micro 2 Flashcards Preview

MOHD IV > micro 2 > Flashcards

Flashcards in micro 2 Deck (66):
1

treponema pallidum

syphilis
aerobes, attach to endothelial cells
Primary
-infection of vessels and perivascular area
- ID50

2

congenital syphilis

spontaneous abortion
late stigmata
-hutchinson teeth: chalky, soft abnormally formed
-sabre shins

3

treponememes tx

tests
-non-treponemal agglutenation of beef- initial screen
-flourescent treponemal ABs
--false + with RA
-ABs can be detected by serology but not effective in immunity
-PCR
TX
-primary - IM of Penicillin G
--complication: Jarisch-Herxheimer reaction
---mild endotoxemia:HA, fever, hypotension
-quinolones, amioglycosides, sulfa not effectivive

4

Borrelia

spirochetes, microaerophiles
relapsing fevers
Lyme disease
tx with antibiotics- Jarisch-Herxheimer reaction

5

Borrelia recurrentis

spirochete, microaerophiles
relapsing fever
louse bourne
4-10 days high fever and hypotension

6

Borrelia hermsii

spirochetes, microaerophiles
relapsing fever
tick bourne
4-10 days high fever and hypotension

7

Borrelia burgdoferi

Lyme disease
spirochetes, microaerophiles
vector deer ticks
bulls eye rash-> arthritis, myocarditis, dementia like
responds easily to antibiotics
jarisch-herxheimer reactioin

8

Rickettsia rickettsii

Rocky Mountain spotted fever
spirochetes, have LPS
zoonotic- dog and deer ticks
endemic to ozarks and appalachian mountains
target endothelial cells
utilize actin polymerization for locomotion like shigella and listeria
incubation 5-7 days
SX: fever, chills, HA, myalgia, rash starts on hands and feet (2-3 days later)
path: increase vascular permeability, hypovolemia, edema, ischemia, organ damage/failure; AB mediated immunity
TX: tetracyclines

9

ricketsia akari

spirochetes, lps
milder chicken pox disease
house mice mite vector

10

Ehrlichia chaffeensis

Human monocytic ehrlichia
small G- cocci, obligate intracellular pathogen
form vacule bound colonies-> morulae
dog and lone star ticks
natural hosts: deer, dogs, goats
5-10 days incubation
range of symptoms like RMSF without rash

11

Ehrlichia equi

Human granulocytic ehrlichia; anaplasma
G- cocci, obligate intracellular pathogen
form vacule bound colonies-> morulae
deer and dog tick vectors
5-10 days incubation
range of symptoms like RMSF without rash

12

mycobacterium general

High wax-resistant to drying
facultative intracellular pathogens of PMN/macrophages
divide 24 hours, colonies 4-6 weeks
virulence factors
-Wax D: acid fastness, adjuvant, muramyl dipleptide
-cord factor: serpentine growth; leukocyte toxicity, trehalose dimycolate
-tuberculin: Pure protein derivative (PPD)
mycobactin: Fe chelator
sulfo-glyco and sulfolipids: prevent fusion of phagosome and lysosomes

13

tuberculosis disease

Ghon complex- first complex in lung with productive cough
spreads systemically: miliary TB
-granulomas in: lymphnodes, spleen, kidneys
-"millet seed granulomas in: Liver (Low O2)
Returns to apical and subapical lungs
delayed hypersensitivity 2-3 months into infection
-cycles of productive and non-productive (more prominent) cough, fevers, cachexia, night sweats

14

TB TX

Isoniazid (INH): mycolic acid synthesis inhbitor (always used)
rifampin: RNA synthesis
cycloserine: cell wall synthesis
Ethambutol: cell wall?
ethionamide: ?
pyrazimamide: ?
rifabutin: RNA synthesis

15

atypical mycobacterium

photochormogens: M. Kanasii
-Pigmented when in light
Scotochromogens
-Always pigmented (yellow)
-increased pigment in light
-M. scrofulaceum- cervical lymphadenitis
non-pigmented
-M. avium-intracellulare: associated with HIV
Rapid growers
-M. fortuitum: hospital associated sternal infections

16

M. ulcerans

Makes non protein toxin
-> buruli ulcer
requires surgical removal
tropical disease
TX: rifampin and aminoglycosides

