microbio - viruses Flashcards
True or false : genetic material of viruses may be both DNA and RNA.
False. Never both
Protein coat of viruses
Capsid
Type of RNA virus which are like mRNA, they are immediately translated by the host’s ribosome into protein
Positive sense RNA virus
Type of RNA virus which should be transcribed first into positive sense RNA virus.
Negative sense RNA virus
RNA virus has this enzyme for synthesis.
RNA-dependent RNA polymerase
Type of RNA virus that is transcribed in reverse fashion into DNA
Retrovirus
Retrovirus has this required enzyme for synthesis
Reverse transcriptase
Building block of capsid
Capsomer
DNA virus
HHAPPPy , PHP AHP Parvovirus Hepadnavirus Papovavirus Adenovirus Herpes virus Poxvirus
RNA virus
PCR TCORPR picornavirus Calicivirus Reovirus Toga virus Corona virus Orthomyxovirus Rhabdovirus Paramyxovirus Retrovirus
All DNA virus are double stranded, except…
Parvovirus
All DNA virus have icosahedral capsid, except…
Pox virus
All DNA virus replicates in nucleus, except…
Pox virus which replicates in cytoplasm
All DNA virus have linear DNA, except…
Papovavirus
Hepadnavirus
All RNA virus are SIngle stranded, except…
Rotavirus
Reovirus
Segmental viruses
BORA bunyavirus Orthomyxovirus Reovirus Arenavirus
All RNA virus are enveloped, except…
PCR
Picornavirus
Calicivirus
Reovirus
All RNA virus have helical capsid symmetry, except…
PCRFT, R Picornavirus Calicivirus Reovirus Flavivirus Togavirus Rhabdovirus - bullet-shaped
All RNA virus replicates in cytoplasm, except…
Retrovirus
Orthomyxovirus
Steps of viral replication
- Adsorption and penetration
- Uncoating
- Synthesis and assembly of viral products
- Release of virions from host cell (by lysis or by budding)
Host cell outcome
- Death
2. Transformation - oncogene
Positive sense RNA virus
PCCRaFT Picornavirus Calicivirus Coronavirus Reovirus Flavivirus Togavirus
Negative sense RNA viruses
"Always Bring Polymerase Or Fail Replication" Arenavirus Bunyavirus Paramyxovirus Orthomyxovirus Filovirus Rhabdovirus
Non defective parvovirus strain
B19 virus
Smallest virus
Picornavirus, parvovirus
Disease caused by b19 virus of parvovirus with characteristic “slapped cheek” rash.
Erythema infectiosum
Diseases caused by b19 strain of parvovirus
Erythema infectiosum
Transient aplastic anemia crisis
Disease caused by parvovirus which ensues when the virus stops the production of RBCs in the bone marrow
Transient aplastic anemia crisis
Parvovirus that requires helper virus to replicate
(+) and (-) strand DNA are carried on separate particles
Defective parvovirus
What are the papovaviruses?
Papillomavirus (HPV)
Polyomavirus
Vacuolating viruses (SV40)
Papovavirus that causes warts
HPV
HPV type that causes common warts
e.g. Verucca plantaris, skin warts
HPV type 1, 2, 4 and 7
HPV type that causes genital warts
HPV type 6,11,16,18
HPV type that causes laryngeal warts
HPV type 6,11
HPV type that causes verucca vulgaris and condylomata accuminata (hallmark: koilocytes)
HPV type 6,11
HPV type that causes cervical cancer
HPV type 16,18
Papovavirus
Polyomavirus that causes mild and ASYMPTOMATIC infection in children. Also seen from immunosuppressive kidney transplant patients and HPV.
BK polyomavirus
Papovavirus
Polyomavirus that causes Progressive multifocal leukoencephalopathy (PML) characterized by degenerative cns white matter disease
JC polyomavirus
Chemical treatment for genital warts
Podophyllin
HPV genes implicated in carcinogenesis
E6, E7 genes
DNA virus that causes childhood URTI such as rhinitis, sore throat, fever and conjunctivitis, and the epidemic keratoconjunctivitis (pink eye)
Adenovirus
causes the epidemic keratoconjunctivitis.
Adenovirus type 8
DNA virus which is circular and ds. The complete strand not covalently closed circle and other strand is missing approximately 25% of its length
Hepadnavirus
Herpes viruses
Herpes simplex virus type 1 and 2 HSV
Varicella-zoster virus VZV
cytomegalovirus CMV
Epstein-Barr virus EBV
Alpha group herpes virus
HSV-1
HSV-2
VZV
Beta group herpesvirus
CMV, HSV-6
Gamma group herpesvirus
EBV, HSV-8
Herpesvirus causes this type of infection where in the virus migrates up to the nerves to sensory ganglia and reside there. It will be activated in peripheral skin
Latency
Herpesviruses has this effect, especially HSV 1&2, and VZV. This results in separation of epithelium and causes blisters.
