Microbiology Flashcards
(299 cards)
1
Q
what type of organism causes gonorrhoea?
A
Neisseria gonorrhoea - obligate intracellular gram - diplococcus
2
Q
what does gonorrhoea develop into if left untreated when transferred to child from the birth canal?
A
Opthlmia neonatorum - neonatal conjunctivitis
3
Q
25 year old male with complement deficiency presents with tenosynovitis, dermatitis and polyarthralgia - likely diagnosis?
A
disseminated gonococcal infection (from Neisseria gonorrhoea)
4
Q
what is the gold standard for diagnosing Gonorrhoea?
A
Culture from smears - Rectal or urethral
5
Q
what is the difference in sensitivity when diagnosing gonorrhoea from either urethral or rectal smears?
A
urethral - 95%
rectal - 20%
6
Q
What is the treatment for gonorrhoea?
A
- ceftriaxone IM - 250mg single dose
OR
cefixime PO 400mg single dose
7
Q
How does symptomatic gonorrhoea infection manifest in women?
A
vaginal pruritus +/- mucopurulent discharge
8
Q
What % of gonorrhoea infections become complicated?
A
10%
9
Q
How does complicated gonorrhoea infection manifest?
A
prostitis in men
pelvic inflammatory disease (PID)/Salpingitis
10
Q
What is he most common cause of female infertility in europe?
A
Ascending complicated gonnorhoea infection resulting in PID / salpingitis
11
Q
What % of chlamydia is unsymptomatic?
A
80% female
50% men
12
Q
What organism causes chlamydia?
A
Chlamydia trachomatis - gram negative
13
Q
what are the complications of chlamydia?
A
PID, tubal factor infertility (TFI), risk of ectopic, risk of endometriosis, chronic pelvic pain, epidydimitis, reiters syndrome, adult conjunctivitis
14
Q
What serovars of chlamydia cause genital infection?
A
D-K
15
Q
How do you diagnose Chlamydia?
A
NAATs (nucleic acid amplification tests)
16
Q
Whats the Tx for uncomplicated chlamydia?
A
Azithromycin (1g) stat
doxycycline 100 mg BD 7/7
17
Q
what is the name for lymphatic infection with Chlamydia trachomatis?
A
lympho-granuloma venereum (LGV)
18
Q
What is the likely diagnosis when you see: painless genital ulcer, non-indurated, balanitis, proctitis (cerivcitis)?
A
Early LGV - 1st stage
19
Q
Which serovars are responsible for LGV?
A
L1 L2 L3 Chalmydia trachomatis
20
Q
What is the infectious agent causing syphilis?
A
Treponema pallidum - an obligate gram negative spirochaete
21
Q
Name the nontreponemal tests for syphilis
A
VDRL slide test - detects lipoidal antibody on both host and treponemal cells
RPR (modified VDRL)
22
Q
What are the 2 types of test for syphilis
A
Non-treponemal (RDR)
Treponemal (detects Abs from specific Treponema antigens - e.g. TPPA)
23
Q
Tx for syphilis
A
IM benzathine penicillin (or doxycycline if allergic)
24
Q
What tests must you do to diagnose Trichomonas vaginalis?
A
Wet prep microscopy, PCR
25
Tx for trichomoniasis vaginalis?
Metronidazole
26
How is BV diagnosed?
- microscopy of gram stain
- whiff test
- raised pH (more alkaline as vagina is naturally quite acidic)
- clue cells (epithelial cells coated with bacteria)
27
What is the Tx for Hep B infection?
- vaccine
- antivirals = interferon alpha
direct acting antivirals (DAAs)
tenofivir, entecavir,emtrictabine (esp with HIV infection)
28
What 5 tests would you do if you suspect hep C infection/.
```
Hep C antibodies (via immunoassay or recombinant immunoassay (RIBA)
NAATs
LFTs - ALT probably raised
viral genotype
transient elastography
```
29
Tx for Hep C?
- may have spontanous eradication (45% patients)
| - sofosbuvir therapy + velpatasvir
30
what is the difference between bacteriuria and cystitis?
bacteriuria = presence of bacteria in the urine - not necessarily a problem!
cystitis = inflammation of the bladder, often caused by infection
31
what are the proper terms for lower and upper urinary tract infections?
```
upper = pyelonephritis
lower = cystitis
```
32
what is the prevalence of women experiencing a UTI in their lifetime?
40-50%
33
What is the most common organism causing UTI?
E. coli (95%)
34
what is the 2nd most common cause of UTIs in young women?
Staph. saprophyticus
35
Which organism is commonly present in UTIs involving calculi/stones?
Proteus mirabilis
36
What are the 3 host defences against UTIs?