17

M. leprae

obligate intracellular pathogen
spectrum disease
Indeterminant
-one hyper/hypopigmented lesion without loss of sensation
tubercoid (pauci bacillary)
-multiple lesions
-peripheral nerve damage
-contained by Tdth
Lepromatous (multi bacillary)
-no immune response
-deformity
-blindness from loss of lashes and no blinking
-localized to the surface
-contagious
-erythema nodosum leprosum (type III hypersensitivity) after ABx
-genetic susceptibility
TX: dapsoen and rifampin and clofazimine

18

+RNA viruses

Naked
-picornaviruses
-calicivirus
enveloped
-flaviviruses
-togaviruses
-coronaviruses
-retroviruses

19

picornaviruses

1. Rhinoviruses- common cold
2. hepatitis A- primarily GI
3. Enteroviruses
--poliovirus
--coxsackie viruses
Capsid: 3 proteins->1protomer-> 5protomers->1pentamer->12pentamers= capsid

20

Rhinovirus

picornavirus
replicates in URT- receptors ICAM or LDLr
not cytopathic in nasopharanx-> weak immune response
#1 cause of common cold

21

polio virus

picornavirus
poliomyelitis
vaccines
-salk-killed
-sabin-attenuated

22

non-poli enteroviruses

picornaviruses
enterovirus a-d
-fever, rash uri, aseptic meningitis
coxsackie A and enterovirus 71
-Hand foot and mouth disease
coxasckie B
Pleurodynia, mycarditis and pancreatitis

23

hepatitis A

picornavirus
fecal oral
very stable
Sx 4 weeks after infection (immune mediated)
-fever, N/v, diarrhea, juandice
DX: clinical picture+ high ALT+ IgM
no tx but good vaccine

24

Flaviviridae

+RNA, enveloped icosohedral
4 genera
-flavi (arboviruses)
--St. Louis encephalitis
--West nile virus (encephalitis)
--yellow fever (hemorrhagic)
--dengue (hemorrhagic
-hepaci: hep C
-Pegi: HPgV- common commensal
-Pesti: animal viruses

25

WNV

Flaviridae
crow-> mosquito-> humans/horses (dead ends)
encephalopathy 1%
-meningitis, encephalitis, post infection tremor, others
non-specific fever 21%
DX: IgM elisa, pcr

26

Dengue Virus

flaviridae
Hemorrhagic
dengue fever: break bone disease
-rash, fever, intense muscle/joint px
-masks more rare diseases in tropics
Dengue hemorrhagic fever
-frequently lethal
-2nd dengue type cross reaction (AB dependent enhancement)

27

Yellow fever virus

flavividae
Hemorrhagic
Initial phase (non-specific)
-fever, HA, chills, back px, decreased appetite, N/V
Toxic phase (visceral; 15%)
-hemorrhagic fever, jaundice, cardiovascular shock
Vaccine- live attenuated

28

spirochetes

Related to G-, LPS
endoflagella
treponema-syphilis
leptospira
borrelia- relapsing fever and Lyme disease

29

Hepacivirus genus

flaviviridae
Hep C, "non a non b" hepatitis
highest risk of transmission IV drug use
usually chronic-> twenty years to have symptoms (cirrhosis, HCC)
screening
-every body 1945-1965
-if Elisa +-> RT-PCR confirmation
CD8+ tcell mediated
viral titer variable, AB response is slow

30

togaviridae

enveloped, +RNA, icosohedral
larger than flaviviridae
-contrast: produce full length and subgenomic RNA
alphaviurses (arboviruses)
-west and east equine encephalitis
--crow (amplify)-> mosquito-> humans/horses (deadend)
--SX: mild fever/HA to encephalitis
No TX or vaccine

31

rubella

togavirus
transmission: resp or intrauterine
3rd childhood exanthem
SX: rash, fever, arthalgia
congenital rubella
-deafness, blindness, mental retardation, heart disease
Vaccine: live attenuated

32

rubella

togavirus
transmission resp or intrauterine
3rd clinical exanthem
sx: rash, fever, arthralgia
congenital
-death, blind, mental retardation, heart disease
Vaccine-live attenuated

33

coronavirus

enveloped, non-seg +RNA, helical
usually resp track but some GI
2nd leading cause of common cold
also SARS, MERS and some animal viruses

34

SARS

coronavirus
Bats->civet cats-> humans
10-20% mortality
viral pneumonia
-fevers, cough, sob, ha, alveolar damage
-syncital formation
-mixed cytololytic/immunogenic pathogenesis

35

MERS

coronavirus
originated in Saudi Arabia
bats-> camels -> humans
similar pathology to SARS
vaccines in developement

