oral microbiology- dr harshavardhan patwal

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