The seminar discusses the bacteria that colonize human skin, focusing on their roles in maintaining skin health and the factors influencing their colonization. Key bacteria include Staphylococcus, Propionibacterium, and Corynebacterium, which support skin health but can also lead to conditions like acne when imbalanced. Understanding these dynamics can aid in promoting a healthy skin microbiome and preventing skin infections.

1. ENUGU STATE UNIVERSITY OF SCIENCE AND TECHNOLOGY
FACULTYOF APPLIED NATURAL SCIENCES
DEPARTMENTOF APPLIED MICROBIOLOGY AND BREWING
SEMINAR PRESENTEDBY
Onyekwere Uchenna Samuel
REGISTRATION NUMBER: 2020030194715
SEMINAR TOPIC: Bacteria colonizationon human skin.
COURSE CODE: AMB 481
COURSE TITLE: SEMINAR
SUPERVISOR: MR. J.E. ILOPUTAIFE
DATE: FEBRUARY2024

2. TABLE OF CONTENT
• Abstract
• Introduction
• Bacteria that colonizes the skin
• Factors influencing Bacteria colonization
• The role of Bacteria in maintaining skin health
• Implications of imbalanced bacteria on the skin
• Conclusion
• References

3. ABSTRACT
Our skin is home to a diverse community of bacteria, collectively known as
the skin microbiome. Some bacteria found on the skin includes
staphylococcus which are the major skin colonizers, propionibacterium and
corynebacterium.These bacteria play crucial roles in maintaining skin health,
including protection against harmful pathogens and regulation of skin pH.
There are some factors that influence bacteria colonization thereby affecting
how they establish on our skin. These factors includes environmental factors,
PH levels, moisture levels, sebum production, etc. However, imbalances in
the skin microbiome can lead to various skin conditions and infections.
Understanding the dynamics of bacterial colonization on the skin can provide
insights into maintaining a healthy skin microbiome and developing targeted
interventions.

4. INTRODUCTION
The skin is the largest human organ and it’s colonized by a wide variety
of microorganisms. During colonization, bacteria need to make sure
that attachment is established. Bacteria have special structures on their
surface such as Pili or firmbriae, that allow them to adhere or attach to
the skin cells. Additionally, our skin has natural oils and sweat that can
create a nourishing environment for bacteria. Once they find a spot,
they start forming communities and become part of our skin
microbiome.

5. CHART 1:BACTERIATHAT COLONIZES THE SKIN
1. Staphylococcus:They are widelyregarded as the most importantcolonizers ofthe human skin, there are certain species of
staphylococcus that colonizes the skin, there are:
• Staphylococcus epidermis:They are the main specie colonizingvarious areas ofthe skin.
• staphylococcus aureus:Theyare commonlyregarded as the major and dangerous human pathogenfoundon the skin, it can lead to
skin infections such as boils or impetigo.
2. Propionibacterium:They are commonlyfound on the skin, one of the main specie is calledpropionibacterium acnes.It can be
found on the skin of most individuals. It is well known as a contributor to the developmentofskin disease called acne. Other species
includes,Propionibacterium avidum,Propionibacterium propionicum, etc.
3. Corynebacterium:Theyare commonlyfound on human skin,theyare part of the skin’s natural microbiota.There are various
species of Corynebacteriumsuch as corynebacterium diphtheroids,Corynebacterium minutissimum,etc.
Sources: Rogers et al.(2008).

6. Source: Yang,2022.
FIGURE 1: SKIN STRUCTURES AND
PATHOGENESIS OF BACTERIA
Bacteria

7. CHART 2: FACTORS INFLUENCING BACTERIA
COLONIZATION
1. Sebum production: Sebum is an oily substance produced by the sebaceous
glands in the skin, it provides a comfortable environment for certain bacteria
to grow and colonize.
2. moisture levels: The level of moisture on the skin can impact bacterial
colonization.
3. PH levels: The PH level of the skin plays a role in determining which
bacteria can thrive. Differentbacteria have different PH preferences, so the
skin’s PH can influence their colonization.
4. Environmental factors: Environmental conditions such as temperature and
humidity can impact bacterial colonization.
Sources: Chilleret al.(2001).

8. CHART 3: THE ROLE OF BACTERIA IN
MAINTAINING SKIN HEALTH.
1. Bacteria promote wound healing: Bacteria like staphylococcus
epidermis plays a role in promoting wound healing by producing a
molecule that prevents inflammatorycytokine release from skin cells
2. protecting against harmful bacteria: The commensal bacteria can help
prevent harmful bacteria from taking over.
3. Supporting the immune system:certain bacteria can stimulateour
immune system,they help to strengthen our body against infections and
diseases.
4. Skin hydration: some bacteria produce substancesthat helps to
moisturize the skin, keeping it hydrated and preventing dryness.
Source: Lai,(2009).

9. CHART 4: IMPLICATIONS OF IMBALANCED
BACTERIA ON THE SKIN
1. Imbalances can cause skin Infections
2. Inflammation
3. Skin conditions such as eczema.
4. Body Odor
5.Imbalances can delay the healing process.
6.Acne
Sources: Daniele et al.(2019).

10. CONCLUSION
Our skin is home to a diverse community of bacteria, forming the skin
microbiome. This microbiome plays a crucial role in maintaining skin
health and protection against harmful pathogens. However, imbalances
in the skin microbiome can lead to various skin conditions and
infections. Understanding the dynamics of bacteria colonization can
provide insights into promoting a healthy skin microbiome and overall
skin well-being.

11. REFERENCES
• Chiller,K., Selkin,B. and Murakawa,G. (2001). Skin microflora and bacterial infections of the skin.
Journalof InvestigativeDermatologySymposiumProceedings,6(3):170-4
• Dagnelie,M.A., Montassier,E., Khammari,A., Mounier,C., Corvec S., Dreno,B.(2019). Inflammatory
skin is associated with changes in the skin microbiota composition on the back of severe acne
patients. Journal Of Dermatologyand Skin Science, 28:961–967
• Lai,Y.(2009). Commensalbacteria regulate toll-like receptor 3-dependent inflammationafter skin
injury. JournalOf Nature Medicine, 15(12):1377–1382
• Mak,T.N., Schmid,M., Brzuszkiewicz,E.,Zeng,G., Meyer,R., Sfanos,K.S., Brinkmann,V., Meyer,T.F.,
Bruggemann,H.(2013).Comparative genomics reveals distinct host-interacting traits of three
major human-associatedpropionibacteria. JournalOf Biomed Central Genomics,14:640
• Nakatsuji,T.(2017). Antimicrobials from human skin commensal bacteria protect against
Staphylococcus aureus and are deficient in atopic dermatitis. JournalOf Science Translational
Medicine,9:378
• Rogers,K.L., Rupp,M.E. and Fey,P.D.(2008). The presence of icaADBC is detrimental to the
colonization of human skin by Staphylococcus epidermidis. Research journal of Applied and
EnvironmentalMicrobiology, 74:6155–6157