Infectious diseases Flashcards
Measles
RNA paromyxovirus
Rash from behind ears
Koplik spot
Warthin finkeldy giant multinucleate cells
pneumonia, otitis media, keratitis, encephaitis
subacute sclerosing panencephalitis
at risk if vit A defic - blindness
Mumps
RNA paromyxovirus
parotid, orchitis, pancreatitis, asceptic meningitis
acute transient viruses
measles
mumps
polio - 1% symptomatic
west nile virus
viral haemorrhagic fever
alpha latent viruses
Infect epithelial cells, latent in neurons
HSV1, HSV2, VZV
Beta latent viruses
lymphotropic, invade variety cell types
CMV, HHV6 (roseala infantum), HHV7
Gamma latent viruses
EBV, HHV8 (kaposi assoc)
latent in lymphoid cells
CMV cells
owls eye
large cells, large inculsion bodies surrounded by halo
pleomorphic
EBV
atypical cytotoxic T cells
mono
reed sternberg like cells
assoc B cell neoplasm and burkitts
HPV
DNA virus
infects squamous epithelial
6&11 low risk
16&18 high
proteins E6+7 supress p53
Staph aureus virulence factors
surface protein aderence host cells
enzymes e.g. lipase S degrades lipids
toxins - alph beta, superantigens(TSS)
proteins causing AB resistance
Beta haemolytic trep
group A - pyogenes - pharyngitis, scarlet fever, erysipelas, impetigo, rheumatic fever, toxic shock, neck fasc, GN
group B - agalacticae - female genital tract, chorioamnionitis, neonatal sepsis
Alpha haemolytic strep
pneumoniae - CAP, meningitis
viridans - mutans group caries and endocarditis
Strep virulence factors
GBS + pneum - encapsulated
Pneum - pneumolyin destroys cell membranes
pyogenes - m protein inhibits complement and destroys cell membranes, exotoxin causing fever and rash (scarlet)
Encapsulated bacteria
Group B Streptococcus (agalacticae), Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Escherichia coli, Salmonella species, Klebsiella, and Pseudomonas aeruginosa.
Yes some killer bacteria have pretty nice capsules
Diphtheria
gram +ve rod
grey exudate over pharynx or skin
membrane off -> bleeding risk asphyxiation
upper airway infections –> heart and nerves
AB toxin
Listeriosis
INTRACELLULAR gram +ve rod facultative anaerobe
food bourne
still birth and neonatal sepsis
NK cells early, T cells late
gram +ve intracellular bacilli in CSF
Intracellular bacteia
Legionella, Listeria, and Mycobacterium.
Obligate - mycoplasma, rickettsia
Anthrax
gram +ve spore forming rod, facultative anaerobe
cutaneous - fine
resp - death
GI - 40% mort
AB toxin
Neisseria
gram -ve aerobic diplococci ENCAPSULATED
meningitides - lots of serotypes, 10% mort
gonorrhoea - 2nd most common STI, neonatal conjunctivitis
invade non ciliated epithelia CD46
has OPA protein
Pertussis
gram -ve aerobic coccobacillus
dx PCR
invades ciliated epithelial cells
AB toxin
+ toxin paralyses cilia
Pseudomonas
opportunistic gram-ve aerobic rod
sever in CF, burns, neutropenic
AB toxin
phospholipase C lyses RBCs and surfactant
Elastase degrades ECM
necrotising inflamation
Infections caused by pseudomonas
HAP
keratitis (contact lenses)
swimmers otitis externa
hot tub folliculitis
necrotic lesions in burns
endocarditis IVDU
osteomyelitis IVDU
catheter associated UTI
Mantoux test false
-ve - overwhelming viral infection, other viral, sarcoid, malnutritino, immunosupression
+ve - vaccination, atypical mycobacterium
TB interleukins
dendritic -> IL12 -> Th1 -> TNFy
Leprosy types
mycobacterium
tuberculoid - less severe, granulomas, asymmetrical Th1
lepromatous - symetrical, invades schann cells Th2
Syphillis
trepenema pallidum
gram -ve spirochete
primary - single chancre
secondary 2-10w - fever, multiple lesions inc palms and soles, asymptomatic neurosyphilis
tertiary - cardiac aortitis, neuro, benign gumma
Lyme
gram -ve spirochete
borrelia burgdorferi
1. spirochetes in dermis, erythema marginatum
2. migratory joint pain, arrhythmia, meningitis, lymphadenopathy
3. arthropathic large joints, can have neuropathy and encephalitis
no toxins produced - damage from host response
C perfringens
gram +ve anaerobic rod spore forming
