Antimicrobials Part 1 Flashcards
What organisms are part of the oral microbiome
Bacteria
Fungi
Viruses
Protozoa
What are modulating factors of the oral microbiome
Anatomy
Saliva
Givgival Crevicular fluid
Microbial factors
Local environment- moisture, pH, antimicrobial therapy, diet(sugars), fluoride
The oral microbiome constitutes mainly of what type of organisms?
Bacterial
500-700 common species of bacteria
Of the 500-700 common bacterial species, what percentage of them are culturable?
only around 50%
How are you able to identify non-culturable organisms?
Molecular technology
The taxonomy of the oral flora changes based on …
Sequencing of ribosomal RNA
The human microflora is a mixture of …
bacteria, fungi and viruses
How is the human microflora kept in balance?
Kept in balance by the immune system
Oral habitats can change over time. Give some examples of some changes that can occur in the oral habitat
Deciduous exfoliation
Prostheses
Give examples of stagnation areas in the mouth
Occlusal fissures
Poor restorations
Malaligned teeth
List some aerobic gram positive cocci found in the oral cavity
S mutans
S salivarius
S anginosus
S mitis
S pyogenes
What bacterial microorganism causes strawberry tongue?
Streptococcus pyogenes
List some other gram positive cocci
Anaerobic streptococci
Stomatococci
Staphylococci
Micrococci
Give examples of gram positive rods and filaments
Lactobacilli
Propionibacteria
Actinomycetes
Give examples of gram negative cocci
Neisseria
Veillonella
Give examples of facultative anaerobic bacteria (gram negative rods)
Haemophilus
Aggregobacter
Eikenella
Capnocytophaga
Give examples of obligate anaerobes (gram negative rods)
Porphymonas
Prevotella
Fusobacteria
Leptotrichia
Wolinella
Selelnomonas
Treponema
Give examples of viruses of the oral cavity
Papovaviruses
Adenoviruses
Herpesviruses (Herpes labialis)
Orthomyxoviridae
Papilloma viruses
Paramyxoviridae
Picornaviridae
Rhinoviruses
Togaviridae
Coxsackieviruses
Orthomyxoviridae viruses cause…
Influenza
What papilloma virus is associated with oropharyngeal cancer?
HPV-16
What microorganism is responsible for >90% of human candida infections?
Candida Albicans
Candida infections are often opportunistic. What are the predisposing factors to candida infections?
Ill fitting or poor hygiene of oral appliance
Disturbed oral ecology e.g. xerostomia or antibiotic therapy
Immunological or endocrine disorder e.g. diabetes mellitus
Malignant or Chronic disease
Heavy smoking
What is the treatment for candida infections involve?
Identifying and addressing the predisposing factor
What factors modulate microbial growth
Saliva
GCF
Hard to clean areas
Local pH
Antimicrobial therapy
Diet (sugars)
Fluoride
How are saliva and GCF able to impact microbial growth?
Flush microbes
They are a complex mix of organic and inorganic components
Source of microbial nutrients (carbohydrates and proteins)
Growth inhibition (lysozyme, lactoferrin IgA)
Buffering capacity maintaining pH (acidic saliva favours cariogenic bacteria)
The periodontal condition of an individual may favour what kind of bacteria ?
Proteolytic bacteria
How is colonisation resistance achieved in the oral microbiome?
Competition for receptors for adhesion (e.g. to hard tissues)
Production of toxins
Production of metabolic products (acids which lower the pH)
Use of metabolic products
S. salivarius produces ________ which inhibits ________
Enocin
S. pyogenes (strawberry tongue)
What species of bacteria makes use of acids produced by S. mutans?
Veillonella spp.
What is the consequence of dental colonisation/infection?
Caries
Periodontal disease
Dento-alveolar infections (pyogenic)- apex of necrotic tooth
What is the meaning of a pyogenic infection?
