Microbiology Flashcards
1
Q
What type of organism is neisseria gonorrhoea
A
Intracellular gram neg diplococcus
both chlamydia and gonorrhoea are intracellular- but chlamydia can’t be cultured- hence do NAAT for both!
2
Q
Treatment of gonorrhoea
A
IM Ceftriaxone single dose 1g
3
Q
Name of chlamydia bacteria
A
Chlamydia trachomatis
4
Q
What bacteria is chlamydia trachomatis
A
Obligate intracellular gram-ve that can not be cultured on agar
5
Q
Typical presentation of chlamydia
A
Asymptomatic especially in women (80%)
Men get dysuria and discharge
Women get vaginal discharge and bleeding
6
Q
How are chlamydia infections classified
A
By serovars
A-K
7
Q
Division of chlamydia serovars and where they affect
A
A-C- trachoma
D-K- genital chlamydia
L1,2,3 are cause of LGV
(A-see (C) is trachoma)
(D-K affects your DicK)
8
Q
What is trachoma
A
The keratoconjunctivitis cause by chlamydia trachomatis- most common infective cause of blindness worldwide
9
Q
What happens in trachoma
A
Keratoconjunctivits and then can get downward curling of eyelashes into the eye
10
Q
Treatment for chlamydia
A
Doxycycline
2nd line azithromycin
11
Q
What is lymphogranular venereum
A
Infection of the lymphatics by chlamydia trochomatis L1-3
12
Q
Which people does LGV occur in
A
Typically those in endemic regions by more recently MSM
13
Q
Complications of chlamydia PID
A
Tubal factor infertility
Ectopic pregnancy
Chronic pelvic pain
14
Q
Disease course of LGV
A
Primary stage (3-12 days)- painless ulcers, proctitis, balanitis and cervicitis
Secondary stage (2wks-6mths)- painful inguinal buboes, fever, malaise
Late LGV- inguinal lymphadenopathy, genital elephantiasis. frozen pelvis, perianal ulcers
15
Q
Diagnosis of LGV
A
NAAT to detect L1-3
16
Q
What bacteria causes syphillis
A
Treponema pallidum- obligate gram negative spirochaete
17
Q
What are the stages of syphillis infection
A
Primary
Secondary
Latent
Tertiary
18
Q
Primary syphillis
A
Painless solitary genital ulcer that developed from a macule -> papule
Regional adenopathy
single, indurated, painless ulcer = chancre
19
Q
How long after transmission do you get ulcer in syphillis
A
1-12 weeks
20
Q
What is a chancre
A
Ulcer seen in primary syphillis
21
Q
Secondary syphillis
A
Disseminated syphilis
Get systemic bacteraemia after syphilis reaches the lymphatics
Fever, malaise, lymphadenopathy
Maculopapular rash on trunk -> limbs -> soles and palms
Genital warts (condyloma lata)
22
Q
How do condyloma acuminate appear
A
Smooth white and painless
23
Q
What happens in latent syphillis
A
Asymptomatic but still a serological infection
24
Q
3 types of tertiary syphillis
A
Gummatous- skin/bone/mucosa granulomas (gumma = granuloma) BARELY ANY SPIROCHAETES here
Cardiovascular- aortic dilation and aortitis
Neurosyphilis- tabes dorsalis, argyll-robertson pupil, dementia/any focal neurology
ARP = near-light dissociation
syphillis has predisposition to aorta
25
What is tabes dorsales
Degeneration of the posterior spinal chord
Get loss of proprioception and vibration
## Footnote
get ataxic gait as lack of proprioception
26
What is argylles robertson pupil
Lose light reflex but not the accommodation reflex
27
What is investigation for neurosyphilis
CSF spirochaetes
28
How is syphilis diagnosed
Spirochaetes seen in primary lesions using dark microscopy
Confirmed using serology
Non-treponemal
- RPR
- VDRL
- anti-cardiolipin
BUT CAN GET FALSE POSITIVE SO NEED TO CONFIRM WITH....
Treponemal
- T pallidum haemoaglutinin test
29
Which tests can be used to monitor syphilis treatment
Non-treponemal tests. RPR in particular
Ideally will see a 4 fold decrease
## Footnote
as treponemal tests +ve for whole life! even when cleared e.g. EIA
30
Treatment for syphilis
- if penicillin allergic
Single dose IM benzathine penicllin (aka penicillin G)
Doxycycline if allergic
31
What is common reaction to syphilis treatment
Jarisch herxheimer reaction
Get flu like reaction which will clear in 24 hrs
## Footnote
as bacterial cells all die simultaneously so release of toxins
32
What is congenital syphilis
Where baby gets syphilis infection from birth or pregnancy
Presents with symptoms over first couple of years
- rash
- fever
- neurosyphilis
- pneumonitis
33
What is chancroid caused by
Haemophilus ducreyi- gram neg coccobacilis
34
Symptoms of chancroid
Mutliple painful ulcers
Inguinal lymphadenopathy
## Footnote
ducreyi aka 'do cry' hence painful
35
How is chancroid diagnosed
Culture on chocolate agar, PCR
## Footnote
chancroid and chocolate agar (ch and ch)
36
What causes donovanosis
Klebsiella granulomatis- gram negative bacillus
Typically seen in African, Indian, aborigenese populations
37
What are beefy red ulcers seen in
Donovanosis (aka granuloma inguinale)
38
How is donovanosis diagnosed
Giemsa stain of biopsy
See Donovan bodies
39
Treatment for donovanosis
Azithromycin
40
What causes trichomoniasis
Flagellated protozoa- trichomoniasis vaginalis
## Footnote
watch microscope vid- https://en.wikipedia.org/wiki/Trichomonas_vaginalis
41
Problem with trichomoniasis
Increased risk of HIV infection
## Footnote
The damage caused by T. vaginalis to the vaginal epithelium increases a woman's susceptibility to an HIV infection.
42
How is bacterial vaginsosi diagnosed
Amsel criteria- must have at least 3/4
- white discharge
- pH above 4.5
- clue cells on microscopy
- positive whiff test
## Footnote
AMSEl criteria
Adherent bacteria (clue cells: vaginal epithelial cells that have bacteria adherent to surface) + Milky discharge + Stench (strong amine odour) on KOH whiff testing + Elevated pH (4.5+)
need>= 3/4 for Dx of BV
43
What are clue cells
Vaginal epithelial cells with bacterial rods on the cell membrane
44
What is the whiff test
Done in bafcterial vaginosis
Add potassium hydroxide to discharge- if positive will get fishy odour
45
What happens if get molloscum contagiosum if immunosuppressed
Widespread lesions
46
What are condylomata acuminate
Genital warts
NOT Seen in secondary syphilis - condyloma lata
HPV 6 or 11 (low risk strains)
47
How are viral warts diagnosed
Clinical diagnosis
48
How are viral warts treated
Hyperkeratotic- cryotherapy
Soft non-hyperkeratotic- podophyllotoxin
49
Who is podophyllotoxin contraindicated in
Pregnant women
## Footnote
toxic to embryos
50
CXR of HIV child with diffuse changes but is well
Lyphoid interstitial pneumonitis
## Footnote
Lymphocytic interstitial pneumonia (LIP) is a syndrome secondary to autoimmune and other lymphoproliferative disorders. Symptoms include fever, cough, and shortness of breath. Lymphocytic interstitial pneumonia applies to disorders associated with both monoclonal or polyclonal gammopathy.
Possible causes of lymphocytic interstitial pneumonia include the Epstein–Barr virus, auto-immune, and HIV.
