The protein sequence of mcr-1 showed its similarity to the polymyxin-producing bacterium, Paenibacillus spp., which showed the possibility of gene transfer occurring. The mcr-1 gene enables protection from polymyxin. The mechanism that the authors proposed on how the mcr-1 gene confers colistin resistance is that mcr-1 causes a modification in lipid A, present in the lipopolysaccharides of most bacteria, which leads to lessened polymyxin affinity. The lipid A has phosphoethanolamine added to it, which in turn, inhibits the bacteria from any attachment. Q3E: What is the origin of the mcr-1 gene, and what evidence do the authors use to support this
The Bile Esculin agar test has its medium as selective and differential. Black medium shows a positive result for esculin hydrolysis. In the agar, Gram-positive cannot grow in the presence of bile while certain Gram-negative bacteria can hydrolyze esculin with bile present. MR-VP broth contains glucose and peptone. The enteric bacteria will oxidize glucose for ATP, but there are different fermentative pathways that allow glucose to be fermented.
Remove excess water from the surface of the gram stained glass slide and observed under 1000X oil immersion microscope. Gram-staining have performed for Staphylococcus aureus (control); Enterococcus faecalis (control); Nostril microflora in NA, MSA, and PYCa. Gram-staining provides results of the bacteria morphology, type of gram-stain. Catalase test was also done prior to gram-staining. MicrobactTM Biochemical Identification Kit was used for identifying gram-negative aerobic and facultatively anaerobic bacteria.
Paragraph 1 The objective of the experiment is to test; how will water temperature affect the rate of reaction of an alka-seltzer tablet? The dependent variable of the experiment is the dissolving time. When an alka-seltzer tablet starts to fizz it begins to dissolve, due to the citric acid and sodium bicarbonate the tablet contains (Clark, “Why does Alka-Seltzer fizz?). When the tablet is in solid form, the two ingredients are not yet mixed together, but by dropping the tablet in water, a chemical reaction is catalyzed between them, creating a fizzing sensation (Clark, “Why does Alka-Seltzer fizz?). When the sodium bicarbonate is placed in water, it begins to split apart and form bicarbonate and sodium ions (Science Buddies, Carbonation Countdown:
The second method is agar slope culture where Escherichia coli are grown on a slant agar in a test tube. Escherichia coli are transferred into the medium through an inoculating loop and are later slide from the bottom to the top forming a straight line. The bacteria appear to have effused as it spreads outwards. This shows that Escherichia coli are not motile as it only spread out from the straight line. The third method is stab culture.
The Benedict’s test is useful for reducing sugars. Reducing sugars are a carbohydrate that can either be straight chains with an aldehyde group at the end or as ring forms with a ketone group (Hill, 1982). Monosaccharides and most disaccharides will reduce copper (II) sulfate. The Benedict’s solution contains cupric ions and the aldehyde groups at the end of the sugars will reduce the cupric ions to cuprous ions (Cu+). There will be a precipitate of copper (I) oxide when the cuprous ions combine with oxygen (Hill,
1998) of the parasitic cells. The quinine group of ubiquone gets reduced to the quinol and helps in transferring the electron through an oxidation reduction cycle (Tielens A G M and Hellemond J J V 1998; Kroger A. and Gwith M K 1973). Atovaquone too has a quinine group and thus, it can mimic ubiquone and binds selectively to the Q0 site of parasitic mitochondria thereby block the parasitic mitochondrial respiration (Ridley R G 2002). In the present study, we report binding characteristics of trans and cis-isomers of atovaquone with cytochrome bc1 of yeast using docking technique in order to address the basic question, why trans isomer of atovaquone has much higher drug potency than that of its cis isomer? Recently, Hunte et al reported ( Hunte et al.
In the example of Listeriosis the bacteria is able to avoid the destruction of itself in the phagocytosis process. It is able to escape through the membrane of the phagosome and seep out to the cytoplasm. The bacterium makes pores in the host’s membrane. The bacteria must break down the phagasome membrane to gain access to the host cells cytoplasm. In the phagosome is a gamma interferon which the bacteria makes use of which counteracts the activities of other enzymes.
It is also known as the klebs –Laffer found in temperature zones but also found in other parts of the world. Diphtheria is an infection caused by this bacteria, is transmitted from one person to another usually through respinary droplet, like from coughing or sneezing. CONCLUSION Commercial probiotics contain viable cultures, they are essential to maintain and modify the structures and functions of the intestinal epithelium, and to fight pathogenic bacteria. Diary and fermented products mostly contain probiotics. Probiotics help in reducing some diseases while maintaining others.
Entry of S. flexneri at the basolateral surface is dependent on the bacteria’s ability to colonize the intestinal epithelium by the exploitation of epithelial-cell functions, and circumvention of the host immune response (Ashida, et al., 2009). Primarily, this is accomplished through the action of invasion plasmid antigens B and C (ipa B and ipaC). IpaC functions to reorganize cellular cytoskeletal elements leading to membrane ruffling upon contact with the epithelial cell. Acting with ipaB, it forms a channel through which T3SS- secreted effector proteins are translocated into the epithelial cell (Blocker, et al., 2001). The reason for the preferential entry of S. flexneri through the basolateral membrane remains unknown (Jennison & Verma,