Wednesday, December 11, 2019
Microbiology Steps in Adenoviral DNA
Question: What is latency, and which viruses have the potential for latency and why? Why are vaccines for influenza not always effective? Define cytopathic effect. How do viruses differ from bacteria? List the eight human herpesviruses, describe their similarities, and how they affect humans. Describe each of the hepatitis viruses, include nucleic acid type, transmission, and effect on humans. Answer: Describe how viruses multiply. Viruses do not have enzymes for protein or energy production. A virus multiplies by invading host cells and directing the host machinery to produce viral enzymes, proteins and nucleic acids. Its uses host cells ATP storage to power through the processes (IbriimoviÃâÃ¢â¬ ¡ et al.,2013). What is latency, and which viruses have the potential for latency and why? Latency is the capacity of some viruses to lie dormant in a host cell for a prolonged period (Sin Dittmer, 2013). Several eukaryotic viruses including herpesviridae and retroviridae show latency. Latency is a part of certain virus life cycle. After initial infection, the viral particles stop proliferating and any reaction with the host cell stops. Why are vaccines for influenza not always effective? The effectiveness of influenza vaccines depend upon age, risk group and health of the patient. The year and the time also influence the effectiveness of flu vaccine. Define cytopathic effect. When viral infections cause structural changes in host cells, the resulting effect is called cytopathic effect. The virus lyses the host cell and treats it as its own reproductive unit. How do viruses differ from bacteria? Bacteria have ribosome while viruses do not, bacteria have cell wall but viruses do not have cell wall, bacteria reproduce by fission while viruses reproduce by invading host cells. These are the few differenced between bacteria and viruses. List the eight human herpes viruses; describe their similarities, and how they affect humans. The eight human herpes viruses are: HHV-1, HHV-2, HHV-3 or VZV, HHV-4, HHV-5, HHV-6A and 6B, HHV-7, HHV-8 HHV-1,2 and 3 are from the alpha subfamily. Whereas HHV-5,6A, 6B and HHV-7 are from the beta subfamily and HHV-4 as well as HHV-8 are from the gamma subfamily. HHV-1 and 2 cause oral and genital herpes, HHV-3 cause chickenpox and shingles, HHV-4 causes a number of infectious disease. The other viruses affect also cause infections. HHV-1: site of latency-neuron, transmission-sexual contact, effect-oral/genital herpes HHV-2: site of latency-neuron, transmission-sexual contact, effect- oral/genital herpes HHV-3: site of latency-neuron, transmission-respiratory and close contact, effect- chicken pox and shingles HHV-4: site of latency-B-cell, transmission- close contact, transfusion, tissue transplant and congenital, effect- infectious diseases HHV-5: site of latency-monocyte and lymphocyte, transmission- saliva, urine and breast milk, effect- infectious mononucleosis-like symptom HHV-6A and B: site of latency-T-cell, transmission-Respiratory and close contact, effect- sixth disease HHV-7: site of latency-T-cell, transmission- not decided, effect- roseola infantum HHV-8: site of latency-B-cell, transmission- close contact, effect- Kaposis Sarcoma, etc. Describe each of the hepatitis viruses, include nucleic acid type, transmission, and effect on humans. HEP A HEP B HEP C HEP D HEP E HEP F HEP G Nuclei Acid Type SSRNA DNA SSRNA Negative sense SSRNA SSRNA - SSRNA Transmission Faeco-oral route Blood bourne Blood bourne Faeco-oral route Faeco-oral - Faeco-oral Effect on Humans Fever, Jaundice, Altered LFT Fever, Hepatitis leading to fulmina failure More chronic hepatitis, fever, Jjaundice, altered LFT Fever, Altered LFT, Jaundice Fever, Altered LFT, Jaundice - Mild to no symtptoms References IbriimoviÃâÃ¢â¬ ¡, M., Lion, T., Klein, R. (2013). Combinatorial targeting of 2 different steps in adenoviral DNA replication by herpes simplex virus thymidine kinase and artificial microRNA expression for the inhibition of virus multiplication in the presence of ganciclovir.BMC biotechnology,13(1), 1. Sin, S. H., Dittmer, D. P. (2013). Viral latency locus augments B-cell response in vivo to induce chronic marginal zone enlargement, plasma cell hyperplasia, and lymphoma.Blood,121(15), 2952-2963.