Mini essays

Question 1

Intro for anti virulence, quorum quenching?

Answer 1

Quorum-sensing is the control of gene expression with regard to fluctuations in cell-population density, essential in bacterial infection and disease (Miller and Bassler, 2001)

Question 2

Part 1 of paragraph 1 (quorum quenching)?

Answer 2

Quorum-sensing is primarily regulated via small signal molecules known as acylated homoserine lactones (AHLs). AHL’s release, transmission, and detection between bacterium, results in the stimulation of gene expression, resulting in the control of virulence factors and biofilm formation (Rasko and Sperandio, 2010).

Interfering agents may act as agonists or inhibitors of AHLs, such as synthetic compounds, , enzymes and antibodies.

These formations have the potential to prevent the signal molecules carrying out their function, and therefore inhibit the ability of the bacteria to infect and cause disease. (Rasko and Sperandio, 2010

Question 3

Part of quorum quenching main paragraph 1?

Answer 3

quorum quenching is a procedure in which AHL-degradation enzymes isolated from eukaryotes and bacteria, disable AHL molecules (Dong and Zhang, 2005)

In a study conducted by Lin et al. (2003), an AHL signalinactivating bacterium called Ralstonia sp., was obtained from a mixed-species biofilm. The gene which encodes for the AHL inactivation was cloned, and the protein produced was shown to be significantly similar to aculeacin A acylase from Actinoplanes. The gene was expressed in Escherichia coli and successfully inactivated the three AHLs tested.

Question 4

Conclusion for paragraph 1?

Answer 4

Hence it has been shown that quorum quenching is an effective method in anti virulence, give a reason why it might not be a valid study as well, and who it affects (businesses)

Question 5

Introduction for biofilms paragraph 2?

Answer 5

Biofilms can be defined as communities of microorganisms attached to a surface. Undergo transition from being planktonic free swimming organismsto cells that are part of a complex, surface-attached community.

have identified genes and regulatory circuits important for initial cell-surface interactions, biofilm maturation, and the return of biofilm microorganisms to a planktonic mode of growth. (both O’Toole G, 2000)

public health problems such as outbreaks of foodborne pathogens, difficult to eradicate due to their resistant phenotype (Simões M, 2010)

Question 6

Main paragraph 2, biofilms?

Answer 6

. pre-conditioning of the adhesion surface either by macromolecules present in the bulk liquid or intentionally coated on the surface
; 2. Transport of planktonic cells from the bulk liquid to the surface;
3. Adsorption of cells at the surface;
4. Desorption of reversibly adsorbed cells;
5. Irreversible adsorption of bacterial cells at a surface;
6. Production of cell–cell signalling molecules;
7. Transport of substrates to and within the biofilm;
8. Substrate metabolism by the biofilm-bound cells and transport of products out of the biofilm. These processes are accompanied by cell growth, replication, and EPS production;
(breyers, 2004)

Question 7

Main paragraph part 2 about biofilms?

Answer 7

Staphylococcus aureus is a major human pathogen that produces diverse virulence factors, such as α-toxin, which is hemolytic.

Staphylococcus aurus biofilm formation aids it in drug resistance

(Lee K, 2014), showed that cis-nerolidol at 0.01 % markedly inhibited S. aureus biofilm formation.

three essential oils and cis-nerolidol at below 0.005 % almost abolished the hemolytic activity of S. aureus.

down-regulated the expressions of the α-toxin gene (hla), the nuclease genes, and the regulatory genes.

Concluding in provision of these factors can if yielding correctly could be essential as an anti virulence therapy against staphylococcus aurus