1. urine (pH, osmolality)
2. urine flow
3. urinary tract mucosa
37
What is a specific risk factor for bacterial infection of the bladder in children resulting in pyelonephritis and possibly renal scarring?
urinary tract defects such as vesicoureteral reflux (retrograde flow of urine from bladder into kidneys)
38
what are 4 examples of neurogenic causes of bladder outflow obstruction?
diabetic neuropathy
polio
spinal cord injury
tabes dorsalis (untreated syphilis)
39
what is an organism which can cause UTIs and abscesses via the haematogenous route? (ie bacteraemia & seeding in the kidneys)
Staph. aureus
40
what are the classic features of UTI infection?
abdominal / flank pain
dysuria
frequency
41
what type of organism are rigors typically associated with?
gram negative bacteria
42
What investigations should you do for a suspected UTI?
1. urine dipstick
2. MSU for urine microscopy, culture and sensitivities
3. Bloods - FBC, UE, CRP (inflammatory markers and renal function) if suspect pyelonephritis or more severe
COMPLICATED
4. Renal USS
5. IV urography
- to look at structure/flow of urine
43
What positive test in a urine dispstick indicates the likely presence of coliform bacteria?
Nitrites (coliform bacteria have an enzyme that converts nitrates to nitrites)
44
why are pregnant women particularly vulnerable to UTIs?
outflow obstruction due to gravid uterus
45
what are squamous epithelial cells on a urine microscopy usually indicative of?
contamination.
46
what does a urine sample with <10^5 cfu/mL indicate?
No infection
47
What is the general threshold for cfu/mL in the bladder for indicating a urine infection?
>10^5 cfu/mL (colony forming unit)
48
what is the empirical therapy for UTIs in the community?
Trimethoprim
49
What is the resitance level of trimethoprim?
40%
50
what is the common empirical treatment for UTIs in hospitals?
NOT trimethoprim due to resistance
| SO cefalexin
51
What is the Tx for catheter associated UTIs?
- remove the catheter (due to biofilm buildup and intro of organisms)
- gentamycin
52
What is the Tx for pyelonephritis?
antibiotics:
| co-amoxiclav + aminoglycoside (gentamycin
53
In men, what investigation should be done in pyelonephtitis?
USS - to look for structural problems perhaps causing obstruction
54
What are 4 complications of UTIs?
- perinephric abscess
- chronic pyelonephritis due to scarring
- septic shock
- acute papillary necrosis
55
why would you never use nitrofurantoin in catheter patients?
because it concentrates in the patient's bladder - catheter drains continuously.
56
When should you advise patients to take nitorfurantoin tablets to Tx a UTI?
after they have just voided their bladder - it concs in thebladder so no point taking and then emptying bladder - wont clear
57
The presence of what would indicate a poorly taken urine sample
squamous epithelial cells
58
what is the difference between treponemal and non trepoemal tests for syphilis?
non-treponemal = detect biomarkers that are released during the cellular damage occuring from syphilis' spirochete - Ab that reacto to cardiolipin
treponemal = antibodies: IgG IgM and IgA
59
What is the drawback of nontreponemal tests?
decreased sensitivity in early primary syphilis and late latent - and false positive reactions due to other infections
60
What is the likely cause of diarrhoea when the symptoms develop within 2-7 hours?
Staph aureus
61
What is the likely causative organism in a patient who had a chicken bbq at the weekend and has florrid diarrhoea at the end of the week?
campylobacter
62
What is the likey causative organism in a pt who presents with diarrhoea symptoms 24h after eating some prawns?
Vibrio parahaemolytics
63
what does a staphylococcal enterotoxin (SE) superantigen bind to?
directly to T cell receptrs ad MHC molecules (outside the peptide binding site)
64
what organism produces enterotoxin which can act as a superantigen in the GI tract
Staph. aureus
65
what does Staph aureus enterotoxin in the GI tract cause the release of, and what symptoms does this cause
IL1 and IL2
```
vomiting
watery diarrhouea (non bloody)
```
66
how do you trea Staph aureus food poisoning?
Fluid resus
| not Abx as its a pre formed toxin!
67
what organism is assocated with food poisoning from reheated fried rice?
Bacillus cereus
68
Why does heating rice not kill B. cereus?
very heat stable emetic toxin
69
What symptoms does Bacillus cereus infection cause (including 2 serious complications?)
watery non bloody diarrhoea - self limited
bacteraemia
cerebral abcess
70
What organism is associated with honey and infants?
Clostridium botulinum - which is a preformed toxin which causes botulism
71
where organism is normal flora of the colon but not the small bowel, resulting in food poisoning from reheated meat?
Clostridium pefringens
72
which bacteria causes pseudomembranous colitis after cephalosporin treatment?
Clostridium Difficile
73
What is the treatment plan for a patient with active diarrhoea C. diff
side room
stop offending antibiotics
metronidazole and vancomycin
74
what is a beta haemolytic organism which is aesculin positive and has tumbling motility?
