechanical heart valves, and urinary (Foley) catheters.
What are the causes of prosthetic valve endocarditis?
Microorganisms may attach and develop biofilms on components of mechanical heart valves and surrounding tissues of the heart, leading to a condition known as prosthetic valve endocarditis. The primary organisms responsible for this condition are S. epidermidis, S. aureus, Streptococcus spp ., gram-negative bacilli, diphtheroids, enterococci, and Candida spp. These organisms may originate from the skin, other indwelling devices such as central venous catheters, or dental work ( 3 ). The identity of the causative microorganism is related to its source: whether the contaminating organism originated at the time of surgery (early endocarditis, usually caused by S. epidermidis ), from an invasive procedure such as dental work ( Streptococcus spp.), or from an indwelling device (a variety of organisms). Implantation of the mechanical heart valve causes tissue damage, and circulating platelets and fibrin tend to accumulate where the valve has been attached. Microorganisms also have a greater tendency to colonize these locations ( 3 ). The resulting biofilms more commonly develop on the tissue surrounding the prosthesis or the sewing cuff fabric used to attach the device to the tissue ( 22, 23) than on the valve itself ( 24 ). Antimicrobial agents are usually administered during valve replacement and whenever the patient has dental work to prevent initial attachment by killing all microorganisms introduced into the bloodstream. As with biofilms on other indwelling devices, relatively few patients can be cured of a biofilm infection by antibiotic therapy alone ( 25 ). Illingworth et al. ( 22) found that a silver-coated sewing cuff on a St. Jude mechanical heart valve (St. Jude Medical Inc., St. Paul, MN) implanted into a guinea pig artificially infected with S. epidermidis produced less inflammation than did uncoated fabric. Although the number of attached organisms was not determined, the authors concluded that the degree of inflammation was proportional to the number of viable organisms. Carrel et al. ( 23) also found this approach was effective in in vitro studies with different organisms.
What organisms are in a urinary catheter?
The organisms commonly contaminating these devices and developing biofilms are S . epidermidis, Enterococcus faecalis, E. coli, Proteus mirabilis, P. aeruginosa, K. pneumoniae, and other gram-negative organisms ( 1 ). The longer the urinary catheter remains in place, the greater the tendency of these organisms to develop biofilms and result in urinary tract infections. For example, 10% to 50% of patients undergoing short-term urinary catheterization (7 days) but virtually all patients undergoing long-term catheterization (>28 days) become infected ( 1 ). Brisset et al. ( 26) found that adhesion to catheter materials was dependent on the hydrophobicity of both the organisms and the surfaces; catheters displaying both hydrophobic and hydrophilic regions allowed colonization of the widest variety of organisms. Divalent cations (calcium and magnesium) and increase in urinary pH and ionic strength all resulted in an increase in bacterial attachment. Tunney et al. ( 27) stated that no single material is more effective in preventing colonization, including silicone, polyurethane, composite biomaterials, or hydrogel-coated materials. Certain component organisms of these biofilms produce urease, which hydrolyzes the urea in the patient's urine to ammonium hydroxide. The elevated pH that results at the biofilm-urine interface results in precipitation of minerals such as struvite and hydroxyapatite. These mineral-containing biofilms form encrustations that may completely block the inner lumen of the catheter ( 27 ). Bacteria may ascend the inner lumen into the patient's bladder in 1 to 3 days ( 28 ); this rate may be influenced by the presence of swarming organisms such as Proteus spp. (D. Stickler, pers. comm.). Several strategies have been attempted to control urinary catheter biofilms: antimicrobial ointments and lubricants, bladder instillation or irrigation, antimicrobial agents in collection bags, impregnation of the catheter with antimicrobial agents such as silver oxide, or use of systemic antibiotics ( 29 ). Most such strategies have been ineffective, although silver-impregnated catheters delayed onset of bacteriuria for up to 4 days. In a rabbit model, biofilms on Foley catheter surfaces were highly resistant to high levels of amdinocillin, a beta-lactam antibiotic ( 30 ). However, Stickler et al. ( 31) found that treatment of a patient with a polymicrobial biofilm-infected catheter with ciprofloxacin allowed the catheter to clear and provide uninterrupted drainage for 10 weeks. Morris et al. ( 32) found that time to blockage of catheters in a laboratory model system was shortest for hydrogel- or silver-coated latex catheters and longest for an Eschmann Folatex S All Silicone catheter (Portex Ltd., Hythe, Kent, England). Biofilms of several gram-negative organisms were reduced by exposure to mandelic acid plus lactic acid ( 33 ). In a study in which ciprofloxacin-containing liposomes were coated onto a hydrogel-containing Foley catheter and exposed in a rabbit model, the time to development of bacteriuria was double that with untreated catheters, although infection ultimately occurred in the rabbits with treated catheters ( 34 ).
How do biofilms affect human health?