Cytopathic effect - cause cell destruction
Diseases caused by HSV 1
Gingivostomatitis
Encephalitis
Keratoconjunctivitis
Herpes labialis
Primary infection of HSV 1
Gingivostomatitis - painful group of vesicles on the lips and mouth, which ulcerate and has usually without leaving a scar. Often accompanied by fever and viral symptoms
Recurrent infection of HSV 1
Herpes labialis (fever blisters,cold sore)
Mode of transmission of HSV-1
Direct contact of mucus membrane
HSV 1 latency in …
Trigeminal ganglia
HSV type lesions above the waist
HSV 1
HSV type lesions below the waist
HSV 2
Diseases caused by HSV 2
Genital herpes
Neonatal herpes
Aseptic meningitis in neonates
HSV 2 latency in …
Lumbar or sacral sensory ganglia
Disease caused by HSV 6
Roseola infantum (6th disease, exanthem subitum)
Characteristic appearance in roseola
Nagayama spots - in uvopalatoglossal junction
HSV 6 transmission
Transmitted by saliva
HSV 8 transmission
Sexually transmitted especially in homosexual men
Disease caused by HSV 8
Kaposi’s sarcoma
Castleman’s disease (lympho proliferative disorder)
Primary effusion lymphoma
TORCHES can cross blood-placental barrier
Toxoplasmosis Rubella CMV Herpes, HIV Syphilis
Diagnostic preparation in isolating HSV
Tzanck smear, cowdry A
Varicella is highly contagious. It causes what disease?
Chickenpox
Incubation period of chickenpox
10-21 days
Characteristic appearance of the vesicle rash in chickenpox
Dew drop lesion on the top of a rose petal
Recurrence of VZV leads to what disease?
Shingles - painful eruption of vesicles isolated in a single dermatome. The vesicles dry up and form crusts which disappears in about 3wks.
Re activation to zoster from…
Dorsal root ganglia
Treatment fro HSV 1&2 and VZV
Acyclovir
CMV infection recurrence in immunocompromised patients, especially AIDS patient.
CMV retinitis
CMV infection recurrence in immunocompromised patients, especially bone marrow transplant patients
CMV pneumonitis
Hematologic hallmark in CMV
Owl’s eye inclusion
Herpesvirus that cause infectious mononucleosis
EBV
Treatment for CMV infection
Ganciclovir
Largest virus
Poxvirus
DNA virus that has brick-like appearance
Poxvirus
Diseases caused by poxvirus
Smallpox
Molluscum contagiosum - small white bumps with central dimple (like wart). Often found in genital region.
Vaccine for poxvirus
Vaccinia virus - an avirulent pox virus
RNA viruses that cause common cold.
Coronavirus and rhinovirus (picornavirus)
Picornaviruses
Enterovirus: poliovirus, coxsackie A&B, echovirus, hepatitis A
Rhinovirus
Arthropod borne viruses (arbovirus)
Togavirus
Flavivirus
Bunyavirus
Togavirus that is not arbovirus
Rubivirus
Bunyavirus that is not arbovirus
Hantavirus
RNA viruses that cause gastroenteritis
Rotavirus (reovirus)
Calicivirus
RNA virus that causes rabies
Rhabdovirus
Caliciviruses
Norwalk virus
Hepatitis E
Reoviruses
Respiratory, Enteric, Orphan
Most common viral cause of infant diarrhea
Rotavirus
Diseases caused by flavivirus
Yellow fever Dengue fever Japanese encephalitis St. Louis encephalitis West Nile encephalitis Hepatitis c
Also known as break bone fever
Dengue fever
Togaviruses
Alpha virus:
WEE
VEE
EEE
Rubivirus
RNA virus that cause rubella (German measles/ 3-day measles)
Rubivirus
Vaccine for rubella
MMR vaccine
Measles
Mumps
Rubella
Retroviruses
Oncovirus
Lentivirus
Aka slow virus
Lentivirus
Orthomyxovirus
Influenza virus (a,b,c)
Virulence factor / glycoproteins of Orthomyxovirus
Hemagglutinin (HA)
Neuraminidase (NA)
Glycoprotein that binds with sialic acid, often found in the surface of RBC.
HA
Glycoprotein the breaks down neuraminic acid, an important component of mucin
NA
Disease caused by influenza virus
Flu fever
Influenza A infects..
Human and animals
Influenza B and C infects…
Human only
Complication of influenza virus infection
Secondary bacterial pneumonia in elderly
Reye’s syndrome: children who use aspirin and get liver and brain disease
Do not give aspirin in children for fever,. You give what?
