Past Paper corrections Microbiology Flashcards
community acquired pneumonia management?
based on curb-65 score
0-1 = amoxicillin
2 = amoxiciliin + clarithromycin
2-3 = admit and give IV (C)o-amoxiclav and IV (C)larithromyin
Typhoid fever treatment
IV ceftriaxone + PO azithromycin
teenager with meningitis. glucose is normal, protein in normal and white cells are raised (mononuclear cells).
most likely causative organism?
this is aseptic meningitis
viruses are cause
and enteroviruses!! = most common = cocksackie!!!!, echovirus
(other viruses - mumps, hsv2)
A medical student undergoes blood-borne virus screening before starting clinical placements. They test positive for HBsAg and Anti-HBc; negative for IgM anti-HBc and anti-HBs.
What is their HBV infection status?
what does each marker indicate if positive?
chronic infection
positive HbsAg (surface antigen) = Hep B infection!! (outside is touching u*)
positive anti HBs = Antibody tos HbsAg = immunity to HepB either due to prior vaccination or prior infection
positive anti HBc = If IgM then acute infection(, if IgG = chronic infection or prior exposure -> answer depends on presence of HbsAg
*essentially, look at HbsAg first to guide answers
(HbeAg presence = high transmissibility)
During pregnancy, pregnant women are offered vaccines. One of these is Covid vaccine. State one of the other 2
influenza, whooping cough
What 3 infections are checked in pregnant women according to UK screening program?
hep B, HIV, syphilis?
Which fungus that can cause respiratory disease in immunocompromised cannot be treated using a certain type of antifungal (cos it doesn’t have ergosterol in its cell wall), it’s normally treated with co-trimoxazole?
pneumocystis jirovecii
Man with cavitating pneumonia and blood speckled phlegm, dx organism
hemophilus influenzae
A man with HIV, CD4 count under 50, non-compliant with HAART develops diarrhoea and abdo Sxs. Acid and alcohol fast bacilli. Which atypical mycobacterium caused this?
ulcerans
-> note crytptospordium causes diarrhea too but this is a parasite
Hepatitis antigen & Abs bloods. What would the serology show in someone who has previously recovered but is at risk of reinfection if they become immunocompromised?
Hep surface Ag -ve, core Ab +ve, surface Ab -ve?? -> double check
note - negative surface antibody so it means they have no immunity!!
Lady with bronchiectasis known to be colonised with fully sensitive Pseudomonas aeruginosa, what antimicrobial should be used?
ceftazidime
A 19 yo boy has meningococcal Meningitis. Dad Says he is deathly allergic to penicillins and cephalosporins due to anaphylactic reactions. Which antibiotic should you use instead?
chloramphenicol
Elderly gentleman presents with pneumonia symptoms, coughing up yellow sputum. Culture shows gram-ve coccobacilli.
Haemophilus,
What species of Coagulase Negative Staphylococcus is a common cause of lower urinary tract infection in young women?
staphylococcys saprophyticus, it is urease test positive, as is proteus and klebsiella
A 67-year-old woman presents with a chronic cough, haemoptysis and fevers particularly at night. She states she has lost 10 kg of weight over the past 3 months and her chest X-ray shows left upper zone shadowing. Her son reports she has a history of excess alcohol consumption. What is the most likely causative organism?
klebsiella pneumoniae?? - double check
What double stranded DNA virus is associated with nephritis in renal transplant recipients on immunosuppresive therapy?
CMV
A 72 year old woman is referred from the Emergency Department with signs and symptoms consistent with meningitis. She is known to have hypertension and type 2 diabetes mellitus. She is not confused and has no features. suggestive of encephalitis. A lumbar puncture has been performed and she has been commenced her on ceftriaxone 2g IV twice daily. There are no known drug allergies. Given this clinical picture, what one anti-microbial should be given in addition?
amoxicillin (due to RF for listeria ie young or old)
Serology for what polysaccharide is used for the diagnosis of invasive Aspergillus infection? -
galactomannan
A 32 year old woman has been diagnosed with a superficial infection of a caesarean section wound. The preliminary report from a wound swab states: Staphylococcus Aureus isolated with susceptibilities to follow. The pre-operative MRSA screen was negative and there are no known any drug allergies: She is breast feeding her new daughter. What narrow Spectrum antimicrobial would you prescribe to treat his infection?