51
What proportion of children will get HIV from untreated mothers
1/3
52
How can HIV be transmitted vertically
Breastfeeding (hence CI in this country, in LEDC countries more promoted as lack of other nutrition)
In utero
Intra partum
53
What is main predictor of vertical transmission of HIV
Viral load after primary infection settles
54
What is miliary TB
Disseminated haematogenous spread of TB
55
Initial investigations for TB
CXR- see upper lobe cavitation
3 sputum samples- if cant get sputum do BAL
Do NAAT to look for resistance
56
What is gold standard Ix for TB
Culture myobcaterium for 6 weeks on lowenstein jensen medium then do ziehl neelson stain
57
What type of bacteria are mycobacteria
ROd shaped gram positive non motile
## Footnote
'myco' as look like fungus/produce fungus like film
many but not all are intracellular
58
What is treatment for TB
RIPE for 2 months
Rifampicin and isoniazad for 2 more months
## Footnote
4 for 2 and 2 for 4
59
When do you treat TB for longer
Subacute meningitis
Potts disease
60
What is prophylaxis for TB
Isoniazid monotherapy
## Footnote
for latent TB think it's just R and I
61
Side effects of each TB medication
Rifampicin-orange secretions
Isoniazad- peripheral neuropathy (hence pyridoxine (B6) needed)
Pyrazinamide- hepatoxic, gout
Ethambutol- optic neuritis
62
Second line for TB
Amikacin
Kanamycin
Quinoloines
## Footnote
RIPE Apples (amikacin)
63
What is hansens disease
Leprosy
64
What is the organism which causes leprosy
Mycobacterium leprae
65
Presentation of leprosy
Skin depigmentation
Nodules
Trophic ulcers
Nerve thickness- causes sensory (tested with monofilament) and motor defects
## Footnote
derformities 2ndary to no sensation
66
What are lower resp tract infections
Broad term for lung infection- includes pneumonia, bronchitis, empyema, abscess
Tend to not have CXR changes
67
What is bronchitis versus pneumonia
Bronchitis- nflammation of medium sized airways- mainly in smokers
Pneumonia is infection of lung alveoli
68
Most common cause of HAP
Pseudomonas aeruginosa
## Footnote
HAP has AP ie PA (pseudomonas aeruginosa) in the name
69
What causes rusty coloured sputum CAP
S pneuominae
## Footnote
The sputum produced by those with S. pneumoniae is described as “blood-tinged” or “rust-colored,” however, the sputum produced by those infected by Klebsiella pneumoniae is described as “currant jelly.” The reason for this is that K. pneumoniae results in significant inflammation and necrosis of the surrounding tissue.
70
What type of organism is s pneumoniae
+ve diplococci
71
What type of organism is h influenzae
-ve cocco-bacilli
## Footnote
'influenzae' so -ve as name like a virus, cocco bacilli as name is like a virus so not 1 or the other. Haemophilus influenzae received its name because it was first isolated from the lungs of individuals who died during an epidemic of influenza virus infection in 1890.
chocolate agar
72
What bacteria causes grape bunch clusters
Staph aureus
## Footnote
Staphylococcus aureus, from the Latin aurum for gold (as eg gold crust of impetigo?), and Staphylococcus albus (now called epidermidis), from the Latin albus for white
73
What CAP seen in alcoholics
Klebsiella pneumonia
Often see haemoptysis
## Footnote
as huge inflammation with klebsiella
74
What type of organism is klebsiella
-ve rod, enterobacteriaceae
75
What organism associated with cavity in CAP
S aureus
## Footnote
also klebsiella and TB
76
What precedes staph aureus CAP
influenza infection
77
What is treatment for atypical pneumonias
Clarithomycin
## Footnote
atypicals don't have cell walls so penicillins don't work
78
Which pneumonia causes hepatitis and hyponatraemia
Legionella pneumophilia
## Footnote
high LFTs and low Na+ (hypoNa+ presents as confusion)
79
Presentation of mycoplasma pneumoniae
Dry cough
Arthralgia
Erythema multiforme
## Footnote
cold agglutinin also
80
Which pneumonia is associated with uni students/ boarding schools
Mycoplasma pneumoniae
81
Tests for mycoplasma
Cold agglutin test
82
What pneumonia is associated with birds
Chlamydia psitticae
83
Pneumonia in patient who just had bone marrow transplant
CMV
## Footnote
CMV can cause multi-organ disease after SCT including pneumonia, hepatitis, gastroenteritis, retinitis, and encephalitis.
84
What pneumonia in patients who have neutropenia
Aspergillus (fumigatus)
## Footnote
Aspergillus was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Micheli was reminded of the shape of an aspergillum (holy water sprinkler)
85
Which type of bacteria are splenectomy patinets at risk for pneumonia
Encapsulated bacteria
- H.influenzae
- S.pneumoniae
- N.meniningitidis
## Footnote
NHS
86
What bacteria are worried about in cystic fibrosis
Pseudomonas aeruginosa
Burkholderia cepacia (absolute CI to lung Tx)
87
Investigations for pneumonia
CXR
Sputum MC&S- consider BAL if non-productive
Work out CURB-65
88
Investiations if atypical pneumonia
Legionella urine antigen (other urine AG is strep p)
Serum antibody tests (mycoplasma)
## Footnote
atypical as virus like presentation + harder to culture
89
Crtieria for CURB-65
Confusion
Urea- >7
RR- >30
BP- <90/60
65- aged older than 65
90
Treatment for CURB 65 0-1
Oral amoxicillin 5 days
Allergic to penicillin- clarithomycin
## Footnote
0u1patients
91
Treatment for CURB65 2
Oral amoxicillin and oral clarithomycin
Consider admission
92
Treatment for CURB65 3-5
IV co-amoxiclav
IV clarithomycin
Admission
## Footnote
ITU 3 letters so 3+ CURB
93
1st line for HAP
Ciprofloxacin and vancomycin
## Footnote
vanc for MRSA? cipro (fluoroquinolone) for pseudomonas?
94
2nd line for HAP
Tazocin and vancomycin
## Footnote
MRSA and pseudomonas?
95
Aspiration pneumonia treatment
Tazocin and metronidazole
got 2 problems - anaerobic gut bact (+ some gram +ve) and pneumonitis
## Footnote
Bacteria involved in aspiration pneumonia may be either aerobic or anaerobic.[12] Common aerobic bacteria involved include:
Streptococcus pneumoniae[13]
Staphylococcus aureus[13]
Haemophilus influenzae[13]
Pseudomonas aeruginosa[13]
Klebsiella: often seen in aspiration lobar pneumonia in alcoholics
Anaerobic bacteria also play a key role in the pathogenesis of aspiration pneumonia.[14] They make up the majority of normal oral flora
96
What are some causes of HAP
Pseudomonas
Haemophilus
S aureus
Klebsiella
## Footnote
Mnemonic – All Hospital Pneumonias Kill (Aureus, haemoph, pseudomonas, klebs)
97
Best treatment if confirmed pseudomonas
Tazocin and gentamicin
98
What organism is common causative agent in young females UTI- not most common though
Staphylococcus saphrophyticus
## Footnote
i think about 20% of 20 y/os with UTI (women)
99
Which antibiotics inhibtis cell wall synthesis
Beta lactams
Glycopeptides
## Footnote
hence gram -ves with thin cell wall (but outer membrane)- b lactams and glycopeptides not effective against them
100
What are the beta lactams
Penicillin
Cephalosporin
Carbapenems
101
How do beta lactams work
Inactivate the enzymes involved in cell wall synthesis (transpeptidases)
Only work when bacteria dividing (remember eagle effect!)