Acetaminophen
Influenza a treatment
Amantadine and rimantidine
Rimantadine and amantadine action
Prevents viral un coating in influenza A
Neuraminidase inhibitors that can shorten course of influenza A and B infection
Zanamivir (inhaled)
Oseltamivir (oral)
Small mutations resulting in minor changes in the antigenicity of NA or HA. This results in epidemics go the common flu.
Antigenic drift
Only occurs in inflenza A because of trading of RNA segments between animals and human strains. It is a reassortment, a major changes of the HA and NA resulting in devastating influenza pandemics.
Antigenic shift
Most common viral encephalitis in the Philippines
Japanese encephalitis
Japanese encephalitis vector
Culex mosquitoes
Dengue fever is a biphasic fever. What is its vector
Aedes mosquitoes
Paramyxoviruses
Parainfluenza virus
RSV
Mumps virus
Measles virus (rubeola)
Difference between Orthomyxovirus and paramyxovirus
Combined HA and NA Glycoprotein (wherein in Orthomyxovirus they are separate)
Has fusion protein (F protein)
Protein found in paramyxovirus that results in multinucleated giant cells (called syncytial cells)
F protein
Paramyxovirus that only has HA and F protein
Measles (rubeola)
The koplik’s spot in measles occur after 1-2days of prodrome. It is small red based blue-white centered lesions in the mouth found specifically in..
Opposite the 2nd upper molar
Recurrent infection of measles after 2 years
Subacute sclerosing para encephalitis (SSPE)
Diseases caused by mumps virus
Parotitis
Orchitis (in post pubertal male
Meningitis
Encephalitis
Disease caused by parainfluenza virus characterized by strider and barking cough due to infection and swelling of larynx
Croup
Paramyxovirus that has no HA and NA
RSV
Most common viral cause of infant pneumonia
RSV
Eosinophilic intracytoplasmic inclusion in rabies virus
Negri bodies
Focal micro glial nodules in rabies
Babes nodules
Hydrophobia and foaming of mouth in rabies is due to
Laryngospasm
Disease that travels to the cns in a retrograde fashion up to the nerve axon
Rhabdovirus
Filoviruses
Ebola virus
Marburg virus
Filovirus that cause mucus membrane bleeding (hemorrhagic fever)
Ebola virus
Most common cause of common cold
Rhinovirus
Rhinovirus is acid-labile or acid-stable?
Acid-labile
Rhinovirus replicates better in what temperature
33 degrees centigrade
Virus that cause common cold and has prominent halo and spikes
Coronavirus
Arenaviruses
Lymphocytic choriomeningitis virus (LCM)
Lassa virus
RNA virus that contains nonfunctional ribosomes on its surface.
Arenavirus
Diseases caused by bunyavirus
Encephalitis
Korean hemorrhagic fever
Hantavirus pulmonary syndrome
Muerto canyon virus
RNA virus that cannot replicate without hepa B
Deltavirus
Family of hepa A virus
Picornavirus
Family of hepa B virus
Hepadnavirus
Family of hepa C virus
Flavivirus
Family of hepa D virus
Deltavirus
Family of hepa E virus
Calicivirus
Family of hepa G virus
Flavivirus
Entire infectious unit
Virion
Envelope is acquired from
Budding
Wheel-shape appearance
Rotavirus
Sandy appearance
Arenavirus
Small infectious agents that cause diseases of plants.
Viroids
Infectious particles composed solely of protein with no detectable nucleic acid.
Prion
T or F: Icosahedral viruses tend to be stable, losing little infectivity after several hours at 37 °C.
True
Enveloped viruses are heat labile
True
Phase of viral growth cycle where in soon after interaction with a host cell, the infecting virion is disrupted and its measurable infectivity is lost.
Eclipse period
physical separation of the viral nucleic acid from the outer structural components of the virion so that it can function.
Uncoating
Virus particle that is functionally deficient in some aspect for replication
Defective virus
Steps in viral pathogenesis
- Viral entry
- Primary viral replication
- Viral spread
- Cellular injury
- Host immune responses
- Viral clearance
- Viral shedding
Diagnosis for parvovirus
PCR
Mode of transmission of HSV-2
Sexually transmitted
Host-coded proteins that are member of cytokines and which inhibits viral replication.
Interferon (IFN)
Type I or viral IFN
IFN alpha and beta
type II or immune interferon
IFN Gamma
T or F: IFN does not protect virus-infected cell and not itself the antiviral agent
True
Coxsackie A or B:
In mice, it causes paralysis and death with extensive skeletal muscle necrosis
Coxsackie A
Coxsackie A or B:
In mice, it causes paralysis and death with multiple organ damage
Coxsackie B
Diseases caused by coxsackie A
Herpangina - fever, sore throat and small red-based vesicles over the back of the patient’s throat
Hand-foot-and-mouth disease
Diseases caused by coxsackie B3 and B5
Devil’s eye
Myocarditis and pericarditis
Pleurodynia (Bornholm’s disease)
Most important antigen of EBV
Viral capsid antigen (VCA)
Hematologic hallmark of Monocucleosis
Atypical lymphocytes
Mononucleosis is a dse of young adults. As with viral infections, the lower the socioeconomic class, the earlier children are indeed and the milder disease. American teenagers living in high socioeconomic class with better sanitation are infected later in life through social contact such as kissing. Thus the reference to kissing’s disease. What virus causes this?
