Concept explainers
Use of multiple antibiotics is not a bad idea if ill of the bacteria are killed. In the case of sane persistent infections, this is an effective strategy. However, it does provide very strong selective pressure for rare genetic events that procure multiple resistances in a single bacterial species. For this reason, it is not a good idea for it be the normal practice The more bacteria that undergo this election for multiple resistance, the more likely a will arise. This is helped by patients not taking their entire course of antibiotic because bacteria may survive by chance and proliferate, with each generation providing the opportunity for new mutations. This is also complicated by the horizontal transfer of resistance via resistance plasmids, and by the existence of transposable genetic elements that can move genes from one piece of DMA to another.
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<LCPO> BIOLOGY
- From: "Towards a universal flu vaccine" Each year, the flu vaccine includes antigens from two strains of Influenza A and two strains of Influenza B. These antigens are from the head of the H spikes an area that sticks out from the virus and so, is very easy for human immune cells to detect. However, the problem with using the head of the H spike as an antigen is... O The H spike head mutates very rapidly, so quickly changes to forms not recognized by human immune cells. O The H spike head is exposed on the surface of the virus for only a short period of time. Viruses quickly pull the H spikes back inside the virus, shiclding them from human immune cells. O The H spike head is often too big for the human immune cells to attack. O The H spike head is often too small for the human immune cells to bind to.arrow_forwardFlow cytometry analysis was performed on the blood of an individual known to have been recently exposed to both rhinovirus (RV) and Mycobacterium tuberculosis (M.tb; an intracellular bacterial pathogen). Although an effective T cell response against RV was detected, a T cell response against M.tb was absent. Subsequently, genetic testing was performed, and the individual was found to possess two mutations. Below, indicate the MOST LIKELY mutations. A. T-bet; IL-12 B. CD28: IL-2Ra C. RORyT: IL-17 D. CD3: CD4arrow_forward. Susceptibility of the bacteria will be determined by observing for the production of plaques. Describe how these plaques are formed. Would the different strains/species of bacteria be susceptible to bacteriophage T2? Explain why b. How does a viral plaque compares to a bacterial colony? c. Which organism is identified by the use of bacitracin? What does the absence of bacterial growth around the bacitracin disc indicate?arrow_forward
- A researcher wants to compare the pathogenicity of a mutant pathogen relative to wild type in an animal model. The mutant is marked with the constitutive expression of a foc gene that turns colonies blue on X-gal agar. The input ratio of the experiment Dilue/white colonies) was 10:1. The output ratio of the infection experiment tant to d type was 1-100 a. What is the CI? Show your work. 1. Define the Cr and describe what it measures in your answer Which of these genotypes does better during infection, the mutant or the wild-type?arrow_forwardAs everyone is aware of, suspected COVID-19 patients are being diagnosed using the Nasopharyngeal Swab Test through Reverse-Transcriptase Polymerase Chain Reaction. Explain its principle; its advantages and disadvantages.arrow_forwardBased on your disc susceptibility results for E. coli R-, which ONE of the following is correct if considering treatment of an infection caused by this organism? Select one: A. All drugs evaluated could be considered for treatment in this case B. Zone sizes were too large so the results are inconclusive and should be repeated C. Ciprofloxacin is the most potent drug so this should be used preferentially over all others D. Nitrofurantoin and fosfomycin are the most potent so either drug should be used preferentially over all others E. High drug potency is associated with increased toxicity so the drug with the lowest potency should be considered preferentiallyarrow_forward
- Penicillin was first used in the 1940s to treat gonorrhea infections produced by the bacterium Neisseria gonorrhoeae. In 1984, according to the CDC, fewer than 1% of gonorrhea infections were caused by penicillin-resistant N. gonorrhoeae. By 1990, more than 10% of cases were penicillin resistant and a few years later the level of resistance was 95%. Explain the various ways this resistance could be spread among the cells. Could this resistance pass to other infectious bacteria from N. gonorrhoeae?arrow_forwardA plaque assay is an effective way to determine the concentration of lysogenic phage in a solution. A. True B. Falsearrow_forwardAntibiotic resistance can be transferred from one bacterial cell to another. Describe how this process can occur.arrow_forward
- min+ = confers resistance to minocycline cep+ = confers resistance to cephalexin van+ = confers resistance to vancomycin The following table shows the results of your experiments. Transformation of the recipient cells was conducted, using the DNA of the donor cells. You next selected for recipient cells that had undergone transformation by plating the transformed cells on media containing minocycline. This enabled you to select for min+ cells. The min+ cells were then replica plated onto media containing cephalexin or vancomycin in order to determine the antibiotic resistance phenotypes with respect to these other two antibiotics Questions a) Of the three potential orders of these genes, which orders are possible and which are impossible based on your knowledge of the relative distance? b) Finally, determine the correct order of the three genes. Please include a DIAGRAM to illustrate how you deduced the correct gene order, as well as an explanation of your reasoning.arrow_forwardA covid-19 vaccine is a biotechnology product intended to provide acquired immunity against coronavirus disease covid-19. As of december 2020, researchers are testing 59vaccines in clinical trials on humans and 16 have reached the final stages of testing. A covid vaccine developed by pfizer has been already approved for use in the uk and the first doses have been given to patients. vaccine typically require years of research and testing before reaching the clinic but in 2020, scientists embarked on a race to produce safe and effective coronavirus vaccine in record time. 1. companies developing vaccines,drugs and diagnostic for covid-19 for being forced to scale up manufacturing challenges to meet the enormous demand, what the manufacturing challenges to meet the covid-19 vaccine demand.arrow_forwardFrom: "Towards a universal flu vaccine" Each year, the flu vaccine includes antigens from two strains of Influenza A and two strains of Influenza B. These antigens are from the head of the H spikes - an area that sticks out from the virus and so, is very easy for human immune cells to detect. However, the problem with using the head of the H spike as an antigen is.. • The H spike head mutates very rapidly, so quickly changes to forms not recognized by human immune cells. O The H spike head is exposed on the surface of the virus for only a short period of time. Viruses quickly pull the H spikes back inside the virus, shielding them from human immune cells. O The H spike head is often too big for the human immune cells to attack. The H spike head is often too small for the human immune cells to bind to.arrow_forward