SKIN
Bacillus subtilis . produces bacitracin on the skin, a toxin that helps it in fighting with
other microbes.
Staphylococcus epidermidis and other coagulase-negative Staphylococci.
Corynebacterium , Propionibacterium and Brevibacterium .
The most commonly isolated fungal species is Malassezia sp .
which is especially prevalent in areas of the skin enriched in sebaceous glands.
The Demodex mites viz. Demodex folliculorum and Demodex brevis
NASAL
Streptococci are sparsely present in the nasal
cavity.
Corynebacterium ,Aureobacterium , Rhodococcus and Staphylococcus.
Staphylococcus epidermidis in 79% cases, whereas diphtheroids were in 41% cases)
Staphylococcus aureus (in 34% cases).
Haemophilus influenzae in 5% cases and
Streptococcus pneumoniae in 0.5% case.
The anaerobic bacteria found were Propionibacterium acnes in 74.5% cases and
Peptococcus magnus in 3.5% cases.
ORAL
600 species with distinct combination at different habitats. Most organisms that are
colonizing are beneficial to human health but some microbes transit from a commensal
relationship to pathogenicity oral microbiome includes the species of;
Actinobacteria, Bacteroidetes, Chlamydiae, Chloroflexi, Euryarchaeota, Firmicutes,
Fusobacteria, Proteobacteria, Spirochaetes, Streptococcus, Synergistetes and
Tenericutes .
Review Question?
1. What is the difference between the terms “normal microbiota” and “carrier state”?
2. If the normal flora of the colon is suppressed by certain antibiotics, which disease can
results?
3. Explain the important anaerobes in the normal flora of the colon?
4. The vagina of some women are colonised by Escherichia coli. What is the significance of
this observation? If the organisms were group B streptocooci, what would be the
significance?
5. If a urine culture grew many colonies of Streptococcus epidermidis, what would be your
interpretation?