Bactericidal
## Footnote
inhibit PBPs so no cross linking of PG cell wall
102
Why dont beta lactams work against mycoplasma and chlamydia
Lack peptidoglycan cell wall
## Footnote
as gram -ve
103
Why dont beta lactams work on abscesses
Bacteria arent dividing
Also not divinding in biofilms
## Footnote
eagle effect
104
How can s aureus defend against penicillin
Produce beta lactamases
## Footnote
ESBLs
105
Coverage of each methicillin antibiotics
Penicillin- gram positive, streptococci, clostridia
Amoxicillin- quite a broad spectrum- covers more gram negatives
Flucloxacillin- produced to replace penicillin. More stable to beta lactamse
106
How does clavlulanic acid and tazobactam work
Beta lactamase inhibitor- given with penicillins
107
What is tazocin
Combination of piperacillin and tazobactam
108
What is different between different gen cephalosporins
Increasing generations increases cover against gram negative and pseudomonas
All are stable to beta lactamase
109
What are extended spectrum beta lactamases
Enzymes which can act agaisnts cephalosporins
Increasingly common in E coli and klebsiella
110
Advantage of carbapenems
Stable to ESBL enzymes
## Footnote
very powerful drugs so use with caution- as best defence (can't afford resistance to develop)
111
What is used by bacteria against carbapenems
Carbapenemase produced
112
Key features of beta lactams
Non toxic
Renally excreted
Short half life
Dont cross BBB- but can if meninges inflammed (hence why can be used in meningitis)
113
What are glycoppetides active against
Gram positive- c diff, MRSA
Cant do gram neg as too large to pass through cell wall
## Footnote
MRSA resistant to methicillin hence penicillins
114
Disadvantage of vancomycin
Nephrotoxic
Must monitor
115
MOA of glycopeptide
Inhibit transpeptidase and transglycoside enzymes in cell wall cross links
116
Abx which inhibit protein synthesis
Tetracyclines
Aminoglycoside
Macrolides
Chloramphenicol
Oxazolidinines
TAMCO
117
Problems of aminoglycoside
Nephrotoxic and ototoxic
118
Indication of aminoglycosides
Gram negative
## Footnote
amiNoglycosides ans gram Neg
119
Indication of tetracycline
Intracellular pathogens- chlamydia and mycoplasma
## Footnote
e.g. doxy for chlamydia infection
120
Who cant you give tetracyclines to
Children
Pregnant women
## Footnote
in kids- associated with impaired bone growth and permanent discoloration of teeth and enamel hypoplasia
can give >12s
121
Indication of macrolides
Gram+ in penicillin allergy
Atypical penumonia
**Campylobacter**
## Footnote
gram +ves obvs as if pen allergic, and used alongisde beta lactams for atypical pnuemonias
122
Indication of chloramphenicol
Eye drops- bacterial conjunctivitis
## Footnote
rememebr grey baby syndrome- CI in kids
Each ribosome is composed of small (30S) and large (50S) components, called subunits, which are bound to each other:
(30S) has mainly a decoding function and is also bound to the mRNA
(50S) has mainly a catalytic function and is also bound to the aminoacylated tRNAs.
chloramphenicol inhibits the 50S ribosomal subunit, preventing peptide bond formation.[40] Chloramphenicol directly interferes with substrate binding in the ribosome, as compared to macrolides, which sterically block the progression of the growing peptide
complete side note- tetracyclines irreversibly stain teeth if given to children
123
INdications of oxalizininoes
Gram+ve
MRSA and VRE
124
Which Abx inhibit DNA synthesis
Fluoroquinolones
Nitroimidazole
## Footnote
quinolones and gyrase
nitro as DNA contains nitrogenous AAs - metronidazole (key for anaerobes! and protozoan)
125
Fluroquinolones indications (ciprofloxacin)
Gram negative
126
Indications of nitroimidazole
Anaerobes and protozoa
127
Which antibiotic is nitrofurantoin similar to
Metronidazole
## Footnote
think e coli (nitro in UTI)- e coli is facultative anaerobe (ie anaerobic but if O2 available releases ATP via aerboic resp)
nitrofuran and nitroimidazole
128
MOA of rifamycins
Inhibit RNA synthesis
129
Indications for rifamycins
Mycoplasma
Chlamydia
TB
130
Which antibiotics target cell membrane through toxins
Polymyxin
Cyclic lipopeptide
## Footnote
Polymyxins are antibiotics. Polymyxins B and E (also known as colistin) are used in the treatment of Gram-negative bacterial infections. They work mostly by breaking up the bacterial cell membrane.
bind to LPS- Lipopolysaccharides (LPS) are important outer membrane components of gram-negative bacteria.
131
Example of polymyxin
Colistin- gram negative
132
Example of cyclic lipopeptide
daptomycin- gram +ve, MRSA, vancomycin resistant enterococcus
133
Which antibiotics inhibit folate metabolism
Sulfonamides (sulfamethoxazole)
Diaminopyrimidines (trimethoprim?)
134
What is indication of sulphonamides
PCP
Combine sulphamethoxazole and trimethopin
## Footnote
pcp = co-trimoxazole
135
Mechanisms of resitance
Bypass antibiotic sensitive step
Enzyme mediated drug inactivation
Impair accumulation of the drug
Modify the target of the drugs
**BEAT**
136
Give an example of bacteria inactivating the antibiotic
Beta lactamases
carbapenemases
137
Give an example of alered target
MRSA
Encodes gene (mecA) which produces a novel penicillin binding protein which cant bind to the antibiotic
138
How is strep penumoniae resistant
Stepwise mutations in PBP- if low resistance increase the dose
Is an issue in meningitis as not many beta lactams can cross the BBB
139
Mechanism of macrolide resistance
Altered target by **methylating ribosome**- reduces the bindnig
Encoded by erythromycin ribosome methylation gnes
## Footnote
50s ribosomes as macro
aminoglycosides are 30s
140
Most common reaction to antimicrobial agents
GI upset
141
Factors which affect prescribing abx for a patient
CHAOS
Host characteristics
Antimicrobial susceptibilities
Organism itself
Site of infection
142
What is MIC
Minimum amount of antibiotic needed to stop growth in a bacteria in vitro
## Footnote
minimum inhibitory concentration
remember type 1,2,3 (type 1 = amniglycosides, 2= beta lactams, 3= macrolides)
143
When must specimens for cultures be taken
Before start Abx
144
First investigation done on culture
Gram stain
## Footnote
Gram staining differentiates bacteria by the chemical and physical properties of their cell walls. Gram-positive cells have a thick layer of peptidoglycan in the cell wall that retains the primary stain, crystal violet. Gram-negative cells have a thinner peptidoglycan layer that allows the crystal violet to wash out on addition of ethanol. They are stained pink or red by the counterstain,[3] commonly safranin or fuchsine. Lugol's iodine solution is always added after addition of crystal violet to strengthen the bonds of the stain with the cell membrane.
Gram staining is almost always the first step in the identification of a bacterial group.
145
Other than gram stain what tests will be done on bacteria in microbiology
Immunofluorescence
PCR
146
When do you do gram stain
CSF
Joint aspirate
Pus
147
How long is N meningitidis treated for
10 days
## Footnote
can be hard to cross BBB
148
How long is Acute osteomyelitis treated for
6 weeks
## Footnote
hard to target bone
149
How long is Infective endocarditis treated for
6 weeks
150
If patient hasnt responded in 48 hours to abx what could be cause
Actually have infection?
Catheter
Infective endocardiitis
## Footnote
abscess?
151
Most narrow spectrum for e coli
Amoxicillin
152
What is an opportunistic infection
Organism which does not normally cause disease or where symptomology becomes worsened based off the patients immune system
Can be endogenous- reactivated
Exogenous
153
What causes oral thrush and CMV retinitis
HIV
## Footnote
ie indicates aids
154
Sources of infection in SCT?
Virus from graft
Viral reactivation in host
Infection from social contact
155
Order of greatest relative risk of opportunistic viral infection
Steroids
Cytotoxic chemo
Monoclonal AB therapy (depends on specifics)
Solid organ transplant (as ongoing immunosupp)
HIV (as untreated- no T cells)
Allogenic stem cell transplant
156
What does JC virus cause
Progressive multifocal leukoencephalopathy
157
What does PML cause
Get demyelination of white matter leading to personality changes, cognitive dysfunction and focal neurology
158
What causees haemorrhagic UTI (haemorrhagic cystitis) post stem cell transplant
BK virus
v rare complication
The BK virus rarely causes disease but is typically associated with patients who have had a kidney transplant; many people who are infected with this virus are asymptomatic
## Footnote
The BK virus, also known as Human polyomavirus 1, is a member of the polyomavirus family. Past infection with the BK virus is widespread,[1] but significant consequences of infection are uncommon, with the exception of the immunocompromised and the immunosuppressed. BK virus is an abbreviation of the name of the first patient
159
Prophylaxis for monkeypox
Small pox vaccine
160
Treatment for monkey pox
Analgesia (as viral infection)
Tecovirimat if very severe
## Footnote
Tecovirimat SIGA is a medicine to treat smallpox, monkeypox and cowpox, three infections caused by viruses belonging to the same family (orthopoxviruses). It is also used to treat complications that can happen following vaccination against smallpox.