Pus producing
Give examples of periodontal disease
Necrotising Ulcerative Gingivitis
Aggressive periodontitis
Chronic periodontitis
What is the function of leukocytes?
counteract infections and foreign substances
can also destroy host tissue
What are osteoclasts?
They are differentiated monocytes/macrophages
Break down bone tissue
What is Pus?
A collection of dead leukocytes
Give examples of pus collections
Abscess localised to the tooth
Diffuse cellulitis
Diffuse cellulitis can become …
Ludwigs angina
If pus becomes systemic, what are the potential consequences of this?
Bacteraemia
Septicaemia
Sepsis
Periodontitis is mediated by …
the immune system
What causes chronic periodontitis?
Apical spread of subgingival plaque biofilm
The depth of the pocket provides an anaerobic environment
What is the treatment for chronic periodontitis?
Cleaning properly
What is NUG (necrotising ulcerative gingivitis)?
infective disease of gingival soft tissues
Painful infection of the gums
Are antibiotics indicated for NUG?
Yes
What are the associations for aggressive periodontitis?
Impaired lymphocyte activity
A. actinomycetecomitans
Specialist treatment of aggressive periodontitis may include…
Antibiotics
Briefly state the caries progression to systemic infection
Caries–> pulpal inflammation–> pulp necrosis –>pulp infection—> periapical abscess –> sepsis/cellulitis
What bacteria do you usually find in a dental abscess?
Polymicrobial
Strict (obligate) anaerobes are usually the majority e.g. anaerobic cocci, prevotella, fusobacterium which are hard to isolate and grow in culture
Facultative anaerobes e.g. viridans streptococci, Strep. anginosus
Few aerobes
Some unculturable microbes e.g. Treponema species
How are researchers able to identify un-culturable species of bacteria?
Make use of genetic techniques
What is Ludwigs angina
A bacterial infection (cellulitis) that affects the neck and floor of mouth
Not contagious
Typically starts from a tooth infection (abscessed tooth)
can spread rapidly and cause life threatening swelling that can affect your ability to breathe
What is bacteraemia?
This is the presence of bacteria in the blood
Give some instances that may lead to bacteraemia
Cleaning teeth or chewing (usually asymptomatic)
Extractions
Endodontics
Periodontal treatment
What is septicaemia?
Sepsis of the blood
Large number of organisms in the blood producing clinical signs such as fever
What is Sepsis ?
Systemic inflammatory response to microbial products in the blood
What does NEWS stand for ?
National Early Warning Score
What are the physiological parameters considered by the NEWS score?
Respiration rate
Oxygen saturations
Any supplemental oxygen
Temperature
Systolic BP
Heart rate
Level of consciousness
What are the Antimicrobial Prescribing and Stewardship Competencies (October 2013)?
Infection prevention and control
Antimicrobial resistance and antimicrobials
Prescribing Antimicrobials
Antimicrobial stewardship
Monitoring and Learning
Infection prevention and control involves…
Standard (universal precautions)
Vaccinations against blood borne viruses
HTM01-05- Decontamination in primary care dental practises 2013)
What is included in the HTM01-05 document?
Decontamination of instruments, surfaces and equipment
General hygiene e.g. hand washing, personal protective equipment
Impressions and prostheses
List some ways we can prevent dental infections
DBOH- OHI, diet advice, fluoride
Denture hygiene advice (denture induced stomatitis)
Avoid aerosols (herpes labialis)
Post extraction advice (clean socket gently with hot salt mouth wash or CHX)
Antibiotic prophylaxis?
What does co-amoxiclav constitute of ?
Clauvalic acid (beta latamase inhibitor)
Amoxicillin
What are the general rules for treating infections?
Drain and remove source of infection; RCT, extract tooth, debride perio pocket/operculum
When are antibiotics indicated for treating dental infections?
