Mycology & Virology Lecture Transcripts PDF

MYCOLOGY & VIROLOGY LECTURE TRANS. filterable agent Tobacco Mosaic Virus as one of his most INTRODUCTION TO VIROLOGY renowned works. Virology...

MYCOLOGY & VIROLOGY LECTURE TRANS. filterable agent Tobacco Mosaic Virus as one of his most INTRODUCTION TO VIROLOGY renowned works. Virology is the branch of microbiology that focuses Louis Pasteur (1822) on the following aspects of viruses: ❖ invented vaccines against rabies ❖ their structure, even though viruses are not yet ❖ classification and evolution, discovered at that time. ❖ their historical impact to each other and other organisms, Adolf Mayer (1876) ❖ their ways to infect and exploit host ❖ proved that Tobacco Mosaic cells for reproduction, Disease is contagious. ❖ their interaction with host organism physiology and immunity, Friedrich Loeffler and Paul Frosch ❖ the diseases they cause, ❖ the techniques to isolate and culture (1898) them, genomics, clinical significance ❖ discovered the virus that causes of each and their use in research Foot and Mouth Disease. and therapy. Walter Reed (1899) ❖ discovered the virus that causes General Characteristics of Viruses Yellow Fever and found out that it 1. Viruses are infectious acellular agents is an arthropod vector. with nucleic acid bases surrounded by proteinaceous capsomeres that form the Thomas Milton Rivers (1926) coat called the "capsid", and some also ❖ described that viruses are obligate have capsules. parasites. 2. They are obligate intracellular parasites. 3. Very minute and can only be seen via Jonas Salk and Albert Bruce Sabin Electron Microscope. 4. Their genetic material could either be RNA (1950s ) or DNA. ❖ separately invented the vaccines 5. Viruses have little to no treatment or against poliomyelitis. medications and antiretroviral therapies are usually ineffective. Stanley Prusiner ( 1982) 6. Viral infection gives us a greater risk of ❖ is credited for the discovery of having cancers. prions. Why Viruses Challenges How We Define Luc Montagnier (2008) Life ❖ won the Nobel Peace Prize winner 1. They do not respire. for the discovery of HIV. 2. They do not display irritability. 3. They do not move. Virions: 4. They do not grow or develop. A virion is the complete, infective form of 5. They do not make their own energy. the virus outside the host cell. The structural unit of Viruses. Brief Historical Development of Virology Prions: Prions are misfolded proteins that Dmitry losifovich Ivanowsky ( characterize several fatal 1892) neurodegenerative diseases in humans ❖ is a Russian Botanist and is and many other animals. credited as the discoverer of viruses Proteinaceous infectious particles that are and the field of virology "Father of more prevalent in animals than in Virology ''. humans. Composed of single protein PrP 27-30. Martinus Beijerinck ( 1898) Examples of prion diseases include ❖ is a Dutch Microbiologist and is Creutzfeldt-Jakob Syndrome, Fatal also considered as one of the Familial Insomnia Gerstmann-Straussler founders of virology with the Syndrome, Bovine Spongiform Contagium vivum fluidum with the Encephalitis, Scrapie, Mad Cow Disease and Kuru. __________________________________________________________ LUCKY 7 1  Viral Disease Causative Viral Structure Cytopathic Virus Effect A. The capsid is the protein coat or shell enclosing the viral nucleic acid-base and is Cowdry Type Herpes HSV I and II made up of repeating subunits called A Body "Capsomers". They can either be Helical (most rigid and flexible), Icosahedral (rotational Cowdry Type Poliomyelitis Poliovirus B Body symmetry ) or Complex (neither of the two ). Koilocytes Genital Warts Human B. Genome is can either be made up of DNA or Papillomavirus RNA nucleic bases Negri Bodies Rabies Lyssa Virus Viral Culture Torres-Council Acute viral Yellow Fever Animal Inoculation man Bodies Encephalitis Virus - recommended for the culture of Tzanck Smear Chickenpox VZV Coxsackievirus. and Syncytia Embryonated Egg Viral Culture Downie Bodies Herpes HSV I and II - recommended for the culture of Guarnieri Cowpox Vaccinia Influenza viruses. Bodies Cell Culture - most commonly implied in a Paschen Smallpox Variola laboratory