Listeria monocytogenes
75
Treatment for Listeria infection?
ampicillin
76
which parts of the colon does E. coli eterotoxins act on?
ileum and jejunum but not on large bowel
77
Give the 4 types of E. coli
1. ETEC (E. coli enterotoxigenic)
2. EPEC (pathogenic)
3. EIEC (invasive)
4. EHEC 0157 (haemorrhagic)
78
which type of E. coli can cause HUS?
EHEC - E. coli 0157
79
What are the 3 antigens found on Salmonellae species?
```
O = cell wall
H = flagellum
Vi = capsular, virulence, antiphagocytic
```
80
give the 3 species of salmonellae
1. S. Typhi
2. S. enteriditis
3. S. cholerasuis
81
What kind of bacteria are non lactose fermenters, H2S producers
Salmonellae
82
give 2 characteristics of S. typhi
constipation, splenomegaly, rose spots, Blood culture positive, anaemia, leucopenia
83
what organisms causes dysentry and is the most effective enteric pathogen - only needing an infective dose of 50
Shigellae
84
which group of vibrios causes epidemics?
group 01
85
what organism is transmitted by contaminated water and human faeces - shellfish, oysters, shrimp, and causes massive volume of rice water stool
Vibrio cholerae
86
what type of agar is required to grow Vibrio parahaemolyticus
Salty 8.5% NaCl
87
What organism causes cellulitis in shellfish handlers?
Vibrio vulnificus
88
How do you treat Vibrio vulnificus?
doxycycline
89
what organisms do you need special oxygen deplete jars to grow?
Campylobacter - microaerophilic
90
when would you treat campylobacter and how?
If immunocompromised - with a macrolide
91
how is campylobacter transmitted?
contaminated food & water with animal faeces
92
classic signs of campylobacter infection
watery foul smelling diarrhoea bloody stool, severe abdo pain
93
What are 3 complications of campylobacter infection?
Guillan Barre Syndrome (GBS)
Reiters
Reactive arthritis
94
what organism is known to cause acute diarrhoea, enterocolitis, mesenteric adenitis, and transmitted via food contaminated with domestic animal faeces
Yersinia enterelytica
95
name a protozoan organisms that causes infections on camping holidays when water isnt boiled
entamoeba histolytica
96
how do you treat entamoeba histolytica infection?
metronidazole + paromomycin in luminal disease
97
How does one become infected with Giardia lamblia?
ingestion of cysts from faecally contaminated water/food
98
how is Giardia lamblia diagnosed
stool micro
ELISA
string test
99
what 3 groups tend to be a risk of Giardia lamblia?
MSM
Mental patients
travellers/hikers
100
What type of microorganism is Giardia lamblia?
Protozoa
101
Why is norovirus so prone to outbreaks?
Very low infectious dose (18-1000)
Robust environmental resilience (0-60 deg.C)
No immunity long term
102
What viruses cause diarrhoea?
```
Norovirus
Rotavirus
Adenovirus
Poliovirus
Enteroviruses (coxsackie, ECHO)
Hep A
```
103
Which strains of adenovirus can cause non bloody diarrhoea in children <2 years?
types 40 + 41
104
which types of cholera can you vaccinate against?
01 and 0139
105
What vaccinations vs rotavirus are there?
Rotarix - live attenuated (2 doses)
| Rotateq
106
give 4 viruses we worry about when thinking about intrauterine viral infection?
Rubella, CMV, Parvovirus B19, VZV (also HSV, HIV, Hep B)
107
which 2 viral infections are we concerned about perinatally?
Herpes, VZV
108
What is the classic presentation of a child with parvovirus B19 at the end of infection?
slapped cheek syndrome - erythema infectiosum
109
why is screening for Rubella not offered in pregnancy?
- vey rare now in UK due to MMR vaccine
- also if there is infection, not much you can do as cannot offer vaccine - as it is a live vaccine - little intervention
110
what is the incubation period of CMV?
4-8 weeks
111
main transmission route of CMV?
saliva
112
what is the main congenital infectious cause of profound sensorineural hearing loss?
CMV (accounts for 10-15%)
113
Give some factors which can increase the risk of perinatal HSV infection?
- recent maternal infection
- mode of delivery
- use of scalp monitors during delivery
114
a what point is HSV most commonly acquired periatally?
75-85% at delivery during birth canal exposure
115
What are the 3 clinical presentations of neonatal herpes?
1. SEM disease --> limited to skin, eyes, mouth
2. CNS disease - encepalopathy
3. Disseminated disease - Sepsis, organ involvement, vesicular rash
116
What is the Tx of neonatal herpes infection?
IV aciclovir
117
what is the infectious period for Chicken pox?
2 days before appearance of rash --> when vesicles have crusted / are dry
118
what is the worry if a mother contracts VSV duringthe 1st 20 weeks of pregancy?
risk of congenital varicella syndrome
119
which infection do you get koplik spots?
