Ed's microbiology Flashcards
1
Q
What is the appropriate antibiotic for low severity (CURB65 score 0-1) CAP?
A
- doxycycline
- alternatives: amoxicillin or clarithryomycin
2
Q
What is the appropriate antibiotic for mod/severe (CURB65 score 2-5) CAP?
A
- benzyl penicillin IV and
- doxycycline PO
3
Q
What is the appropriate antibiotic management for infective exacerbation of COPD?
A
- doxycline
- alternative: clarithromycin or amoxicillin
4
Q
What is the antibiotic management for uncomplicated UTI?
A
- nitrofurantoin
- women = 3 days, men = 7 days
5
Q
What is the appropriate antibiotic management for non-severe tissue infection?
A
- flucloxacillin PO
6
Q
What is the appropriate antibiotic management for severe soft tissue infection?
A
- flucloxacillin IV
7
Q
Broad-spectrum antibiotics suppress the normal gut flora. Which bacteria does this allow to develop and how does it cause damage?
A
- Clostridium difficile
- gram-positive rod
- produces exotoxin -> causes intestinal damage
- leading to syndrome called pseudomembranous colitis
8
Q
What is now the leading cause of C. Diff infection?
A
- second + third generation cephalosporins
- eg. ceftriaxone, cefotaxime, cefoxitin
9
Q
How is diagnosis of C. Diff infection made?
A
- Stool sample detecting toxin
10
Q
What is the management of C. Diff infection?
A
- oral metronidazole
- 10-14 days
11
Q
Describe the rash often associated with meningococcal septicaemia/meningitis
A
- petechial or purpuric rash is typically associated w/ meningococcal meningitis
- a rash is noted in 80% to 90% of patients
- most commonly 4-18 hours after initial symptoms of illness
- typically, rash is non-blanching petechial or purpuric
- but a few patients may initially have non-specific erythematous macular rash
12
Q
What is the immediate management of the septic patient?
A
SEPSIS 6 - GIVE 3, TAKE 3
- administer oxygen -> aim sats >94%
- take blood cultures
- give broad spectrum antibiotics -> co-amoxiclav IV + amikacin IV
- give IV fluid challenges
- measure serum lactate
- measure accurate hourly urine output
13
Q
What is the definition of pyrexia of unknown origin (PUO)?
A
- a temperature >38.3 for >3weeks
- with no obvious source
- despite appropriate investigations
14
Q
What are infectious causes of PUO?
A
- abscesses (lung, liver, pelvic)
- empyema
- rheumatic fever
- tuberculosis
- parasites (malaria)
- fungi
- septicaemia
15
Q
What are neoplasmic causes of PUO?
A
- lymphomas
16
Q
What connective tissue disorders might cause PUO?
A
- rheumatoid arthritis
- polymyalgia rheumatica
17
Q
What are other (not infections, neoplasms or connective tissue disorders) causes of PUO?
A
- drugs
- PE
- IBD
18
Q
What investigations would you like to do for common STIs?
A
- detailed examination of genitalia
- urine dipstick and MC+S
- ulcers -> swab for HSV
- urethral smear -> gonorrhoea
- urethral swab -> chlamydia
- blood tests -> syphillis, hepatitis + HIV
19
Q
What is the most prevalent sexually transmitted infection in the UK?
A
- chlamydia
- approx 1 in 10 young women in UK have it
- incubation period = 7-21 days
20
Q
What are features of chlamydia?
A
- asymptomatic in around 70% of women + 50% of men
- women: cervicitis (discharge, bleeding), dysuria
- men: urethral discharge, dysuria
21
Q
The investigation of choice for chlamydia is a urethral swab. What are potential complications of chlamydia?
A
- epididimytis
- PID
- endometritis
- infertility
22
Q
What is the management of chlamydia?
A
- doxycycline (7days)
- or azithromycin (single dose)
- if pregnant -> azithromycin, erythromycin or amoxicillin
23
Q
What are features of the gonorrhoea bacterium?
A
- neisseria gonorrhoea
- gram negative diplococcus
- incubation period = 2-5 days
24
Q
What are clinical features of gonorrhoea?
A
- males -> urethral discharge, dysuria
- females -> cervicitis eg. leading to vaginal discharge
25
What are potential complications of gonorrhoea?
* urethral strictures
* epididimytis
* salpingitis (-\> infertility)
* DIC
26
What is the management of gonorrhoea?
* cephalosporins -\> **ceftriaxone** (500mg IM single dose)
27
**Syphillis** is an STI that is characterised by primary, secondary and tertiary stages. What are these stages?
* **primary** -\> _painless_ _ulcer_ at site of sexual contact, local _non-tender_ lymphadenopathy
* **secondary** (6-10wks after primary infection) -\> _fevers_, lymphadenopathy, _rash_ on trunk, palm + soles
* **tertiary** -\> _granulomatous_ lesions of skin + bones, ascending aortic aneurysms, 'general paralysis of the insane'
28
What is the incubation period for syphillis?
* 9-90 days
29
What is the antibiotic management of syphillis?