setting: Bodies Bollinger Fowlpox Avipoxvirus TYPES OF CELL CULTURE: Bodies Primary Culture - Monolayer of cells capable of minimal cell Warthin Measles Rubeola virus divisions. Finkeldey Cells - Suitable for one use. - Example: PMK cells Henderson Molluscum Molluscum Patterson contagiosum Finite Uses Bodies - Capable of limited cell divisions. - Good for 50 uses. - Example: Human Neonatal Lung cells Nature of the common Human Viruses Continuous Cell Culture DNA Viruses RNA Viruses - Viruses are inoculated into a constantly dividing cell medium. Parvoviridae Orthomyxoviridae - Good for indefinite cultures. Adenoviridae Paramyxoviridae - Example: HeLa cells, Hep2 cells, Vero, A549 Poxviridae Rhabdoviridae Polyomaviridae Hepeviridae Viral Cytopathic Effect 1. The characteristic and distinct visual Hepadnaviridae Coronaviridae changes in virally infected cells. Herpesviridae Bunyaviridae 2. The Cytopathic effects are based on the nature of the viruses. Arenaviridae 3. DNA viruses give off the Intranuclear viral cytopathic effect, whereas RNA Picornaviridae viruses give off the Intracytoplasmic viral Caliciviridae cytopathic effect. Reoviridae Togaviridae Flaviviridae Retroviridae Filoviridae __________________________________________________________ LUCKY 7 2 Virology Chapter II: DNA VIRUSES ❖ Clinical Findings: ★ Acute respiratory All DNA Viruses are dsDNA except disease among Parvoviridae military recruits All DNA Viruses are naked except for Hepadnaviridae, Herpesviridae, and Adenovirus 40-41 Poxviridae - Enteric Adenovirus All DNA Viruses have icosahedral symmetry except for Poxviridae ❖ Disease Caused: All DNA Viruses replicate in the nucleus ★ Gastroenteritis except for Poxviridae ❖ Family Poxviridae ❖ Family Parvoviridae - considered as the largest virus - considered as the smallest virus - The DNA virus that replicates - the only single stranded DNA outside the nucleus virus - the DNA virus that has Complex symmetry Parvovirus B19 - replicates in the immature Variola red blood cells - Viral disease that was ❖ Disease Caused: announced eradicated, yet ★ Erythema recently having infectiosum or reemergence ★ the 5th disease ❖ Disease Caused: ❖ Clinical Findings: ★ Smallpox ★ Transient Aplastic Crisis, ❖ Clinical Findings: ★ Pure Red Cell ★ Paschen Bodies are Aplasia, a distinct ★ Hydrops Fetalis histopathological cytopathic effect of ❖ Family Papillomaviridae smallpox Human Papillomavirus (HPV) - Infectious with HPV give Vaccinia higher risk of having - The viral component in the cervical cancer vaccines used against Smallpox because of its ❖ Disease Caused: ability to cross reacting ★ Common warts, ★ Genital Warts ❖ Disease Caused: (Condyloma ★ Cowpox acuminate) ❖ Clinical Findings: ❖ Clinical Findings: ★ Guarnieri Bodies are ★ Koilocytes are a distinct distinct histopathological histopathological cytopathic effect of cytopathic effect of cowpox HPV infections Molluscum contagiosum ❖ Family Adenoviriade ❖ Disease Caused: - distinct filamentous virus ★ Benign epidermal dome-shaped nodule Adenovirus 1-37 with umbilicated ❖ Disease Caused: centers ★ Epidemic ❖ Clinical Findings: Keratoconjunctivitis, ★ Pharyngoconjunctival ★ Molluscum bodies fever are distinct histopathologic __________________________________________________________ LUCKY 7 3  Cytopathic effect of Molluscum Varicella-Zoster Virus Monkeypox Virus ❖ Complex of two viruses: ❖ Disease Caused: ★ Varicella and Herpes ★ Monkeypox Zoster Orf Virus Varicella ❖ Disease Caused: - More prevalent in early ★ Pox associated with years of life and childhood sheep and goats ❖ Disease Caused: ❖ Family Polyomaviridae ★ Chikenpox JC Virus ❖ Disease Caused: ❖ Clinical Findings: ★ Progressive Multifocal ★ Characteristic “dew drop on Leukoencephalopathy rose petals” skin vesicle BK Virus ❖ Disease Caused: Herpes Zoster ★ Can cause - more prevalent in Nephropathy in adulthood when chicken transplant patients pox becomes reactivated Merkel Cell Virus ❖ Disease Caused: ❖ Disease Caused: ★ Shingles ★ Merkel Cell Carcinoma ❖ Clinical Findings: ★ Brought about by the reactivation of ❖ Family Hepadnaviridae Herpes Viruses Hepatitis B Virus hiding in dorsal root - Infection with HBV give a ganglia higher risk