Microbiology Flashcards
(23 cards)
What is the advantage of a pus aspirate
over a pus swab?
A swab is more likely to be contaminated with
mucosal commensal flora that will contaminate
the pus aspirate and make it more difficult to
interpret results
What are the key safety elements when submitting microbiological or pathological
materials to clinical laboratories?
Needles must be removed from syringes and disposed of correctly
End of syringe must be sealed
Syringe must be labelled
Request form completed
What are the key safety elements when submitting microbiological or pathological materials to clinical laboratories?
The packaging shall consist of at least 3 components:
(a) a primary receptacle
(b) a secondary packaging
(c) an outer packaging
Provide one clinical example of the utility of a Gram stain of pus from a dental abscess?
Informs empiric choice of antibiotics
What us the likely identity of an organism causing infection in dento-alveolar bone?
S.Aureus
What antibiotic is used for S.Aureus?
Flucloxacillin
What is the most likely identity of an organism found in PA abscess?
Streptococcus Anginosus
What AB is used for S.Anginsous?
Pen V
What are the atmospheric conditions required to grow pathogens from dental abscess?
Normal atmospheric air only
Normal atmospheric air with extra CO2
Normal atmospheric air with no O2
How are pathogens from dental abscesses commonly identified in the hospital
microbiology department?
Agar
API biochemical test
Vitek Biochemical tests
MALDI TOF
How are pathogens from dental abscesses susceptibility tested in the hospital
microbiology department?
Disc diffusion
E-test gradient diffusion
Vitek 2 AST
What is antimicrobial resistance?
Occurs when microorganisms such as bacteria, viruses, fungi and parasites change in ways that render the medications used to cure the infections they cause ineffective
How is antimicrobial resistance determined clinically?
When infection is highly unlikely to respond even to maximum doses of antibiotics
What clicnial factors can influence penetration of AB to the site of infection?
Pus
Foreign bodies
What us an example of a Black pigmenting anaerobe?
P.Gingivalis
What is the most common type of resistance mechanism for beta-lactams in Black pigmenting anaerobes?
Enzymatic inactivation through beta-lactamase?
Why is Phenoxymethyl Penicillin now the first line beta- lactam for the management
of dento-alveolar infections?
Equally effective as Amoxicillin but less harmful to resident flora
Which of the following micro-organisms from dental infections are usually
susceptible to metronidazole?
Peptostreptococcus micros
What are the mechanisms that result in metronidazole resistance?
Enzymatic inactivation
Modified target
Decreased uptake
Increase efflux
What antibiotics are part of the 4Cs group?
Co-amoxiclav
Clindamycin
Ceftriaxone
Ciprofloxacin
-> these are associated with Clostridium difficile infection
How is antimicrobial stewardship best defined?
Teamwork to minimize antimicrobial resistance
-> coherent actions to promote use of antimicrobials responsibly
What are the barriers to collecting pus aspirate in General practice?
Time
Resources (syringes, needles and postal containers)
Finance & clinical competence in obtaining samples