36

caliciviruses

naked 30 nanometer icosohedral +RNA
very stable
fecal oral
types
-norwalk and norwalk like-> noroviruses
-HepE

37

norovirus

calicivirus
world wide
common on cruise ships
#1 case of non bacterial diarrhea

38

HEV

calicivirus
FO
endemic in developing tropical countries
acute hepatitis without chronic infection

39

orthomyxoviruses

segmented -RNA (8, packed with RDRP) helical enveloped
types
-influenza A- variable
-influenza B- not variable
-influenza C- mild uri
important structure
-HA: hemaglutinin (16 serotypes)-VAP, must be cleaved by serine protease
-NA: neuraminidase: (9 serotypes), required for cleaving sialic acid for exiting
M1: matrix
M2: ion channel; escape endosome by acidification

40

paramyxoviruses

enveloped, helical, -RNA
similar life cycle to orthomyxovirues
-differences
--replication in cytoplasm
--doesn't steal caps from mRNA
types
-mumps
-measles
-parainfluenza
-respiratory syncitial virus
-metapneumovirus

41

mumps

paramyxovirus
path
-parotitis,
-neck swelling
-orchitis-> sterility
-40% symptomatic

42

measles

paramyxovirus
rubeola (1st childhood exanthem)
path
-first koplik spots (buccal)- prodrome
-high fever
-pneumonia
-possible encephalitis
--infection of neurons
--immune mediated post infection encephalitis
--subacute sclerosing pan-encephalitis
major killer of infants and toddlers in africa

43

parainfluenza

paramyxovirus (1-4)
-type 4 > mild uri
-1-3 > severe resp infection-> immunity short lived
--87% of croup
no tx or vaccine

44

respiratory syncitial virus

paramyxovirus
leading cause of bronchiolitis
-LRT infection
-syncitial cells cause airway plugging
pneumonia
possible encephalitis
no long term immunity
winter infection
tx: ribavirin- not very effective; IVIG

45

metapneumovirus

paramyxovirus
recently indentifed/ not growable
associated with bronchiolitis
15% common cold in children

46

Rhabdoviridae

Rabies virus
enveloped, helical, bullet shaped, -RNA
zoonosis: mostly bats
-bites and aerosol
replicates in muscle, slow progression to clinical symptoms
Pathology-negri bodies
post exposure tx
-clean, passive immunity, vaccine

47

bunyaviruses

enveloped -RNA, segemented (3) helical
Hantaviruses
-sin nombre and snl viruses
--murin vector (deer mice and other rodents)
--pan american zoonosis
--aerosolization of excreta
-La crosse virus
--arboviruse
--small rodent>mosquito> humans (dead end)
--encephalitis (2nd leading cause of arbo encephalitis, 1st WNV)
-other bunyaviruses
--California encephalitis
--rift valley fever virus
--crimean-congo hemorrhagic fever virus

48

Reoviridae

naked, icosohedral, dsRNA, segmented
world wide spread
FO
members
-reoviruses
-rotaviruses
--#1 cause of sever GE in children world wide (mortality)
--disrupt epithelium
--2 vaccines: 3 doses 6 to 32 months

49

herpes

Large dsDNA icosohedral, enveloped
eight types
Alpha- blister
-HSV-1
-HSV-2
-VSV (HHV-3)
Beta mono herpes
-HCMV (HHV-5)
-HHV-6
-HHV-7
Gamma
-EBV (HHV-4)
-KSHV (HHV-8)

50

HSV-1

herpes virus
common world wide, close contact spread
symptomatic and asymptomatic shed
infection site
-initial: mucocutaneous surfaces> cytopathic
-spread to sensory nerves (trigeminal ganglion)
--reactivation damage T cell mediated
primary infection sites
-primary gingivostomatitis
-ocular herps
-herpetic whitlow-fingers
-genital herps
dx
-multinucleated giant cells and inclusion bodies
TX acyclovir and foscarnet

51

HSV-2

herpes virus
less prevalent than HSV-1 (more in women) but more severe
usually spread sexually, frequently unkown
latent in spinal ganglia
primary disease
-asymptomatic
-genital herps
-neonatal herps (mostly HSV-2)
-primary gingivostomatitis (mostly HSV-1)
tx same as HSV-1

