Microbiology Flashcards
(377 cards)
1
Q
What is post-primary tuberculosis?
A
aka secondary TB.
Due to reactivation of latent M. tuberculosis or reinfection with M. tuberculosis.
2
Q
What part of the lungs does post-primary TB usually affect?
A
Lung apices
3
Q
What is the classic lesion in post-primary TB?
A
caseating granuloma.
4
Q
by what processes does the lesion in post-primary TB heal?
A
fibrosis and calcification
5
Q
What is a Ghon focus?
A
Primary lesion, usually subpleural, caused by M. tuberculosis.
6
Q
Granulomatous conditions have a certain type of large cell usually found in them, what is that cell?
A
Langhans Giant Cells
7
Q
What is the first-line treatment in tuberculosis and for how long?
A
RIPE
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
1st two: 6 months. 2nd two: only first 2 months.
8
Q
Side effects of Rifampicin?
A
orange secretions
hepatotoxicity
9
Q
Side effects of Isoniazid? what can you give to combat one of the side effects?
A
peripheral neuropathy - give B6/pyridoxine
10
Q
Lowenstein-Jensen medium is a growth medium commonly used to grow what?
A
M tuberculosis.
11
Q
Ziehl-Neelsen staining is used to detect what specific type of microorganisms?
A
Acid-Fast bacteria
12
Q
A positive Ziehl-Neelsen stain will appear what colour?
A
Red stain = acid-fast bacteria
Blue stain = non-acid fast
13
Q
What are the components of the CURB-65 score?
A
Confusion of new onset blood Urea nitrogen greater than 7mmol/l Respiratory rate greater than 30 Blood pressure lower than 90mmHg systolic or 60mmHg diastolic 65 years or older.
14
Q
The CURB-65 score is used for what?
A
predicting mortality in community acquired pneumonia
15
Q
Rusty-coloured suputum is associated with what infection?
A
Streptococcus Pneumonia
16
Q
What microscopic appearance does Streptococcus Pneumonia have?
A
diplococci
17
Q
What microscopic appearance does klebsiella pneumonia have?
A
rod
18
Q
What microscopic appearance does staphylococcus have?
A
cocci, grape-bunch clusters
19
Q
What microscopic appearance does mycobacterium cararrhalis have?
A
coccus
20
Q
What microscopic shape does Haemophilus influenza have?
A
cocco-bacilli
21
Q
Cold agglutinin test can be used in detecting what bacterial infection?
A
Mycoplasma pneumonia
22
Q
What antibiotics would you prescribe for a mild-moderate Community Acquired Pneumonia with classical bacteria and for how long?
A
Amoxillin or a Macrolide (5-7 days)
23
Q
What antibiotics would you prescribe for moderate-severe community acquired pneumonia with classical bacteria and for how long?
A
Clarithromycin + Co-amoxiclav/Cefuroxime (2-3 weeks)
24
Q
What antibiotic would you use for atypical community acquired pneumonia?
A
Macrolide/tetracycline
25
What is 1st line antibiotic treatment for hospital acquired pneumonia?
Ciprofloxacin +/- Vancomycin
26
Genital ulcers in herpes can be painful or painless?
Painful
27
Genital ulcers in syphilis can be painful or painless?
Painless
28
What type of bacteria is Neisseria gonorrhoeae?
Gram negative diplococcus
29
Opthalmia neonatorum is caused by what organism(s)?
Neiserria gonorrhoeae or Chlamydia trachomatis
30
Who does opthalmia neonatorum affect and what symptoms does it produce?
It affects newborns
| neonatal conjunctivitis: pain/tenderness of eyeball; conjuctival discharge; swollen eyelids.
31
What can people with complement deficiencies get with gonococcal infections?
Disseminated gonococcal infections --> septicaemia, rash and/or arthritis.
32
What does NICE recommend to prescribe for uncomplicated anogenital gonorrhoea?
Ceftriaxone 500mg IM as a single dose, plus azithromycin 1g orally.
33
Cephalosporins are bactericidal or bacteriostatic?
Bactericidal
34
Cephalosporins belong to what class of antibiotics?
B-lactams
35
What are the B-lactams' mode of action?
Bacteriocidal.
B-lactams irreversibly bind to penicillin-binding proteins which prevents final crosslinking of peptidoglycan layers in cell wall synthesis.
36
What gram type is Chlamydia trachomatis?
Gram-negative
37
What colour are gram positive bacteria upon staining?
Purple (P for positive/purple)
38
What colour are gram negative bacteria upon staining?
Red/pink
39
What are the different biovars of chlamydia trachomatis and what conditions do each cause?
Biovar = a strain within a species
Serovars A, B, C: Trachoma = infection of the eyes --> blindness
Serovars D-K: CUPPP (neonatal Conjuctivitis, Urethritis, ectopic Pregnancy, Pelvic inflammatory disease, neonatal Pneumonia)
Serovars L1-3: Lymphogranuloma venereum
40
What is NICE first-line treatment for Chlamydia?
Azithromycin 1g single dose OR doxycycline 100mg BD for 7 days.
41
What is NICE treatment for Chlamydia infection in pregnant/breastfeeding women?
Azithromycin 1g single dose OR
Amoxicillin 500mg TDS for 7 days OR
Erythromycin 500mg QDS for 7 days
42
What organism is lymphogranuloma venereum caused by?