Biofilms can be found almost anywhere and may impact human health both positively and negatively. One example of a positive effect includes the biofilms of commensal bacteria such as Staphylococcus epidermidis, which can impede the colonisation of potentially pathogenic bacteria through the stimulation of host-cell immune defences and the prevention of adhesion. However, biofilms are more often associated with many pathogenic forms of human diseases and plant infections. One common example is cystic fibrosis, the most frequently passed genetic disorder in Western Europe. Cystic fibrosis (CF) patients suffer from chronic P. aeruginosa infections. When infecting the CF lung, P. aeruginosa undergoes a characteristic transition from an acute virulent pathogen to a CF‑adapted pathogen, allowing it to persist in the lung for years or even decades. This is due to the overproduction of the matrix polysaccharide alginate, leading to the formation of a mucoid biofilm that tolerates antibiotics, components of both the innate and adaptive immune response, and resists phagocytosis. The persistence of these mucoid biofilms within the CF lung leads to the development of a distinct antibody response. This prompts chronic inflammation mediated by granulocytes, and results in severe damage to the lung tissue of CF patients (see Figure 3 A). A second example for biofilms in human health is dental plaque potentially leading to dental caries. The consumption of fermentable carbohydrates such as sugary treats or drinks causes an increase in the production and secretion of organic acids by the bacteria found in dental plaque. If left untreated, the increased acidification of the biofilm leads to the demineralisation of the enamel and the formation of dental caries (see Figure 3 B).
Why is biofilm research important?
Due to the widespread distribution of biofilms in diseases and their resilience to numerous antimicrobial treatments , biofilm research is receiving more attention. Owing to increasing antimicrobial resistance , the focus of current research is shifting from targeting bacterial growth/division that causes cell death or dormancy, towards novel approaches. Examples include triggering the dispersal of the biofilm or looking into ways of preventing the initial formation, for instance by re-engineering the surfaces they are prone to develop upon such as urinary catheters and implants.
What is biofilm?
What is a biofilm? A common misconception of microbial living is that bacteria exist as individual organisms in a ‘planktonic state’. Rather, microorganisms have been shown to naturally accumulate on a wide variety of surfaces; where they form sessile, sedentary communities.
What is the extracellular matrix?
The matrix consists of extracellular polysaccharides, structural proteins, cell debris and nucleic acids; referred to as extracellular polymeric substances (EPS).
What is a biofilm?
Costeron defined biofilms as spatially structured microbial communities, embedded in a hydrated matrix of extracellular polymeric substances, that they have produced . Their function is dependent on a complex web and syntrophic interactions. (Costerton,1987) Biofilm mode of growth is very beneficial for bacteria, as they build structured communities with fluid channels, waste products, and signal molecules. (Usha, 2010) The subject of biofilms in endodontic infection was widely discussed in literature
What is the most common cause of hospital acquired infections?
species of bacteria that cause problems in healthcare today is Klebsiella pneumoniae. Today K. pneumoniae can be responsible for community acquired infections, but is most commonly observed as a major cause of hospital acquired infections which can be fatal. K. pneumoniae has been observed to develop resistance to antibiotics more easily than most bacteria through the production of new enzymes to break them down. As new resistance mechanisms develop, fewer and fewer treatments are available for infections
What is staphylococcal scalded skin syndrome?
Two of the characterized mutants are affected in the major autolysin (atlE) and in D-alanine esterification of teichoic acids (dltA). It is known formally as staphylococcal scalded skin syndrome. The genetic and molecular basis of biofilm formation in staphylococci is multifaceted. The disease occurs predominantly in children but can occur in anyone. Before antibiotics were available, about 80% of people with S. The enterotoxins and TSST-1 are associated with toxic shock syndrome. Skin infections
Is Gardnerella a gram positive?
gram-positive anaerobic bacteria that colonizes the vaginal tract. As an opportunistic pathogen, Gardnerella is predominantly known to cause bacterial vaginosis (BV). Bacterial vaginosis is a dysbiosis in women that is caused by an absence of lactobacilli and including an overgrowth of Gardnerella vaginalis and other bacterial species (Vick et al., 2014). BV can cause many risks in women with this infection that include inflammatory disease, STIs, and pregnancy complications such as preterm birth (Vick
Is biofilm a complication?
Abstract: Biofilm formation poses a universal complication to all implantable prostheses or devices in the human body. Medical costs rise substantially with biofilm formation and may lead to further life-threatening conditions. Researchers are looking into the anti-bacterial efficacy of different surface-coatings such as metals, polymers, nanoparticle texturing, and composites of each. The method through which bacteria adhere and/or aggregate is different across each surface-coating. While each have shown significance in the reduction of biofilm production in vitro, researchers have yet to perform effective in vivo experiments to confirm durability, adhesion specificity, cytotoxicity, and overall efficacy. It has been supposed that multifaceted “smart” surface-coatings are optimal for inhibiting biofilm production. However, there are still many complications inherent in both the smart-coating’s structure and chemistry that renders it unfeasible as a long-term solution.