MicroBio (Intro & History) (w1)

dental relevance of microbio (2)

1) oral cav - complex microbial system

2) biofilms = primary cause of caries and perio disease

clinical implications of microbio (3)

1) cross-contam risk

2) instrument sterilization

3) patient-to-patient transmission

asepsis? how to achieve (2)?

absence of micro-orgs

free from contam of microorgs

state of being free from contam by microorgs

1) excluding/removing/destroying microorgs

2) maintaining sterile conditions in tissues/instruments/environ

what’s infection control?

procedures to prevent disease transmission (sterilization, disinfect, proper clinical technique)

chain of aesepsis is? (fyi?)

continuous sequence of infection control practices designed to prevent contam

dental setting risk (3)

• aerosol

• blood/saliva exposure

• contam surfaces

important terms to define

• microbio

• bacteriology

• mycology

• parasitology

• entomology

• immunology

• epidemiology

• microbio - study of microorgs

• bacteriology - branch of microbio studying bacteria

• mycology - study of fungi

• parasitology - study of protozoa, helminths

• entomology - insects and arthropods (vectors of disease)

• immunology - immune system (innate and adaptive

• epidemiology - distribution of disease

3 types of beneficial roles of microorgs

1) environmental

• photosynth (cyanobact prod O2)

• nutrient cycling (Carbon, N, S cycles)

• decomp (breakdown org matter)

2) industrial/medical

• fermentation (food prod)

• drug prod (antibiotics like penicillin)

• biotech (genetic engineering)

• 
  

3) human host benefits

• normal microbiota (prevent colonization by pathogens

• vit prod (k and b)

• immune sys dev (stim immune resp)

whats human microbiome? density distribution? what oral microbiome exist as?

total microorgs living in/on body

• highest density in GI tract

• skin, oral cav, resp tract

oral microbiome exist as biofilm, many unculturable orgs

ratio of human cells:microbial cells? microbiota varies by? (mult)

1:1 ratio human:microbial cells

vary by loc, diet, age, health

dysbiosis (discruption of microbial balance) can lead to what? why?

disease

• acidogenic bacteria cause caries

• perio disease caused by anaerobic pathogens

• host response contrib to inflam and tissue destruction

key factors causing dysbiosis

• poor oral hygiene

• high sugar

• reduce saliva flow

• immune changes

harmful roles of microorgs (4)

1) infections & disease

• microbes can act as pathogens (cause = local infections like caries, systemic infects

2) virulence mechs

• virulence factors = adhesion (to tissues), toxin prod, enzyme secretion

3) biofilm formation

• structured microbial communities w/ inc resistance to antibiotics & host immune defenses

4) antibiotic resistance

• genetic mutations or gene transfer (global health concern)

whats ecological plaque hypothesis?

diseases result from:

1) environ changes

2) selection of pathogenic species

what’s spont generation VS. germ theory? key transition

Spont Gen (rejected)

• life arises from non-living matter (supported for centuries)

Germ Theory (accepted)

• microorgs can cause disease

• microbes come from existing microbes

experimental evidence replaced belief

father of bacteriology? contribs?

• antony van leeuwenhoek

• discovery of microorgs

Lazzaro Spallanzani contrib?

conducted experiments to challenge spont generation

• he prevented air exposure in it and critics argued u needed it for life

father of microbio?

Louis pasteur

disproved spont gen theory & estalished germ theory

(aka microorgs can cause disease and microbes come from existing microbes)

Developed pasteurization (heat treatment for foods that kill bact while preserve taste)

Ignats Semmelweis

Introd hand hygiene

• saviour of mothers bc ppl were delivering babies after dealing w cadavers

• This also helped w nosocomial infection (within hospital) so cross contam betw patients

Joseph Lister

Developed antiseptic surgery (sterilizing instruments + using chemical disinfectants

• important bc dental sterilization and infection control protocols

Edward Jenner? introd concept of what? (aka relevance to dh)

• first successful vax (smallpox)

• Foundation of immunology - led to irradiation of smallpox

• introd concept of acquired immunity

what’s immunology? 2 things it protects against

• study of immune sys and host defense mechs

1) microbial infection

2) toxins and foreign subs

clinical relevance of immunology (3)

• inflamm in perio disease

• tissue destruction

• microbial challenge

Hans Gram? findings relevance to dh

• developed gram stain

• differentiation betw gram pos/neg is cell wall struct

• signif bc rapid bacterial identification (diagnose & antibiotic selection)

• relev = oral pathogens have gram pos (streptococ) and gram neg (perio pathogens)

Paul Ehrlich findings?

• proposed chem treatment of infectious disease

• “magic bullet” = selectively targets pathogen w/o harming host

• proposed that immunity is mediated by subs in blood (antibodies)

• modern antibiotics, and how its overuse can cause antibiotic resistance

Robert Koch

• linked specif microorgs to certain diseases

• dev Koch’s Postulates (4 specific scientific rules that prove this^)

• introd pure culture techniques, solid media (agar), improve staining

koch’s postulates (what is it briefly and its limitations )

• same org present in all cases of disease

• isolated or grown in pure culture

• cause disease in host

• pathogen reisolated from host

• COMPLTE***

Willoughby Miller (father of..?) + signif?

• father of oral microbio

proposed chemico-parasitic theory of dental caries

• caries result from bacterial metabolism of carbs, prod of organic acids, demineraliation of enamel and dentin

signif = first to link microorgs + diet = dental disease

• foundation for caries prevention and role of biofilm (plaque)

Alexander Flemming

• discovered penicillin (first widely use antibiotic)

• observed mold (penicillium) inhibit grow of staphylococc bact

• beginning of antibiotic era

relevance = treating oral infect, antibiotic resistance