Chlamydia trachomatis
43
What site-specific signs/symptoms can lymphogranuloma venereum present with?
External sex organs: abscesses in the groin (around draining lymph nodes)
Rectal: Proctocolitis
44
The primary stage of lymphogranuloma venereum occurs how long after infection?
3-12 days after infection
45
The secondary stage of lymphogranuloma venereum occurs how long after infection?
10-30 days later or even up to six months after infection.
46
What sign/symptom do people get in primary lymphogranuloma venereum?
Painless genital ulcer.
47
What signs/symptoms can people get in secondary lymphogranuloma venereum?
unilateral painful buboes (enlarged lymph nodes)
48
What is first-line treatment for lymphogranuloma venereum? An alternative?
Doxycycline 100mg BD for 21 days
alternative: Erythromycin QDS for 21 days.
49
What organism causes syphilis?
Treponema pallidum
50
Treponema pallidum is what gram-type?
negative
51
What blood tests can we use to diagnose syphilis?
Non-treponemal tests: Venereal Disease Research Laboratory (VDRL) and Rapid Plasma Reagin
Treponemal tests:
Treponemal pallidum particle agglutination (TPHA) or Fluorescent Treponemal Antibody Absorption (FTA-Abs)
52
What signs may a person have with primary syphilis?
Macule --> papule --> ulcer/erosion.
1-12 weeks following transmission.
53
What is a chancre?
Painless solitary ulceration associated with treponema pallidum infection. Appear approximately 3 weeks after infection.
54
Condylomata lata are associated with what organism?
Treponema pallidum
55
What skin symptoms can secondary syphilis present with?
Symmetrical, reddish, non-itchy maculopapular/pustular rash on the trunk, palms and/or soles.
56
What non-specific symptoms can syphilis present with?
Fever
Sore throat
Weight loss
Headache
57
How long after initial infection does tertiary syphilis present?
YEARS, like 3-40 years later.
58
What three different forms of tertiary syphilis are there?
Gummatous syphilis
late neurosyphilis
cardiovascular syphilis
59
What form in gummatous syphilis and where?
Gummas - soft, tumour-like balls of inflammation.
| Can affect skin, bone, liver but can occur anywhere.
60
What are Argyll Robertson pupils and what are they a sign of?
Small pupils that constrict to near objects (accomodate) but do not constrict in response to bright light.
Sign of neurosyphilis, diabetic neuropathy.
61
What is General Paresis?
neuropsychiatric disorder caused by chronic meningoencephalitisi leading to cerebral atrophy in neurosyphilis.
62
What is Tabes Dorsalis?
Demyelination of the dorsal columns in the spinal cord
63
What are late symptoms of neurosyphilis?
General paresis, Tabes Dorsalis, Menigovascular syphilis
64
What is first-line treatment for syphilis?
Benzathine benzylpenicillin
65
The Jarisch-Heimer reaction is classically caused by what?
Antibiotic treatment of syphilis.
66
How soon does a Jarisch-Heimer reaction occur and what are the signs/symptoms?
Hours after administration of antibiotics.
Fever, chills, rigor, hypotension, tachycardia, myalgia, flushing - it mimics septicaemia basically!
67
What organism causes chancroid? and what gram-type is it?
Haemophilus ducreyi: gram-negative.
68
What is a chancroid?
Painful ulcer, can be found around inguinal lymph nodes
69
What organism causes Granulom inguinale and what Gram-type is it?
aka Donovanosis
Klebsiella granulomatis: gram-negative.
70
What do we do to diagnose granuloma inguinale?
Giemsa stain
| Look for Donovan bodies in tissue biopsy
71
What organism causes trichomoniasis?
Trichmonas vaginalis
72
What can you prescribe in trichomoniasis?
Metronidazole
73
What organism causes molluscum contagiosum?
DNA poxvirus, aka molluscum contagiosum virus.
74
Which organism can cause genital warts?
Human Papillomavirus 6 or 11.
75
Which HPV types are associated with cervical/anal/penile cancers?
16 and 18
76
What is Tinea?
Common fungal infection of the skin, e.g. Athelete's foot.
77
What are the signs/symptoms in Tinea versicolor?
Fine-scaling of the skin
| Hypopigmentation eruption on trunk/proximal extremities.
78
Polyenes antimycotics work by what action?
Bind to ergosterol in fungal cell membrane, reduce integrity and can cause K/Na loss.
79
Azole antimycotics work by what action?
Inhibit lanosterol-->ergosterol conversion in cell membrane thereby inhibiting cell growth.
80
How do echinocandins work?
Inhibit glucan synthesis in cell walls
81
Herpes Simplex Virus is ssDNA or dsDNA?
dsDNA
82
Which organism causes Mollaret's Meningitis?
HSV
83
What is Mollaret's meningitis?
benign recurrent aseptic meningitis >4 weeks
84
Signs/symptoms of Mollaret's meningitis?
```
Meningism (Neck stiffness, photophobia, irritation)
CSF pleocytosis (increased cell count) with large endothelial cells.
```
Symptom-free periods of weeks/months inbetween bouts.
85
Primary infection in the ocular region with HSV can manifest in what condition, the symptoms/signs of which are?
