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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BIOLOGY
- . 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_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_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_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_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_forwardPenicillin 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_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_forwardThere were two patients without COVID-19 vaccines that came into the hospital with COVID-19 symptoms. A quick onsite point-of-care COVID-19 antibody test was done to see if they have a recent infection that could be active (as in the patient should not be around others because they could have the ability to spread the virius. The doctor found out that patient A's serum contains anti-COVID-19 IgG but not IgM and patient B's serum contains anti-COVID-19 IgM but not IgG. Which patient(s) have been infected with COVID-19? Of the patient(s) infected, is the infection(s) more likely to be in its early or later stage?arrow_forwardPlease help explain this figurearrow_forward
- A 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_forwardDuring the development process of a vaccine for the newly discovered Sars-COV-2 (COVID- 19) virus, pharmaceutical companies developed two potential vaccine candidates, BNT162b2 and Ad26.COV2. Some researchers postulated that BNT162b2 will be more ef- fective than Ad26.COV2 because only BNT162b2 directly targets the protein-manufactur- ing mechanisms in the cell. To test this claim, researchers proposed an experiment in which data will be collected about the efficacy of the two vaccine candidates. In the proposed study, two groups of mice will be randomly assigned one of the vaccine candidates and then infected with the virus. Data about the severity of symptoms in each group will then be collected. Which of the following describes a potential method for measuring the dependent variable in this experimental design? A B с D measure the amount of virus administered to each group measure the time between vaccine administration and virus infection in each group measure the amount of vaccine…arrow_forwardWhy is antibiotic resistance a problem and how can antibiotic resistance be prevented? (List the 7 methods for preventing resistance.)arrow_forward