Microbiology of Infection Flashcards
(24 cards)
What micro-organisms might be present in a dental abscess?
Mixed microbial lesion
- Anaerobes play a key role.
Streptococcus Anginosus
Prevotella Intermedia
What would be the ideal specimen from a dental abscess?
Aspirational biopsy of pus from the abscess.
- this means that the sample is not contaminated by the aerobic environment.
- Will determine the bacteria that is causing the abscess.
What bacteria might be present in a periodontal abscess?
Streptococcus Anginosus
Prevotella Intermedia
What bacteria might be present in pericoronitis?
Mixed oral anaerobes
- Prevotella Intermedia
- S.Anginosus.
What bacteria is present in Osteomyelitis?
Anaerobic Gram negative rods
Streptococcus Anginosus
Staphylococcus Aureus
What bacteria is commonly found in Ludwig’s Angina?
Anaerobic gram negative bacilli- Prevotella Intermedia
Streptococcus Anginosus
Staph Aureus may also be present.
What is an SOI?
Severe odontogenic infection.
Give examples of SOIs.
Ludwig’s Angina
Osteomyelitis
What can SOIs lead to if not treated?
Sepsis.
What is sepsis?
Life threatening organ dysfunction caused by dysregulated host response to infection.
Systemic inflammatory response syndrome (SIRS)+ suspected/confirmed infection.
What signs would suggest systemic inflammatory response syndrome?
Temperature- less than 36 or greater than 38
Pulse- greater than 90 beats per minute
Respiratory rate- greater than 20 breaths a minute
WCC less than 4 or greater than 12
Do they seem confused?
Have they passed urine in the last 24 hours?
Cold or blotchy hands and feet
Uncontrolled shivering
Signs of infection
What guidance can GDPs use to assess sepsis?
General practice Sepsis Decision Support Tool.
What questions would you ask the patient?
Do you feel systemically unwell- fever, fatigue, malaise, lymphadenopathy.
Are carers/family members concerned?
Has there been deterioration?
Confusion?
Passed urine in the last 18 hours?
What red flags symptoms would warrant you to phone 999?
Heart rate- greater than 130 beats per minute
Respiratory rate- greater than 25 breaths in a minute
Blood pressure- systolic blood pressure less than 90mmHg
Needs oxygen to keep oxygen saturation above 98%
Not passed urine in the last 18 hours.
Non blanching rash or mottles/ashen/cyanotic.
What antibiotics would you prescribe for a dental abscess?
Phenoxymethylpenicillin- 250mg tablets, 2 tablets 4 times a day for 5 days.
If allergic to penicillin- can prescribe metronidazole- 400mg tablets, 1 tablet 3 times a day for 5 days.
If antibiotics were required for a gingival or periodontal condition, what would you prescribe?
Metronidazole- 400mg tablets, 1 tablet 3 times a day for 5 days.
What is antibiotic resistance?
Micro-organisms no longer respond to anti-microbials- they have changed in ways that render the medication ineffective.
How might bacteria become resistant to antibiotics?
Intrinsic resistance- naturally resistant to the antibiotic- i.e. from having a thick capsule.
Acquired resistance- mutation, acquisition of new DNA.
Describe some of the mechanisms of antibiotic resistance.
Altered target site- Streptococci
Enzymatic inactivation- Prevotella Intermedia, Fusobacterium.
- usually from beta-lactamase.
Decreased uptake of antibiotic
When it comes to choosing an antibiotic, what does S, I and R mean?
S- Susceptible at standard dose
- High likelihood of therapeutic success using standard dosing regimen of the agent.
I- Increased exposure (requires increased dose)
R- resistant even with increased exposure.
- High likelihood of therapeutic failure even when there is increased exposure.
What is antimicrobial stewardship?
An organisational or health-care system wide approach to promoting and monitoring judicious use of antimicrobials to preserve their future effectiveness.
What can be done to improve antimicrobial stewardship?
Educate members of the dental team- not just prescribers
Guidelines about appropriate clinical indications for antibiotic use
Undertake audit and feedback of prescribing against the guidelines
Patient-facing material to help deliver key messages in relation to antibiotic stewardship ind dentistry.
Reducing the need for antibiotics- patient education in OH, diet advice, prevention.
Why is Pen V recommended for use in dentoalveolar infections instead of amoxicillin?
Amoxicillin is a more broad spectrum antibiotic.
- Both active against gram negative anaerobes but Amox is also active against gram negative cocci and members of the family Enterobacteriaceae.
So there is a greater impact on selection of resistance in the host microflora compared to pen V.
If you are prescribing Pen V to a patient, what should you do in the days after prescribing it?
Arrange to review the patient after 24 hours- either in person or over the phone.