Measles
120
what are the complications of measles
```
opportunistic bacterial infections
otitis media
pneumonia
bronchitis
encephalitis
subacute sclerosing pan encephalitis (SSPE)
```
121
What should happen if a pregnant woman comes into contact with suspected measles
Can give human immunoglobulin to attenuate the illness
122
How long is someone infective with measles?
4 days before and 4 days after the appearance of the rash
123
26 week pregnant patient has developed chicken pox 2 days ago - what is the treatment?
aciclovir
124
what virology Ix would you advise in a mother who has foetal microcephaly on USS?
CMV and Rubella serology
HSV rarely transmitted in utero so less likely than these 2
125
what are the major transmission routes of CMV?
saliva, intrauterine (infected maternal secretions, breast milk), sex, blood transfusion, organ transplant
126
what type of virus is zika?
Flavivirus
127
what is the incubation period for Zika virus?
3-12 days (no more than 2 weeks - so if symptoms develop 2 weeks post returning from danger area, will not be Zika)
128
what are the 3 most common causes of bone/joint infection?
1. Staph aureus
2. E. coli
3. Pseudomonas aeruginosa
129
What are the 3 levels of SSI/
1. superficial incisional
2. deep incisional (fascial and muscle layers)
3. organ/space infection
130
Why is obesity a risk factor for infection in surgery?
- adipose tissue poorly vascularised, so poor oxygenation and functioning of the immune response = increased risk of SSI
131
What is the biggest risk for SSI following cardiothoracic surgery/
S. aureus carriage in nares (20-30% people carry it)
132
Why can hypothermia increase the risk of SSIs?
causes vasoconstriction, resulting in decreased delivery of oxygen to wound space and subsequent impairment of neutrophil function
133
give 3 routes of viral infection in a transplant patient
1. virus from the graft
2. viral reactivation from the host
3. novel infection from infected individual
134
which antibodies indicate chronic and acute infection?
```
chronic = IgG
acute = IgM
```
(remember IgM = IMmediately and IgG= aGes)
135
where does CMV remain latent?
B lymphocytes
136
where does EBV remain latent in the body? (2 sites)
leucocytes & epithelial cells
137
which herpes viruses remain latent in the sensory nerve ganglia?
HSV1 HSV2 VZV
138
where does HHV8 remain latent
epithelial cells
139
where do HSV1 and HSV2 remain latent?
in the sensory nerve ganglia
140
what are the complications of VZV infection in immunocompromised patients?
1. bacterial superinfection
2. bullous/haemorrhagic skin lesions - purpura fulminans
3. visceral involvement - pneumonitis, hepatitis
141
If an immunocompromise patient appears to have VZV skin lesions with no dermatomal distribution - what is this called and what is the risk?
Atypical generalised zoster
| risk of visceral involvement
142
What is the firt linke treatment for HSV and VSV infection?
Aciclovir
143
What is the basic action of Aciclovir against HSV?
potent inhibitor of HSV encoded DNA polymerase
144
After aciclovir, what is the 2nd line drug you would use to treat HSV?
Valaciclovir
145
What is the other name for HSV4?
Epstein Barr Virus (EBV)
146
What is the general name for the acute infection of EBV?
Infectious mononucleosis
147
What is the treatment plan for someone with suspected post transplant lymphoproliferative disease? (PTLD)
Rituximab (CD-20 (a B cell marker) monoclonal antibody therapy)
148
What is the biggest risk (in terms of donor and recipient status) for a lung transplant patient when thinking about CMV endogenous reactivation?
D+ R-
149
What is the biggest risk (in terms of donor and recipient status) for a Bone Marrow transplant patient when thinking about CMV endogenous reactivation?
D- R+
150
what are the 2 types of antibiotics which inhibit cell wall synthesis?
1. beta-lactams (penicillins, cephalosporins and carbapenems)
2. glycopeptides (vancomycin and teicoplanin)
151
what is the target of beta lactam antibiotics?
transpeptidase enzymes (involved in synthesis of peptidoglycan cell wall)
152
what is co-amoxiclav made of and what is the purpose of the combination>
amoxicillin + clavulanic acid. The clavulanic acid is beta-lactamase inhibitor - so protects the amoxicillin from being broken down by b lactamase produced by bacteria like S. aureus
153
What are two types of glycopeptides?
vancomycin and teicoplanin
154
What is the mechansm of action of glycopeptide antibiotics?
target cell wall synthesis
155
Which b-lactam antibiotics are ESBL stable?
carbapenems
156
What are ESBL infections?
extended spectrum beta lactamase producing organisms- resistant to all cephalosporins as well as penicillins
157
what is a) IV b) oral vancomycin commonly used to treat
a) MRSA
| b) C. diff
158
What do aminoglycosides bind to?
the amino-acyl site of the 30s ribosomal subunit
remember: a Gentleman in his 30s called amino went deaf due to the pseudoscience of snorting grams of neg and protein
159
What is the mechanism of action of aminoglycosides?
