oral microbiology- dr harshavardhan patwal
TRANSCRIPT
Dr Harshavardhan G Patwal
INTRODUCTION
HISTORY
NORMAL MICROFLORA OF HUMAN ORAL CAVITY
MICROFLORA OF PERIODONTAL DISEASE
VIRULENCE FACTORS
BACTERIA IN PATHOGENESIS OF PERIODONTAL
DISEASE
MICROBIAL DIAGNOSIS
CONCLUSION
INTRODUCTION
• FROM AMOEBA TO Aa, Pg
• BACTERIAL PLAQUE- CAUSATIVE OF
PERIODONTAL DIS
• LARGE COMPLEX MIXTURE OF BACTERIAL
SPECIES
HISTORY• 1683 - ANTON VON LEEWENHOEK
• 1890 - WD MILLER
• 1965 - LOE, THEILADE AND JENSEN
• 1880 TO 1890 – AMOEBAE, SPIROCHETES,
MILLER’S BACTERIA, STREPTOCOCCI
• 1890 – 1930 SPECIFICITY THEORY
• 1930 – 1970 NONSPECIFICTY THEORY
• 1970 ONWARD RETURN OF SPECIFICITY THEORY
NORMAL FLORA• 300 – 400 SPECIES FOUND IN HUMAN
SUBGINGIVAL PLAQUE
• INDIGENOUS FLORA
• SUPPLEMENTAL FLORA
• TRANSIENT FLORA
FACTORS INFLUENCING NORMAL FLORA• THE ENVIRONMENT THE INDIVIDUAL IS RAISED
• THE DIET
• ORAL HYGIENE HABITS
• INFECTION POTENTIAL FROM FAMILLY MEMBERS
• INFECTION POTENTIAL FROM PETS
• TOOTH ERUPTION
• PRESENCE OF PERIODONTAL POCKET
• HORMONAL EFFECTS
• PERIODIC EXPOSURE TO VARIOUS TREATMENT
ACQUISITION OF BACTERIA
• STARTS AT BIRTH
• DERIVED FROM FROM THE IMMEDIATE
ENVIRONMENT
• MODULATED BY HOST FACTORS
SUBGINGIVAL FLORA ASSOCIATED WITH HEALTH
• STREPTOCOCCUS MITIS
• S SANGUIS
• S EPIDERMIDIS
• ROTHIA DENTOCARIOSA
• ACTINOMYCES VISCOSUS
• ACTINOMYCES NAESLUNDII
• SMALL SPIROCHETES
RELATIVE PROPORTION OF MICROORGANISMS
MICROBIAL FLORA OF PERIODONTAL DISEASE
CONCEPTS OR HYPOTHESISES – WALTER LOESCHE 1976
NONSPECIFIC – THE ENTIRE PLAQUE FLORA IS
RESPONSIBLE
SPECIFIC – ONLY CERTAIN PLAQUE IS PATHOGENIC
RANKING OF SUSPECTED BACTERIAL PATHOGENS
MODERATE• S intermedius• P micros• F nucleatum• E corrodens• Eubacterium
STRONG• P intermedia• C rectus• E nodatum• Treponema sp
VERY STRONG• A actinomycetemcomitans• P gingivalis• B forsythus
VIRULENCE FACTORS
VIRULENCE - THE QUALITY OF BEING DAMAGING;
THE DISEASE PRODUCING POWER OF A
MICROORGANISM
GLOSSARY OF PERIODONTAL TERMS
1984
OTHER FACTORS :
CONCENTRATION OF MICROORGANISMS
VIRULENCE FACTORS
1. THE CAPACITY TO COLONIZE
2. THE ABILITY TO EVADE ANTIBACTERIAL HOST DEFENSE
3. THE ABILITY TO PRODUCE SUBSTANCES THAT CAN
DIRECTLY OR INDIRECTLY INITIATE TISSUE
DESTRUCTION
COLONIZATION
FACTORS INFLUENCING COLONIZATION
1. AVAILABILTY OF SURFACES TO ATTACH
2. ABILITY TO MULTIPLY
3. ABILITY TO COMPETE SUCCESSFULLY AGAINST
OTHER MICROORGANISMS
ATTACHMENT
SITES FOR ATTACHMENT1. THE TOOTH2. THE SULCULAR / POCKET EPTHELIUM3. OTHER BACTERIAL SPECIES
BACTERIAL FACTORS FACILITATING ATTACHMENT4. ADHESINS5. COAGGREGATION