* benzylpenicillin
30
How might **Herpes Simplex** present clinically?
* primary infection may present w/ severe **_gingivostomatitis_** (inflammation of oral mucosa)
* cold sores
* painful genital ulceration
31
What is the antibiotic management of herpes simplex?
for both **gingivostomatitis** and **genital herpes**:
* **_oral aciclovir_**
32
A common cause of attendance at GUM clinic would be genital warts. What are these caused by?
* caused by many varieties of HPV
* type 16 and 18 predisposes to cervical cancer
33
What do genital warts look like?
* small **fleshy** protuberances which are slightly **pigmented**
34
What is the management of genital warts?
* topical **podophyllum** or **cyrotherapy**
35
How does thrush (candida albicans) present?
* commonest cause of discharge
* classically described as **white curds**
* vulva + vagina may be red, fissured + sore
36
What is the management of thrush?
* **clotrimazole** pessary
37
How does bacterial vaginosis present clinically?
* causes **_fishy smelling_ discharge**
* vagina is not inflammed
38
What is the antibiotic management of bacterial vaginosis?
* **oral metronidazole (5-7 days)**
* 70-80% initial cure rate
* relapse rate \>50% within 3 months
39
What is pelvic inflammatory disease (PID)?
Term used to describe infection and inflammation of the **_female pelvic organs_** including the uterus, fallopian tubes, ovaries and the surrounding peritoneum
It is usually the result of ascending infection from the **endocervix**
40
What are causative organisms for PID?
* **chlamydia trachomatis** - most common cause
* neisseria gonorrhoea
* mycoplasma genitalium
* mycoplasma hominis
41
What are clinical features of PID?
* lower abdo **pain**
* **fever**
* deep **dyspareunia**
* dysuria + menstrual irregularities may occur
* vaginal or cervical **discharge**
* cervical excitation
42
What is the investigation for PID?
* screen for chlamydia and gonorrhoea
43
What is the antibiotic management of PID?
* oral ofloxacin
* oral metronidazole
44
What are complications of PID?
* infertility
* chronic pelvic pain
* ectopic pregnancy
45
What are the life-threatening complications of **malaria**?
* **_AKI_** - usually due to dehydration + hypovolaemia, can also be due to acute tubular necrosis in severe disease
* **_hypoglycaemia_** - common w/ severe disease + may be worsened by quinine therapy, preg women are most at risk
* **_severe anaemia_** - most common in young children due to direct red cell lysis
* **_DIC_** - bleeding gums, epistaxis + petechiae in severe disease
* **_septicaemia_**
* **_seizure_** **or other** **_CNS complications_**
46
What are risk factors for typhoid fever?
* **_overcrowded living_** in endemic areas (eg. india)
* **_poor sanitation_**/untreated water in endemic areas
* poor **_personal hygeine_** in endemic areas
47
What are symptoms and signs of typhoid fever?
* **HIGH FEVER** -\> sometimes occurs in a _stepwise fashion_ with 5-7 days of daily increments in max temp of 0.5 to 1 celcius
* dull frontal headache
* abdominal pain
* anorexia
* apathetic-lethargic state
* constipation
* cough
* diarrhoea
* malaise
Signs include **_rose spots_** (**blanching erythematous maculopapular lesions**) reported in 5-30% of cases; usually occurs on abdo + chest
48
What are the 3 types of UTI?
* infecious **cystitis** is the most common UTI, caused by bacterial infection of bladder
* **pyelonephritis** is an infection of kidney often occurs via bacterial ascent
* **urethritis** is an infection causing inflammation of the urethra
49
What are risk factors for UTI?
* sexual activity
* spermicide use
* post-menopause (absence of oestrogen)
* positive FHx
* history of recurrent UTI
* presence of a foreign body
50
What organisms cause UTI?
* ***E. Coli*** is the cause in 70-95% of **uncomplicated** cases
* ***Staph saprophyticus*** is cause in 5-20% of cases
* broad range of bacteria cause complicated UTIs, many are resistant to multiple antimicrobial agents
51
What are the clinical features of UTI, specifically for cystitis?
* frequency of micturition by day and night
* painful voiding (dysuria)
* suprapubic pain + tenderness
* haematuria
* smelly urine
these symptoms relate to bladder + urethral inflammation, commonly called '**cystitis**' + suggest lower urinary tract infection
52
Which symptoms would suggest extension of the infection to the pelvis and kidney, ie. **pyelonephritis**?
* loin pain + tenderness
* fever
* systemic upset
53
In whom is it important to always bear in mind the possibility of UTI and why?
* **in small children**
* cannot complain of dysuria
* symptoms often 'atypical'
* possibility of UTI must always be considered in the freful, febrile child who fails to thrive
54
Which investigations are important for UTI?
* **urine dipstick** -\> most effective in _UTI w/ high bacterial count_, diagnosis better if used in combo with other tests. Results = nitrite + leukocyte esterase positive
* **urine microscopy** -\> used to confirm _organism type_ + guide antibiotic selection in complicated UTI or pyelonephritis. Result = bacteria, WBC, possibly RBC
* **urine culture + sensitivity** -\> _most specific and sensitive test._ Result = growth of \>105 CFU/mL
55
What is the management of **uncomplicated** UTI (where there is normal renal tract + function)? How long is this for?