Herpetic keratitis
Blepharoconjuctivitis (swelling of lids and conjuctiva)
Lid vesicles
86
Define a dendritic ulcer?
A linear branching corneal ulcer.
87
What symptoms might a person with a dendritic ulcer complain of?
Sensation of foreign-body
Redness
Light sensitivity
Blurred vision
88
In what condition do dendritic ulcers usually appear?
Herpetic Keratitis
89
Disciform keratitis usually manifests itself how?
Disc shaped area of corneal oedema
90
Disciform keratitis is caused by what organism?
HSV
91
In which trimester of pregnancy is the foetus at greatest risk when the mother has a primary HSV infection?
3rd trimester
92
Which HSV is the usual suspect in viral encephalitis?
HSV-1
93
What are some symptoms of herpesviral encephalitis?
CCC
Confusion
Changes in personality
Consciousness reduced
as well as ...
N+V, fever, focal neurology
94
What one test would you like to perform to confirm a diagnosis of herpesviral encephalitis? What are you looking for?
Lumbar puncture and analyse CSF.
Look for:
Lymphocytic pleiocytosis
Presence of virus - PCR
95
How would you treat somebody you suspect of herpesviral encephalitis?
IV acyclovir ASAP!
96
What are the signs/symptoms of herpes gladiatorum?
Scrum pox (painful blisters around the neck, face, chest, stomach, legs; inguinal lymphadenopathy)
97
Tzanck cells can be found in what infections?
'Her Very Heavy Pearly Case'
Herpes Simplex
Varicella + Herpes Zoster
Pemphigus vulgaris
Cytomegalovirus
98
If indicated, what would you prescribe for chickenpox?
Aciclovir
99
Shingles is caused by what infection?
Herpes Zoster
100
What is the presentation of congenital cytomegalovirus infection?
Generalised: IUGR; Microcephaly; Chorioetinitis; Thrombocytopenia; Hepatosplenomegally; Impaired IQ.
101
What diseases are immunocompromised patients at risk of when exposed to CMV infection?
CHERP
```
CMV Colitis
CMV Hepatitis
CMV Esophagitis
CMV Retinitis
CMV Pneumonitis
```
102
What would you prescribe to an immunocompromised patient with CMV infection?
Ganciclovir
103
What infection causes roseola infantum?
HSV 6 and HSV 7 aka Roseola Virus
104
Who is most likely to develop roseola?
Children under 2 years old
105
What is a typical presentation in a patient with Roseola?
A few days of fever, subsides and then a red rash appears spreading to legs/neck.
106
What might you prescribe to a patient with Roseola?
Ganciclovir, foscarnet or cidofovir
107
What is the characteristic presentation of infectious mononucleosis?
Triad of:
Fever
Sore throat
Lymphadenopathy
108
What type of rash can a person develop in infectious mononucleosis?
Maculopapular rash
109
A positive monospot test indicates what?
Epstein-Barr Virus infection
110
The monospot test responds to the presence of what specifically?
antibodies produced in response to EBV
111
Which infection is associated with Kaposi's sarcoma?
HHV-8
112
What does PUO stand for?
Pyrexia of Unknown Origin
113
What is the classical definition of PUO?
>38.8C fever
Persisting >3 weeks
Despite >1 week of intensive investigations
114
What conditions are classed as 'classical PUO'
5 categories:
1) Infections
2) Neoplasms
3) Connective Tissue Diseases
4) Miscellaneous (e.g. alcoholic hepatitis, granulomatous conditions)
5) Undiagnosed
115
How can you define nosocomial PUO?
Pyrexia that develops in patients that have been in hospital >24 hours
116
Causes of nosocomial PUOs?
Think of a patient lying on a bed post-surgery:
```
Surgery
Immobilisation
IV lines
Urinary catheters
Drugs
```
117
How can you define neutropaenic PUO?
Pyrexia with neutropaenia (
118
Causes of a neutropaenic PUO?
Chemotherapy
| Haematological malignancies
119
What are the different classes of PUO?
1) Classical
2) Nosocomial
3) Neutropaenic
4) HIV-associated
120
Which organism causes Typhoid? What gram-type is it?
Salmonella typhi
| Gram negative
121
What is Faget sign?
Fever paired with bradycardia
122
What skin changes can be seen in Typhoid?
Rose spots (red macules 2-4mm )
123
What are the symptoms of untreated Typhoid?
Fever, abdominal pain, headache, epistaxis, exhaustion.
124
What test do you want to perform to confirm your diagnosis of Typhoid?
Blood or stool cultures
125
What is first-line treatment of Typhoid?
IV fluids
| Fluoroquinolones, e.g. ciprofloxacin.
126
Which species cause malaria?
```
P. Falciparum
P. Vivax
P. Ovale
P. Malariae
P. Knowlesi
```
127
On a blood film you see:
Young trophozoites alonside crescent-shaped gametocytes.
What is the cause?
P. Falciparum
128
A patient with P. Falciparum would show what on a blood film?
Young trophozoites (rings). Crescent-shaped gametocytes.
129
How can you treat P. Falciparum?
One option is using 'Artemisinin based combination therapies' aka ACTs.
Another option is Quinine plus tetracycline/doxycycline/clindamycin for 7 days.
130
You see a blood film report: 'Schuffner's dots' are present. What could have caused this?