161
Where is natural resevoir for influenza A
Ducks- any water bird
162
What are 2 types of influenza
A and B
163
What are 2 spike proteins in influenza
Haemaglutinin
Neuraminidase
164
Risks of aminoglycosides
Ototoxic
Nephrotoxic
165
Side effect of tetracyclines
Light-sensitive rash
166
Why dont use chloramphenicol in neonates
Risk of aplastic anaemia
Get grey baby syndrome in neonates as cant metabolise the drug
167
Risks of oxazolidinones
Thrombocytopenia
Optic neuritis
168
MOA of fluoroquinolones
Binds to alpha subunit of DNA gyrase
Bactericidial
169
MOA of nitroimidazoles
Rapidly bactericidal
## Footnote
as blocks DNA synthesis
for anaerobes! i.e. metro for gut bact
also used for protozoa
170
MOA of rifampicin
DNA dependant RNA polymerase is target
Bactericidal
171
Why is rifampicin so susceptible to resistance
Get rapid resistance as chromosomal mutations lead altered target in the beta subunit of RNA polymerase
172
When is only time give rifampicin alone
Prophylaxis in meningococcal infection
173
Which bacteria use beta lactamases as their major mechanism of resistance to Beta lactams
Staph aureus
Gram negative bacili- E coli and pseudomonas
NOT MRSA and streptococci
174
How is MRSA resitant to beta lactams
Encodes gene (mecA) which produces a novel penicillin binding protein which cant bind to the antibiotic
175
How are e.coli and klebsiella becoming resistant to Cef
ESBL
## Footnote
they are gram -ve cocci - cefalexin has some gram -ve cover? ESBL by def = resistant to cephalosporins
176
What is bacteriuria
Presence of bacteriuria
Not necessarily pathogenic as common in elderly in particular
Get commensal bacteria in urethra
177
What is a complicated UTI
This occurs in people with structurally abnormal urinary tracts- catheters, calculi
Normally occurs in men and patients with catheters
178
Most common infective organism in UTI
E.coli but this is done by a select group of serovars
179
Organism if getting recurrent UTIs
Pseudomonas
180
Which bacteria is associated in presence of renal stones
Proteus mirabilis
181
Antibacterial host defence in Urinary tract
Urine- pH, organic acids, osmolality
Urine flow
Musoca has cytokines
182
What increases risk of UTI structurally
Literally anything which interferes with urine flow or abnormalities
Neurogenic dysfunction too
183
What increases risk of UTI in children
Vesicoureteral reflux
184
What is common cause of abscesses in kidney
If haematogenous then staph aureus- IE
Rarely see gram negative bacilli abscesses from haematogenous route- typically ascending
185
How treat abscess in kidney caused by s aureus
IV flucloxacillin
186
How does UTI present in elderly patients
Tend to be non-specific
Abdo pain
Change in mental status
187
Which patients dont you do urine dip in
Those over 65 as often have bacteria in tract anyway
As false +ves (non pathological bacteriuria common)
188
When is only time treat asymptomatic bacteriuria
Pregnancy
189
What does mixed growth suggest on urinary MCS report
Poorly taken sample
Only reports it 1 orgnaism predominate
190
What are squamous cells indicative of on urine dip
Contamination
191
What can sterile pyuria suggest
Prior treatment with abx
Calculi
TB
Bladder neoplasm
STI
192
Which is main risk factor for candida UTI
Catheter
193
Treatment for catheter UTI
Can give stat aminoglycoside and then remove it
194
Complications of pyelonephritis
Abscess
Chronic
Septic shock
Acute papillary necrosis
195
UTI guidelines for women under 65 for investigations
Once ruled out pyelo and other vaginal/sexual health causes of symptoms
Does have
- dysuria
- new nocturia
- cloudy urine
If has 2 or more do urine culture
If has 1 do urine dipstick
196
Urine dip guidelines for women under 65 urine dip
If nitrite positive or leukocyte and RBC positive UTI likely- send for culture and give consider abx or back
If neg nitrite and pos leukocyte UTI equally likely as other diagnoses- send for culture and give consider abx or back
If all neg isnt UTI
197
What should be interpreted as positive UTI on urine culture
Culture of over 10^4/5 colony forming units unless E.coli or staphylococcus saprophyticus where 10^3 colony forming units
10^5 colony forming units mixed growth with 1 orgnaism predominating
ALWAYS IN CONJUNCTION WITH SYMPTOMS
198
Treatment for pyelonephritis
IV co-amoxiclav and gentamicin
## Footnote
ciprofloxacin?
199
Treatment for uncomplicated female UTI
Cephalexin PO 3 days or nitro oral 7 days
200
Treatment for uti if female or breastfeeding
1st line cefalexin oral 7 days
2nd line co-amoxiclav
If allergic consult micro
201
Treatment for UTI if male
Cephalexin for 7 days
If suspect prostatis ciprofloxacin 14 days
202
Treatment for UTI chronic prostatitis
Oral cipro for 4-6 weeks
203
Treatment for urosepsis
Aminoglycoside
204
Treatment for catheter associated UTI
Give macrolide before removal
205
What tests cant you use in an immunocompromised patient
Serology
206
What is done if immunosuppressed patient becomes unwell
Screening based on syndromes
- csf
- resp
- gut biopsy
- blood
207
How does HSV present in immunocompromised
Mouth ulcers
Oesophagitis
Pneumonitis
Hepatitis
DOES NOT INCREASE RISK OF ENCEPHALITIS
208
Where does herpes lie latent
Sensory neurones
Dorsal root ganglia (eg HSV-1 commonly trigeminal ganglion, HSV-2 sacral ganglia)
209
How can varicella present in immunocompromised
Pneumonitis
Encephalitis
Hepatitis
Progressive outer retinal necrosis- PORN
Acute retinal necrosis
Multidermatomal shingles is herpes zoster not varicella!
210
How can varicella present in immunocompromised in neo-nates
Purpura fulminans
211
How can zoster present in immunocompromised
Shingles that is multidermatomal
212
How is varicella treated in immunocompromised
IV aiclovir until no new lesions, PO until all crusted
213
How is zoster treated in immunocompromised if disseminated
IV aciclovir and analgesia
214
What is post transplant lymphoproliferative disease
When immunosuppressed B-cells containing latent EBV get polyclonally activated
## Footnote
i.e. body is immunosupressed (in either HSCT or SOT) so EBV can drive B cell proliferation!
215
When does post transplant lymphoproliferative disease occur
Solid organ transplant
Allogenic haematopoietic stem cell transplant
216
How is post transplant lymphoproliferative disease confirmed
Lymph node biopsy
Suspicion when see rising EBV and CT scan
217
What are issues of EBV in immunosuppressed
Onchogenesis
B-cell lymphoma
Post transplant lymphoproliferative disease
218
Management of EBV when immunosuppressed
Rituximab
Reduce immunosuppression
## Footnote
EBV has preference for B cells!