Signs of systemic spread of infection
Immunocompromised patient
Need to refer to specialist for treatment
What is alveolar osteitis?
it is also knowns as dry socket
It is inflammation of the bone
classically occurs as a post operative complication of an extraction
Why does alveolar osteitis occurs?
Failure of blood clot to form in the socket or loss of blood clot from the socket
This leaves an empty socket where the bone is exposed to the oral cavity
What are the characteristics of alveolar osteitis?
White slough- macrophages breaking down the clot and not the infection
Pain- exposed bone which is not protected by the clot
What is the treatment for inflammatory dental conditions?
Analgesics for pain and remove the cause
Antibiotics do not cure toothache. What is the tag-line for prescription of antibiotics for dental infections?
No Pus- No antibiotics
What is GDC standard 7.1?
You must provide good quality care based on current evidence and authoritative guidance
You must only prescribe medicine to meet the dental needs of your patient
Other than in emergencies, you should no prescribe medicines for anyone whom you have a close personal relationship
What are the GDC guidance on prescribing medicines?
Make an appropriate assessment of patients condition
Prescribe within your competence
Keep accurate records
Have an understanding of patients current health and medication, including any relevant medical history in order to prescribe medicines safely- if necessary contact their GP or other appropriate health care professionals
Amoxicillin is the first choice antibiotic for _______. What does, frequency and duration is required?
Abscess
500mg, TDS (3x daily), up to 5 days
Review at day 3
Metronidazole is the first choice antibiotic for what conditions? Stage the dose, frequency and duration
Pericoronitis
NUG
400mg, TDS, up to 5 days
Review at day 3
When is antimicrobial prescribing in primary care indicated?
As an adjunct for management of infections
For definitive management of infective disease e.g. NUG
Where definitive treatment has to be delayed due to referral to a specialist
Antimicrobials are only indicated as an adjunct to definitive treatment where there is …
an elevated temperature
evidence of systemic spread
local lymph gland involvement
Trismus
What is pericoronitis?
Swelling and infection of gum tissue around the wisdom teeth
Prior to implant placement, what pre-op antibiotics can you prescribe?
Amoxicillin 2g 1 hour pre op
Clindamycin 600mg 1hr pre op
For oro-antral communication, what antibiotics (include frequency) can you prescribe?
Amoxicillin (up to 5 days)
Doxycycline (up to 5 days)
Patients with a risk of reduced vascular supply have an increased risk of osteonecrosis. What medication can increase the risk of osteonecrosis?
I.V. Bisphosphonates
Radiotherapy
Anti-angiogenics
How do you manage patients who have an increased risk of osteonecrosis?
Don’t extract teeth unless absolutely necessary
If tooth can’t be saved, call OMFS colleagues for advice
What is infective endocarditis?
Inflammation of the endocardium of the heart valves which results from an infection
Acute infective endocarditis is linked to which microorganisms?
Staphylococcus aureus
Streptococcus pyogenes
Chronic infective endocarditis is linked to …
Viridans streptococci
Vegetations in the left side valves in infective endocarditis are less commonly involved. True or false
False
More commonly involved
Vegetations on the right side valves in infective endocarditis are usually an indication of …
IV drug users
What is the consequence of infective endocarditis?
long hospital stay
Extended antibiotics
What people are at risk of infective endocarditis?
-Acquired valvular heart disease with stenosis of reguritation
-Hypertrophic cardiomyopathy
-Previous infective endocarditis
-Structural congenital heart disease (including surgically corrected or palliated structural conditions but excluding isolated atrial septal defect, fully repaired ventricular septal defect or fully repaired patent ductus arteriosus and closure devices that are judged to be endothelialised
-Valve replacement
Any episode of infection in people at risk of IE should be investigated and treated promptly to reduce the risk of endocarditis developing. True or false
True
What are the benefits of use of prophylaxis in Infective endocarditis
can reduce bacteraemia for a limited period
There is currently evidence for which dental procedures are high risk for infective endocarditis. True or false
False
There is currently no evidence
What are the risk of prophylactic treatment with antibiotics
Adverse reactions to antibiotics e.g. anaphylaxis, diarrhoea, C. difficile infection
Selecting for resistant bacteria
List the symptoms of infective endocarditis?