cellulitis, myonecrosis, surgical gas gangrene, food poisoning
degrades ECM with hyaluronidase an collagenase
alpha toxin releases phospholipase C degrading membranes RBCs, plts and muscles
C tetani and botulinum
gram +ve anaerobic rod spore forming
tetani - neurotoxin causing inc muscle tone, spasm, lock jaw, prevents release inhib neurotransmitters
botulinum - inhibits ACh release, flacid paralysis
c difficile
gram +ve anaerobic rod spore forming
toxin A - fluid secretion and inflam response
toxin B - cytotoxin - cell death
Chlamydia
obligate intracellular rod, gram -ve
needs host for ATP
asymptomatic male and female
most common STI
dx amplified nucleic acid test
Rickettsia
obligate intracellular gram -ve rod
vector transmission
epidemic typhus
scrub typhus
rocky mountain spotted fever
ehrlichiosis
Candida
can shift phenotypes
binds to cell with integrins and agglutinins
forms biofilm
systemically can cause abscesses
Th17
Cryptococcus
encapsulated yeast, polysaccharide capsule
bird dropping or soil
cavitating lung lesion, meningitis
stains red
Aspergillus
Mould
opportunistic in lung cavities
necrotising pneumonia
from lung to heart and brain
in neutropenic or steroid use
Resistance to malaria
point mutation globin - sickle
globin deficiency - thalassaemia
red cell membrane defect - DARC absence
red cell enzyme mutation - G6PD
prolonged repeat exposure
Virulence malaria falciparum
infect cell any age
red cell clumping
proteins inhibit cytokine production
antigenic variation
Protozoal illnesses
unicellular eukaryotic organisms
malaria
babesiosis - ticks
leishmaniasis - infllam skin, MMs, viscera
chagas - heart
african tryponosomiasis
Taenia solium
tape worm from pig
cysts (undercooked pork) - attac abdo wall, tape work grows in abdo
eggs (faecal food/ water)- through gut wall t blood -> cystericosis to brain, seizures
Schistosomiasis
fresh water snails
blood to liver
liver fibrosis
blood in stool
haematuria if in bladder
risk bladder SCC
tx praziquantel
Prions
lack RNA an DNA
in neurons
cause spongiform encephalitis
Human bite organisms
strep viridans
staph aureus
h influenzae
anaerobes
eikenella corrodens
Aschoff bodies
nodules fond in heart with rheumatic fever
RNA viruses
HCV, Ebola, SARS, influenza, polio, measles, mumps and retrovirus including HTLV-1 HIV
Causes aseptic meningitis
eterovirus
pleomorphism
raised wcc
raised protein
normal glucose
Osteomyelitis IVDU/ post UTI
E coli, Pseudomonas, and Klebsiella
Cholera
secretory diarrhoea
endotoxin - alpha subunit in cytoplasm activates adenyl cyclase which inc cAMP, open CFTR SI
Campylobacter
most common bacterial diarrhoea western world
chicken water milk
15% dysentry
flagella, adherence molecules, cholera like toxin
assoc GBS and arthritis
Shigella
unencapsulated
Gram negative rod facultative anaerobe
50% dysentery
high death
resistant to stomach acid
endotoxin
reiters and HUS
Salmonella
typhoid and non typhoid diarrhoea
typhoid dysentry SI
90% +ve BCs if febrile
Gram negative rod
Yersinia
pork, water milk
ilium, appendix, asc colon
reiters syndrome, GN, myocarditis
ETEC
enterotoxigenic
travellers diarrhoea
heat stable toxin inc cGMP
heat labile inc cAMP
SI
EHEC
enterohaemorrhagic
large outbreaks
dysentry, shigella like toxin
HUS, thrombotic thrombocytopenia purpura
EIEC
enteroinvasive
no toxins
colitis
dysentry
EAEC
enteroaggregative
fimbrae
shigella like toxin
non bloody diarrhoea
assoc aids
viral gastro
noro - rna most common
rota - dna - most common kids
adeno - dna - second most common
What do rickettsia and chlamydia invade
Ricketsia endorhelium
Chlamydia epithelium
Gram positive rods
Clostridium (spore anaerobe)
Anthrax
Nocardia (aerobic)
Diphtheria
Listeria
Gram positive rods
Clostridium (spore anaerobe)
Anthrax
Nocardia (aerobic)
Diphtheria
Listeria
Paramyxoviridae
RNA
Measles
Mumps
Polio virus type
Enterovirus
RNA
Doesn’t enter dorsal root ganglion
Bacteria using phospholipase c
Pseudomonas
C perfringen
Bacillus cereus
Staph aureus
