microbiology_flashcards
Which mechanism mediates flucloxacillin resistance in S. aureus?
Alteration of the target
By which mechanism is ESBL E.coli resistant to ceftriaxone?
Enzymatic inactivation of antibiotic
A patient has grown a fully susceptible E.coli in their urine. Which of the following is the narrowest spectrum agent you should de-escalate to?
a. Amoxicillin
b. Ceftriaxone
c. Co-amoxiclav
d. Meropenem
e. Piperacillin/tazobactam
Amoxicillin
What is the most common syndrome of HAI?
Urinary tract infection with catheter
What is C. difficile?
Gram pos spore-forming anaerobe
What is the most frequent route of entry of pathogens into CNS?
Haematogenous spread
What would meningococcal meningitis be classified as?
Acute meningitis
In addition to CSF from a lumbar puncture, what 3 other microbiological samples should be sent when you suspect meningitis?
Blood culture, throat swab, blood PCR
What are fungi?
Eukaryotic organisms with chitinous cell walls and ergosterol containing plasma membranes
Which is the commonest cause of fungal infections in humans?
Candida spp
Mr A is complaining of a painful mouth and his tongue looks strange. What is wrong with his tongue?
Oral candidiasis
Which one is the yeast?
A (Candida Gram stain). Both gram positive. Yeasts are larger
Which animal is Cryptococcus associated with?
Pigeons
What type of ink is used for a cryptococcal stain?
India
Why might antifungals targeting the cell membrane not work in PCP?
It lacks ergosterol in its cell wall
Which one of the following viruses is the most contagious?
Measles
Vaccination with a live vaccine should be deferred if: 2 correct answers
a. Patient has received immunoglobulin in past 3 months b. Patient is receiving systemic high dose steroids
What percentage of the worlds population is infected with TB?
33%
The laboratory calls you saying they have found Acid Fast Bacilli in a clinical sample. Which answer is most appropriate?
Thank them and recommend the start of TB therapy
A 23 year old male is a close contact of a person with smear positive pulmonary TB. What is his lifetime risk of developing active TB?
10%
What infection test is NOT currently included in routine screening of pregnant women?
Toxoplasmosis
What is the most common cause of early onset neonatal sepsis?
Group B strep
What is the most common type of meningococcal disease in the UK?
Men B
What is the commonest cause of death worldwide in children under 5 years?
Pneumonia
Which of the following is associated with a reduced risk of SSI?
Bactericidal concentration of antibiotic in serum at time of incision
What is the most likely pathogen?
Coagulase negative staphylococci
What cells are these?
Squamous epithelial cells
Which one of the following cell types on microscopy suggest a poorly taken sample?
Squamous epithelial cells
Which of the following dipstick parameters is a product of nitrate reductase and suggestive of a UTI?
Nitrites
A 51-year-old with a recent HSCT is unwell. Which is the most appropriate test? ALT = 800 IU/mL
HEV PCR
Which type of immunosuppression carries the greatest relative risk of developing a viral infection?
Allogeneic stem cell transplant
A patient who received a stem cell transplant 2 weeks ago presents with mouth ulcers. Which of the following viruses would you test for on the mouth swab?
HSV PCR
Which of these is NOT an antiviral?
Rituximab
Which patient has previously had Hepatitis B Infection?
sAg-, cAb+, sAb-
What is the definition of gastroenteritis?
More than 1 week of symptoms
Which risk factors are associated with gastroenteritis?
a. Elderly b. Infancy c. MSM
Which extra-intestinal manifestations are associated with Salmonella infection?
a. Erythema Nodosum b. Abscess formation c. Aortitis
Aortitis
Which virus is commonly associated with outbreaks?
Norovirus