They bind to the 30S ribosomal subunit of bacteria, preventing elongation of the polypeptide chain and causing misreading of codons along the RNA - thereby inhibiting protein synthesis
160
What are two negative side effects of aminoglycosides?
ototoxic and nephrotoxic so levels must be monitored
161
What is a common example of an aminoglycoside antibiotic?
Gentamycin
162
What are the 5 types of antibiotics which are protein synthesis inhibitors?
ATOMC
```
aminoglycosides
Tetracyclines
Oxyzolidinones
Macrolides
Chloramphenicol
```
163
what is the mechanism of action of macrolide Abx?
they bind to the ribosomal 50s subunit, interfering with translocation and stimulation dissociation of peptidyl tRNA
164
What is the mechanism of action of chloramphenicol eye drops?
binds to 50s ribosomal subunit, inhibiting protein synthesis
165
Why is chloramphenicol rarely used despite its very broad action
risk of aplastic anaemia and grey baby syndrome in neonates
166
which protein synthesis inhibiting antibiotic is used as eye drops commonly?
chloramphenicol
167
give the example of an oxazolidinone abx
Linezolid
168
What gram type is linezolid very active against?
Gram + e.g. MRSA
169
What are the 2 types of antibiotics which inhibit DNA synthesis?
fluoroquinolones and nitromidazoles
170
What is the mechanism of action of ciprofloxacin?
it's a fluoroquinolone so a DNA synthesis inhibitor - acts on the alpha-subunit of DNA gyrase
171
What antibiotics inhibit RNA synthesis?
Rifamycins eg rifampicin
172
what does the antibiotic linezolid bind to
the 23s component of the 50s subunit
173
What is co-trimoxazole useful for treating?
PCP
174
what are the four mechanisms of antibiotic resistance?
```
BEAT
Bypass the antibiotic sensitive step
Enzyme mediated
Accumulation inhibition (either by enhancing efflux or impaired uptake)
Target modification
```
175
what is the mutation in MRSA which makes it so resistant to beta-lactams?
it modifies the target - the mecA gene codes for a new Penicillin binding protein which has a low affinity for beta lactams - therefore survives
176
what does MRSA stand for?
methicillin resistant staph. aureus
177
What Abx should you use in mild CAP?
amoxicillin
178
what Abx should you use for severe CAP?
co-amoxiclav + clarithromycin (covers atypicals)
179
what Abx should you use for HAP?
tazocin or amoxicillin + gentamycin
180
what are the components of tazocin?
piperacillin - a penicillin with extended beta lactamase coverage and pseudomonas, + tazobactam which is a beta lactamase inhibitor
181
what Abx should you use for nosocomial UTIs?
co-amoxiclav or cephalexin
182
What triad of abx should you usually use for severe sepsis?
tazocin/ceftriaxone and metronidaxole +/- gentamycin
183
What abx should you use for C. diff colitis?
metronidazole PO
184
Which antibiotic can cause grey baby syndrome?
chloramphenicol
185
What is grey baby syndrome and how can you treat?
Due to the accumulation of chloramphenicol antibiotic in neonates as they lack the liver enzymes required to metabolise it - resulting in reduced electron transport in liver myocardium and skeletal muscle. may need exchange transfusion
186
What type of flu is H5N1
Bird flu
187
What are the 3 antigenically distinct types of influenza that tend to strike humans every year?
```
Influenza A (H1) - Jan
Influenza A (H1N1) - Dec
Influenza B - March
```
188
the loss of which gene is associated with a more severe influenza infection?
IFITM3
189
what is the mutation making influenza A resistant to the antiviral treatment amantadine
a single amino acid mutation in the M2 ion channel --> S31N
190
how are oseltamivir, zanamivir (relenza) and peramivir adminisrated?
```
O= oral
Z = inhaled
P = IV
```
191
what is Tamiflu?
an antiviral drug for influenza - oseltamivir
192
what antiviral treatments are available for influenza
amantadine
| neuraminidase
193
What are the 2 most common organisms causing hospital acquired UTI
E. coli and Klebsiella
194
which antibiotics predispose patients in hospital to acquiring C. diff?
3 Cs
Clindamycin
Cefalosporins
Ciprofloxacin
195
what are he 3 types of non tuberculosis mycobacteria (NTM) that can infect humans?
M. aviam intracellulare
M. marinum
M. ulcerans
196
What is the likely diagnosis - patient in A&E with multiple superficial papules on his hands, is an aquarium cleaner
Mycobacterium Marinum
197
describe features of extra-pulmonary TB
- lymphadenitis (aka scrofula)
- GI
- peritoneal
- genitourinary - slow progression to renal disease and lower urnary tract
- bones and joints - spinal tb, Pott's disease
198
What investigations should you consider if you suspect TB?
imaging - CXR to look for caseation esp in upper lobes. can do a CT.
