Gram stain: Color ________ Gram reaction ________ Cell Morphology ________ Endospore stain: Color ________ Endospores present: Yes ________ No ________ Acid Fast stain: Color ________ Acid fast cells: Yes ________ No ________ Complete the table and highlight ALL that are consistent with your unknown. If none are, provide a possible explanation. Gram reaction Cell morphology Endospores? Acid fast? Enterococcus faecalis + Cocci - No Staphylococcus aureus + Cocci - No Mycobacterium smegmatis + Bacillus - Yes Escherichia coli - Bacillus - No Bacillus subtilis + Bacillus * No Pseudomonas aeruginosa - Bacillus - No Clostridium sporogenes + Bacillus * No Micrococcus luteus + Cocci - No Corynebacterium xerosis + Bacilli - No Indicate whether the results are positive or negative and the name of the dye resulting in the pink color for each of the following Positive or negative Dye Pink color after Gram stain Neg. Safranin 0.25% Pink color after endospore stain Neg. Safranin 0.25% Pink color after acid fast stain Positive Carbolfuchsin Bacillus subtilis is a Gram positive rod that produces endospores and is not acid fast. What color will it be after each of the staining procedures? What dye is responsible for the color? COLOR Dye Gram stain Purple Crystal Violet Endospore stain Green Malachite Green Acid fast stain Blue Methylene Blue
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Step 1: Based on the information provided, the unknown bacterium is a Gram-negative rod-shaped bacterium. Show more…
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Please fill each box of the table below (0.5 point for each box). For the steps of the Gram Stain procedure, be sure to list the stain being applied and the time or number of drops used; you may omit the water rinses between each step. For the color of the microorganism, state the color it will be after that step and give an explanation as to why, being sure to mention the charges of the stain and the cell wall composition. Three answers have been completed for you. Steps of Gram Stain procedure Color of Gram positive cells and explanation Color of Gram negative cells and explanation Bacteria are purple, since the positively charged (cationic) dye crystal violet is attracted to the negatively charged thick layer of peptidoglycan in the cell wall. Add 2-3 drops of Gram's alcohol. Bacteria are pink/red, since the newly exposed thin layer of peptidoglycan can take up the red dye safranin
Supreeta N.
1. If you accidentally used an acidic dye instead of a basic dye during the simple stain, what result would you expect? 2. Find three examples of Gram-negative rod bacteria and the disease they can cause when infecting the human body. For example, Salmonella typhi is a Gram-negative rod that causes Typhoid. 3. Why is the negative stain less damaging to cell shape and size than a simple stain? 4. Why must the slide be placed over a steaming beaker during the endospore stain? 5. Why could endospore-forming bacteria be used as a bioterrorist agent? 6. Summarize the acid-fast stain in the following table: Step Reagent used Color of Mycobacterium Color of non-mycobacterium Primary dye Decolorizer Counterstain
Adi S.
The Gram-negative bacterium Yersinia pestis, the causative agent of the plague, is extremely virulent. Upon infection, $Y$. pestis injects a set of effector proteins into macrophages that suppresses their phagocytic behavior and also interferes with their innate immune responses. One of the effector proteins, YopJ, acetylates serines and threonines on various MAP kinases, including the MAP kinase kinase kinase TAK1, which controls a key signaling step in the innate immune response pathway. To determine how YopJ interferes with TAK1, you transfect human cells with active YopJ (YopJ $^{\mathrm{WT}}$ ) or inactive YopJ (Yop] $^{\mathrm{CA}}$ ) and with FLAG-tagged active TAKI (TAK1WT) or inactive $TAKI (TAK1$ $^{K 63 W}$ ), and assay for total TAKI and for phosphorylated TAK1, using antibodies against the FLAG tag or against phosphorylated TAK1 (Figure $Q 23-1$ ). How does YopJ block the TAK1 signaling pathway? How do you suppose the serine/threonine acetylase activity of YopJ might interfere with TAK1 activation?
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