219
What is diagnosis of african kids with big jaws
Burkitts lymphoma
220
Where does CMV lay dormant
In dendritic cells so in transplants, some are transplanted
## Footnote
just hoe ebv has a preference for B cells, CMV has a preference for dendritic cells
221
Which patients is CMV a problem in
SCT
HIV with CD4 under 50
222
How do cells with CMV appear
Owls eye inclusions
223
How does CMV present
Encephalitis
Polyradiculopathy
Retinitis
Pneumonitis
Colitis
224
Treatment for CMV
1st line-Ganiciclovir IV or valganciclovir PO
2nd line- Foscarnet
3rd line- Cidofovir
225
What is difference in challenges between CMV in SOT vs HSCT
SOT- problem is if donor is positive as immunosuppressed patient now has disease
HSCT- problem is if recipient is positive as new immune system naive to it
226
How is CMV infection prevented post transplant in HSCT vs SOT
HSCT- CMV viral load measured twice weekly for 100 days
SOT- Valganciclovir for 100 days
227
What is problem of ganiciclovir
Suppresses the BM
228
What is problem of cidofovir and foscarnet
Nephrotoxic
229
How is progressive multifocal leukoencephalopthy diagnosed and treated
MRI and CSF PCR
Cidofovir
230
Which immunocompromised patients specificay is JC virus seen in
Mycophenolate
MS patients on Natalizumab
231
Where does the BK virus reside
Kidney
## Footnote
remember as bK K for kidney
232
How does BK virus present in renal transplant patients versus in BMT
Renal transplant- BK nephropathy
BMT- haemorrhagic cystitis
233
Treatment for BK virus
Cidofovir- nephrotoxic so also reduce immunosuppression
234
What can happen to Hep B in immunocompromised
Carriers will have flare up
Those who have had infection will reactivate
235
How to prevent Hep B
Lamivudine
Tenofovir and entecavir
236
How can monkeypox present
Atypical rash
Fever
Myalgia
Pain
Lesions on penis and anus
237
Complications of monkeypox
Rectal perforation
Penile oedema
238
Treatment for monkeypox
Analgesia and supportive
If severe tecovirimat
239
Define PUO
Depends on the category but all with fever over 38.3
Classic- over 3 weeks and at least 3 days of hospital evaluation
Nosocomial- admitted over 24 hours ago with no fever, evaluated for 3 days
Immune deficient- neut count under 500 and eval for over 3 days
HIV- confirmed case, lasted over 4 weeks as outpatinet, 3 days outpatient
240
What are 4 types of PUO
Classic
Nosocomial
Immune deficient (neutropenic)
HIV-associated
## Footnote
CHIN
241
When does IgG begin to rise
After 2 weeks
242
PUO from lebanon
Brucella
243
What is unique for adult onset stills
Very high ferritin from macrophage activation
244
PUO malignancy
NHL
Leukaemia
RCC
HCC
245
What to do if patinet with PUO and recent travel history
Refer to RIPL
Rare and imported pathogen lab
246
How are zoonoses classified
Companion versus wild
Tropical versus UK
247
Resevoir for salmonella
Poultry
Reptiles/amphibians
248
How is salmonella transmitted
Contaminated food
Poor hand hygiene
249
3 types of shigella
Shigella sonnei- watery diarrhoea
Shigella flexneri- bloody diarrhoea fever aswell with antibiotic resistance
Shigella dysenteriae-
## Footnote
acc sonnei, flexneri, dysenteriae + 4th type (boydii)
250
Presentation of cat scratch disease
Macule at site of innoculation which can become pustular
Local adenopathy
Systemic symptoms
251
Investigations of bartonella henselae
Serology
Do histopathology with bacillary angiomatosis
252
Resevoir for toxoplasmosis
Cats
Sheep
253
Resevoir for brucellosis
Cattle
Goats
## Footnote
direct contact/milk
254
Transmission of brucellosis
Unpasteurised milk
Undercooked meat
Mucosal splash
Aerosolisation
255
Presentation of brucella
Fever which peaks in evening (undulating fever)- normally just this
Back pain
Orchitis
Focal abscesses (granulomatous hepatitis)
256
Management of brucellosis
Doxycycline plus streptomycin
257
What causes Q fever
Coxiella burnetii
258
Resevoir for coxiella
Goats
Sheep
Cattle
259
Transmission of Q fever
Aerosolisation of secretions/waste of farm animals
260
Resevoir of rabies
Dogs
Bats
261
Cause of rabies
Lyssa virus
262
Presentation of VHF
Flu like illness with fever
Bleeding
263
Management of VHF
Supportive
264
Investigations for VHF
PCR
Serology
265
Infection with renal pulmonary syndrome
Hanta virus
## Footnote
mouse reservoir
266
How is herpes diagnosed
Lesion swab for PCR
267
What causes foetal herpes infection
Ascending infection in premature rupture of membrane
268
What are 3 types of gential herpes infection
Primary infection- 1st episode of genital HSV
Non-primary infection- 1st episode of genital HSV (HSV-2) but antibodies to HSV1
Recurrent- infection but with antibodies to HSV (can be symptomatic or asymptomatic)
269
What is main problem of HSV in pregnancy
Main problem is primary infection in final trimester
- greatest risk of transmission so if active HSV in last 6 weeks fo C-section
270
Complications of HSV infection in utero-infection
Miscarriage
Congenital abnormalities- ventriculomegaly, CNS abnormalities
Preterm
IUGR
271
How does neonatal HSV eye disease present
Excessive eye watering and conjunctival erythema
Can get periorbital vesicles
272
Complications of maternal varicella
Varicella pneumonia
Encephalitis
## Footnote
as state of immunocompromise
dont forget FVS
273
What do if maternal CMV suspected in pregnancy
Check serology then refer to fetal medicine for USS
Urine and saliva CMV PCR within 21 days of birth
274
How will CMV infection present in pregnancy
Maculopapular rash
Mononucleosis presentation
275
What type of virus is rubella
Togavirus- positive sense ssRNA
276
Rubella presentation in pregnancy
Prodrome pre rash
Macular rash which is mildly pruritic
Starts on face spreads to trunk and limbs rapidly
277
Examination finding of rubella infection
Tender
Post auricular/cervical/suboccipital
Forchheimer spots on palate (these are red
278
Rubella infection in pregnancy implications
Early infection within 10 weeks- abortion and fetal defects common
Later from 13 weeks associated with hearing defects and retinopathy
279
Infacny presentation of congenital rubella syndrome
PDA
VSD
Microcephaly
Purpura
Hepatosplenomegaly
## Footnote
congenital deafness, congenital cataracts, learning disability, CHD (PDA, pulmonary stenosis)
rememebr I love (heart) ruby earrings
280
Later presentations of congenital rubella syndrome
Intellectual disability
Hearing loss
Cataracts and retinopathy
DM very late
## Footnote
i heart ruby earrings
281
Difference in rash in measles and rubella
Rubella- very fast progression from face to trunks
Measles- starts at hairline/ear then spreads cephalocaudally
282
Presentation of measles
Prodrome for a few days
Conjunctivitis
Koplik spots
Rash
283
What is name of measles virus
Morbillivirus
## Footnote
ie makes you morbid
284
Complications of meales
Pneumona
Secondary bacterial infection
Otitis media (the most common complication)
Encephalitis (SSPE)
285
Measles complications in pregnancy
Typically no abnormalities
Can lead to fetal loss and preterm delivery
Can get subacute sclerosing panencephalitis 7-10 years after infection
286
Presentation of parvovirus 19 infection in pregnancy
Slapped cheek and rash
Polyarthropathy
Fever and malaise
287
Difference in complications of parvovirus B19 across pregnancy