ADHESINS1. FIMBRIAE
a. TYPE --1b. TYPE –2c. TYPE –3d. TYPE – 4
2. CELL ASSOCIATED PROTEINSa. 300-330 kDa PROTEINb. 70, 90 kDa PROTEINc. 40 kDa PROTEIN
RECEPTORS FOR ADHESINS ON TISSUE SURFACES• GALACTOSYL VESICLES• SIALIC ACID• PROLIN-RICH PROTEINS OR STATHERIN• TYPE-I AND IV COLLAGEN
FIMBRIAE
ADHESINS ORGANISM
FIMBRIAE E corrodensA viscosus
PROTEINS
F nucleatum (300-330 kDa protein)T denticolaP gingivalisStreptococcus mitis (70, 90 kDa protein)B loeschei ( fimbriae associated 75 & 45
kDa polypeptide)
EXAMPLES OF ADHESINS
RECEPTOR ADHESINS SITE ORGANISMS
GALACTOSYL RESIDUE
PROTEINFIMBRIAE
EPITHELIAL CELLSFIBROBLASTSPMLSALIVA COATED SURFACES
E corrodens (PROTEIN)B gingivalis (FIMBRIAE)A viscosus (TYPE 2 FIMBRIAE)A naeslundii (FIMBRIAE)T denticola (PROTEIN)F nucleatum (300-330 kDa Protein)B loeschi (FIMBRIAE)
SIALIC ACID PROTEIN SALIVA COATED SURFACES
S mitis (70, 90 kDa PROTEIN)
PROLIN-RICH PROTEINS OR STATHERIN
FIMBRIAE MINERALIZED SURFACES A viscosus (TYPE 1 FIMBRIAE)
TYPE-I AND IV COLLAGEN
BASEMENT MEMBRANE B gingivalis ( NOT KNOWN)
MANNOSE RESIDUE PROTEIN FIBROBLASTS T denticola (PROTEIN)
SALIVA TREATED HYDROXYAPPATITE
FIMBRIAE MINERALIZED SURFACES A viscosus (TYPE 1 FIMBRIAE)
KNOWN RECEPTORS FOR BACTERIAL ADHESINS
COAGGREGATION
Sl. No. TARGET SPECIES RECEPTOR ON TARGET SPECIES
SPECIES ADHESINS
1 B gingivalis GALACTOSYL RESIDUE
F nucleatum PROTEIN
2 S sanguis GALACTOSYL RESIDUE
B loeschi FIMBRIAE ASSOCIATED 75 AND 45 kDa POLYPEPTIDE
3 S sanguis GALACTOSYL RESIDUE
A viscosus TYPE 2 FIMBRIAE
4 S sanguis POLYSACCHARIDE WITH REPEATING HEPTASUCCINATE
A viscosus FIMBRIAE
MULTIPLICATION OF BACTERIA
FACTORS INFLUENCING MULTIPLICATION
1. CREVICE TEMP
2. GCF pH
3. OXIDATION REDUCTION POTENTIAL
4. AVAILABLE NUTRIENTS
INTERBACTERIAL RELATIONSHIP• FAVORABLE RELATIONSHIP
• FACILATITING ATTACHMENT
• PRODUCING GROWTH FACTORS
– BRANCED CHAIN FATTY ACIDS
– POLYAMINES
– VITAMIN K ANALOGUES
– LACTATE / FORMATE /HYDROGEN
• PRODUCTION OF EXTRACELLULAR ENZYMES THAT
UNCOVER BINDING SITES FOR ONOTHER
ORGANISM
ANTAGONISTIC RELATIONSHIP
• COMPETITION FOR NUTRIENTS
• COMPETITION FOR SITE
• PRODUCTION OF SUBSTANCES LIMITING /
PREVENTING GROWTH
INTERRELATIONSHIP FOR NUTRITIONO2
SUGARCO2
SALIVA DIET
GCFSALTS
NH4
AMINO ACIDS
STRPTOCOCCUSACTINOMYCES
PABAS MUTANS
CAPNOCYTOPHAGAE CORRODENSAa
FUSOBACTERIUMEUBACTERIUMBACTEROIDSPEPTOCOCCUSPEPTOSTREPTOCOCCUSA
Thiamin pyroPPutrescineisobutyrate
CO2NH4
T macrodentium
lactate
Veillonella acetate
Eubacterium
H2
CampylobacterWolinella
formate
P melaninogenicusP gingivalis
Hemin
OVERCOMING HOST DEFENSESl. No DEFENSE