52

VSV

herpes virus
resp spread, no asymptomatic shedding
pathogenesis
-primary infectionreplication in macrophages and pneumocytes
-traffics through lungs to other organs
-week 2 skin lesions
-infection spread by cough and sneeze
-latency> ascends neurons to sensory ganglia
zoster reactivation
-follows dermatomes, may cause post herpetic neuralgia
vaccine-live attenuated
TX> IVIG, nucleoside analogs (acyclovir like)

53

eptstein barr virus (HHV-4)

herpes gamma
ubuiuitous, rate of acquisition depends on demographics
close contact-kissing
symptomatic and asymptomatic shed
pathogenesis
-primary in oropharanx-lytic
-spreads to circulating B cells
-swollen nodes and spleen
-productive replication in B cells
-latency also occurs
--reactivation> reinfection of oropharanx for shed
-B cell controlled by CD8 T cells
initial SX: fever, pharyngitis, lymphadenopathy, hepatosplenomegaly
Cancers
-B cell lymphoma, african burkett's lymphoma, nasopharyngeal carc

54

CMV

Beta herpes virus
world wide; acquisition rates depends on demographics
close contact, sex
symptomatic and asymptomatic shed
-saliva, urine, cervical fluid, semen, milk
primary
-mono syndrome- like EBV c more visceral adenopathy
congenital
-most common infectious cause of birth defects
-deaf, vision impair, developmental abnorm
-passed through placenta
TX- canciclovir, foscarnet

55

HHV-6

Beta herpes
nearly ubiquitous, close contact
asymptomatic and symptomatic shed
pathogenesis
-spread by saliva
-latency in T cells, monocytes and macrophages
disease: exanthem subitum- roseola, fever
no vaccine
TX: camciclovir

56

HHV7

beta herpes
rarely associated with disease
spread like HHV6
can cause roseola

57

HHV-8/Kaposi sarcoma virus

gamma herpes
Low prevalence, sexual spread
symptomatic and asymptomatic shed
common in aids
Path
-infects B cells, endothelium, monocytes and sensory nerves
-latency in B cells
-shed in saliva and semen
Immune suppressed
-endothelial tumors
-castlemens's disease
-1degree effusion lymphoma
TX- underlying immune deficiency

58

Poxviruses

larges viruses, enveloped, complex, linear DNA
life cycle
-makes all enzymes necessary for DNA and RNA
replication in the cytoplasm
types
-orthopox-small, cow, monkey pox, vaccina
-parapox-orf-goats
-yatapox
-moluscum contagiosum- direct or fomite

59

polyomaviruses

small, naked, circular dsDNA
life cycle
-replicate in nucleus
-early and late transcripts
ubiquitous resp spread
systemic-kidneys, cns, bm
reactivate with immunosuppression
-BK: urinary tract disease
-JK: progressive multifocal leukoencephalopathy
--white matter disease with no inflamation
No Tx
New discovered
-KI and WU: resp disease
-Merkel cell virus- merkel cell carcinoma

60

papilomavirus

icosohedral, DNA virus
E7 blocks RB
E6 blocks p53

61

adenovirus

naked icosohedral linear dsDNA
interacts with CAR receptor
life cycle
-nuclear replication, host RNA machinery
-viral DNA via DDDP
-lytic egress
infects FO or resp route
-conjunctiva, nose, mouth, RT, GI
path- intranuclear inclusions
no tx of vaccine

62

Parvoviruses

Fifths disease, B19
smallest DNA virus, naked, icosohedral ssDNA
hairpin loops serve as privers for DDDP
replicates in nucleus (host DNA and RNA machinery)
primary infection cytopathic
second phase type III rash and arthritis
-lingering arthritis in adults
-aplastic anemia with preexisting RBC disorder (sickle cell)
congenital
-hydrops fetalis
-fetal loss
-fetal anemia
no vaccine, maybe IVIG

63

6 childhood exanthems

1. measles- vacc
2. scarlet fever- GAS- no vacc
3. VZV- vacc
4. rubella, german measles- vacc
5. parvovirus no vacc
6. HHV6-roseola no vacc

64

primary syphalis

Non tender chancre

65

secondary syphylis

systemic
fever, sore throat, lymphadenopathy, HA rash on palms and soles
possible nephrotic syndrome (type III hypersenitivity)
-nephritis, arthritis, arthralgia
condylomata lata

66

tertiary syphilis

after latency period
- 4 years: late latency
gummas: nonprogressive granulomatous dermal lesions 20%
neurosyphilis: paralytic dementia, AML like disease, meningitis, seizure, optic atrophy 7%
great vessel aneurysms: 10%