P. Vivax or P. Ovale.
131
In malarial investigations, what can we use a thick film for?
Detect the presence of parasites
132
In malarial investigations, what can we use a thin film for?
Distinguishing malarial species
133
What are the classic triad of symptoms in botulism?
1) bulbar palsy (CN IX, X, XI, XII) and descending paralysis
2) lack of fever
3) clear sense and mental status
134
Classical sources of botulinum toxin?
```
Honey (children)
Canned food
Open wound
Inhalation (lab workers)
Inappropriate injection
```
135
What gram-type is Clostridium Botulinum?
Gram Positive
136
Sources of C. Perfringens?
Reheated/poorly heated meats
Decaying vegetation
Faeces
Marine sediment
137
Effects of C. Perfringens infection?
Food poisoning - third most common cause of food poisoning in the UK.
138
Signs/symptoms of C. dificile?
```
>3 watery stools in 24 hour period
Recent Abx exposure
Abdominal pain
Fever
Foul odour stool
```
139
Sources of Bacillus cereus?
Poorly refrigerated cooked rice, milk or infant formula.
140
What is the route of transmission for E. coli?
faeco-oral route
141
Which enterotoxins does ETEC produce?
LT and ST enterotoxins
142
What are the effects of ST enterotoxin produced by ETEC?
stimulates cGMP accumulation in target cells
| leads to fluid/electrolyte moving into intestinal lumen
143
What gram-type is E. Coli?
Negative
144
What gram-type is Salmonella?
Negative
145
What gram-type is Shigella?
Negative
146
Through what route does Shigella invade the host?
Through M cells within the small intestine
147
Common symptoms of Shigella infection?
```
Diarrhoea
Nausea
Vomiting
Fever
Stomach cramps
```
148
What gram-type is Yersinia enterocolitica?
Negative
149
What is the usual source of Yersinia enterocolitica?
Poorly cooked pork
| Contaminated water, meat, milk
150
Symptoms of Yersinia enterocolitica?
Diarrhoea
Fever
Mimics shigella infection/appendicitis
Later, lymphadenopathy
151
What conditions is Yersinia enterocolitica associated with?
Reactive arthritis
| Erythema nodosum
152
What is a common source of Vibrio parahaemolyticus?
raw, undercooked seafood
153
Vibrio parahaemolyticus is what gram-type?
Negative
154
What are three types of Vibrio vulnificus infections?
Acute gastroenteritis - consuming raw, undercooked seafood
Necrotising skin wounds - contamination from contaminated waters
Septicaemia
155
Sources of campylobacter jejuni?
Poultry
| Unpasteurised milk
156
What gram-type is Campylobacter jejuni?
Negative
157
Is Campylobacter jejuni aerobic or anaerobic?
Microaerophilic
158
What would you prescribe for Campylobacter jejuni infection?
Erythromycin or Ciprofloxacin
159
What gram-type is Listeria monocytogenes?
Positive
160
Signs and symptoms of a Listeria monocytogenes infection?
Diarrhoea
Fever
Muscle aches
161
What is the treatment of choice for Listeria infection?
Ampicillin
162
What type of organism is Entamoeba Histolytica?
Protozoan
163
What is the active form of Entamoeba Histolytica and where can it be found?
Trophozoite
| Within host or fresh faeces
164
How is entamoeba histolytica transmitted and in what form is it found?
Consumption of contaminated food/drink
| Exists as a cyst outside of the human body
165
A pathology report comes back describing 'flask-shaped ulcers' on bowel histology. What's the cause?
Entamoeba Histolytica
166
What is the characteristic lesion caused by Entamoeba Histolytica?
Flask-shaped ulcer
167
What is tenesmus?
A recurrent inclination to evacuate the bowels.
168
What could you prescribe for somebody with entamoeba histolytica intestinal infection?
Metronidazole and paromomycin
169
What type of organism is Giardia lamblia?
Protozoa
170
In the faeces of an unwell patient you find a cyst with 4 nuceli and a retracted cytoplasm. What could be causing this?
Giardia lamblia
171
Signs and symptoms of Giardiasis?
Loose/watery stools
Diarrhoea
Bloating
Sulphurous burping
172
What test would you like to perform to confirm your diagnosis of Giardia lamblia infection?
ELISA
173
What type of organism is Cryptosporidium Parvum?
Protozoa
174
If you wanted to prescribe something for Giardia lamblia infection, what would you prescribe?
Metronidazole
175
What would you like to prescribe for somebody with a Cryptosporidium parvum infection?
Paromomycin
176
Which antibiotics can predispose to C. difficile infection?
The Three Cs
Clindamycin
Cephalosporins
Ciprofloxacin
177
Pseudomembranous colitis is associated with which condition?
C. difficile
178
What is a prion?
An infectious agent composed entirely of protein
179
What do prions cause?
Transmissable spongiform encephalopathies
180
What agent causes CJD?
A prion
181
CSF contains 14-3-3 protein. What is the diagnosis?
CJD
182
You suspect CJD in a patient and collect a sample of CSF. What are you looking for?
14-3-3 protein.
183
What are the signs/symptoms of CJD?
```
Rapid dementia
Memory loss
Personality changes
Hallucinations
Myoclonus
Ataxia
Seizures
```
184
What type of organism is Brucella?