MECHANISMVIRULENCE FACTOR SPECIES
1 SPECIFIC AbIgA, IgG PROTEASE B gingivalis
B intermediaB melaninogenicusCapnocytophaga
2 SALIVARY MACROMOLECULES
AFFINITY FOR HIDDEN RECEPTORS (CRYTITOPES)
A viscosus
3 PNL
LEUKOTOXIN Aa
CAPSULE B gingivalis
INHIBITION OF DEGRANULATION T denticola
INHIBITION OF SUPEROXIDE PRODUCTION Treponema
4LYMPHOCYTE
LEUKOTOXIN – LETHAL Aa
LEUKOTOXIN – NONLETHAL SUPPRESION Aa
SUPPRESSED IMMUNE RESPONSE B intermedia
INHIBIT RESPONSE TO MITOGENS AND ANTIGENS
B intermediaB endodontalisT denticolaAa
5 ANTIBIOTIC THERAPY
CONJUGAL TRANSFER OF RESISTANCE PLASMID
T denticolaB intermedius
FACTORS CAUSING TISSUE DAMAGESl. No. ENZYMES SPECIES
1 COLLAGENASE P gingivalisAa
2 PROTEASE P gingivalisP intermedia
3 KERATINASE P gingivalisT denticola
4 ARYL SULFATASE W recta
5 NEURAMINADASE P gingivalisB forsythusP melaninogenicus
6 FIBRONECTIN DEGRADING ENZYMES
P gingivalisP intermedia
7 PHOSPHLIPASE P intermediaP melaninogenicus
BACTERIAL PREPARATION INHIBITING MAMMALIAN CELL GROWTH
Sl. No. BACTERIAL PREPARATIONS ORGANISM AFECTED CELLS
1 CULTURE SUPERNATANTS P gingivalis FIBROBLASTS
2 LPS Aa FIBROBLASTS
3 CAPSULE Aa FIBROBLASTS
4 SONIC EXTRACTS P gingivalisT denticola
FIBROBLASTS
5 SONIC EXTRACTS AaP gingivalis
EPITHELIAL CELLSENDOTHELIAL CELLS
Environmental and acquired risk factor
Host im
muno-inflam
matory
response
Ct &
bone metabolism
Clinical signs of disease
initiation & progression
Genetic risk factor
Cytokines
MMPs
Ab
PMN s
Ag
LPS
Othervirulence factors
Microbial challenge
MECHANISM OF PERIODONTAL DISEASE PRODUCTION
BACTERIA ASOCIATED WITH SPECIFIC PERIODONTAL DISEASE
DISEASE ORGANISM
ADULT PERIODONTITIS P gingivlis, P intermedia, B forsythus, C rectus, E corrodens, F nucleatum,
REFRACTORY PERIODONTITIS B forsythus, P gingivlis, C rectus, P intermedia
LJP Aa, Capnocytophaga
PRAGNENCY GINGIVITIS P intermedia
ANUG P intermedia, Intermediate-sized spirochetes
PERIODONTITIS IN JUVENILE DIABETICS
Capnocytophaga, Aa
PERIODONTAL ABSCESSES P gingivalis, Fusobacterium, Capnocytophaga, Vibrio sp
MICROBIAL DIAGNOSIS OF PD
• MICROSCOPIC ASSAYS
• CULTURE ASSAYS
• IMMUNOLOGIC ASSAYS– ELISA
– IMMUNOFLUORESCENCE
• DNA PROBE ASSAY
• ENZYME-BASED ASSAYS
AVAILABLE DIAGNOSTIC AIDS• CULTURE
Aa P gingivalis
P intermedia Capnocytophaga
Wolinella Sp Eikenlla Sp
Peptostrptococcus micros
• DNA PROBE
Aa B forsythus
P gingivalis C rectus
• BANA
T denticola B forsythus
P gingivalis
CONCLUSION• COMPLEXITY IS THE PRINCIPAL PROBLEM
• REMARKABLE RESEARCH EFFORTS HAVE
RESULTED IN UNDERSTANDING THE MICROBIAL
ETIOLOGY
• MORE WORK REQUIRED TO DEVELOP
DIAGNOSTIC TESTS