Viruses Flashcards
What are the RNA enveloped viruses?
Orthomyxovirus Paramyxovirus - para of M's (mumps and measles) Arbovirus Rhabdovirus Retrovirus
What are the RNA naked viruses?
cpR
calicivirus
picoRNAvirus
reovirus
What type of genetic makeup is orthomyxovirus?
ssRNA that is segmented
What are the four segmented viruses?
BOAR
Bunyaviridae
Orthomyxovirus (contains influenza)
Arenaviridae
Reoviridae
How are influenza viruses classified?
based on their nucleocapsid antigens
How is influenza spread?
respiratory droplets
After an influenza infection which microorganism can lead to fatalities due to post influenzal complications?
staph aureus
What is the most common influenza?
Influenza A
What does the ability of influenza A to cause epidemics depend on?
antigenic changes in the hemagglutinin and neuroaminidase
What are the two types of changes in a virus or bacteria?
antigenic shift
antigenic drift
What is antigenic shift?
major changes based on reassortment of genome pieces
This leads to new surface molecules (change in the envelope)
What is antigenic drift?
minor changes based on random mutations
What is the treatment for influenza A
Amantidine/ Rimantidine
What does amantidine do?
inhibits replication of influenza A by interfering with viral attachement and uncoating. It is effective in prophylaxis and treatment of influenza A.
what disease can lead to Reyes syndrome if you take aspirin?
Influenza A
What virus comes from parainfluenza virus?
paramyxovirus
What diseases come from paramyxovirus?
parainfluenza virus
RSV
Mumps
Measles
What type of genome is paramyxovirus?
ssRNA
What is syncytia formation?
The disease induces cells to form multinuceated giant cells.
What is a virus that can lead to syncytia formation?
paramyxovirus
How is parainfluenza transmitted?
respiratory droplets and direct contact
What is a common symptom of parainfluenza?
Croup (acute laryngotracheobronchitis) and pneumonia in children
What treatment is there for paramyxovirus?
There is none
What is RSV?
Respiratory syncytial virus
What population is prone to getting RSV?
infants
What is the most common cause of pneumonia and bronchiolitis in infants?
RSV
Which is the only paramyxovirus that lacks the glycoproteins hemagglutinin and neuroaminadase (surface spikes)
RSV
What is the treatment of RSV?
ribavarin
CRibavarin for babies
How are mumps transmitted?
respiratory droplets
What are common symptoms for mumps?
parotitis (unilateral or bilateral) and orchitis
What is Rubeola?
Measles
How is Rubeola transmitted?
respiratory droplets
what are common symptoms of rubeola?
Koplik’s spots in the oral cavity
What are koplik’s spots?
small, bluish-white lesions surrounded by red ring. Generally they are found opposite to molars in the oral cavity and associated with measles.
What are the three C’s of symptoms with measles?
Cough, Coryza, Conjunctivitis
What is arbovirus
arthropod borne viruses
what are the 3 different arbovirus categories?
Togavirus
Flavivirus
Bunyavirus and Arenavirus
What is another name for Rubivirus?
Rubella or german measles
What category of Arboviruses is rubivirus in?
Togavirus
How is Rubivirus transmitted?
respiratory droplets
What is the only Togavirus NOT transmitted by respiratory droplets?
Rubivirus
What is a symptom of german measles?
erythematous rash
what is the prevalence of Rubivirus?
It is almost eradicated due to the MMR vaccine
What are the placenta crossing organisms aka teratogens?
TORCHes TOxoplasmosis gondi Rubella CMV HErpes zoster and HEpatitis BCE Syphilis
What type of malformations can Rubella cause in an embryo?
Heart - patent ductus arteriosus
Eyes - cataracts
Brain - deafness and intellectual disabilities
What does Flavivirus mean?
Flavi means Yellow, so Yellow Virus
What are the flavivirus diseases?
Yellow Fever
Dengue fever
West Nile Virus
Hepatitis C
What causes yellow fever?
mosquitos that have a monkey and human reservoir.
What are symptoms of yellow fever?
fever, black vomit, jaundice (yellow)
pneumonic
remember “a skeeter on a monkey’s peeter, bites it and likes the flavir then bites you and makes you yeller.”
What virus is in the bunyavirus and arenavirus category that we should know?
Hantavirus
What is the transmission of Hantavirus?
Rodent borne
Think “Bunny’s playing with rodents in the arena)
What does Rhabdovirus cause?
rabies
What is the histology of rhabdovirus?
Negri bodies
What does rhabdovirus infect?
warm-blooded animals
What shape is rhabdovirus?
a bullet
What is Retrovirus?