Tuberculin skin test to see if primary infection has occurred.
Culture - sputum (x3) and can do bronchioalveolar lavage. Microscopy: gram + rods, acid fast, intracellular, aerobic.
IGRA - interferon-gamma release assay: measures release of interferon gamma on exposure to antigen
NAAT - CR probe assay
Jenson medium is the gold standard but takes about 4 weeks for results
199
when diagnosing TB how many repeats of the sputum culture should you do?
3
200
what are the 1st ine meds for TB treatment?
```
RIPE
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
```
201
what should you prescribe alongside isoniazid and why?
To prevent peripheral neuropathy - give vitamin B6 pyrodoxine
202
Which viruses are responsible for 8090% cases of aseptic meningitis?
Enteroviruses e.g. Coxsackieviruses and echoviruses
203
which virus i becoming the leading cause of encephlitis internationally?
West Nile Virus
204
out of the the most common bacterial causes of meningitis, which one is Gram - cocci and which one is gram + cocci?
Neisseria meningitides = gram negative
Strep. pneumoniae = gram +
205
Which bacteria are more commonly causes of meningitis in the elderly and neonates?
Group B strep and Listeria monocytogenes
206
Treatment for meningitis?
Ceftriaxone 2g IV bd
| + amoxicillin if >50 or immunocompromised
207
Tx for meningoencephalitis?
Aciclovir 10mg/kg tds
Ceftriaxone 2g iv BD
+ amoxicillin if >50 or immunocompromised (2g IV 4hourly)
208
What is the likely diagnosis from these CSF results: Slightly turbid, high WCC mainly monocytes, high protein,
TB meningitis / cryptococcal
209
What is the likely diagnosis from these CSF results:Glucose normal, WCC high with polymorphs
partially treated bacterial meningitis
210
What is the likely diagnosis from these CSF results: normal glucose, high WCC mononuclear cells, normal protein
Aseptic meningitis (vira)
211
The antiviral which is given to untreated pregnant women with HIV to prevent vertical transmission of the virus during childbirth.
Nevirapine - has been shown to be more effectve than zidovidine
(NEVER give the baby HIV)
212
An antiviral which can be used in aerosol form to prevent respiratory syncytial virus in children with heart and lung disease
Ribavirin
| aerosol spray to prevent RSV smells like RIBS
213
The drug which can be delivered by inhalation to treat both influenza A and B.
zanamivir
214
A forty year old ornithologist presents with malaise, muscular pains and a cough. On examination he has a fever and several distinctive rose spots on his abdomen. Chest x-ray reveals a diffuse pneumonia.
Parrot fever - psittacosis
| parrott in a pitta - cosis
215
The final metabolite of the antiviral used to treat Herpes Simplex
Aciclovir triphosphate
216
The synthetic nucleoside analogue ganciclovir is the drug of choice against which infective virus?
CMV
217
how to NRTIs and NNRTIS differ in their modes of action?
NRTIs - nucleoside reverse transcriptase inhibitors - are analogues of deoxynucleotides needed for DNA synthesis - so they competitive fr incorporation into growing strand, but as they lack a 3' hydroxyl group they cause chain termination.
NNRTIs - non-nucleoside reverse transcriptase inihbitors work by completely different mechanism - they bind directly to the enzyme, preventing DNA synthesis and therefore are non-competitive inhibitors.
218
what is the main side effect of NRTIs?
lactic acidosis
219
What are the 5 most important cytochrome p450 substrates
1. Warfarin
2. Anti-epileptic drugs
3. OCP and prednisolone
4. Ciclosporin A, Tacrolimus
5. NNRTIs and PIs
220
Which are painful out of Janeway lesions and Oslers nodes?
```
Oslers = painful nodular
Janeway = painless haemorrhagic
```
221
Which part of the heart is most commonly affected in infective endocarditis of an IVDU?
Tricuspid valve (52%)
222
what is the name of the Criteria for diagnosing infective endocarditis?
Duke's criteria
223
What are the major and minor criteria for diagnosing infective endocarditis?
DUKES CRITERIA
Major:
- Echo shows vegetation
- Blood culture repeatedly + for suspicious organisms such as Strep Viridans and S. aureus
- Persistent bacteraemia
Minor
- predisposing heart condition or IVDU
- Fever >38
- signs of immune complex formation e.g. glomerulonephritis, splinter haemorrhages
- signs of vascular phenomena -septic emboli janeway lesions and oslers nodes
- blood cultures
- echo sugestive
224
what are the most common organisms causing Infectious endocarditis?
Strep. Viridans
Enterococci
S. aureus
225
What is the antibiotic regimen for infective endocarditis caused by Strep. Viridans?
Benzopenicillin + Gentamycin
226
What are classic examples of Gram negative bacilli?
