Dwayne Hill.
BC34M
November 30, 2007
Lab Partner: Sasha-Kaye Graham
Experiment 6 : Lectin Agglutination
Aim:
To study the agglutination pattern of different strains of Psuedomonas aeruginosa to different sialic acid-binding lectins.
Absract:
The cell membrane of two strains of Psuedomonas aeruginosa, P22 and P201 were treated the sialic acid lectins SNA I, WGA, MAL and HAA to confirm the presence of sialic acid carbohydrates in the cell surface membranes of these strains. This was done by using two sets of samples-one treated with trypsin and the other without. The sample treated with trypsin showed agglutination for all lectins while the untreated sample showed little to no agglutination. A control was also used with the cells
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aeruginosa.
P.aeruginosa
Control
SNA
WGA
MAL
HAA
P22 (treated)
0
+++
+++
++
+++
P201 (treated)
0
+++
++
+
+++
P22 (untreated)
0
0
0
0
++
P201 (untreated)
0
0
0
0
0
0, no agglutination
+, weak agglutination
++, moderate agglutination
+++, strong agglutination
Questions:
1.It is important to study sialic acid binding lectins because their glyco-conjugates on the cell membrane of microorganisms are usually associated with virulence factors that cause disease eg. Streptococcus suis which has a high sialic acid content on its cell membrane causes infections in pigs and humans resulting in cases of meningitis and endocartis. Sialic acid is also associated with P. aeruginosa and the virulence it normally induces. Other lectins that are also of importance in microbiology and/or cell biology are mannose binding lectins which are also associated with virulence.
2.The agglutination is based on binding of the sialic acid to the cell membrane. To confirm that sialic acid carbohyrates are responsible for the binding the cells can be stripped of sialic acid and the experiment repeated.
The cells are treated with sialidase from C. Perfringens to remove sialic acid carbohydrates from the cell surface membrane.
Cell are given a 6 hour growth period
Cells are then centrifuged and re-suspended in sialidase and buffer and incubated to remove any sialic acid carbohydrates.
Cells are then washed in PBS
5. Heat treatment was used to denature the sucrase that was added to the control test tube. In the experimental test tube, alkaline
Staphylococcus, Enterococcus and Streptococcus is considered as a leading cause of many diseases. They are considered different due to their morphology. The Staphylococci and Streptococci acquires a round, spherical cell shape. On the other hand, the arrangement of cells is considered different for both the organisms. For instance, Staphylococcus aureus is a gram-positive, cluster-forming cocci and a nonsporeforming facultative anaerobe which is found in grape like structures. Enterococcus is also gram-positive cocci with short chains and are considered to be facultative anaerobes. They can grow at a temperature range of 10-45 degrees Celsius. Enterococcus is acknowledged as the leading cause of the nosocomial infections. The golden
The analysis of the results by single type of mild stress (first analysis) as well as the analysis of the interactions (second analysis) indicates that the exposure to the OCC did not have a negative effect on the viability of Leuconostoc mesenteroides. In all the analysis performed by single type of mild stress (fist analysis) the same pattern was found; there were no significant differences between the negative and positive controls, low and medium levels of stress-agent within a given type of mild stress except for the highest levels of stress-agents which were significantly detrimental. In acid mild stress the survivability of Leuconostoc mesenteroides ranged from 103-63% the highest being the positive control and the lowest being exposure to pH 4.0 (Figure 4.1). Figure 4.2 shows that with the heat mild treatment no significant differences were found among both controls and all levels of mild heat stress (P > 0.05). The survivability ranged from 105- 100% (Figure 4.2). With ethanol, the survivability of Leuconostoc mesenteroides in the OCC was only different when exposed to 15% ethanol (v/v) (P < 0.05). The highest viability was obtained with the positive control which was 106% and the lowest with the 15% ethanol (v/v) with was 62%. (Figure 4.3). With the prior exposure to the oxidative stress, the viability in the OCC raged from 106-80% the highest being the positive control and the lowest being the 7.5 mM concentration of hydrogen peroxide which