Gram-negative bacteria
185
What is the source of transmission of Brucella?
```
Contaminated food (untreated milk/dairy)
Laboratory acquired
```
186
What is the classical triad of symptoms in Brucella infection?
1) Undulant fever (peaks in evening, better by morning)
2) Sweating (smells like wet hay)
3) Migratory myalgia/arthritis
187
When investigating Brucella, what agglutination titre would you consider significant in non-endemic areas?
> 1:160
188
When investigating Brucella, what agglutination titre would you consider significant in endemic areas?
> 1:320
189
Which antibody are you looking for when investigating Brucella?
Anti-O antibody
190
What treatment options are there for Brucella?
Tetracyclines
Doxycycline with Streptomycin
Doxycycline with Rifampicin
191
What type of organism is Rabies?
Rhabdovirus
192
You see Negri Bodies. What condition is it? Where are these bodies found?
Rabies.
Found in CNS.
193
Signs/symptoms of Rabies?
Prodrome of fever, headache, sore throat.
Leads to ...
Partial paralysis, anxiety, insomnia, agitation, paranoia, hallucinations, hydrophobia.
194
What to give to treat Rabies?
Human Rabies immunoglobulin
195
Which organism causes Plague?
Yersinia pestis
196
What type of organism is Yersinia pestis?
Gram negative anaerobe
197
How is the bubonic plague spread?
flea bites
198
What type of organisms are Leptospira?
Gram negative spirochaetes
199
How is Leptosira transmitted?
Urine of infected animals, e.g. dog/rat
200
What are the signs/symptoms of Leptospirosis?
First phase: Fever; Chills; Headache; Myalgia; Red eyes.
Second Phase: Meningitis
201
treatment for leptospirosis?
Amoxicillin, ampicillin or doxycycline
202
Which organism causes Anthrax?
Bacillus anthracis
203
What would you prescribe for Anthrax?
Fluoroquinolones e.g. ciprofloxacin
| Doxycycline
204
What is the cutaneous form of Anthrax otherwise known as?
Hide Porter's Disease
205
Hide Porter's Disease is caused by what organism?
Bacillus anthracis
206
What are the skin manifestations of Anthrax?
painless round black lesions and rings of oedema
207
What type of organism is Borrelia burgdoferi?
Diderm (not gram positive/negative) spirochaete
208
Bullseye rash is classically associated with which condition?
Lyme disease
209
Lyme disease can manifest itself on the skin in what way?
Bullseye rash aka Erythema Migrans
| Borrelial lymphocytoma - purplish lump
210
What are the early phase signs/symptoms of Lyme disease?
```
Malaise
Lymphadenopathy
Hepatitis
Carditis
Arthritis
```
211
What are the late phase signs/symptoms of Lyme disease?
Arthritis, focal neurology, neuropsychiatric disturbance, ACA (acrodermatitis chronic atrophicans) = a skin condition, reddish blue in colour on back of hands/feet in elderley.
212
What is your first choice of treatment in Lyme disease?
Doxycycline
| or amoxicillin
213
Which organism causes Q fever?
Coxiella burnetii
214
What gram-type is coxiella burnetii?
Gram-negative
215
What are the signs/symptoms of Q fever?
Abrupt onset of flu-like symptoms
fever
malaise
headache
50% of people have no symptoms
216
What would you prescribe for Q fever?
Doxycycline
| Tetracycline
217
What type of organism is Leishmania?
Trypanosomes, a type of protozoa
218
Which Leishmanias can cause cutaneous leishmaniasis?
L. major
| L. tropica
219
Which leishmanias can cause muco-cutaneous leishmanias?
L. braziliensis
220
Which leishmanias can cause visceral leishmaniasis?
L donovani
221
How is cutaneous lesihmaniasis transmitted?
Bite of the sandfly
222
What are the signs/symptoms of cutaneous leishmaniasis?
Skin ulcer at site of bite - heals after a year, leaves a depigmented scar.
223
What Past medical history would get you thinking about Infective Endocarditis?
```
Right Heart failure
Congenital heart disease
Cardiac surgery
Valve Replacements
Long term lines
Bacteraemias
IVDU Hx
```
224
Signs/Symptoms of Infective Endocarditis?
FROM JANE
Fever
Roth Spots
Osler nodes
Murmur
Janeway lesions
Anaemia
Nail haemorrhage (splinter haemorrhage)
Emboli
225
What is the Dukes Criteria?
BE FEVEER
Major:
Blood culture positive >2 times
Endocardial involvement seen e.g. echo (e.g. vegetations, abscess, valve loose)
Minor:
Fever
Echo findings not meeting a major criteria
Vascular (e.g. major arterial emboli, stroke, PE)
Evidence that of blood culture that does not meet Major
Risk factors - like heart surgery, IVDU, etc.
226
What are the three common culprits of infective endocarditis?
Staphylococcus aureus
Streptococci of the Viridans group
Coagulase negative staphylococci
227
What is the HACEK group?
Gram-negative group of bacteria responsible for uncommon causes of infective endocarditis
```
Haemophilus parainfluenzae
Aggregatibacter/Actinobacillus
Cardiobacterium hominis
Eikenella corrodens
Kinglla kingae
```
228
Infective endocarditis causative agent is Staphylococcus Aureus, it is most likely resistant to penicillin. What will you give instead?