```
E. coli
Shigella
Klebsiella
Yersinia
-
```
227
What is the treatment for enterococcal infective endocarditis
ampicillin + gentamycin
228
treatment for MSSA endocarditis?
Fluclox for 4 weeks and moitor for abscesses refer to cardio
229
treatment for MRSA endocarditis
vancomycin + gent/rifampicin/fucidin
230
what are the indications for surgery in infective endocarditis?
1. severe valvular dysfunction
2. congestive heart failure
3. 1+ septic emboli
4. unresponsive to Abx
5. perivalvular abscess
6. uncontrolled infection
231
What are some complications of Brucellosis?
osteomyelitis, endocarditis, meningoencephalitis
232
How do you treat Brucellosis?
Oral doxycycline + rifampicin for 8 weeks
233
What are Negri Bodies and what are they pathognomic for?
eosinophilic, sharply outlined, pathognomic inclusion bodies found in nerve cells infected with Rabies virus
234
What is he organism causing the plague
yersinia pestis - a gram negative lactose fermenter
235
how do you diagnose plague?
molecular methods - PCR
236
What is the treatment for infection with yersinia pestis?
doxycycline, streptomycin, gentamycin, chloramphencol (meningitis)
237
what are the early, early disseminated and late symptoms of lyme borreliosis?
early: cyclical fevers, non-specific flu like symptoms, erythema migrans (bulls eye rash)
Early disseminated - malaise, lymphadenopathy, hepatits, carditis, arthritis
late: focal neurology, neuropsychiatric disturbance, ACA - acrodermatitis chonic atrophicans, encephalopathy
238
What is the vector in lyme borreliosis?
Ixodes ticks
239
what infection is acrodermatitis chronic atrophicans associated with
Lyme Borreliosis
240
what is the name of the bullseye rash associated with early focal lyme disease?
Erythema chronicum migrans (or just erythema migrans)
241
what is the chronic fibrotic skin condition associated with late lyme borreliosis?
Acrodermatitis chronicum atrophicans
242
How do you diagnose Lyme disease?
Biopsy at the edge of the erythema migrans if possible and ELISA for anti-lyme antibodies.
243
Treatment fo lymes disease?
3 weeks doxycycline, or IV ceftriaxone if CNS symptomes
244
which types of leishmania cause Visceral leishmania aka Kala-azar
L. infantum and L. donovani
245
what is the vector for leishmania/
Sand fly
246
which herpes type causes encephalitis?
HSV-1 (remember 1 brain)
247
What are the complications of chicken pox?
Pneumonitis, scarring, Reye's syndrome, haemorrhage, eye involvement, encephalitis
Can get neurological complications - Guillan-Barre, acute cerebellar ataxia, facial palsy
248
What skin test should you do to diagnose VZV chicken pox?
Tzanck smear - get scrapings looking for multinucleated giant cells called Tzanck cells
249
what can you give to help alleviate itch in children with chicken pox?
chlorphenamine if >1 year old
| or calamine topical lotion
250
What should you advise parents with a child with chicken pox about infecting others?
Most infective 2 days before the rash started, but then remains infective until the lesions crust over so should stay off school until that has happened. Should also avoid anyone who is immunocompromised, pregnant women and children under 4 weeks old.
251
what are 3 encapsulated organisms you should worry about in a splenomectomy patient with respiratory symptoms?
H. influenza, S. pneumonia, N. meningitides - remember SHiN
| - should offer vaccinations to these paients
252
which organisms should you worry about in Cystic fibrosis patients?
Pseudomonas aeringinosa, Burkholderia cepacia, Staph aureus, MRSA
253
What are the most common pathogens causing pneumonia in infants 0-1 month old?
GBS, E. Coli, Listeria
| think birth canal
254
What are the most common pathogens causing pneumonia in infants 1 month-6 months
chlamydia trachomitis, RSV, S. aureus
255
What are the most common pathogens causing pneumonia in 6 months-5 years
mycoplasma, influenza
256
Whatt is the likely organism: 65 year old man presenting with SOB, low sats 91%, confusion, bilateral interstitial changes, Chest exam normal, Hyponatraemia
Legionella pneumophilia - remember low sodium in legionella and sometimes hepatitis
257
how do you diagnose Legionella pneumophilia
Clinical picture
antigen in urine/serum
+ special culture on buffered charcoal yeast extract
258
what symptoms/signs is legionella pneumonia associated with?
SOB, fevers, confusion, hyponatraemia, abdo pain, diarrhoea,
259
What vacinnes are available for pneumonia in high risk groups?
pneumococcal vaccine: PCV available for children uunder 2 years old, and the PPV available for over 65s
also influenza vaccine - offered to children and people at high risk e.g. healthcre workeers
260
Treatment for PCP
Co-trimoxazole
261
For which pneumonia organisms are there urine antigen tests available?