of having hepatocellular carcinoma Epstein- Barr Virus (EBV) - mode of transmission is - Associated with Burkitt’s transferring infected blood Lymphoma or other body fluid parenteral, vertical or ❖ Disease Caused: sexual ★ Infectious - Infection can be through the mononucleosis or Dane Particle Kissing Disease - HBsAg is the first antigen to rise and an indication of ❖ Clinical Findings: acute or chronic infections ★ Presence of Variant Lymphocytes type II ❖ Disease Caused: in the PBS. ★ Acute and Chronic Heterophile positive Viral Hepatitis type of Infectious mononucleosis ❖ Clinical Findings: ★ Jaundice, Ictericia, Cytomegalovirus (CMV) Hepatic Cirrhosis ❖ Disease Caused: ★ Infectious ❖ Family Herpesviridae mononucleosis -like Herpes Simplex 1 (HSV-1) and Congenital ❖ Disease Caused: Disorders ★ Cold Sores, Fever ❖ Clinical Findings: Blisters ★ TORCH positive, Heterophile Herpes Simplex Virus 2 (HSV-2) negative type of ❖ Disease Caused: Infectious ★ Genital Herpes mononucleosis __________________________________________________________ LUCKY 7 4  Human Herpesvirus 6 (HHV6) ❖ Disease Caused: ★ Roseola infantum /Exanthem subitum or the 6th disease Human Herpesvirus 7 (HHV7) ❖ Disease Caused: ★ Associated with roseola Human Herpesvirus 8 (HHV8) - Lymphoma associated with AIDS patient ❖ Disease Caused: ★ Kaposi Sarcoma ❖ Clinical Findings: ★ Vascular tumor or Mixed cellular composition __________________________________________________________ LUCKY 7 5 VIROLOGY CHAPTER III: RNA VIRUSES ❖ Family Reoviridae Rota Virus All RNA viruses are ssRNA except - Specimen of choice is feces for Reoviridae All RNA Viruses replicate in the ❖ Disease Caused: cytoplasm except for Influenza ★ Acute Gastroenteritis Virus (Orthomyxoviridae) and Retroviridae ❖ Clinical Findings: ★ More Prevalent in ❖ Family Picornaviridae Childhood and Polio Virus infantile and in - Vaccine invented winter seasons separately by Sabin and Salk Coltivirus - Mode of transmission is ❖ Disease Caused: through insect bites ★ Paralytic Poliomyelitis ❖ Disease Caused: ★ Colorado Tick Fever Coxsackie Virus A ❖ Disease Caused: ❖ Family Togaviridae ★ Pleurodynia, Rubella Virus Myocarditis ❖ Disease Caused: ★ Rubella or German Rhinovirus Measles - Acid labile Virus ❖ Clinical Findings: ❖ Disease Caused: ★ Three-day measles ★ Common Colds ❖ Family Flaviviridae Hepatovirus (HAV) Dengue Virus - Mode of transmission is ❖ Disease Caused: through fecal oral ★ Dengue transmission Hemorrhagic Fever ❖ Disease Caused: ❖ Clinical Findings: ★ Hepatitis A ★ NSAg 1 and 2, IgG and IgM positive as ❖ Family Caliciviridae a diagnostic Norwalk Virus serological tool. ❖ Disease Caused: ★ Decreased in ★ Epidemic Acute platelet count Gastroenteritis Yellow Fever Virus ❖ Clinical Findings: ❖ Disease Caused: ★ More prevalent in ★ Acute Viral Adults and in winter Hemorrhagic seasons Disease ❖ Family Hepeviridae ❖ Clinical Findings: Human Hepatitis E Virus (HEV) ★ Jaundice and - Mode of transmission is Ictericia. through fecal-oral ★ Torres-Councilman transmission Bodies are distinct histopathological ❖ Disease Caused: cytopathic effect of ★ Fulminant disease in yellow fever pregnant women infections __________________________________________________________ LUCKY 7 6  Hepatitis C Virus (HCV) - also known as the ‘’Post ❖ Family Rhabdoviridae Transfusion Viral Hepatitis” Lyssa Virus ❖ Disease Caused: ❖ Disease Caused: ★ Rabies ★ Hepatitis C ❖ Clinical Findings: ❖ Clinical Findings: ★ Bullet Shaped virus. ★ Jaundice and ★ Presence of negri Ictericia. bodies is a ★ Increased in liver histopathologically enzymes seen in the brain of the infected individual when ❖ Family Coronavirus investigated in a CoronaVirus forensic autopsy ❖ Disease Caused: after death ★ Common Colds, ★ Middle East ★ Respiratory ❖ Family Paramyxoviridae Syndrome (MERS), Measles Virus ★ Severe Acute ❖ Disease Caused: Respiratory ★ Measles or Rubeola ★ Syndrome (SARS) ★ Summer Diarrhea ❖ Clinical Findings: ★ Koplik-spots, ❖ Family Retroviridae ★ characterized by Lentivirus fever, rash and - Capable or reverse respiratory transcription symptoms ❖ Disease Caused: Mumps Virus ★ HIV/AIDS ❖ Disease Caused: ★ Mumps or Parotitis ❖ Clinical Findings: ★ CD4+ of