Before 20 weeks- hydrops fetalis, foetal anaemia and HF
After 20 weeks- no documented risk
288
Management of parvovirus B19 infection during infection
Refer to fetal medicine for monitoring with possibility of intrauterine transfusion
289
How can enteroviruses present
Hand foot and mouth
Encephalitis
Myocarditis
290
Which enterovirus presents with most severe outcomes in newborns and what can cause
Cocksackie
- fulminant hepatitis
- encephalitis
- bleeding
291
What type of virus is zika
Enveloped falvivirus positive sense ssRNA
292
How can zika virus present in newborn
Severe microcephaly and craniofacial disproportion
Deafness and retinopathy
Talipes
Hypertonia
293
Zika virus advice
If pregnant avoid the areas where prevalent
Only get tested if symptomatic or abnormalities identified on antenatal USS
294
Causes of surgical site infections
If abdo- likely to get gram neg like Ecoli
If joint likely to be staph aureus
Pseudomonas another common cause
295
How are surgical site infetions diagnosed
Colony of over 10^5 microorganisms
296
What are 3 levels of SSI
Superficial incisionial- skin and subcut
Deep incisional- affects muscle and fascial
Organ/space infection- any part of anatomy other than incision
297
Risk factors for surgical site infection
Obesity
DM
Old age
RA
298
What are the factors involved with preventing SSI
Hair removal
Showering
Reduced number of people in the room
Positive air ventialtion
Aseptic surgical technique
299
What is significant risk factor for septic arthritis
Rheumatoid arthritis
300
Rfs for septic arthritis
Any arthritis
Joint prosthesis
IV drug use
DM
Renal diseases
Any trauma
301
What are some techniques for pathogenesis in joints for bacteria
S aureus has a receptor for fibronectin
Kingella kingae adheres to synovium with pili
302
What is associated with fulminant septic arthritis
Strains producing rhe PVL (panton valentine leucocidin) cytotoxin
303
Organisms which cause septic arthritis
Staph aureus most common
Streptococci pneumonia
Strep pyogenes
Ecol
H influenza
Neisseria gonorrhoea
Rare- TB, brucella, lyme
304
What diagnoses septic arthritis
Synovial count over 50,000 WBC cells/mm3
Negative culture does not exclude however
305
Management of septic arthritis
Culture then give abx- iv ceph or fluclox
Synovial fluid aspiration for MCS
Arthroscopic washout may be needed
306
Best imaging for septic arthritis
MRI
Use US for guided aspiration
307
What are causes for vertebral osteomyelitis
Acute haematogenous
Disc surgery
CNS spread
308
Most common cause of vertebral osteomyelitis
S aureus
Strep
Gonorroea
Most commonly lumbar
309
Most sensitive imaging for vertebral osteomyelitis
MRI
310
When get osteomyelitis what causes can cause granuloma
TB
Brucella
311
What are brodies abscesses
When get chronic osteomyelitis of pyogenic source in cancellous (metaphyseal) bone
Normaly in children at proximal or distal tibia
312
Management of osteomyelitis
Culture
IV abx
MRI
Bone biopsy for culture and histology
313
How can chronic osteomyelitis be treated surgically
Masquelet technique
1. Removal of foreign bodies; filling the defect with antibiotic 2. loaded cement spacer and external fixation
In 6-8 weeks , remove the cement spacer, and fill the defect with autologous bone graft
314
Causes of prosthetic implant infection most likely cause
Coagulase negative staphylococci (epidermis)
315
How can prosthetic implant infection be managed
2 ways
- on histopathology infection defined as over 5 neutrophils per high power field
- intraoperative micro sampling taken from at least 5 sites and if 3 specimens yield infection of same source then indicative of infection
316
Desaturation after walking around a room
PJP
## Footnote
or PE
317
How is h influenzae becoming resistant to typical abx
Production of beta lactamase
318
Difference in susceptibility of amoxicillin and fluclox to beta lactamase
Fluclox very stable however amox very susceptible
319
Give an example of each gen cephalosporin
1st gen- cephalexin
2nd gen- cefuroxime
3rd gen- ceftriax, cefotaxime
320
How is adult onset stills disease diagnosed
At least 5 criteria with 2 or more major
Major
- temp over 39 for 1 week
- leukocytes over 10,000
- typical rash
- arthralgia over 2 weeks
Minor
- sore throat
- lymphadenopathy
- splenomegaly/hepatomegaly
- faulty LFTs
- negative ANA or RF
DONT NEED TO KNOW EXACTLY JUST BE AWARE
321
Investigation and mangement of salmonella
Investigation- stool culture
Management- ciprofloxacin (against gram -ves) and azithromycin
## Footnote
salmonella is gram -ve rod (as enterobacteriaciae)
322
What diseases does bartonella henselae cause
Cat scratch disease
Bacillary angiomatous in immunocompromised
323
How does bacillary angiomatosis present
Cat bite
Skin papules around area
Disseminated multiorgan and vascular involvement
324
Management of cat scratch disease versus bacillary angiomatosis
Both need erythomycin and doxycyline
Add rifampicin if bacillary angiomatosis
325
Presentation of toxoplasmosis
Fever
Adenopathy
In adult flu like
326
Managment of toxoplasmosis
Spiramycin
Pyrimethamine
## Footnote
acc. Rx is pyrimethamine + sulfadiazine, in pregnat give spiramycin to stop foetal infection
327
Presentation of q-fever
Fever
Atypical pneumonia
Can cause- pneumonia, endocarditis, epatitis, focal abscesses
328
Management of q fever
Doxycycline
329
Presentation of rabies
Seizures
Excessive salivation
Agitation
Confused
Headache
330
Investigation and management of rabies
Serology
Brain biopsy
Management- IG, vaccine
331
When bitten by rats what are often the resposible organisms
Streptobacillus moniliforms
Spirillum minus
## Footnote
both causes of rat bite fever
332
Presentation of rat bite fever
Fever
Polyarthralgia
Maculopapular rash developing to purpuric rash
333
Investigation rat bite fever
Joint fluid MCS
334
Management of rat bite fever
Penicillins
335
Which mycobacterium cause TB
M. tuberculosis- not just!
336
How does mycobacterium avium present
Disseminated disease resembling TB in immunocompromised
337
What given if isoniazid resistant TB
Levofloxacin
338
What type of virus is influenza
Negative sense segmented genome (8 segments)
339
Difference between antigenic drift and shift
Drift- accumulation of point mutations from error prone RNA polymerase which changes antigenicity
Shift- recombinatino of genomic material from 2 co-infecting strains leads to completely novel strain
340
What are 2 main phenotypes of influenza virus and their role
Haemagglutin- binds to sialic acid receptor allowing entry of virion
Neuraminidase- cleaves sialic acid on exitting from cell which disreupts mucin barrier
341
What are the antivirals available for influenza and what are their target
Oseltamivir- neuraminidase inhibitor
Zanamivir- neuraminidase inhibitor
Amantadine- M2 protein inhibitor
342
Treatment of influenza
Oseltamivir- neuraminidase inhibitor
343
What is used in treatment of influenza if underlying lung disease or immunosuppressed
Zanamivir
344
What sort of vaccine is given to under 18s for influenza
Live attenuated
## Footnote
LAIV- 2-17 y/os
345
What sort of vaccine is given to those at risk of influenza virus
Inactivated subunit rich in haemagglutin
## Footnote
e.g. elderly, asthmatics?