* **nitrofurantoin** 50mg PO 6hourly
* **women -\> 3 days**
* **men -\> 7 days**
* _alternatives_: 3day course of **trimethoprim**/sulfamethoxazole
56
What is the management of **complicated** **UTI** (abnormal renal/GU tract, voiding problems, virulent organism) and/or **pyelonephritis**?
* **co-amoxiclav** IV 1.2g, 8hrly
* then oral when afebrile
* complete 7-day course
57
Abacteriuric frequency or dysuria can be termed 'urethral syndrome'. What are causes of abacteriuric dysuria?
* postcoital bladder trauma
* vaginitis
* atrophic vaginitis
* urethritis (in elderly)
* interstitial cystitis
In symptomatic young women w/ 'sterile pyuria', **chlamydia infection** and **tuberculosis** must be excluded.
58
What are the 3 clinical manifestations of herpes simplex virus?
* cold sores
* painful genital ulceration
* severe gingivostomatitis
59
How does herpes zoster manfiest clinically?
* AKA _shingles_
* acute, **unilateral** painful blistering rash
* caused by reactivation of **Varicella Zoster** virus
60
How does herpes simplex **keratitis** present?
* presents w/ a dendritic corneal ulcer
* leads to red and painful eye
61
**_Infectious mononucleosis_** (glandular fever) is caused by EBV in 90% of cases. A classic triad of symptoms is seen in around 98% of patients. What is the triad?
* **sore throat**
* **lymphadenopathy** -\> may present in anterior + posterior triangles of neck
* **pyrexia**
Other features include malaise, anorexia, headache, splenomegaly and lymphocytosis
62
Meningitis is the _inflammation_ of the meninges usually caused by bacterial, viral or fungal infection. What are the signs and symptoms for this?
* headache
* nausea or vomiting
* neck stiffness
* fever
* photophobia
* confusion + seizures
63
How do you diagnose meningitis?
* **_lumbar puncture_**
* blood culture in patients where LP is delayed
64
What is the management of meningitis?
**All patients should be transferred to hospital urgently**
* patients in pre-hospital setting (eg GP) -\> _IM benzylpenicillin_
* hospital -\> _ceftriaxone_ + _aciclovir_
65
What is encephalitis?
* **inflammation of the brain parenchyma**
* associated w/ _neurological dysfunction_ eg. altered state of consciousness, seizures, personality changes, cranial nerve palsies + speech problems
* it is the result of _direct inflammation_ of the brain tissue
* as opposed to inflammation of the meninges
* can be the result of **infectious** or **non-infectious** causes
66
What are signs and symptoms of encephalitis?
* **fever** -\> seen in infectious causes
* **rash** -\> eg. vesicular eruption in HSV, erythema nodosum in TB
* **altered mental state**
* **focal neurological deficit** -\> eg. aphasia, hemiparesis, ataxia
67
How is diagnosis of encephalitis made?
* **lumbar puncture**
* **bloods** -\> FBC, U+Es, LFTs, blood cultures
* **imaging** -\> CXR, CT brain
The treatment depends on the underlying cause
68
What might cause CNS/cerebral abscesses?
* extension of sepsis from middle ear or sinuses
* trauma or surgery to scalp
* penetrating head injuries
* embolic events from endocarditis
69
What are the signs + symptoms of a cerebral abscess?
* presenting symptoms will depend upon **_site of abscess_** (those in critical areas eg. motor cortex will present earlier)
* abscesses have a considerable **_mass effect_** in brain + raised ICP is common
* although fever, headache + focal neurology are highly suggestive of a brain abscess, in the absence of 1+ of these does **not** exclude diagnosis
* fever may be absent and even if present, is usually not the swinging pyrexia seen with abscesses at other sites
70
How is diagnosis of cerebral abscess made?
* assessment of patient includes imaging with **CT scanning**
71
What is the management of a cerebral abscess?
* treatment usually **surgical**
* **_a craniotomy_** performed + abscess cavity debrided
* the abscess may reform bc the head is closed following abscess drainage
72
Which organisms are likely to cause meningitis in 6-60 year olds?
* neisseria meningitidis
* streptococcus pneumonia
73
What changes in the CSF would suggest a diagnosis of viral, bacterial and TB meningitis?
74
What are the indications for a lumbar puncture?
* suspicion of _meningitis_
* suspicion of _subarachnoid haemorrhage_ (SAH)
* suspicion of CNS diseases such as _Guillain-Barre syndrome_
75
What are the possible complications of LP?
* coning
* introduction of infection into CSF
76
What are the contraindications for lumbar puncture?
* local skin **sepsis**
* bleeding diatheses eg. **anticoagulant therapy**
* signs of spinal cord compression
* papilloedema or other signs of **raised ICP**
* suspicion of **intracranial or cord mass**
* congenital neurological lesions in lumbosacral region
* **coagulation** abnormalities
* after **convulsions** until stabilised
