Antimicrobial Biofilm

Biofilms play a crucial role in the persistence of lung infections in CF patients due to the protective extracellular matrix that is formed by the bacterial community (5). This barrier limits the penetration of antibiotics and results in varying nutrient gradients, allowing for a diverse range of bacteria (5). Bacteria inside this biofilm are able to sense the presence of other cells, and alter their properties accordingly to suit the environment. This is particularly interesting as the bacterial communities within a biofilm may compete with each other for dominance in the biofilm (6). Therefore, bacterial competition may impact the treatment and actions needed to treat biofilms in the lungs of CF patients

The bacterium is capable of producing biofilms that allow microorganisms to stick to solid surfaces forming an attachment, which is enclosed by a slime layer ("Staphylococcus epidermis"). Biofilms protect pathogens from being destroyed by disinfectants inside human bodies ("Staphylococcus epidermis"). In other words, biofilms aid pathogens in causing diseases by releasing microbial products ("Staphylococcus

The development of biofilms on medical devices has become an increasingly prevalent problem as biofilms are making the bacteria stronger and more resistant to treatment which then increases the potential for patient infection (Dolan 2001). As a result, by studying biofilm strength, it is possible to better understand what factors allow this biofilm formation and how it can be reduced to limit the risks of patient infection.

A biofilm is a layer consisting of various combinations of many different organisms, autotrophic and heterotrophic. They are dense, organized communities of cells, encased in a self-produced slime. The bacteria grow together in water like atmospheres, attaching to a solid surface, forming a small ecosystem. Biofilms are known as a micro-environment, a micro-habitat, or a slime matrix. They help decompose dead organisms and recycle carbon and nutrients.

Biological agents, coming in a variety of forms, have unique abilities amongst themselves and all categories of environmental health agents. Bacteria holds the ability to

Collecting and analyzing the growth of over the two different aspects of oral biofilms. Biofilms are one of the most common and abundant species in nature and have both beneficial and harmful effects on plants, animals, and humans. Reasons for studying biofilms range from medically to industrially and hit home to us in our very mouths. For this experiment we collected two types of environment that are nutrient rich for biofilms to grow in and then observed them over eight types of media selecting for different components. Our results

Both, Dr. Bassler and Dr. Dalino, explain how bacteria communicate and work together through quorum sensing. As Basler explained in her TED talk, bacterial cells make single producing proteins that attract other surrounding bacteria. They are able to receive these signals trough the signal receptor protein; this protein allows the bacteria to recognize when the cell density is high or low. If the cell density is high enough to perform the desired action, the group behavior turns on and they are able to work effectively as a way to reach their purpose. By working together, they are able to control pathogenicity and virulence; they continue to grow in their biofilms until they know they will be successful. Additionally, these single producing proteins are specific for intra-species communication meaning that the protein

Penicillin was discovered by accident in 1928 by Alexander Fleming. After leaving bacteria containing Petri dishes in a lab over a weekend they became contaminated with mould. Alexander Fleming realised that the bacteria calls around the mould were dying. It was through further testing that he realised the mould was creating a substance that destroyed bacteria, which he later called Penicillin.

This pathogen secretes an Mottola et al. demonstrated that staphylococcus aureus and other microorganisms growing on the biofilms are not as resistant when isolated (2016). When staphylococcus strains were grown separately and treated with distinct antimicrobial agents, their minimum inhibitory concentrations were lower than on biofilms. Pathogens growing on biofilms are able to resist 10 – 10,000 times the concentrations of antimicrobial drugs that would kill an isolated strain; those concentrations can also be lethal for human beings. Mottola et al.’s experiment also showed that the minimum biofilms inhibitory and eradication concentrations values of antibiotics acting against isolated MRSA were higher than the minimal inhibitory concentrations values. some antibiotics such as for isolated pathogens were about the same for most of the antimicrobial agents studied. Although some antimicrobial agents such as Clindamycin were able to inhibit biofilms, but could not eradicate them (2016). Thus, there might still be some risks of