346
What type of virus is coronavirus
Single stranded positive sense RNA virus
347
What does SARS COV 2 bind to
ACE2
348
Treatment for COVID19
Dexamethasone
Remdesivir
349
How are viruses screened for/ monitored in an immunosuppressed patient undergoing a treatment
Viruses are screened for beforehand with serology
Then after become immunosuppressed we monitor using PCR as serology doesnt work as well in these patients
350
What is difference in immunosuppression between solid organ transplant and HSCT
SAT- induction immunosuppression (i.e. high dose to stop acute rejection) and then maintenance
HSCT- undergo conditioning regime beforehand with total body irradiation or cyclophsophamide to eradicate immune system (making space for SCs and less rejection). Then have ongoing to prevent graft versus host disease
## Footnote
key in SOT main principle is to stop rejection
in HSCT - stop GvHD and allow acceptance
351
How is HSV treated in immunocompromised
Aciclovir
NOTE IS INCREASED RESISTANCE IN THESE PATIENTS
352
What is the MOA of aciclovir, ganiciclovir and valganiciclovir
Competitive guanosine analogue which inactivates DNA polymerase (nucleoside analogue)
353
MOA of cidofovir
Cytidine analogue terminator
354
MOA of foscarnet
Non-competitive inhibitor of viral DNA polymerase
355
What is ramsay hunt syndrome and what causes it
Varicella
Facial nerve palsy with vesicles in the ear
356
How is ramsay hunt treated in immunocompromised
Aciclovir and steroids
357
When on rituxumab or other B cell therapies which infection are particularly worried about reactivating
Hep B
358
Problem of Hep A if immunosuppressed and how manage
More severe infection
Vaccinate
## Footnote
remember vaccine only for hep A and B
359
Problem of Hep C if immunosuppressed and how manage
Increased fibrosis
Traet with NS3/4 protease inhibitors- telapravir
360
Problem of Hep E if immunosuppressed and how manage
Chronic infection
Reduce immunosuppression
361
How is Hep B treated
Interferon alpha
Lamivudine
Entecavir and tenofovir
362
MOA of lamivudine
nucleoside reverse transcriptase inhibitor (HIV) + nucleoside analogue (HBV)
363
MOA of tenofovir
Nucleotide analogue
364
How is Hep C treated
Peg inteferon alpha
Telaprevir
Ledipasvir
365
MOA of telaprevir
NS3/4 protease inhibitor
366
MOA of ledipasvir
NS5A inhibitor which blocks release
367
How does monkeypox present
Atypical rash on genitals and perianal area
Systemic effects
368
What is pathophysiology of prion disease
Prion proteins normally found in the brain however can undergo transformation to beta pleated sheet (form alpha helices) insoluble version where all normal prion proteins are triggered to undergo the conversion
## Footnote
chromosome 20 PRPN gene
369
What is the most common prion disease
Sporadic creutzfield jacob- also has the most rapid deterioratino
370
What is classficaion of prion diseases
Sporadic- CJD
Acquired- variant CJD, Kuru, iatrogenic from surgical tools or transplants
Genetic conditions
371
Presenation of sporadic CJD
Older person
Rapid dementia
Myoclonus
Cortical blindness (problem is in brain)
Aphasia
LMN weakness
372
Investigations for sporadic CJD
EEG- periodic triphasic complexes
MRI- basal ganglia and cortical increased signal
CSF- 14-3-3 protein, S100
DIAGNOSIS CONFIRMED ON BRAIN BIOPSY
373
What are the CSF markers of sporadic CJD
14-3-3 protein
S100
374
Brain biopsy of sporadic CJD
Spongiform vacuolation
PrP amyloid plaques
375
Presentation of variant CJD
Younger person
Initial psych presentation of hallucinations, depression and paranoia
Then get dementia, myoclonus and sensory abnormalities
376
Investigations for variant CJD
MRI- pulvinar sign
Tonsillar biopsy
Neurogenetics- all MM variant of PrP
377
What is pulvinar sign on MRI seen in
Variant CJD
378
What are the familial prion diseases
Fatal familial insomnia
Gerstmann-straussler strackman
All will present with family history of someone dying of MS, dementia etc
379
What causes kuru disease
Cannibalistic feasts leading to cerebellar symptoms and dementia
380
What prion disease are florid plaques seen in
Variant CJD
381
How is prion diseases treated
Treat myoclonus- clonazepam
Delay conversino to PrPsc- Quinacrine
382
What genetic polymorphism is associated with prion diseases
Codon 129- MM
383
Presentation of HSV in neonates
Most cases- skin, eye mouth disease (SEM herpes)
Chance of progression to CNS involvement with lethargy, seizure and poor feeding
Can also get disseminated disease with multorgan failure sepsis
## Footnote
rememebr SEM, DIS and CNS disease
384
What subunits do antibiotics affecting protein synthesis bind to
30s
- aminoglycoside
- tetracycline
23s
- oxazolidinones
50s
- chloramphenicol
- macrolides
ALL BACTERIOSTATIC EXCEPT FOR AMINOGLYCOSIDE WHICH BACTERIACIDAL
## Footnote
TAMCO
385
To what antibiotic is the method of resistance: bypassing antibiotic sensitive step
MRSA
Also encodes MECA for altered target
## Footnote
also e.g. trimethoprim resistnce
386
To what antibiotic is the method of resistance preventing accumulation of drug
Tetracycline
## Footnote
efflux pumps
387
Examples of live vaccines
MMR
Yellow fever
BCG
Under 18s flu
388
Example of inactivated vaccines
Influenza
Cholera
Polio
Hep A
Pertussis
## Footnote
always ripp for the killed
389
Examples of toxoid vaccines
Tetanus
Diphteria
390
Examples of subunit vaccines
Hep B
HPV
391
Example of conjugate vaccine
HIB
Meningococcus
Pneumococcus
392
Example of heterotypic vaccine
BCG?
## Footnote
a vaccine e.g. used on humans but of another animal
e.g. BCG uses mycobacterium bovis
393
Examples of viral vectored vaccines
Ebola
AZ COVID vaccine
394
Examples of nucleic acid vaccines
Pfizer and moderna COVID vaccines
395
What happens in viral vectored vaccines
Incorporate genetic material into DNA of virus that does not cause harm in humans
396
What is risk of using chimp adenovirus
Vaccine induced thrombocytopenia and thrombosis
Capillary leak syndrome
Seen in AZ covid vaccine
397
Risk of pfizer covid vaccine
Myocarditis
398
Ways to get CNS infection
Haematogenous spread
Direct implantation- instruments
Local extension- cribriform plate abnormality
PNS into CNS- rabies
399
Pathogenesis of neuro damage meningitis
Bacterial toxicity
Excessive inflam response
Hypoperfusion or seizures from systemic hypoperfusion
400
Most common n.meningitidis form
B
401
Meningococcal septicaemia problems
Capillary leak- hypovolaemia
Coagulopathy
402
Causes of chronic meningitis
TB
Crytococcus
Spirochetes
403
Complications of TB meningitis
Granulomas
Abscesses
Cerebritis
404
Aseptic causes of meningitis
Enteroviruses
HSV
405
Encephalitis causes in UK
HSV
Enteroviruses
More recently flaviviridae- western nile virus
406
Bacterial cause of encephalitis
Listeria
407
Amoebic causes of encephalitis
Naegleria fowleri which inhabits warm water in the UK
408
Parasitic causes of encephalitis
Toxoplasma gondii
409
Spinal abscess causes
Iatrogenic
Haematogenous spread- IVDU in particular
410
Best imaging for brain infections
MRI
411
What do HHV6 and HHV7 cause
Exanthema subitum
412
What activates aciclovir
Viral thymidine kinase
413
2nd line for HSV and VZV
Foscarnet
Cidofovir
414
Prophylaxis for CMV before tansplants
Solid organ transplant- valganciclovir
BMT- letermovir
415
How is zanamavir given
Inhaled if uncomplicated
IV if serious
416
Treatment for severe RSV
Ribavirin
IVIG
417
How is RSV prevented
Palivisumab
418
When treat monkeypox with tecovirimat
Over 100 lesions
Near eyes
Sepsis
419
How is BK haemorrhagic cystitis treated
Cidofovir
420
Where does adenovirus affect
GI
Conjunctiva
Resp infection
421
Treatment for severe adenovirus
Cidofovir
422
What is test for hep A
Anti-HAV IgM
423
How long do you need to be HBsAg +ve for to be classed as chronic hep B
Over 6 months
424
What does positive HBeAg suggest
Active virus replication
425
MOA of entacavir
Nucleoside analogue
426
Test for acute Hep E
Immunocompetent- HEV IgM and IgG
Immunosuppressed- HEV PCR