flucloxacillin
A 26 year old woman presents with fever, headache and confusion. She has an HIV infection and has refused to take antiretroviral therapy for the past 4 years. What rapid test should you ask the microbiology laboratory to perform on her serum sample to confirm the likely diagnosis? -
cryptococcal antigen -> cryptococcus neoformans
A 2-day old neonate develops meningitis. The microbio laboratory telephone to report that a Gram stain of her CSF shows Gram- negative bacilli. What is the most likely causative organism?
e coli
The following antimicrobials can be used for the treatment of community acquired pneumonia. Which has activity against Mycoplasma pneumoniae?
doxycycline
(Tetracyclines (eg doxy) and macrolides can be used)
A 76 year old man with a long term indwelling urinary catheter which was changed earlier in the day becomes unwell. He is pyrexial and has been having rigors. He is tachycardic heart rate of 123 bpm, and hypotensive blood pressure 94/62 mmHg. He is known to be colonised with an ESBL producing E.coli Which antimicrobial would be the mast appropriate empiric therapy?
(Carbapenems are used for this = meropenem, imipenem, ertapenem)
Which agent is an Interleukin 6 (IL-6) inhibitor, indicated for treatment of severe COVID-19 infection with hypoxia?
Tocilizumab
(key word here is IL-6 inhibitor)
Which antiviral agent is used for the treatment of Influenza A?
Zanamivir (a neuraminidase inhibitor like oseltamivir. Baloxavir is a polymerase inhibitor that is also used
A 72 year old woman was admitted 6 days ago after a fall, she has had a dynamic hip: screw inserted. She now has evidence of a hospital acquired pneumonia. Which is the most likely causative organism?
Escherichia coli. (enterobacteriae most common cause of HAP)
Blood cultures taken from a 57 year old patient on renal dialysis have grown a glyCOpeptide resistant Enterococcus faecium (gram +ve). Further susceptibilities are to follow. Which antimicrobial is an appropriate choice for initial treatment of this infection?
linezolid
-> resistant to Taicopianin
and Vancomycin
Man has recently returned from trip to India, has high fever and abdominal pain but no diarrhoea. His blood cultures - gram-ve bacilli. Malaria rapid diagnostic test is -ve. What is the most appropriate antibiotic therapy
ceftriaxone
(salmonella typhi)
Which human herpes virus is associated with post transplant lymphoproliferative disorder
EBV
Woman has hot, swollen and painful left knee. Gram stain of joint aspirate - gram +ve cocci in clusters. Patient has no drug allergies and MRSA screen is -ve. What narrow spectrum antibiotic is indicated
flucloxacillin
Patient receiving chemotherapy for leukaemia. She has prolonged neutropenia and ongoing fever, raised inflammatory markers despite broad antibacterial therapy with meropenem and amikacin. CT head scan shows multiple nodules with surrounding hypo-attenuation (halo sign). What is the most likely organism?
toxoplasma gondii
Young woman has severe headache, neck stiffness, fever. She is HIV+ve but is poorly compliant with medication, does not attend her appointments. She has yeasts in her CSF. What is the causative organism?
cryptococcus neoformans
72 year old man has returned from a 7 day holiday in Italy. He has signs of pneumonia and Legionella urinary antigen is positive. Which of the following antibacterials is the most appropriate initial therapy?.
Azithromycin
(Macrolides and quinolones (eg ciprofloxacin)
Which of the following serological tests is useful in the diagnosis of invasive Candida albicans infections?
Beta-D-Glucan
Which of the following antivirals is used for chronic hepatitis B treatment?
Tenofovir
Streptobacillus moniliformis is the causative organism of which of the following infections?
Rat bite fever
What is the commonest form of prion disease?
Sporadic Creutzfeldt-Jakob disease
Receptor mutation that could be protective in HIV?
CCR5? Didn’t they ask for cytokine not receptor? MIP-1a?
Cat scratch disease full name (genus and species) of bacteria:
bartonella henslae
Name 1 of the 3 characteristics of Influenza A that could cause a pandemic?
novel antigenicity
Alcoholic man is on ceftriaxone for meningitis, what organism is he at risk of which this does not cover for?
listeria monocytogenes
Has contact with someone with TB, what is the risk of getting active TB?
10%
What is the definition of herd immunity threshold?
1- (1/R0)
Gram +ve cocci UTI in a woman?
staphylococcus saphrophyticus
name the virus that causes Progressive Multifocal Leukoencephalopathy
John Cunningham virus
Most common virus causing aseptic meningitis
Enteroviruses (Coxsackie or Echovirus, polio)
Treatment for MRSA.
