Microbiology & Antimicrobials Flashcards
What growth conditions do aerobic microorganisms require?
oxygen
What growth conditions do capnophilic microorganisms require?
carbon dioxide
What growth conditions do facultative microorganisms require?
with & without oxygen
What growth conditions do strictly anaerobic microorganisms require?
without oxygen
What type of organism is Prevotella Intermedia?
gram negative
In which dental conditions might you find prevotella intermedia?
periodontal disease
What is antimicrobial resistance?
Microorganism such as bacteria, viruses, fungi and parasites CHANGE in ways that render the medications used to cure the infections they cause ineffective
What are the two types of antimicrobial resistance?
- intrinsic resistance
- acquired resistance (mutation or acquisition of new DNA)
What can cause antimicrobial resistance?
Resistance by enzyme inactivation
- enzymes destroy antibiotics or prevent binding to target sites
Improper use of antibiotics (eg finishing course early)
What are beta-lactamases?
Important group of resistance mechanisms in bacteria
What would be the last therapeutic option to treat complex infections caused by MDR bacteria?
Carbapenems
What does ESBL stand for?
extended spectrum beta lactamase
How can periapical infection occur?
- infection via carious cavity or traumatised crown
- infection via periodontal ligament
how can dental abscess infections be described?
- endogenous
- often mixed infections by mixture of microorganisms
- strict anaerobes important
what does endogenous mean?
our OWN microflora causes infection
What would be the idea specimen of a dental abscess?
ASPIRATED PUS (with no saliva etc.)
What microorganisms can cause periodontal abscesses?
- anaerobic streptococci
- prevotella intermedia
what microorganisms cause pericoronitis?
- p. intermedia
- s. anginosus
when should antibiotics be given for pericoronitis? what antibiotic would be given?
ONLY if systemic signs/symptoms
- metronidazole
does dry socket require antibiotic treatment?
NO
What predisposes a patient to development of osteomyelitis of the jaw?
- bisphosphonate therapy (MRONJ)
- impaired vascularity of bone (radiotherapy, Paget’s disease)
- foreign bodies (implants)
- compound fractures
- impaired host defences (diabetes)
What type of microorganism causes osteomyelitis of the jaws?
- anaerobic gram negative rods
- anaerobic streptococci
Give examples of microorganisms found in osteomyelitis of the jaws?
- S. anginosus
- S. aureus
What microorganism can cause salivary gland infection?
- S. aureus
How are salivary gland infections treated?
- drainage (painful especially if parotid due to capsule)
- prescribe flucloxacillin & metronidazole
What MUST YOU DO when you come across microbiological infections in dentistry?
- Document your diagnosis
- Document antibiotic choice, dose, route & duration
- Document a review date
- Document deviation from guidance
What is SOI? What does it mean?
severe odontogenic infection
- spread of infection into tissue planes
- systemic symptoms & signs of sepsis
what is Ludwig’s angina?
Bilateral infection of submandibular space
What bacteria causes Ludwig’s angina?
- anaerobic gram negative bacilli = prevotella intermedia
- S. anginosus
- anaerobic streptococci
what microorganism must you watch out for in cases of severe odontogenic infections?
S. aureus
- can be fatal
What SIMD group is most commonly hospitalised from dental infection?
SIMD1
(most deprived areas)
What is the key management strategy for severe odontogenic infection?
REMOVAL OF SOURCE OF INFECTION
what is sepsis?
life-threatening organ dysfunction caused by dysregulated host response to infection
What is our roles as GDPs in SOI and Ludwig’s angina?
Sepsis detection!
- any signs of SIRS
What are the red flag signs of sepsis?
- systolic BP <90mmHG
- HR >130 bpm
- RR >25 per min
What does S, I & R mean for a choice of antibiotic?
S = susceptible at standard dose
I = increased exposure (increased dose)
R = resistant even with increased exposure/dose
what clinical confounding variables can contribute to antibiotic resistance?
- Co-morbidities
- Pus collections
- Site of infection
- Foreign bodies
- Biofilm
what is antimicrobial stewardship?
organisational or healthcare-system-wide approach to promoting and monitoring judicious use of antimicrobials to preserve their future effectiveness
