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