This is Biochemistry Please I need help with Q1a and B. thanks Discussion HMW 3

Question

This is Biochemistry Please I need help with Q1a and B. thanks

Discussion HMW 3 Q1. Infection due to a rare, virulent strain of group A streptococcus has appeared relatively recently. In approximately 25 to 50% of these cases (reported in Great Britain and the United States), infection resulted in necrotizing fascitis, a rapidly spreading destruction of flesh, often accompanied by hypotension (low blood pressure), organ failure, and toxic shock. If antibiotic treatment is not initiated within 3 days of exposure to the bacterium, gangrene and death may result. Similar cases were reported in the 1920s. However, these earlier cases had a significantly lower fatality rate, although antibiotics were not then available. (Physicians reported treating affected areas by washing with acidic solutions.) Group A streptococci are converted into the pathogenic form by becoming infected with a certain virus. This virus's genome contains a gene that codes for a tissue-destroying toxin. a. Can you describe in general terms how a viral infection might cause a permanent b. Considering the apparent difference in virulence between the bacterium in the change in the pathogenicity of a group A streptococcus bacterium? 1920s and the present, propose a method for determining whether the same strain of group A streptococcus is responsible for both sets of cases? Preserved specimens of infected tissue from these early cases are available.

Explanation / Answer

Answer of A:

The Virus which infect the Group A Streptococcus bacterium is a type of Bacteriophage which contains the lysogenic cycle. The bacteriophage is a virus that infects and replicates within Bacteria. They carry out a specific set of reactions in order to make more of themselves. First, the phage must be able to recognize a bacterium that it can multiply in by binding to the bacterial cell surface. Next, the phage injected their genome, capsulated, into the bacterial cytoplasm. Then the Bacteriophage's viral genome become replicated by lysogenic cycle, where the viral DNA is inserted into the Streptococcus's DNA and reproduces as the bacteria replicate. The Virus remains in that state for numerous replications of the  Streptococcus's DNA until it excises itself from the bacteria and released after packaged. At the time of excision, extra genes carried by the virus get expressed into the bacteria. these genes can change the properties of the bacteria. this process is known as phage conversion. In this case, the tissue-destroying toxin gene is left out by the virus which is carried out by Group A  Streptococcus's DNA. The Bacteria converted into a pathogen.

Answer of B:

The experiment can be designed by treating both bacterial genes ( 1920's and present) by the same type of restriction enzymes and see the result by Agarose Gel Electrophoresis. If the strains have remained same then the fragments shown in the Gel will be of same molecular weight. Restriction enzymes will cut DNA in specific restriction sites which are unique. If both of the strains have that unique sites in the same position, they will get cut into the same.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.