427
What are the 3 types of helminths
Cestodes
Trematodes
Nematodes
428
Examples of nematodes
Ascarid
Strongyloide
429
Examples of trematodes
Schistomiasis
430
Definitive host of tapeworm
Human
431
What is cystericosis
Parasitic infection of brain tissue with larvae containing taenia solium
432
Management of tape worms and hydatid
Praziquantel
## Footnote
albendazole? as well
433
What is host of hydatid
Dog
434
Proper name for tape worm and hydatid
Tapeworm- taenia solium
Hydatid- echinoccus
435
Treatment of schistomiasis
Praziquentel
436
Host for schistomiasis
Human veins
437
What is the most common malaria
Plasmodium falciparum
438
How are malarias classfied
Plasmodium falciparum versus non falciparum
439
What is most common non-falciparum malaria
Plasmodium vivax
440
What classifies severe malaira
Parasitaemia over 2%
441
What is investigation for malaria
Thick and thin blood smear x3
442
Difference between thich and thin blood films
Thick- screen parasiets
Thin- identify species and quanitfy parasitaemia
443
Management of falciparum malaria
Mild- riamet
Severe- IV artesunate
444
Management of non-flaciparum malaria
Chloroquine
445
Prsentation of dengue fever
Fever
Rash- sunburn
Arthralgia
Myalgia
Coming back from urban areas in south east asia
## Footnote
breakbone fever
saddle back fever
retro-orbital headache
446
Problem of dengue fever
If reinfected with different serotype then get haemorrhagic fever
- bleeding from gums
- haematemesis
- GI bleeding
447
What transmits dengue
Aedes mosquito
448
What type of bacteria is typhoid
Gram negative flagellated rods
449
What causes enteric fever
Typhoid
450
Most common cause of adult onset epilepsy worldwide
Cystericosis
451
Congenital toxoplasmosis presentation
Majority asymptomatic but then go on to develop low IQ, deafness and microcephaly
If symptomatic
- choroidretinitis
- microcephaly
- intracranial calcifications
- hepatosplenomegaly
452
What is classed as neonatal infection and what predisposes infants
Onset in first 4-6 weeks of life
Risks
- immune system not mature
- prematurity as IgG not passed over, exposure to organisms in hospital
453
What type of bacteria are GBS
Gram positive coccus
Catalase negative
454
Late onset sepsis causes
Coagulase nagative staphylococcus
S.aureus
Enterococcus
Klebsiella
Pseudomonas
455
What is invasive pneumoccal disease
Where get strep pneumoniae cultured in blood or in normally sterile area
Problem is that pneumococcal vaccine does not cover all of the strains
456
Which age group of children does mycoplasma pneumoniae tend to affect
3-4 year olds
Get epidemics
457
Complications of mycoplasma infection
Haemolysis (IgM to I antigen on erythrocyte in 60% of patients)
Enchephalitis
Cardiac
Joint problems
Otitis media
458
What consider in children when resp infections fail to respond to abx
Bordatella pertussis
TB
459
What are fungi
Eukaryotic organisms
- Chitinous cell wall
- Ergosterol membrane
460
Difference between yeast and moulds
Yeasts- single celled which reproduce by budding
Moulds- multicellular hyphae which grow by branching and extension
461
Examples of yeast
Candida
Cryptococcus
462
Examples of moulds
Dermatophytes
Aspergillus
Murcomycoses
463
Most common cause of fungal infection in humans
Candida
464
Candida presentations
Oral thrush
Oesophagitis
Vulvovagintis
465
Treatment for different candida infections
Oral thrush- topical nystatin
Vulvovaginitis- topical clotrimazole or oral fluconazole
Localised cutaneous- topical clotrimazole
Oesophagitis- oral fluconazole
466
How does candida appear compared to gram positive cocci on gram stain
Larger and more ovoid
467
Rfx for candidaemia
Burns
Malignancy
Long lines
468
Management of candidaemia
Beta-D-glucan
Echo to rule out endocarditis
Fundoscopy
Echinocandin (caspofungin, anadulafungin)
469
Where can invasive candida occur and what are the rfx for them
CNS- dissemination, trauma
Endocarditis- abnormal/prosthetic valves, long lines, IVDU
UTI= catheters
Bone and joint- dissemination, trauma
Intra-abdominal- peritoneal dialysis, perforation
470
Which cryptococcus affects immunocompetent patients
Cryptococcus gatti (serotypes B&C)
471
Which animal does cryptococcus associate with
Pidgeon
472
Management of cryptococcus
Amphotericin B and flucytosine
473
Management of mild pulmonary cryptococcus disease
Fluconazole
474
What measure serologically in candida
Beta-d glucan
475
What measure in aspergillus serologically
Galactomannan
Aspergillus antibodies
476
Management of aspergillus
Voriconazole
477
Management of PJP
Co-trimoxazole
478
Why do antifungals not work on PJP
Lacks ergosterol in cell membrane
479
What is elevated in PJP serologically
Beta-d glucan
480
What are mucormycoses
Rhizopus species
481
Management of mucormycosis
Amphotericin B
482
Cellulitis of orbit with black discharge from palate and nose
Proptosis and opthalmoplegia
Mucormycosis
483
Organism for tinea pedis and cruris
Tricophyton rubrum
484
Organism for tinea capitis
Tricophton rubrum or tonsurans
485
Cause of onchomycosis
Tricophyton unguium
486
What causes piyriasis versicolor
Malassezia furfur
487
What are dermatophytes
Fungi which invade dead keratin of skin, hair and nails
488
What are the 3 targets of antifungals
DNA synthesis
Cell wall
Cell membrane
489
Which antifungals target the cell membrane
Polyene
- amphotericin and nystatin
Azole
490
How do azoles work
Inhibit lanosterol 14 alpha demethylase which converts lanosterol to ergosterol
491
How do polyenes (amphotericin B work)
Binds sterols in fungal cell membrane which causes electrolye leak
492
Main side effect of antifungals which target cell membrane
Nephrotoxic
493
Which antifungals target the cell wall
Echinocandins
494
How do echinocandins work
Inhibit beta d glucan
495
Management of non-albicans candida
Echinocandins
496
Which antifungals inhibit DNA synthesis
Pyrimidine analogues- flucytosine
497
How does flucocytisine work
Affects DNA synthesis
498
Which viruses belong to herpesviridae family
VZV
CMV
HSV
HHV6
HHV8
EBV
499
What is virology of herspesviridae viruses
Enveloped dsDNA
500
What are the polyomaviridae
BK
JC
501
What is virology of polyomaviridae
Unenveloped dsDNA
Adenovirus is too as why all treated with cidofovir
502
What are the flaviviruses
Hep C
Dengue
503
Coagulase negative versus positive staph
Staph aureus- positive
Staph epidermis- negative
504
Virology of Hep A and E
Unenveloped positive sense ssRNA genome
505
Virology of Hep B
Enveloped DNA with RNA hybrid
506
Virology of Hep C
Enveloped positive ssRNA
## Footnote
flavivirus
507
Management of Hep D
Peginterferon alpha
508
What are the treatment options for Hep C and how remember names
previr- NS3/4 protease inhibitors
asvir- NS5A protease inhibitor
uvir- direct polymerase inhibitor
509
How is leptospirioris transmitted
Swimming in contaminated waters
Rats urine
510
How does bacillus anthrax present
Cutaneous- Painless black round lesions
Pulmonary- Mediastinal haemorrhage
511
Which countries is leishmaniasis endemic to
India
South America
East africa
512
What spreads the protozoa leishmaniasis
Sandflies
513
Where does leishmaniasis divide
Macrophages
514
How does cutaneous leishmaniasis present
Open sore that takes a year to recover and scars
515
How does muco-cutaneous leishmaniasis present
Oral and skin ulcers
516
How does visceral leishmaniasis present
Hepatosplenomegaly
BM failure- anaemia, infections
Hyperpigmentation
517
What use to diagnose superficial versus deep fungal infections
Superfical - woods lamp
Deep- serological
518
MOA of ritonavir
Protease inhibitor
519
Name for brucella organism
Brucella melitensis
520
What type of organism is brucella
Small gram negative cocco-bacilli
521
What medium is used for brucella melitensis
Castenadas
522
Management of leishmaniasis
Amphotericin B
523
Which bacteria commonly causes infantile diarrhoea
Enteropathogenic e coli
524
What are the paramyxoviruses
RSV
Mumps
Measles
Parainfluenza