Vancomycin
229
Are influenza viruses RNA or DNA viruses?
RNA
230
What family of viruses do the influenza viruses belong to?
Orthomyxoviridae
231
What do the 'H' and 'N' refer to in influenza classifications, e.g. H1N1 or H1N2?
```
H= haemagglutinin
N= neuraminidase
```
Refers to the H or N antigens they express.
232
What population is the main reservoir for Influenza A?
Wild aquatic birds, e.g. ducks
233
What is the other name for neuraminidases?
Sialidases
234
What is the function of neuraminidases?
Cleaves sialic acid residues to expose receptors on host cells and disrupts the mucin barrier.
235
What is the function of influenza haemagglutinin?
1) Recognise vertebrate cells through sialic acid binding
| 2) Facilitate viral genome entry by fusing endosomal membrane with viral membrane
236
What is antigenic drift?
Variations arising in viruses due to natural mutations in the genes coding for antigens, e.g. haemagglutinin and neuraminidase.
237
In which strains of influenza does antigenic drift occur?
A, B and C
238
What is antigenic shift?
When two or more viruses combine to form a new strain of virus with a mixture of antigens.
239
In which strains of influenza does antigenic shift occur?
Influenza A
because A infects more than just humans
240
Name the classes of antivirals and give a couple of examples for each
Neuraminidase inhibitors, e.g. oseltamivir (Tamiflu) and Zanamivir (Relenza)
M2 protein inhibitors, e.g. Amantadine and Rimantadine.
241
What is the mechanism of action of Aciclovir?
Aciclovir --> Aciclovir Monophosphate (converted by viral thymidine kinase)
Aciclovir monophosphate --> Aciclovir triphosphate (converted by host cells)
A-Tri-P inhibits and inactivates HSV-specific DNA polymerases
242
Which conditions is Aciclovir used for?
Herpes simplex infection
Chickenpox
Shingles
243
Ganciclovir is used in treating what?
cytomegalovirus infections
244
What conditions can CMV cause?
RCHEP
```
Retinitis
Colitis
Hepatitis
Encephalitis
Pneumonitis
```
245
What are the three medications used to treat CMV infections?
Ganciclovir
Foscarnet
Cidofovir
246
What is the major side effect of Foscarnet and Cidofovir?
Nephrotoxicity
Maintain adequate hydration
247
What are three medications we can use to treat herpes simplex virus?
Act Very Fast!
Aciclovir
Valaciclovir
Famciclovir
248
Ground glass hepatocytes are associated with what condition?
Chronic Hepatitis B infection
| not acute Hep B!
249
What is the decision to treat Hepatitis B infection based upon?
1) raised Serum HBV DNA levels (the viral load)
2) raised Serum aminotransferase levels
3) liver biopsy histological stage and grade
250
What are the medical treatment options in Hep B infection?
Viral polymerase inhibitors
Reverse transcriptase inhibitors
Interferons
251
Give examples of Reverse transcriptase inhibitors used in HBV infections.
Tenofovir
252
Give examples of Viral polymerase inhibitors used in HBV infections.
Entecavir (no resistance)
Lamivudine
Telbivudine
253
Give examples of interferons used in HBV infections.
Pegylated Interferon alpha 2a (Pegasys)
254
Which genotypes of Hepatitis C respond best to treatment? and genotypes that respond less well?
Best responders: Genotypes 2 and 3
Less well: Genotypes 1, 4, 5 and 6
255
Name the 3 steps of the PCR procedure.
Denaturation at 94-96C
Annealing at 68C
Elongation at 72C
256
Cause of Kaposi's sarcoma?
Human Herpes Virus (HHV) 8
257
Flucloxacillin is broad or narrow spectrum?
Narrow
258
Usual suspect organisms in septic arthritis?
Staphylococcus aureus
| Streptococci
259
Signs/symptoms of septic arthritis?
Febrile
Red hot swollen joint
Patient unwilling to move joint
260
How would you go about confirming a diagnosis of septic arthritis?
Arthrocentesis: WCC>50,000 cells/mm3
Raised ESR+CRP
Imaging demonstrating effusion
261
How to treat septic arthritis?
IV antibiotics
Analgesia
Joint aspiration
262
What is a Brodie abscess?
A subacute osteomyelitis which may persist for years before becoming frank osteomyelitis.
263
How can we classify osteomyelitis?
Suppurative: Acute vs Chronic
| Non-suppurative: Diffuse/Focal sclerosing
264
Name a likely causative agent in osteomyelitis?
Staphylococcus Aureus
265
What would you like to perform to confirm your diagnosis of Osteomyelitis?
MRI
| Bone biopsy for culture/histology
266
Treatment for Osteomyelitis?
Antibiotics (type depends on causative organism) for weeks/months.
Debridement in severe cases.
267
What is Osteomyelitis?
Infection and inflammation of the bone marrow or bone.
268
Common causative agents of UTIs?
E. Coli
Staphylococcus saprophyticus
Klebsiella
269
Signs/symptoms of UTIs?
Frequency
Dysuria
Abdominal pain
270
Investigations for UTI?
Urine dipstick - nitrites, leukocytes
| MC&S
271
What are you going to prescribe for an uncomplicated UTI?