It refers to the enzyme reverse transcriptase. It can transcribe RNA to DNA.
What are the 3 groups of Retroviruses?
- oncovirus
- lentivirus
- spumavirus - foamy chimpanzee, non pathogenic
What is another name for oncovirus?
HTLV or human T-lymphocytic Virus
What is an oncovirus
a virus that causes cancer
What does oncovirus produce?
leukemias
lymphomas
breast carcinomas
sarcomas
What are the four types of oncoviruses?
HTLV1, HTLV2, HTLV3, HTLV4
What was HTLV3 previously known as but not anymore?`
HIV
What famous disease is associated with lentivirus?
HIV
Which virus kills T helper cells and causes immunosuppression?
Lentivirus
How does lentivirus spread?
Through macrophages throughout the body
What cells do HIV affect?
CD4 or T-helper cells
What fluid is HIV transferred by?
semen, serum, amniotic fluid, breast milk (NOT saliva)
How do new strains of HIV happen?
As a result of errors in transcription. NOT translation!
What is the difference between capsid and nucleocapsid?
capsid - protein coat around viral DNA
nucleocapsid - the capsid + the nucleic acid
What is an viral envelope?
a lipid bilayer that surrounds the capsid
What are the DNA viruses?
HHAPPP (happy)
Herpes HepaDNA Adeno Papova Parvo Pox
What is the only virus that is diploid as opposed to haploid?
retrovirus
How does a virus adsorb onto a cell?
ONLY through cell receptors and a viral surface component. NOT via phagocytosis or using cell energy etc…
What is positive sense and negative sense?
positive sense: RNA has the same base sequence as the mRNA
Negative sense: a complimentary sequence as the cell mRNA. The virus must carry its own RNA-dependent RNA polymerase.
What are two examples of negative sense RNA virus?
orthomyxovirus and paramyxovirus
What is a bacteriophage?
a virus that can only infect bacteria
What are the two life cycles of a bacteriophage?
lytic phase
lysogenic phase
What is another name for lytic phase? what is this phase?
virulent phase - when the virus is active and will kill the cell via lysis.
What is another name for the lysogenic phase? what is this phase?
temperate phase: when the virus is inactive and integrates into chromosomes.
What is a prophage?
a bacteriophage genome that has integrated itself into a chromosome.
What is phage conversion or lysogenic conversion?
When a good bacteria gets turned toxic or virulent by a virus
What is an example of phage conversion?
C. diphtheria becoming pathogenic after phage conversion
or conversion of erythrogenic toxin by strep pyogenes
What are two ways that diptheria toxin can be triggered?
- phage conversion
2. AND in presence of low iron
Which DNA viruses are not enveloped?
PAP (girls are naked when they get a PAP smear)
Papova
Adeno
Parvo
What DNA virus is the only virus where transcription occurs in the cytoplasm instead of the nucleus?
poxvirus
Which DNA viruses are ds versus ss?
ALL are double stranded except for parvovirus
He has never made a SINGLE PARhole his whole life.
Whic DNA viruses are linear vs circular?
ALL are linear except for Papovavirus and Hepdnavirus
What are HIV-1 infection examples?
gingivostomatitis
keratoconjunctivitis
meningoencephalitis
esophagitis in HIV patients
What is the only virus to obtain their envelopes by budding from the nuclear membrane?
HSV
Where does HSV-1 produce latency? HSV-2?
HSV-1 : trigeminal ganglion
HSV-2: lumbar and sacral ganglion
What is HSV-2 associated with?
cervical carcinoma or cervicitis
How is VZV spread?
respiratory droplets AND direct contact
What is a tzanck test and what is it used for?
its a smear of opened skin vesicles to detect multinucleated giant cells. Its used for HSV-1, HSV-2, and VZV
What disease does EBV cause?
infectious mononucleosis (kissing disease)
What cell does EBV infect?
B cells and some epithelial cells
What is the latent EBV called?
SBV
What can develop from EBV?
Burkitt’s lymphoma
nasopharyngeal carcinoma
hodgkins lymphoma
What is a symptom of EBV
oral hairy leukoplakia
What is the most unique symptom of infectious mononucleosis?
splenomegaly
How can infectious mononucleosis be tested for?
elevated heterophile titer greater than 1:128 (an antibody agglutination test)
What is the major viral cause of birth defects in infants in developed countries? what about non-developed countries?
CMV
Rubella
What is the antiviral used to treat HSV diseases?
Acyclovir
What is another name for Hepadnavirus?
Hepatitis B
What virus is the only virus that has DNA polymerase with reverse transcriptase activity?