Strep. pneumonia
| Legionella
262
first line Tx for HAP
ciprofloxacin +/- vancomycin
263
what is the other name for co-amoxiclav
augmentin
264
what is the pathogen responsible for athletes foot, ringworm and fungal infection of the nail
Tinea - trichophytum rubrum
265
What is ringworm caused by
Fungal infection e.g. with Trichophyton
266
what organisms causes pityriasis versicolour?
Melassazia fungus
267
What does Melassazia fungus cause?
Seborrhoeic dermatitis, cradle cap, P. versicolour.
268
What test would you do to diagnose invasive candida?
Anti-mannan antibodies
269
likely diagnosis in a neutropenic patient with fever, pleuritic chest pain and haemoptysis
Aspergillosis
270
What dignostic investigation would you do in a HIV patient with insidious meningitis?
serum or CSF cryptococcal antigen
271
What would you use to treat cryptococcal meningigtis?
Amphotericin B
272
What is the most common human prion disease?
Creutzfelt-Jakob disese (CJD) - sporadic, 80% prion diseases
273
What are the five types of human prion diseases known?
1. creutzfelt-Jakob disease (CJD)
2. variant CJD (OR iatrogenic CJD)
3. KURU
4. Familial fatal insomnia
5. Gerstmann-Straussler-sheinker syndrome (GSS)
274
What are the genetic elements of human prion disease
PrP gene is on chromosome 20 - mutations in the PRNP are associated with the inherited prion diseases
Also codon 129 polymorphisms (MM or methionie-methionine) are linked
275
What might triphasic changes on an EEG, and basal ganglia highlights on an MRI in a patient with progressve dementia indicate?
CJD
276
Which of these is NOT true of CJD
a) Median survival time is <6 months
b) Tonsillar biopsy is diagnostic
c) EEG usually shows periodic complexes
d) Mean age of onset is 65 years old
e) CSF markers (S100, 14-3-3) of neuronal damage may be elevated
b) - tonsilar biopsy is not helpful
277
What might the 'pulvinar sign' on an MRI indicate?
vCJD
278
What is the diagnostic test for vCJD?
tonsilar biopsy - 100% specific and sensitive
279
Treatment for bacterial meningitis in young child?
Ceftriaxone and corticosteroids (+ampiccilin to cover listeria)
280
What score can you use to assess prognosis in meningitis?
Glasgow meningococcal septicaemia prognostic score
281
treatment for meningoencephalitis?
aciclovir + ceftriaxone
282
transmission of hep A, hep B and Hep C?
faeco-oral
283
Incubation period for Hep A is:
2-6 weeks (v short compares to the others)
284
How do you diagnose Hep A?
Anti-HAV- IgM antibodies if its a very recent infection/vaccine
OR
Anti-HAV-IgG antibodies if a previous infection/vaccine
285
What is the management of Hep A
Supportive - often resolves sponataneously in 2 months.
- can have painkillers to treat aches and pains
- cool ventilated no hot baths to stop itching
- avoid alcohol, more strain on liver
- stay off school/work for at least a week after symptoms started and avoid sex
- good hygiene
286
Who is at increased risk of Hepatitis A infecton?
MSM
Travellers (to areas of poor sanitation)
IVDU
Occupational e.g. healthcare/sewage workers
287
What are the odds of having severe liver complications from Hep A?
rare - 1 in 250
288
What is the incubation for Hep B?
2-6 months
289
What serology markers would tell you that someone is immune from Hep B?
Negative HBsAg
positive HBsAb
postive HBeAb
290
Treatment of chronic Hep B infection?
pegylated IFN alpha 2b
| lamivudine
291
What are the major complications of chronic HepB infection?
hepatocellular carcinoma
| Liver cirrhosis
292
What is the main test for Heb B infection?
HBVsAg
293
What other tests should you consider if a patient is HBVsAg positive?
- HBVeAg
- HBV DNA level
- IgM antibody to Hep B core antigen
- HepC virus antibody
- HIV antibody
- IgG to Hep A
=- ALT AST GGT serum albumin, total bilirubin, total globulins, FBC and PTT
- test for hepatocellular cacinoma e.g. hepatic ultrasound and alpha-fetoprotein testing
294
What are signs of decompensated liver disease?
encephalopathy, ascites, GI haemorhage
295
What are the incubation times for Hep A, Hep B and Heb C?
Hep A- 2-6 weeks
Heb B- 2-6 Months
Hep C- 6-9 weeks
Remember: i"m 26 + 69
296
What proportion of hep C patients will develop chronic infection?
60-80%
297
Side effects of interferon alpha
flu-like symptoms, depression, fatigue, leukopenia, thrombocytopenia
298
Treatment of HEP C
pegylates IFN alpha 2b + ribavarin + protease inhibitor
299
What is the TORCH screen
screen for congenital infections
```
Toxoplasmosis
Other (HIV, Hep B/C)
Rubella
CMV
HSv
```