Trimethoprim or nitrofurantoin
272
What are the glycopeptide antibiotics mechanism of action?
Bind to amino acids in cell wall and prevent further synthesis.
273
For what gram type bacteria do we give Beta-lactams?
Gram positive
| Gram negative: 3rd generation cephalosporins
274
What is the indication for glycopeptide antibiotics?
MRSA
| C Diff
275
What is the indication for aminoglycoside antibiotics?
Gram negative sepsis
276
What is the basic mechanism of action of tetracycline antibiotics?
Protein synthesis inhibitors
277
What is the indication for tetracycline antibiotics?
ARC UTIs
Acne
Rosacea
Chlamydia
UTIs
278
What is the basic mechanism of macrolides?
Protein synthesis inhibitors
279
What is the indication for macrolide antibiotics?
Gram positive (Strep pneumoniae)
Alternative to Penicillin
Some gram negative (bordetella, haemophilus)
280
What class of antibiotic is gentamicin?
Aminoglycoside
281
What class of antibiotic is Erythromycin?
Macrolide
282
What class of antibiotic is Doxycycline?
Tetracycline
283
What type of antibiotic is Benzylpenicillin?
Beta-lactam - penicillin
284
What type of antibiotic is ceftriaxone?
Beta-lactam - cephalosporin
285
What type of antibiotic is meropenem?
Beta-lactam - carbapenem
286
What type of antibiotic is Vancomycin?
Glycopeptide
287
What type of antibiotic is Teicoplanin?
Glycopeptide
288
What is chloramphenicol's basic mechanism of action?
protein synthesis inhibitor
289
What are Oxazolidinone antibiotics basic mechanism of action?
Protein synthesis inhibitors
290
What type of antibiotic is Linezolid?
Oxazolidinone
291
What is the basic mechanism of action of fluoroquinolones?
Inhibit DNA synthesis
Gram negative = DNA gyrase
Gram positive = topoisomerase IV
292
What class of antibiotic is Ciprofloxacin?
Fluoroquinolone
293
What is the basic mechanism of action of Nitroimidazoles?
Inhibit DNA synthesis
294
What class of antibiotic is Metronidazole?
Nitroimidazole
295
What are the indications for a nitroimidazole?
Anaerobic bacteria and parasitic infections
296
What is the basic mechanism of Rifamycins?
Inhibit RNA synthesis
297
What type of antibiotic is Rifampicin?
Rifamycin
298
What are the indications for Rifamycins?
Mycobacteria
e.g. TB, leprosy, mycobacterium avium complex (MAC)
299
What is the basic mechanism of Polymyxin antibiotics?
Cell membrane toxin
300
What type of antibiotic is Colistin?
Polymyxin
301
What are the indications for Polymyxins?
Gram-negative bacteria (because of the LPS which polymyxins can bind to)
Last resort if there are multi-drug resistant pathogens.
302
What type of antibiotic is daptomycin?
Lipopeptide antibiotic
303
How does daptomycin work?
Cell membrane toxin - causes leak of ions --> depolarisation --> cell death.
304
What are the indications of daptomycin?
Skin infections with Gram positive bacteria
Staph aureus bacteraemia/endocarditis
NOT pneumonia as can bind surfactant.
305
What is the basic mechanism of action of sulfonamides?
Inhibition of folate metabolism
306
What class of antibiotic is sulphamethoxazole?
Sulfonamide
307
What is in tri-moxazole?
Sulphamethoxazole and trimethoprim
308
What is the basic mechanism of action of trimethoprim?
Inhibition of folate metabolism
309
Indications for trimethoprim?
UTI
310
Give examples of antibiotic classes that inhibit cell wall synthesis.
Beta-lactams
| Glycopeptides
311
Give examples of antibiotic classes that inhibit protein synthesis.
MATChO
```
Macrolides
Aminoglycosides
Tetracyclines
Chloramphenicol
Oxazolidinones
```
312
Give examples of antibiotic classes that inhibit DNA synthesis.
Fluoroquinolones
| Nitroimidazoles
313
Give examples of antibiotic classes that inhibit RNA synthesis
Rifamycin
314
Give examples of antibiotic classes that are cell membrane toxins.
Polymyxin
| Lipopeptides
315
Give examples of antibiotic classes that inhibit folate metabolism.
Sulfonamides
| Diaminopyrimidines
316
Give examples of Broad spectrum antibiotics.
Co-amoxiclav
Tazocin
Ciprofloxacin
Meropenem
317
Give examples of Narrow spectrum antibiotics.
Flucloxacillin
Metronidazole
Gentamicin
318
What are the four mechanisms of antibiotic resistance?
BEAT drug action
Bypass antibiotic-sensitive step in pathway, e.g. MRSA
Enzyme-mediated drug inactivation, e.g. B-lactamases
Accumulation of the drug is impaired, e.g. tetracycline resistance
Target in microbe is modified, e.g. Quinolone resistance.
319
What are you likely to prescribe for a community-acquired UTI?
Trimethoprim
320
What are you likely to prescribe for a nosocomial acquired UTI?
Augmentin or cephalexin
321
What are you likely to prescribe for a Community-acquired pneumonia that is mild?
Amoxicillin
322
What are you likely to prescribe for a Community-acquired pneumonia that is severe?