Fever of 38/above
Chills
Night sweats
Headaches
Shortness of breath especially during physical activity
Cough
Fatigue
Muscle and joint pain
Heart murmurs
Spotty red rash on the skin (petechiae)
Splinter haemorrhage
Painful raised lumps that develop on fingers and toes
Painful red spots that develop on the palms of hand and soles of feet
What is antimicrobial prophylaxis ?
prevention of infection by using antimicrobials with the aim of reducing morbidity and mortality
What are the risks of using antimicrobial prophylaxis
Drug interactions
Adverse effects e.g. allergy and toxicity
Resistant micro-organisms MRSA
Disrupt host normal flora; stomach upsets which can affect contraceptive cover; antibiotic related colitis from C.difficile
Give an example of a health care associated infection
Clostridium difficile
What is colitis?
Inflammation of the colon
Antibiotic related colitis is caused by …
a toxin produced by clostridium difficile
C. difficile is resistant to many antibiotics. Give examples of such antibiotics
Co-amoxiclav
Cephalosporins
Clindamycin
(4 C’s)
What is the pathophysiology of antibiotic related colitis?
Antibiotics kill everything in gut except resistant bugs
If C. difficile is present it continues to grow
Toxins produced make patient very ill and can be fatal
What is pseudomembranous colitis?
Medical condition in which the colon gets inflamed in association with excessive intake of antibiotics
What are the symptoms of pseudomembranous colitis?
Watery diarrhoea
Abdominal pain along with cramping
Fever
Mucousy stools
Nausea
Dehydration
What should you discuss with patients to increase efficiency of antimicrobial use?
Their concerns about their condition and whether they want or expect an antimicrobial
What they should do if their condition deteriorates (safety netting advice)
What are the systems and processes for effective antimicrobial medicine use?
-discuss with patients
-document clinical diagnosis (include symptoms) and reason for prescribing (or not)
-do not issue antimicrobial prescription to a patient likely having a self-limiting condition
What is a self-limiting condition
a condition that resolves on its own and has no long term harmful effect on a persons health
What can you prescribe for a cold sore (secondary herpes)
5% aciclovir cream
What can you prescribe for primary herpetic gingivostomatitis?
Aciclovir tablets/suspension
200mg
5x per day for 5 days
What can you prescribe for orofacial herpes zoster (shingles)?
Aciclovir tablets/suspension
800mg
5x per day for 7 days
What can you prescribe for denture induced stomatitis?
Miconazole oromucosal gel- 24mg/ml until 48h after resolution
Fluconazole capsule/oral suspension 50mg daily for 7-14 days
What can you prescribe for pseudomembranous candidisis (thrush)?
Nystatin oral suspension (100,000 units/ml 7 days or longer)- hold in mouth against lesion before swallowing
Miconazole oromucusal gel (7 days or longer)
Fluconazole capsules/oral suspension 50mg daily 7-14 days
How do you treat angular chelitis?
Remove source of infection
Miconazole 2% cream 10 days
Miconazole +hydrocortisone (max 7 days)
Sodium fusidate cream (max 10 days) (only if unresponsive to miconazole/hydrocortisone)
What is antimicrobial stewardship?
An organisation and system-wide approach to promote and monitor the judicious use of antimicrobials by
1. optimising therapy for individual patients
2. preventing misuse and overuse
3. minimising the development of resistance at patient and community level
What is antimicrobial drug resistance driven by?
overuse of antimicrobials
inappropriate prescribing
What percentage of metronidazole prescribing is done in primary care by GDPs?
60%
What is included in the dental antimicrobial stewardship toolkit?
Public health England
British Dental Association
Faculty of General Dental Practitioners
