Microbiology Flashcards
Are gram +ve usually rods or cocci?
Cocci
Which bacteria are exceptions to +ve cocci (are positive rods) (2)?
- C. difficile
- Listeria
Are gram -ve bacteria usually rods or cocci?
Rods
What are some exceptions to gram -ve rods (are usually -ve diplococci) (2)?
- Neisseria (meningitidis/ gonorrhoea)
How is staph aureus differentiated from other staphylococcus?
It is coagulase positive
What are 4 aids defining illnesses?
- Pneumocystis jirovecii pneumonia
- CMV colitis
- Lymphoma
- Oral candida albicans
What is a defining feature of CMV colitis?
Owl eye inclusion bodies
What are the most common bacteria to cause meningitis in those aged over 3 months?
- S. Pneumoniae
- N. Meningitidis
What bacteria most commonly cause meningitis in those under 3 months?
- Group B beta haemolytic strep
- E. coli
- Listeria
Why is group B beta haemolytic strep common in neonates?
It colonises the vagina
What is group B beta haemolytic strep?
S. agalactiae
As well as neonates who else is often affected by listeria monocytogenes?
- Elderly
- Pregnant women (or men)
- HIV infected
What bacteria often causes meningitis in infants but is becoming increasingly rare?
H. influenzae (more rare, due to vaccination)
What viruses commonly cause meningitis (3)?
- Enteroviruses (coxackie, echovirus)
- HSV-2
- CMV
Is viral or bacterial meningitis more common?
Viral
How is suspected meningitis treated in GP?
IM benzylpenicilin
How is meningitis treated in hospital?
- IV Ceftriaxone or cefotaxime
- IV dexomethasone
How is close contacts of those with meningitis treated?
Single dose ciprofloxacin
How soon do you have to notify PHE of a meningitis case?
IMMEDIATELY
What rash is seen with N. meningitidis?
Non-blanching purpuric rash
How is viral meningitis treated?
Acyclovir
What is a hospital acquired pneumonia?
Pneumonia picked up/ symptoms >48 hours after admission
What bacteria cause CAP?
- S. Pneumoniae = MC
- H. influenziae
- Mycoplasma Pneumoniae
- Legionella Pneumoniae
What bacteria commonly cause HAP?
- P. aeruginosa
- E. coli
- Klebsiella pneumoniae
- MRSA
What bacteria are atypical pneumonia?
- M. pneumoniae
- Legionella pneumoniae
- Chlamydia pneumoniae
What virus cause pneumonia?
- Influenza A virus
- CMV
- SARS-COV-2
What fungi cause pneumonia?
P. jirovecii
How is pneumocystis pneumonia (caused by P. jirovecii) treated?
Co-trimoxazole
How are CAP treated?
CURB-65 =
* 2 or less then amoxicillin
* 3 or more then co-amoxiclav + clarythromycin
How are atypical pneumonia treated?
Clarythromycin (amoxicillin resistant)
Which bacteria commonly cause infection in bronchiectasis and CF?
- S. aureus
- H. Influenziae
- P. aeruginosa
Why is P. aeruginosa particularly problematic?
It is resistant to a lot of antibiotics (treat with ciprofloxacin)
What causes TB?
- M. tuberculosis = MC
- M. bovis
+ 2 others don’t need to know
How is TB diagnosed?
Ziehl Neelsen stain = acid fast bacteria, stains bright red
What organisms commonly cause cellulitis?
- Staph aureus
- Strep A (s. Pyogenes)
How is cellulitis treated?
Flucoxacillin
How is MRSA treated?
Vancomycin
What causes whooping cough?
Bordelia pertussis
What bacteria causes UTIs?
- Klebsiella
- Enterobacter
- E. coli = MC (80%)
- Proteus mirabilis
- S. saprophyticus
How are UTIs treated?
- Trimethoprim
- Nitrofurantoin
3 days if simple
When can trimethoprim and nitrofurantoin not be used?
- Trimethoprim = not in 1st trimester as anti folate
- Nitrofurantoin = not in 3rd trimester as increases risk of haemolytic disease of newborn
What is sometimes used for UTIs in pregnant women?
Amoxicillin
How is pyelonephritis treated?
- Co-amoxiclav
- Cefalexin if preggo
How is neisseria gonorrhoea treated?
- IM ceftriaxone
How is chlamydia trachomatis treated?
Doxycycline
7 days
What bacteria cause infective endocarditis?
- Staph aureus (very common in IVDU)
- Strep viridans (poor dental hygiene)
- HACEK
- Enterococci
What fungi can cause IE?
Candida albicans
How is Staph aureus IE treated?
Vancomycin + rifampicin
How is strep viridans treated?
Benzylpenicillin + gentamicin
What extra antibiotic is used for s. aureus infection if the patient has a prosthetic heart valve?
Gentamicin
Which valve is more commonly affected by IE?
Overall tricuspid valve (in non IVDU it is mitral valve as bacteria less commonly staph aureus, so has come from lungs)
What viruses cause diarrhoea in kids vs adults?
- Kids (under 3) = rotavirus
- Adults = norovirus
What are some bacterial causes of diarrhoea?
- Campylobacter jejuni = mc
- E. coli
- C. difficile
- Salmonella
- Shigella
- Cholera
What parasite can infect the gut?
Giardiasis
How is campylobacter jejuni treated?
Azithromycin
What often causes an infection with C. difficile?
Antibiotics
How is C. diff treated?
Vancomycin
How are the other bacteria causing diarrhoea treated (not C.diff or campylobacter jejuni)?
Co-amoxiclav
What bacteria often cause appendicitis?
- E.coli
- Klebsiella
- Enterobacter
- Enterococci
What infection does c. diff sometimes cause in the gut?
Pseudomembranous colitis
How is H. pylori treated?
- Omeprazole (or other PPI)
- Clarythromycin
- Amoxicillin
What bacteria most commonly infects bones and joints?
Staph aureus
What bacteria commonly infects bones in those with sickle cell disease?
Salmonella
What bacteria commonly infects prosthetic joints?
Staph epidermidis
What commonly causes reactive arthritis?
- Chlamydia
- Intestinal (salmonella, shigella, campylobacter)
What commonly causes GBS?
- C. jejuni = mc
- CMV
- EBV
What commonly causes rheumatic fever?
Group A strep (strep Pyogenes)
Which valve is most commonly affected by RHD?
Mitral valve
How is sepsis treated?
- Piperacillin
- Tazobactam