Cefuroxime + clairthromycin
323
What are you likely to prescribe for a hospital-acquired pneumonia?
Cefuroxime
324
What are you likely to prescribe for a bacterial meningitis?
Ceftriaxone
325
What are the TORCH infections?
```
Toxoplasmosis
Other (VZV, HIV, HBV)
Rubella
CMV
HSV
```
326
How are the TORCH infections acquired?
Transmitted from mother to the fetus/baby
327
An aseptic meningitis is usually caused by what organism?
Virus
328
What are the most common causative organisms of meningitis in adults?
Neisseria meningitidis
| Streptococcus pneumoniae
329
What are the most common causative organisms of meningitis in neonates?
Group B Streptococci
Listeria monocytogenes
E. Coli
330
What are some causes of viral meningitis?
Enteroviruses
| Herpes simplex virus 2
331
What is the most common fungal cause of meningitis?
Cryptococcus neoformans
332
What is the normal range of CSF WCC?
0-5 x10^6/l
333
What is the normal range of CSF protein?
0.2-0.4g/l
334
What is the normal range of CSF glucose?
around 2-4mmol/l or >50-60%
335
CSF: low glucose, high WCC with polymorphs. What are you thinking?
Bacterial infection
336
What might you see in CSF analysis with a bacterial infection?
Low glucose
High WCC
Polymorphs
337
CSF: normal glucose; WCC is high with polymorphs. What are you thinking?
Partially treated bacterial infection
338
What might you see in CSF analysis with a partially treated bacterial infection?
Normal glucose
High WCC
Polymorphs
339
CSF: Glucose normal; WCC high with mononuclear cells. What are you thinking?
Viral meningitis/encephalitis.
340
What might you see in CSF analysis with viral meningitis/encephalitis?
Normal glucose
High WCC
Mononuclear cells
341
CSF: High protein; High WCC; Mononuclear cells. What are you thinking?
Mycobacterium TB or cryptococcus.
342
What might you see in CSF analysis with Mycobacterium TB or cryptococcus?
High protein
High WCC
Mononuclear cells
343
What type of virus (RNA, ssDNA, dsDNA) is Hepatitis A?
RNA
344
What type of virus (RNA, ssDNA, dsDNA) is Hepatitis B?
dsDNA
345
What type of virus (RNA, ssDNA, dsDNA) is Hepatitis C?
RNA
346
How is hepatitis A transmitted?
Faecal-oral
347
How is hepatitis B transmitted?
Sexually
Vertically
Blood products
348
How is hepatitis C transmitted?
Blood products
| needles
349
What can we look for when diagnosing hepatitis A virus?
Anti-Hep A Virus IgM
350
What do we look for when diagnosing hepatitis B virus?
HBsAg (Hep B surface antigen)
351
How is parvovirus B19 transmitted?
Respiratory droplets
| Bloodborne
352
What are the signs/symptoms of Parvovirus B19?
Fever
Malaise
Erythema infectiosum 'slapped cheek'
353
What is a potntial complication of parvovirus B19 in those with sickle cell?
Transient aplastic crisis
354
What is a typical incubation period for parvovirus B19?
6-14 days.
355
Rubella is a RNA, dsDNA, ssDNA virus?
RNA virus
356
How is rubella transmitted?
Respiratory
357
Signs/symptoms of rubella?
low grade fever
rash starting on face, spread to trunk/arms
cervical lymphadenopathy
358
What is the risk of rubella infection during early pregnancy?
Infected
359
Signs/symptoms of congenital rubella syndrome?
'Rubber Ducky I'm Blue'
Rubber=Rubella
Ducky = Ductus Arteriosus, Pulmonary artery stenosis
I'm = Eyes (cataracts, glaucoma, retinopathy)
Blue= Blueberry muffin rash (extramedullary haematoposis causing a rash)
Hearing defects
Mental retardation
Splenomegaly
360
What does influenza infection during pregnancy increase the risk of?
```
Stillbirth (~5x)
Preterm delivery (~3x)
```
361
Wgat type of vaccine should you not give during pregnancy?
Live attenuated vaccines
362
What gram type and shape is Staphylococcus?
Positive
| Cocci
363
What gram type and shape is Streptococcus?
Positive
| Cocci
364
What gram type and shape is Enterococcus?
Positive
| Diplococci + chains
365
What gram type and shape is Actinomyces?
Positive
| Rods
366
What gram type and shape is Bacillus?
Positive
| Rods
367
What gram type and shape is Clostridium?
Positive
| Rods
368
What gram type and shape is Diphtheria?
Positive
| Rods
369
What gram type and shape is Listeria?
Positive
| Rods
370
What gram type and shape is Neisseria?
Negative
| Cocci
371
What gram type and shape is Moraxella?
Negative
| Cocci
372
What gram type and shape is Enterobacteriaceae?
Negative
| Rods
373
What gram type and shape is Bordetella?
Negative
| Coccobacilli
374
What gram type and shape is Pseudomonas?
Negative
| Coccobacilli
375
What gram type and shape is Chlamydia?
Negative
| Coccobacilli
376
What gram type and shape is Treponema?
Negative
| Spirochaetes
377
What gram type and shape is Leptospirosis?
Negative
| Spirochaetes