EBV
Major target cell of EBV
B lymphocytes, binding to C3d receptor
Diseases caused by EBV
BHINK
Burkitt’s lymphoma: B cell lympho affecting children in central Africa
Hodgkin’s disease : lymphoma characterized by arising in a single node or chain of nodes, spreading in anatomically contagious nodes
Infectious mononucleosis
Nasopharyngeal carcinoma
Kissing’s disease
Diagnostic tests for EBV
Paul-bundle test
Heterophil antibody test (positive by 2wks of illness)
Monospot test
Hepatitis that is asymptomatic, alone and acute
Hepatitis A
Hepatitis that is blood-borne, big, bad, body-fluid
Hepatitis B
Hepatitis that is chronic, cirrhosis, carcinoma and carrier
Hepatitis C
Hepatitis that is defective and dependent to hepatitis B
Hepatitis D
Hepatitis that enteric and for expectant mother
Hepatitis E
Hepatitis that only carries DNA polymerase within the virion
Hepatitis B
T or F: acute viral hepatitis never becomes chronic in hepatitis A
True
Transmission of hepatitis A and E
Fecal-oral route
Transmission of Hepatitis B, C, D
Blood transfusion
Needle stick
Sexual
Across placenta
Incubation of Hepatitis A
14-45 days
Incubation of hepatitis B
50-180 days
Hepatitis that may cause hepatocellular carcinoma
Hepatitis B and C
Intact virus of hepatitis B
Dane particle
Disassociation of Dane particles leaves..
HBcAg and HBsAg
Antigen found within nuclei of infected hepatocytes
HBcAg
Soluble component of HBcAg and a markers of active disease and highly infectious
HBeAg
Australian antigen
Hepatitis B
Transfusion hepatitis
Hepatitis C
Enteric hepatitis C
Hepatitis E
Appears during early acute phase and disappears before HBcAg is gone
Hep B 37 Ag (HBeAg)
Xanthochromic CSF is a finding in …
Herpes encephalitis
Intranuclear inclusion bodies seen in herpes encephalitis
Cowdry A
Kluver-bucy syndrome
Herpes encephalitis
Causes adult acute t-cell leukemia and tropical spastic paraparesis (partial paralysis of lower limb)
Human T lymphotrophic virus type 1 (HTLV-1)
Catarrhal
Measles virus
Incubation of mumps virus
18-21 days
Mumps virus has only one antigenic type. Therefore, the MMR vaccine is protective. What is the antigen?
“S” soluble antigen
T or F: maternal antibody against mumps virus provide protection during 6months of life
True
Transmission of poliovirus
Fecal-oral transmission
Treatment for poliovirus
Pleconaril - inhibits penetration
Salk vaccine - formalin-killed poliovirus injected subQ
Sabin vaccine (OPV) - attenuated polio virus is ingested
Polio virus initially replicated in the tonsils and Peyer’s patches, spreading to the blood, and across cns barrier to the (anterior,posterior) horn of the spinal cord.
Anterior horn cells
Incubation period of poliovirus
7-14 days or 3-35days
Intranuclear inclusion bodies seen in poliovirus infection
Cowdry B
Most common poliomyelitis
Abortive poliomyelitis
Non paralytic polio
Aseptic meningitis
Diseases caused by poliovirus
Mild flu-like illness
Nonparalytic poliomyelitis: Aseptic meningitis
Paralytic poliomyelitis
Infectious RNA
Hamstring Myalgia
Poliovirus
Bronchiolitis
RSV
Forscheimer spots
Rubella virus
Poxvirus that is Completely eradicated worldwide
Variola virus
Vector of yellow fever virus
Aedes mosquito
Characterized by high fever, black vomitus, jaundice
Yellow fever
Intranuclear inclusion bodies seen in yellow fever virus infection
Councilman bodies - acidophilic inclusion
Most frequent cause of viral (aseptic) meningitis
Mumps virus
Coxsackie
Echovirus
Prion disease
Kuru
Gerstmann-straussler disease
Prion (13-3-3 protein)
Cannibalism-related prion disease
Kuru “shivering”
Autosomal dominant prion disease
Supranuclear gaze palsy
Gerstmann- straussler disease
Creutzfieldt-Jakob syndrome
Heidenheim dementia
90% die in 1year
Corneal transplant
Prion (13-3-3 protein)
