what are the primary bacteria on the teeth
Streptococcus mutans, streptococcus sanguis
what primary bacteria is found on the tongue
streptococcus salivarius
plaque and cavity formation: S. mutans, sanguis, glucose is turned into what
glucose- (undergoes polymerization)- dextran= plaque formation
plaque and cavity formation: S. mutans, sanguis, fructose is turned into what
fructose- lactic acid= tooth decay
what does dextran do?
allows bacteria to adhere to teeth and tongue which initiate tooth decay
what does lactic acid do?
degrades tooth enamel
more S. mutans means what
greater probability of dental caries
sucrose is broken down by what
bacterial exoenzymes
plaque and cavity formation: S. salvarius, fructose is turned into what
fructose- (undergo polymerization)- levan= plaque formation
plaque and cavity formation: S. salvarius, glucose is turned into what
glucose--- lactic acid= tooth decay
sugar free foods contain what
mannitol or sorbitol
sugar free foods cant convert mannitol or sorbitol into what
dextrose
what bacteria can ferment mannitol or sorbitol and this results in formation of acid and cavities
S. mutans
(bacteria of mouth) Mitis Salivarius Bacitracin (MSB) plate purpose and mechanism
- selective for S. mutans
- crystal violet, potassium tellurite, trypan blue inhibit G (-) growth and permits streptococci growth
Mitis Salivarius Bacitracin (MSB) results
1. light blue to black, raised, rough colonies= + for S.mutans
2. smooth colonies and/or flat colonies= - for S.mutans
Sucrose Blood Agar (SSBA) purpose and mechanism
- enrichment medium and differential for hemolysis patterns
- sucrose is added to encourage/promote dextran capsule formation around S.mutans and S. sanguis
- Hemolysis can also be determined since medium contains blood
results for sucrose blood agar plate
1. large raised mucoid (gum drop) colonies= + S. salivarius
2. glistening colonies surrounded by an indentation of agar= + S. sanguis
3. drop of liquid polysaccharide on top of or surrounding colony= + S. mutans
what are the two types of bacteria in the GI tract?
90%= non-enterics
10%= enterics
what are the characteristics of non-enteric bacteria?
- obligate anaerobes
- G + or G-
- bacilli or cocci
what are the characteristics of enteric bacteria?
- facultative anaerobes
- G-
- bacilli
- non-endospore forming (endospores= a tough, encapsulated, dormant form of a bacteria produced when nutrients are exhausted)
what are the two types of enterics?
coliforms and non-coliforms
what are the characteristics of coliforms?
ferment lactose; nonpathogenic
what are the characteristics of noncoliforms?
unable to ferment lactose; pathogenic
(GI tract bacteria) MacConkey Agar (MAC) purpose and mechanism
- selective for G- bacteria; differential for lactose fermentation
- lactose fermenters are coliforms; nonpathogenic
- bile salts and crystal violet inhibit G+ bacteria
- acid accumulation from lactose fermentation= red
- acid accumulation can precipitate
results for MAC
1. growth= G- bacteria
2. no growth= not G-; G+
3. red, hot pink, magenta= + lactose fermentation
4. tan, beige, colorless growth= - lactose fermentation
Tomato Juice Agar (TJA) purpose
- enrichment medium that enhances Lactobacillus (non-enterics) growth
- enrichment so other organisms can grow
TJA results
1. growth when gram stained is G+ bacilli= + lactobacillus
2. growth when gram stained is G+ cocci, G- cocci, G- bacilli= - Lactobacillus