Gram Positives Flashcards
Give examples of Gm +ve cocci
Staph.
- Aureus (MSSA/MRSA)
- Epidermidis (+ other coag. -ve staph)
Strep.
Enterococci
- faecalis
- faceium
- vancomycin resistant enterococci
Give examples of Gm +ve bacilli
Listeria
Clostridia
- Difficile
- Perfringens
Corynebacterium
- AKA diptheroids (not diptheria)
What antibiotic classes are Beta-lactams?
- Penicillin (PLUS Flucloxacillin and Amoxicillin)
- Cephalosporins
- Piperacillin/tazobactam
- Carbepenems
What is the difference between penicillin given IV and oral?
IV = benzyl penicillin Oral = phenoxymethylpenicillin
What is the Minimum Inhibitory Concentration? (MIC)
The concentration of drug required to kill 99.9% of organisms during the 18 to 24 hour period
In order to tackle infections effectively, we must remain above the MIC level. TRUE/FALSE?
TRUE
Name the monobactam which is used in Tayside
Aztreonam
Should gentamicin be allowed to linger in the body?
- No can cause nephro/ototoxicity
- Usually infused quickly to a peak and then out as quickly as possible
- DONT give for longer than 3 days
What sites are hard for antibiotics to reach and how do we get round this?
CNS Eyes Prostate ** due to tight junctions ** Need higher doses of IV antibiotics to get to these places
What type of agar is used to show streptococcus haemolysis?
Blood agar
What is meant by streptococci being “facultative anaerobes”?
They grow in conditions with or without oxygen
Group A strep. follows what classification system?
Lancefield
Why is PCR better at classifying strep. than the Lancefield classification?
Some forms of strep. dont fit the criteria for a Lancefield group
What type of streptococci are in the Group B Lancefield classification?
Streptococcus agalactaiae
How many species of viridans strep. are there?
3 species (each with sub-species of its own)
What streptococcal infection has a link to colon cancer?
Streptococcus gallollyticus
What stain is retained in the thick peptidoglycan layer of the Gm +ve cell wall?
Crystal violet
Strep. pneumoniae usually causes what 3 infections?
Otitis
pneumonia
meningitis
Why is it important to ask if a patient has travelled when you suspect they have Step. pneumoniae meningitis?
Some countries have strains of this which are resistant to penicillin
Give examples of countries which have penicillin resistant strep. pneumoniae
Canada
USA
Mexico
Spain Poland Italy Croatia Greece Turkey
Pakistan
China
Name one important mechanism of antibiotic resistance in bacteria
Enzyme changes to inactivate drug
e.g. beta-lactamase can break down antibiotics containing beta-lactam ring
Where are enterococci usually found and therefore where do they cause infection?
Found in gut
Responsible for peritonitis when gut perforates
OR biliary tract infection
What is the chosen treatment for enterococci infection?
Amoxicillin IV
If enterococci are resistant to amoxicillin what can be given instead?
Vancomycin IV
What antibiotics can be used if treating Vancomycin resistant enterococci?
Linezolid
Daptomycin
Tigecycline
SEPSIS caused by staph. aureus should be treated with what?
Flucloxacillin IV
Vancomycin IV in MRSA
If there is a staph. aureus infection but no sepsis, and the patient cannot tolerate flucloxacillin, what antibiotics can be used?
Oral:
- doxycycline
- Cotrimoxazole
- clindamycin
Many staph. epidermidis are flucloxacillin resistant. TRUE/FALSE?
TRUE
Listeria is a Gm +ve bacillus causing what kind of infection?
Gastroenteritis
What infection is related to reheated/ left out rice?
Bacillus Cereus
What antibiotic is used for a mild C-Diff infection and which is used for SEVERE?
MILD = IV Metronidazole SEVERE = oral vancomycin (treats topically)
Why is there a lot of recurrence in C-Diff?
Due to spore formation
What infection control precaution must you always remember in C-Diff?
WASH HANDS WITH SOAP AND WATER
alcohol gel allows spores to form