Hepadnavirus
What shape is pox virus?
brick-shaped
POX in a brick box (it is also enveloped)
What is the largest and most complex animal virus?
Pox virus
What are three poxvirus diseases?
- Smallpox virus
- Molluscum cantagiosum virus - causes wart-like skin lesions
- Vaccinnia Virus - used to develop vaccines
How are we protected from smallpox?
by vaccination of cow-pox virus (antigenic cross reactivity)
What is a type of Papovavirus?
HPV - human papillo virus
What is the most common VIRAL STD?
HPV
What is the most common STD?
chlamydia
What is a symptom of HPV?
papillomas or warts
What type of virus is HPV?
a DNA oncogenic virus (NOT RNA, that is retrovirus)
What other pathologies is HPV associated with?
cervical carcinoma (HPV16 and HPV18)
also Condyloma Acuminatum (genital warts)
What type of HPV causes cervical carcinoma?
HPV16 and HPV 18
What type of HPV causes condyloma acuminatum?
HPV6 and HPV11
Can HPV be associated with verruca vulgaris?
Yes
ADENovirus pneumonic
A DEN of preschoolers with pink eye and colds
So it causes URI and LRI like a cold
can cause pink eye
How is adenovirus transmitted?
respiratory droplets, fecal-oral, direct inoculation
What is the real name for pink eye?
acute contagious conjunctivitis
What is another name for parVovirus?
ParVovirus B19
What disease is associated with Parvovirus?
5th disease (ParVovirus, the V for 5th)
What is 5th disease?
slapped cheek syndrome or erythema infectiousum
remember 5 fingers slapping a plastic face
What is a complication of parVovirus?
transient aplastic anemia crisis
remember 5 fingers slapping a plastic face
What is a bacterial cell wall like?
rigid and contains peptidoglycan
What is murein?
peptidoglycan
What is unique to the gram positive cell wall?
teichoic acid
What is unique to the gram negative cell wall?
LPS
What bacteria does NOT have a cell wall?
mycobacteria
What are the components of peptidoglycan?
glycan - NAG-NAM
teichoic acid
What are components of LPS?
Core polysaccharide Somatic O polysaccharide Lipid A (Keto-deoxy-octanoate) - endotoxin activity
Which component of LPS has endotoxic activity?
Lipid A
What does Lipid A cause?
release of TNF and IL-1, which cause inflammation
What is the Shwartzman reaction?
an exaggerated response to LPS that results in tissue necrosis
What bacteria are acid fast?
mycobacterium and nocardia
What color is an acid fast stain?
red
What bacteria do not stain?
Rickettsia (gram -)
Mycoplasma
Mycobacteria
Chlamydia (gram -)
What is the best phase of bacterial growth for staining bacteria?
log phase
What type of respiration does strep mutans do?
anaerobic respiration
What is the final electron acceptor?
pyruvate, or organic compound or an intermediate glucose product
Which form of Mutation in bacteria is most susceptible to DNAase? Which is least susceptible?
DNA transformation - most
DNA transduction - least
Which form of mutation in bacteria happens when F-factors or F-plasmid are transferred?
conjugation
Which bacterial mutation can transfer antibiotic resistance?
conjugation (not the other two!)
Which is the only bacteria that does not have a polysaccharide coat? what type of coat does it have?
Bacillus anthracis has D-glutamate or an amino acid capsule
What are inclusion bodies?
also known as granules, they are a storage area in a bacterial cell for nutrients. They store sulfur granules, and Volutin (a type of granule that stores ATP)
What are bacteria that have metochromatic (multi-colored) granules?
Pseudomonas Aeruginosa (Blue green) Cornybacterium diptheriae
What are transposons?
genes that encode proteins necessary for antibiotic resistance that can change position on a chromosome or “jump” from a plasmid to a chromosome.
What are the most important gram positive rods?
Bacillus Anthracis (spore forming)
Clostridium (spore forming)
Corynebacterium
Listeria
What is the difference between clostridium and bacillus?
bacillus is aerobic and clostridium is anaerobic
What chemical is contained within spores?
calcium dipicolinate
What are some characteristics of Bacillus anthracis? (4)
- forms spores
- catalase positive
- Malachai green spore staining
- Obligate aerobe
What major bacteria are obligate aerobes?
Nice Pets Must Breath
Nocardia
Pseudomonoa aerogenosa
Mycobacterium
Bacillus
What are the three different manifestations of anthrax?
- pulmonary (woolsorters disease)
- GI
- Cutaneous (black eschar)
What is woolsorters disease?
