What is meant by biofilm?
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.
What is biofilm of Pseudomonas aeruginosa?
Pseudomonas aeruginosa is an opportunistic human pathogen causing devastating acute and chronic infections in individuals with compromised immune systems. Its highly notorious persistence in clinical settings is attributed to its ability to form antibiotic-resistant biofilms.
What are the virulence factors of Pseudomonas aeruginosa?
In addition to biofilm formation, the principal virulence factors of P. aeruginosa are elastase, phospholipase C, protease A, exotoxins and cytotoxins, flagella and pili, pigment production, and QS regulatory system proteins, which regulate both virulence factor transcription and biofilm formation [25].
Is biofilm formation a virulence factor?
Biofilm virulence factors underlie chronic infection. Bacteria often employ opposing molecular mechanisms to establish acute and chronic infections, thus requiring different strategies for treatment of acute and chronic (biofilm) infections.
What are the three Pseudomonas infection stages?
Pseudomonas species are both invasive and toxigenic. The 3 stages, according to Pollack (2000), are (1) bacterial attachment and colonization, (2) local infection, and (3) bloodstream dissemination and systemic disease.
What type of microbe is Pseudomonas aeruginosa?
P. aeruginosa is a heterotrophic, motile, Gram-negative rod-shaped bacterium about 1–5 µm long and 0.5–1.0 µm wide. It is a facultative aerobe that grows via aerobic respiration and anaerobic respiration with nitrate as the terminal electron acceptor.
Does E coli make a biofilm?
Although most laboratory E. coli K-12 strains are poor biofilm formers, the introduction, either artificially or naturally, in mixed E. coli communities of a conjugative plasmid in these strains induces formation of a thick mature biofilm (Ghigo 2001; Reisner et al.
Why is it called Pseudomonas?
Pseudomonas [soo′′do-mo′nəs] From the Greek pseudo (“false”) + monas (“unit”). In 1894, German botanist Walter Migula coined the term Pseudomonas for a genus he described as, “Cells with polar organs of motility.
What disease is caused by Pseudomonas?
Pseudomonas aeruginosa causes urinary tract infections, respiratory system infections, dermatitis, soft tissue infections, bacteremia, bone and joint infections, gastrointestinal infections and a variety of systemic infections, particularly in patients with severe burns and in cancer and AIDS patients who are …
What is unique about Pseudomonas?
Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen of humans that provokes acute and chronic infections. Due to its resistance to a majority of clinically employed antibiotics, P. aeruginosa is considered one of the most concerning infectious agents frequently associated with nosocomial infections.
Is biofilm a virulence factor?
Biofilm is a crucial virulence factor involved in multitude of severe chronic bacterial infections and accounts for over 65% of all infections [3].
How does biofilm provide virulence?
What does integrity mean?
One may speak of the integrity of a wilderness region or an ecosystem, a computerized database, a defense system, a work of art, and so on. When it is applied to objects, integrity refers to the wholeness, intactness or purity of a thing—meanings that are sometimes carried over when it is applied to people.
What is inimical to the pursuit of integrity?
There are other perhaps more straightforward ways in which social and cultural structures may be inimical to the pursuit of integrity. The ideology of love, for instance, may undermine the integrity of lovers, as it may undermine the possibility of genuine and realistic love.
What is ‘objective integrity’?
Elizabeth Ashford argues for a virtue she calls ‘objective integrity’. Objective integrity requires that agents have a sure grasp of their real moral obligations (Ashford 2000, 246). A person of integrity cannot, therefore, be morally mistaken.
What can a person of integrity not do?
It prohibits attributing integrity to, for example, those who advocate genocide, or deny the moral standing of people on, for example, sex-based or racial grounds. There are things which a person of integrity cannot do.