The formation of hydrated EPS layer surrounding a microorganism will provide protection against desiccation and predation (Suresh Kumar et al., 2007). Furthermore, EPS plays a principal role in cell aggregates formation and initiation of flocculation as well as biofilms. The production of EPS not only involves in anchoring of biofilms to hydrophobic surfaces but also accumulation of recalcitrant PAHs by sorption to exopolymer (Johnsen et al., 2005). This properties are significant to in removal of water pollutant (Singh et al., 2006) and selective plugging in MEOR (Sen, 2008). As a key constituent in cell floc and biofilm formation, EPS helps to facilitate the mechanism of cell adhesion to surfaces and other organisms, as well as uptake of nutrients (Laspidou and Rittmann, 2002). The EPS matrix in biofilm displays as a medium for biochemical interaction among cells in microbial aggregates (Laspidou and Rittmann, 2002). Besides that, EPS can also function as emulsifier and surfactants that are

Bacterial urinary tract infections represent the most common type of nosocomial infections. Often, the ability of bacteria to both establish and maintain these infections are directly related to biofilm formation on indwelling devices or within the urinary tract itself (30). Enterococci (especially E. faecalis) are one of the main causative agents of urinary tract infection and Catheter-associated urinary tract infections (CAUTIs) besides gram-negative pathogens (31, 32). In these infections Biofilm provides a favorable milieu for microbial survival within the host as the organisms are shielded from the host immune response, as well as antibiotics and antimicrobial agents (33, 34). Several studies conducted to introduce main virulence genes of enterococci that are associated with biofilm formation in these bacteria (11, 13,-17), but virulence mechanism and related genes for biofilm formation are not well understood (35). In this study we investigated biofilm formation of clinical enterococci isolates isolated from Urinary tract infections. These strains were characterized for presence of adhesions and secretory virulence factors. Isolates had diverse presence of virulence from lack to highest amount of virulence genes. Several previous studies investigated relation of virulence genes and biofilm formation, especially presence of esp and gel. Enterococci esp has been implicated as a contributing factor in colonization and persistence of infection within the urinary tract

What is the purpose of microbes forming surface-attached communities? What benefits do such arrangements provide to the microbes?

Microbial synergy increases the net pathogenic effect and wound infections severity, which show a correlation between microflora of the gut, skin or oral cavity and pathogens infect wounds (Bowler et al., 2001). Staphylococcus aureus is a commensal gram-positive cocci that considered as a leading cause of wound infections and a potential cause of life-threating infections as sepsis, endocarditis, toxic-shock syndrome, osteomyelitis and pneumonia (Breathnach, 2013). It is an opportunistic pathogens possess many virulence factors, including formation of biofilm that resist host immunity (Foster et al., 2014). Methicillin-resistant S. aureus has a gene known as mecA responsible for resistance to methicillin which revealed high prevalence of infections lately

The bacterial cell-to-cell communication process is referred to as quorum sensing (QS). Pheromones that act as cell-to-cell communicators are also called autoinducers (AIs), as they function to stimulate their own synthesis (Williams, Winzer, Chan, & Camara, 2007). AIs are produced and are continually released by bacteria at relatively low levels. The production, detection, and response of bacterial populations are determined by the concentration of the AIs. As binary fission occurs and the bacterial population density increases, there is an increase in the relative concentration of AIs in the nearby environment. As receptors bind to the AI, a quorum sensing circuit is initiated, and bacteria collectively alter gene expression for processes that benefit from collaborative action, such as: bioluminescence, sporulation, competence, biofilm adherence and formation, antibiotic

Excessive and indiscriminate usage of antibiotics has led to the emergence of multiple drug resistant (MDR) bacterial strains. The need for alternative approaches to combat these MDR strains stem from the fact that 16 million people die annually due to infectious diseases caused by them (Bjarnsholt. et al., 2005 and Rasmussen. et al., 2005). It has been repeatedly observed that bacteria within these specialised structures are around 1000 times more resistant to antibiotics than their free-living counterparts (Martinez and Baquero, 2002). Bacterial behaviour within biofilms is regulated by a process named quorum sensing (QS), where bacteria release chemical signals and express virulence genes in a cell density dependent manner (Ganin et al.