An anthrax disease also known as woolsorters disease. The person can get life-threatening pneumonia and a widened mediastinum
What are the 3 proteins in anthrax toxin?
- Lethal factor (LF)
- Edema factor (EM)
- Protective antigen (PA)
What does edema factor do in anthrax toxin?
imitates adenylate cyclase (increase cAMP)
What the difference of anthracosis and anthrax?
they have nothing to do with each other!
anthracosis is a disease of coal miners by inhaling coal dust, or black lung disease. It is not predisposed to cancer.
What can Gardner’s syndrome lead to?
colon cancer
What are the 4 types of clostridium?
c. botulinum
c. difficile
c. perfringens
c. tetani
What are the 3 normal flora of the GI tract that are pathogenic anywhere else?
ABC’s
Actinomyces
Bacteroides
Clostridium
Is botulism an infection?
No its an intoxication
What syndrome can botulism cause?
Botox
also Floppy Baby Syndrome
Which clostridium bacteria cannot live well inside the body?
C. botulinum
What effect does botulism toxin have on the body?
It the most potent poison known to humans
It binds to presynaptic nerve and blocks Ach release
This leads to flaccid paralysis of muscle known as Floppy Baby Syndrome. Can lead to death due to respiratory failure.
What toxin does C. Difficile release?
Exotoxin A and Exotoxin B
What drug can lead to Cdiff?
Clindamycin
What is the toxin that causes Gas gangrene?
Alpha toxin or lecithinase from C.perfringens
What is alpha toxin?
an enzyme with hyaluronidase, that degrades HA in subcutaneous tissue
What does the tetanus toxin do to the body?
blocks glycine release, which is normally a neurotransmitter inhibitor so it leads to paralysis.
What shape are corynebacterium?
Rods
What disease is caused by corynebacterium diptheria?
pseudomembranous pharyngitis
What are characteristics of C. diptheria? (3)
- Blue red (metachromatic)
- Grows on tellurite agar
- Gram positive rod
What agar does S. aeruginosa grow on?
MacConkey’s agar
What encodes to exotoxin in C. diphtheria?
a bacteriophage via phage conversion
so C. diphtheria alone is not toxic
What is the vaccine for diptheria?
toxoid vaccine
What is the mechanism of C. diptheria?
causes ADP ribosylation of EF-2 preventing protein synthesis (just like in pseudomonas!)
What are the major gram positive cocci?
- Staph
2. Strep
What is the main way to distinguish strep from staph?
catalase test
Staph aureus is positive
strep is negative
Which staph bacteria are coagulase positive and which are coagulase negative?
staph aureus is positive
the rest are coagulase negative
Which gram + cocci can cause a UTI?
Staph saphrocyticus
What is the most common manifestation of staph infection on skin?
cutaneous abcess
What is unique about antibiotics and staph?
staph is resistant to penicillin because it has beta-lactamase.
any skin, bone and joint infection is most commonly caused by?
staph aureus
what gram + cocci is protein A associated with?
staph aureus
what other diseases can staph aureus cause other than skin, bone and joint infections?
food poisoning
toxic shock syndrome
acute bacterial Endocarditis
MRSA
What is the golden bug?
staph aureus (aureus means gold)
what is the incubation period for staph aureus food poisoning?
2-4 hours
What does Protein A in staph aureus?
its a protein that binds to immunoglobulins (the Fc region of IgG) and inhibits complement.
What are the major characteristics of streptococci? (2)
- catalase negative
2. facultative anaerobic gram positive cocci
What is the most prevalent bacteria in the oral cavity?
strep
What role does strep do in dental plaque?
It has GTF that makes dextran
What is the difference between alpha, beta and gamma hemolysis?
alpha - partial
beta - complete
gamma - no
What are the two types of alpha hemolytic strep?
s. pneumoniae Viridans streptococci (s. mutans and s. sanguis)
Alpha hemolytic strep can cause what major pathology?
endocarditis
What is the difference between s. pneumoniae and viridans strep?
S. pneumoniae has a capsule (optochin sensitive)
Viridans strep has no capsule and can cause endocarditis
What is a major bacteria in Group A Strep?
S. pyogenes - bacitracin sensitive
What is a major bacteria in Group B strep?
S. agalactiae - bacitracin resistant
Where is strep pyogenes found?
oropharynx
What causes scarlet fever?
S. pyogenes (think pyro is hot)
What are the two main post streptococcal diseases?
Rheumatic fever
Glomerulonephritis
What is streptomycin used for?
its an ABX for TB
What are the two major groups for gram - rods?
lactose fermenters and non fermenters