The document discusses the normal microbial flora that colonize different areas of the human body, providing benefits to the host through symbiotic relationships. It describes how colonization begins at birth and is dependent on the mother's microflora. The composition of the flora is determined by nutritional and environmental factors at different body sites like the skin, oral cavity, respiratory tract, gastrointestinal tract, and genitourinary tract. The normal flora play protective roles while some can potentially cause disease if they invade sites where they are not normally found.

1. LALU YAN HIDAYAT

2. INTRODUCTION
• The relationship between two organism can be very complex.
• The normal flora present in its normal site in human body provides some benefits to the
host they live in the perfect symbiosis in their natural habitate.
HOST PATHOGEN
Host’s immune system
Microbal faktor inherent

3. • Describes the origin of the indigenous (resident) microbial biota (microbiota) and
the composition at different body sites.
• Discusses the virulence factors that contribute to the invasiveness of organisms,
protective mechanisms the host employs, and how microbes are able to evade
the host’s defenses.
• Describes factors that can make the host more susceptible to infections and how
microbes are transmitted.

4. DEFINITION MICROBIAL BIOTA
• The human microbiome (or human micro biota) is the aggregate of
microorganisms that reside on the surface and in deep layers of skin, in the saliva
and oral mucosa, in the conjunctiva, and in the gastrointestinal tracts. They
include bacteria, fungi. Some of these organisms perform tasks that are useful for
the human host. However, the majority have no known beneficial or harmful
effect. Those that are expected to be present, and that under normal
circumstances do not cause disease, but instead participate in maintaining health,
are deemed members of the normal flora

5. A diverse microbial flora
- Human body Area: the skin and mucous membranes
- Time: shortly after birth until death
- Normal flora may:
- Aid the host
- Harm the host (in sometimes)
- Exist as commensals (no effect to the host)

6. WHEN WE GET COLONIZED WITH NORMAL FLORA
• A human first becomes colonized by a normal flora at the moment of birth and
passage through the birth canal. In utero, the fetus is sterile, but when the
mother's water breaks and the birth process begins, so does colonization of the
body surfaces. Handling and feeding of the infant after birth leads to
establishment of a stable normal flora on the skin, oral cavity and intestinal tract
in about 48 hours.
• The composition of a child’s bacterial flora is dependent on the mother’s micro
flora, since she is the primary source for the child’s bacteria at the outset.

8. SYMBIOSIS
• Symbiosis is define as “life together”. i.e. that two organisms live in an association
with one another.
• Mutualism : Symbiosis as a biological relationship between two or more organisms
where both (host and organism) benefit from one another. Example : lactobacilli
• Comensalism : In the relationship where the organism benefits but there is no
beneficial or harmful effect on the host, the association between organisms. Example :
Proteus Mirabilis
• Parasitism : The relationship may be in which one organism damage the other.
Example : Entamoeba Hystolytica

9. CHARACTERISTICS OF MICROBIAL BIOTA
• Indigenous microbiota : Microorganisms that are commonly found on or in
body sites of healthy persons are called normal.
• Resident microbiota : Microorganisms that colonize an area for months or years
• Transient microbiota.

10. FACTORS THAT DETERMINE THE COMPOSITION OF THE
USUAL MICROBIAL BIOTA
• Nutritional
• Environment

11. NORMAL MICROBIOTA OF THE SKIN
• Normal skin has numerous mechanisms to prevent infection and protect the
underlying tissue from invasion by potential pathogens.
• Fatty acid
• Lysozyme by sweat gland
• Desquamation of the epithelium

12. • The composition of the microbiota on the skin depends on the activity of the sebaceous
or sweat glands
• Organism concentrate the most in areas that are moist, such as the armpit, groin, and
perineum. The apocrine sweat glands in these areas secrete substances metabolized by
the skin bacteria, releasing odorous amines

13. NORMAL MICROBIOTA OF THE ORAL CAVITY
• The oral cavity is a complex environment that encompasses distinct, small microbial
habitats, such as teeth, soft and hard palate, and tongue, which form a species-rich
heterogeneous ecological system.
• microbiota growth is affected :
• Saliva
• Imun system
• pH

14. NORMAL MICROBIOTA OF THE ORAL CAVITY
• The mouth contains large numbers of bacteria, with Streptococcus being the
predominant genus.

15. NORMAL MICROBIOTA OF THE RESPIRATORY TRACT
Respiratory tract
upper
lower
nose, nasopharynx,
oropharynx, and larynx
trachea, bronchi, and
pulmonary parenchyma
The trachea, bronchi, and lungs are protected by the
action of ciliary epithelial cells and by the movement
of mucus. The tissues of these structures are
normally sterile as a result of this protective action

17. NORMAL MICROBIOTA OF THE GASTROINTESTINAL
TRACT

18. NORMAL MICROBIOTA OF THE GENITOURINARY
TRACT

19. ROLE OF THE MICROBIAL BIOTA IN THE PATHOGENESIS OF
INFECTIOUS DISEASE
• Some organisms that make up the microbial biota live off the host’s nutrients, but
in most cases, they provide some benefit to the host, creating a symbiotic
relationship with the host, as mentioned earlier.