The sample of microorganisms in the air were tested with two different types of plates, Sabouraud’s plate and agar plate. Both the Sabouraud’s plate and nutrient agar plate were exposed to the same matter, the air , however, two plates showed different results of bacteria and mold. The Sabouraud’s plate contained 120 mold, but no bacteria, while the nutrient agar plate contained 5 mold, and 92 bacteria. The number of fungal organisms found on the Sabouraud’s plate was way more than the nutrient agar plate. The differences of the colony count is because of the environment of the two plates. The Sabouraud’s plate is acidic with the pH of 4, while the nutrient agar plate has a neutral pH of 7. Also, the Sabouraud’s plate has more carbohydrates and sugar compare to the nutrient agar plate. Accordingly, the environment of the Sabouraud’s plate is more suitable for the fungal organisms to grow than that of the nutrient agar plate. Also, the sample of hard cough contained the presence of the microorganisms. On the blood agar plate, there was partial hemolysis alpha and mold. The partial hemolysis alpha was small with yellow halo around, and mold was big, round, and fuzzy. There was no presence of bacteria that indicated a disease because there was no bacteria with golden yellow. Since the mouth is one of the suitable place where microorganisms can grow, kissing or sharing a
Phosphate-Buffered Saline (PBS) was used to clean the excess media in the cell and to maintain the osmolarity of the cells. In the cell and tissue culture, PBS was needed to remove the serum of media for trypsin to detach the cells from the flask . The salt ions in the PBS was isotonic to the cell because of equal amount of salt ions inside the cells. The cell will burst if the solution contain a few of salt ion and would be shrink if too much contain of salt ions. Therefore, the amount of salt ions and osmolarity in PBS must be correct to keep the cells in an isotonic state.
Pseudomonas aeruginosa produces a pigment called pyocyanin. The pigment is toxic to aerobic and denitrifying bacteria, while it is harmless to fermentative bacteria. The bacteria that cannot ferment are particularly susceptible to attack by pyocyanin.it is absolutely ineffective against p.aeruginosa and other pseudomonas species. Gram positive bacteria are easily killed by it than gram negative bacteria. Glucose is aptly suited for fermentation. When glucose is added to medium, facultative anaerobes can harness it for producing their energy source. Since the activity of pyocyanin toxin requires either robust active aerobic or anaerobic respiration, the toxin cannot inhibit the facultative anaerobes efficiently(Baron and Rowe 1981) when preparing selective media for pseudomonas aeruginosa, if glucose is added, it can harbour facultative anaerobes and anaerobes.
It specifically catalyzing hydrolysis 1,4-beta-linkage between N-acetylmuramic acid and N-acetyl-D-glucosamine which are a very sturdy bond in the bacterial cell. This is where the lysozyme is targeted. In the mucous membrane, there is antimicrobial compounds such as lysozyme and secretory antibodies (IgA). Lysozyme can kill the bacteria but it less effective against the infection. Present of the lysozyme inhibit or kill the bacteria before they can colonized either in the mouth, eye or in other mucous secretion. Throughout this experiment, the lysozyme activity was determine using agarose lysoplate method. Using the sample collected the experiment was conducted within several days to see the clear zone, but the result obtained did not showed any clear zone even after added the coomassie brilliant blue stain. This may due to the plate bacteria inside the plate was dead when the sample was loadedin the well. There is possibility that bacteria was dead because the present of the bacteria in the plate cannot be seen and mybe the environment or the condition in the plate was not favourable for the bacteria to stay
In this experiment we wanted to observe the effects that different types of solutions have on living cells. The three types of solutions that we were looking for was: isotonic solution………
Following experimentation approval and funding, the two main key dates are the initial experimental setup and the completion of experimentation, and along with it, the evaluation of results. Prior to the initial setup, materials must be obtained from online chemical suppliers, a process that can take many weeks. After all the materials are obtained, and proper training in the local laboratory environment is conducted, the cell plates will be set up and exposed to the candidate compounds. Over the course of the experiment, progress will be documented both qualitatively and quantitatively; TRAP assays and flow cytometry will be utilized to measure cell response, and phase contrast microscopy will be used to document cell plate transformations. Finally, following the end of experimentation results will be evaluated, thus concluding the