IV Vancomycin
Non-Tuberculous mycobacterium , some cut on his hand in a man who cleaned a fish tank?
Mycobacterium marinum
Previous IVDU man is given Rituximab - CHOP treatment for Non-Hodgkin’s lymphoma. He later 8 months later develops fulminant liver failure and dies
Hep B reactivation (due to rituximab)
Blood cultures reveal Candida spp (not albicans), what antifungal should be used?
amphotericin B
A woman presents with a 4 month history of weight loss, hamoptysis and night sweats. CXR shows an upper lobe cavitation mass and there are hard palpable lymph nodes superclavicularly. What type of sideroom would you place her in.
negative pressure room?
What virus causes progressive multifocal leukoencephalopathy in AIDS?
John Cunningham virus
add in 2017 past paper corrections
What can be done to prevent overwhelming bacterial sepsis in a sickle cell patient with Howell-jolly bodies on blood film. Name one of the two possible medical interventions.
administer vaccinations
what infection will not cause harm to baby if mother is infected?
hand foot and mouth disease?
Young woman returning from australia 8 weeks ago with non-healing ulcer that has been treated with 2 antibiotics already. Culture of lesion reveals positive acid-face bacilli and Zheel-Niehlson stain. What is the most likely causative organism? (list of atypical mycobaceria)
mycobacterium ulcerans
Which component of SARS CoV-2 is the antigenic target for the vaccines currently used in the UK?
Spike (S) protein
Which class of antibiotics has concentration dependent killing (i.e. the goal of therapy is to maximise peak > MIC)
aminoglycosides
(also fluoroquinolones and daptomycin)
pneumonia and Legionella urinary antigen is positive. Which of the following antibacterials is the most appropriate initial therapy?.
Azithromycin
(remember its pneumonia) Macrolides and quinolones (eg ciprofloxacin)
Bacteria causing scarlet fever?
Strep pyogenes
A 27 year old accountant presents with a 3 day history of abdominal cramps and diarrhoea. She is afebrile, is eating and drinking well and feels her symptoms have started to resolve.
She is currently working from home and one week ago ate a reheated take away chicken curry.
Which treatment is indicated.
No antimicrobial therapy indicated, supportive only
sounds like campylobacter infection
found in chicken and unpasteurised dairy. may or may not be bloody diarrhea
A 4 year old girl presents with pharyngitis. A throat swab has isolated Streptococcus pyogenes (Group A Streptococcus). Her father states she had an anaphylactic reaction to penicillin 18 months ago. While awaiting susceptibilities, which antimicrobial would be most appropriate initial therapy?
Clarithromycin!!
(or azithromycin or clindamycin)
(note -> narrow spectrum cephalosporins can be used to but NOT ceftriaxone which is broad spectrum)
the difference between this and previous question is the condition being treated
Name an infectious microorganism which is a common cause of meningitis in 3 months or older new-borns?
neisseria meningitidis
What zoonotic disease does the Ixodes Tick cause?
lyme disease
Name the main class of drug used to treat HIV
nucleoside reverse transcriptase inhibitor
eg tenofovir
lamivudine
Patient in hospital eight days after a dynamic hip screw develops pneumonia. What is the most likely causative organism?
(Staph A and E.coli were not amongst the options)
Strep. Pneumoniae,
Haemiphilius influenzae
Pseudomonas
Legionella
pseudomonas!!!!
hemophilus is in both HAP and community acquired and is also less likely
Male tested positive for COVID 3 days ago. Emergency intubation on AMU today. What retroviral should be used assuming no contraindications or allergies?
Ribavirin
Tenofivir
Remdesivir
Paxlovid
Tocilizumab
last 3 are used for COVID
only antiretrovirals are remdesiver and paxlovid.
answer = remdesivir
The following antibiotics can be used to treat pneumonia. List them in order of the most narrow spectrum (1) to the most broad spectrum (5)
Amoxicillin
Benzylpenicillin
Co-amoxiclav
Ceftriaxone
Piperacillin/Tazobactam
Benzylpenicillin 1.
Amoxicillin 2
Ceftriaxone 3
Piperacillin/Tazobactam 4
Co-amoxiclav 5
Narrow spectrum = penicillin, flucloxacillin, metronidazole!!, gentamicin!!
Broad spectrum = coamoxiclav (amoxicillin + clauvulunate), tazocin, meropenem (most broad)
interpreting lumbar puncture
High protein in bacterial and viral causes
Glucose is low in bacterial causes
