Microbiology Flashcards
what forms can the cell wall be in?
gram positive or negative
what is LPS?
gram negative outer membrane
what are flagella?
found in gram positive and negative - enables bac to swim
where are fimbriae found?
gram negative
what is a pathogen?
microbe capable of causing host damage
what can staph aureus cause?
MRSA abscesses carbuncle folliculitis impetigo
what does strep pyogenes?
strep sore throat
what are types of gm +ve bacteria?
strep - facultative/obligate anaerobes
staph - facultative
actinomyces
lactobacillus
describe strep mutans?
binds to tooth surface and causes tooth decay
intitiates caries at enamel surface
bind and colonise tooth surface and produce sticky extracellular polysaccharides
produce acid from sugar
tolerate acidic conditions
what is infective endocarditis caused by?
strep sanguinis
describe lactobacilli?
pleomorphic rods acidogenic/aciduric pH 5.5 produces lactic acid from glucose levels in saliva correlate with carbohydrate intake cause dentinal caries
describe actinomyces?
pleomorphic rods anaerobic and facultative fimbrae aid in adherence supra and sub plaque root surface caries abscess and dentoalveolar infections
what are GNABS?
gram negative anaerobic bacilli
what are non motile GNABS?
bacteriodes porphyromonas prevotella tannerella fusobacterium
in a healthy perio pocket what bacteria are present?
gm positive
describe porphyromonas?
dark purple pigmented bacteria GNAB- use ecxternal haeme as iron source. iron scavenging molceules at surface = dark appearance
assachorylitic - produce proteases to breakdown amino acids and peptides
present in sulcus and perio pocket
associated with perio
describe prevotella?
dark purple
non saccharolytic
sulcus and perio pocket
describe tannerella?
saccharolytic non pigmented bacteria
fibrinogen binding BspA
proteases produced
what is BspA?
induced bone resorbing pro inflammatory cytokines
describe fusobacterium?
endotoxins - perio disease
in gingival sulcus
binds with treponema to form fusospirochaetal infection
what is aggregatibacter?
present in gingival sulcus and perio pocket
leukotoxin, collagenases, proteases
what is plaque?
a biofilm - bacterial cells enclosed in extracellular matrix
what is in the organic matrix of plauqe?
host and bacterial products
gingival proteins
what is present in the pellicle?
acidic prp amylase albumin statheirn lysozyme immunoglobulin
how does the pellicle develop?
contact attachment adhesion growth co aggregation microcolony formation biofilm forms climax community
what is the bacterial developnment of the plaque?
- strep
- joined and replaced by actinomyces
- gram negative species replace e.g fusobacterium
what types of bacterial adhesion take place?
cell substratum
homotypic
heterotypic - corn cob/test tube
what is a virus?
nucleic acid genome
protein capsid - protection
poss lipid envelope + virus proteins
what does hep b cause?
malaise
jaundice and liver disease
what is HIV?
a retorovirus
reverse transcriptase
replicates in cells with CD4 marker
Smutans is responsible for?
comes in what forms?
what metabolic pathway do they account for?
dental caries
rods, cocco bacilli
make extracellular polysaccharides from sucrose, convert these to acids
form of actinomyces?
involved in what dentally?
what metabolic pathway are they involved in?
gram positive rods and filaments
plaque, gingivitis, root surface caries
produce lactic acid from glucose
lactobacillus is the cause of?
produce what from glucose?
caries of dentine
lactic acid
Aggregatibacter actinomyctecomitans is the cause of?
form?
what does it stimulate?
produces what?
aggressive forms of periodontal disease in adolescents
stimulates bone resorption
leukotoxins, collegenase, proteases
porphyromonas gingivalis commonly seen in what? why is it black pigmented? fibrous capsule because? how does it attach? what does it produce?
advanced periodontal lesions requires external haem source as energy evades host response fimbrae collagen degrading enzymes, proteases
prevotella seen when?
perio disease
what is fusobacterium?
commonly seen in?
asaccharolytic or saccharolytic?
gram negative anaerobe
periodontal disease
asaccharolytic
prevotella is pigmented?
found where?
yes
perio pocket and sulcus
tannerella is pigmented? saccharolytic or asaccharolytic?
produces what?
saccharolytic
non pigmented
fibrinogen binding BspA and proteases
fusobacterium often found where?
releases what that contributes to perio disease?
causes a fusospirochaetal infection by binding with?
sulcus
releases endotoxins
binds with treponema