This lab demonstrated the active process of endocytosis, which is the movement of a substance into the cell in the form of a vesicle, a small, round sac. This allows the cell to bring extracellular solid material or particles into the cell. In phagocytosis, the particle outside of the cell binds to a receptor on the cell’s membrane which causes the membrane to form extensions called pseudopods. These extensions form a circle around the particle and pull it inward into the cell. Once inside, the vesicle that has formed, called a phagosome, will unite with a lysosome, an organelle that contains enzymes that will break down or digest the
First, the α-2,6 sialylation can block the apoptosis mechanism40-41. Apoptosis is the mechanism of programmed cell death of multicellular organisms. The apoptosis process is induced by binding of cell galectins42-43. Galectins are a type of lectin and lectins are a class of proteins which can bind to specific proteins, via interacting with specific glycans. These galectins bind galactose of cell surface glycans to initiate the killing mechanism. It has been reported that α-2,6 sialyation significantly blocks galectin binding and inhibit apoptosis and this leads to the undesirable growth of cancer cells44-45. The α-2,6 sialyation also significantly blocks apoptosis pathways which use FAS46 and TNFR147 cell receptors.
The current study also has investigated the inhibitory effect of lactose, sucrose and pronase in the coaggregation. Sato et al (1984) demonstrated that coaggregation between actinomycetes and streptococci occurred via lectin-like substances (i.e. substances similar or identical to proteins that bind sugars) on the surface of actinomycetes with carbohydrate(s) on the surface of streptococci.47 Pre-treating Staphylococcus spp. with lactose and sucrose inhibited the coaggregation which indicates the involvement of Staphylococci lectins in the coaggregation which again resembles the finding of the previous study. The ocular isolates of S. aureus and S. epidermidis inhibited the coaggregation with P. aeruginosa and S. marcescens when pre-treated with lactose or sucrose.41 However, the selected inhibitory sugars were unable to stop coaggregation with Micrococcus spp. and Acinetobacter spp. which need
The importance of doing this investigation was necessary as this microorganism, Salmonella is a common bacteria encountered in daily life. Salmonella is a bacterium that is found in a wide variety of animals and mammals (Weese and Fulford, 2011). Gram negative bacteria exhibit appendages on outer surfaces known as pili (Lo et al., 2014). The pili is also named fimbriae, these are chains of protein that form filaments that extend from the outer surface of bacterial cells enabling them to adhere to any host target cell (Proft and Baker, 2009; Kang and Baker, 2012). This makes the pili of clinical importance when assessing clinical manifestation; particularly in pathogenic organisms, when developing drugs such as vaccines (Kang and Baker, 2012). Currently, the use of pili in vaccine development is widespread in research (Wizeman et al, 1999). This suggests that the pilus is the basic structural subunit in all bacterial cells.
To study the role of Lec A and Gb3 interaction, model system was used with Gb3 containing GUv's (giant unilamellar vesicles) to shows the effect of Lec A and Gb3 interaction on curvature of lipid bilayer without role of actin. P.aeruginosa PA01 WT Strain was incubated with GUVs and on other side GUVs was incubated with Lec A mutant strain as shown in Fig1, no difference was notice in growth rates. PAOI WT Strain incubated with GUVs shows at meeting point of Lec A and Gb3 curved GUV membrane along with cluster of lipids which leads to the engulfment of bacteria. Out of 82 ± 6.5%, 45 ± 6.4% was engulfed and in other strain of Lec A mutant only 1 out of 102 showed membrane engulfed bacterium. Role of Gb3 was clearly stated by lowering of Gb3 which showed decrease in engulfed bacterium (Eierhoff et al., 2014).
The lab notebook [Leady, Brenda. Fundamentals of Life Science II Laboratory Manual: BIOL 2180. Macmillan Learning Curriculum Solutions, 2018.] was used. There were no changes in the protocol throughout this experiment.