Microbiology Flashcards
Draw the gram +ve cocci flow chart.
Check diagram.
What is CAP?
What is the most common cause of CAP?
What is the treatment for the most common cause of CAP?
CAP = Community acquired pneumonia (pneumonia symptoms developing within 48 hours of hospital admission).
Most common cause of CAP:
- Streptococcus pneumoniae.
- Amocicillin is the 1st line treatment
- Co-amoxiclav if unresponsive to amoxicillin or very ill (assess with CURB-65).
What is HAP?
What are some of the key causes of HAP?
What is the treatment generally?
- Hospital acquired pneumonia. Symptoms develop after 48 hours of admission.
Key causes:
- E. coli, Klebsiella pneumoniae, pseudomonas aeruginosa, MRSA etc…
Treatment:
- Usually coamoxiclav + gentamycin
What is the first line treatment for all streptococci?
- Amoxicillin is the first line for all streptococci.
Draw the gram +ve bacilli flow chart.
Check notes for answers.
What type of bacteria is clostrium difficile?
- A gram +ve, anaerobic bacilli.
What are the four main inticing agents for clostrium difficile infection?
“4 C’s”
- Clindamycin
- Cephalosporins
- Co-amoxiclav
- Ciprofloxacin
What is the pathophysiology of Clostrium difficile infection?
- Treatment with any of “the 4 C’s” results in the disruption of normal gut flora.
- This leaves the patient open for C. Diff colonization.
What is the treatment for C. Diff?
Vancomycin or oral fidaxomicin.
What is the classification of the neisseria species?
- Gram -ve diplococci.
What are the two common types of neisseria, and what do they commonly cause?
- Nesseria meningitidis (meningeal sepsis).
- Nesseria gonorrhoea (Gonorrhoeal arthritis HAS THE SAME SYMTPOMS AS REACTIVE ARTHRITIS - “can’t see, can’t pee, can’t climb a tree” = uveitis, urethritis and arthritis).
What is the treatment for bacterial meningitis?
- IV cefotaxime (cephalosporin) for all patients.
- Add IV amoxicillin for the over 50’s/immunocompromised (to cover listeria monocytogenes infection).
- One oral dose of ciprofloxacin should be given to all contacts.
How does bacterial meningitis CSF present?
- Cloudy.
- High WCC
- High protein
- Low glucose.
Draw the gram -ve bacilli flow chart.
Check answer in notes.
What is the only gram -ve coccobacilli?
- Haemophilius influenza.
What is the primary cause of UTIs?
- 85% caused by E. Coli.
What is the treatment for UTIs?
- Oral nitrofurantonin or trimethoprim.
- In pregnancy, use cefalexin.
- If simple, 3 day course. If complex, 7 day course.
Which antibiotic classes disrupt cell wall synthesis?
- Penicillins.
- Cephalosporins.
- Vancomycin (used for MRSA).
Which antibiotic classes disrupt folate synthesis?
- Sulfonamides.
- Trimethoprim (hence why it is contraindicated in pregnancy).
Which antibiotic class disrupts DNA gyrase?
- Quinoline antibiotics (e.g. ciprofloxacin).
Which antibiotic class disrupts RNA polymerase?
- Rifampicin.
Which antibiotic classes distrupt 50S subunits?
- Macrolides (e.g. erythromycin which is used in penicillin allergy).
- Clindamycin.
- Chloramphenicol.
Which antibiotics disrupt the 30S subunits?
- Tetracyclines (e.g doxycycline).
What are mycobacteria?
- Atypical, fast growing bacilli.
What is the only mycobacterium I need to know about?
- Mycobacterium tuberculosis (TB).
- What are the four drugs used to treat TB? What are the associated side effects of each?
- Isoniazid - Numb/tingling.
- Ethambamol - Ocular side effects (“etham” = “eye”)
- Rifampicin - Blood in urine (“R-“ for “red” which is blood).
- Pyrazinamide - Arthralgia.
What is the stain used for mycobacteria (e.g. TB)?
Ziehl-neeson stain.
What is a key characeteristic of all mycobacteria?
- Acid-fast bacilli.
What is the suffix used on antifungal drugs?
How effective are they?
“-azole” (e.g. econazole).
Antifungals are not very effective overall.
What are the two main fungal diseases I need to be aware of?
- Candida. Usually the cause of a line/catheter infection, oral infection or vaginal infection.
- Aspergilus fumigatus. Associated with chronic lung infection.
How does Hep B serology work?
Markers are:
- HBsAg.
- Anti-HBc IgM and IgG.
- HBsAb
- IgG +Ve
- IgG -Ve.
HBsAg = marker of active infetcion.
If +ve:
anti-HBc IgM = acute HBV infection.
Anti-HBc IgG = chronic HBV infection.
HbsAb = marker of immunity.
If +ve:
IgG +ve indicates a previous clearance of HBV, so natural immunity.
IgG -ve indicates a Hep B vaccine, so vaccine-induced immunity.
What is the treatment for Hep C?
- DAA (Direct acting antibodies).
What is the biomarker associated with HIV?
How is HIV treated?
- CD4+ cell count.
- HAART (highly active anti-retroviral therapy).
What is the 1st line treatment for HSV?
- Acyclovir (an antiviral).
What are protazoa?
What is the one protazoa I need to know about?
- Protazoa - microscopic unicellular eukaryotes.
- Malaria is the key example.
- What parts of the body does malaria infect?
- Liver and RBC’s.
What is the most important factor in a history regarding malaria?
- Travel history.
What is the most common protazoa that causes malaria?
- P. falciparum.
What is the treatment for malaria?
- Chloroquine if uncomplicated.
- IV artesunate if complicated malaria.
