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Normal and Transient Flora; Host/Parasite Relationships. Microbial Ecology. The study of microorganisms and their environment. www-esd.lbl.gov. Symbiosis. “living together” - PowerPoint PPT Presentation
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Normal and Transient Flora;Normal and Transient Flora;Host/Parasite RelationshipsHost/Parasite Relationships
Microbial EcologyMicrobial Ecology
The study of microorganisms and their environment.
www-esd.lbl.gov
SymbiosisSymbiosis
“living together”Describes the interactions that occur
between two dissimilar organisms (usually 2 different species) that live together or are in close association with one another.
Symbionts the organisms that live together in such a
relationship.
NeutralismNeutralism
Symbiotic relationship in which neither symbiont is affected by the relationship.
Both species are unaffected.
CommensalismCommensalism
Symbiotic relationship in which one symbiont benefits and the other species is not affected (neither harmed nor helped).
Ex. Propionibacterium many species in this genera live on the skin and are thought to
neither hurt nor help humans.
Host An organism that harbors another organism.
MutualismMutualism Symbiotic relationship
that is beneficial to both symbionts.
Ex. Termites and protozoa
Ex. Lichens
Ex. Some species of our microflora (i.e. Escherichia coli.)
Termite
Lichen. botit.botany.wisc.edu
E. coli. www3.niaid.nih.gov
Parasitism Parasitism
Symbiotic relationship in which one symbiont is benefited and the other is harmed.
Ex. Sheep liver fluke
Ex. Opportunistic pathogens of our normal flora.
Sheep Liver Fluke. locksparkfarm.wordpress.com
Synergistic Relationship Synergistic Relationship When two (or more)
microorganisms “team up” to cause a disease that neither could cause by itself.
Called synergistic infections.
Ex. Acute necrotizing ulcerative gingivitis (i.e. “Trench Mouth).
Acute necrotizing ulcerative gingivitis.
www.ohiohealth.com
Normal Flora of HumansNormal Flora of Humans All microbes that reside on and
within a person.
Most commonly inhabited parts of the body.
Eyes Skin Mouth Ears Upper respiratory tract Gastrointestinal tract Genitourinary tract
www.scq.ubc.ca
When do microorganisms take up When do microorganisms take up residence in humans?residence in humans?
Establishing Normal Flora Establishing Normal Flora
www.ehponline.org www.solarnavigator.ne
Transient FloraTransient Flora
Live temporarily on the body.
Often “picked up” from our daily routines.
Why are they temporary?
Importance of Normal FloraImportance of Normal Flora
Often helps prevent infection.
Prolonged use of antibiotics can cause an imbalance.
Ex. Candida albicans
Candida albicans. www.humanillnesses.com
Candida albicans infection. www.lib.uiowa.edu
Microflora of the SkinMicroflora of the SkinConsists of mostly bacteria and fungi.
Most are anaerobes, although some are aerobic.
Anaerobes live in the: deeper layers of the skin hair follicles sweat and sebaceous glands
health.howstuffworks.com
Microflora of the SkinMicroflora of the Skin
The number and variety of microorganisms depends on the:
Amount of moisture present pH Temperature Salinity Presence of chemical wastes such as urea and fatty
acids Presence of other microbes (which may produce
toxic substances)
Groups of Normal Skin FloraGroups of Normal Skin Flora
1. Diphtheroids (Coryneforms) Gram-positive, non-spore forming
rods. Ex. Propionibacterium acnes.
2. Staphylococcus spp. Gram-positive cocci usually arranged
in clusters. Helps maintain normal flora balance.
3. Yeasts – Candida spp. Single-celled fungi. Ex. Causes tinea versicolor.
Propionibacterium acnes. bacteriality.com
Tinea versicolor. georgiahealthinfo.gov
Microflora of the Eyes and EarsMicroflora of the Eyes and Ears Ears
Middle ear and inner ear sterile.
Outer ear and auditory canal contain same types of microorganisms as are found on the skin.
Eyes Does contain some
microorganisms. Tears, mucus, and sebum
that are produced in and around the eye greatly reduce many microorganisms.
www.bluedothealth.com
www.infovisual.info
Respiratory TractRespiratory Tract
Upper Respiratory Tract Nasal passages Throat (pharynx)
Lower Respiratory Tract Larynx (voice box) Trachea Bronchi Bronchioles Lungs www.uic.edu
Microflora of the Respiratory TractMicroflora of the Respiratory Tract
Upper Respiratory Tract Nasal Passages and Throat
– Have many species of microorganisms.– Provide moist, warm environment.– Many are harmless.– Some are opportunistic pathogens.– Some people are carriers of virulent pathogens.
Lower Respiratory Tract Usually microbe free.
Microflora of the Upper Respiratory TractMicroflora of the Upper Respiratory Tract Staphylococcus spp.
Gram-positive cocci in clusters. Often includes S. aureus.
Corynebacterium spp. Gram-positive rods; nonmotile; nonspore-forming. Nonpathogenic species. Collectively called diphtheroids.
Moraxella spp. Gram-negative diplococci. Resemble Neisseria species.
S. aureus
Corynebacterium spp.
Moraxella spp.
Microflora of the Upper Respiratory Microflora of the Upper Respiratory Tract cont.Tract cont.
Haemophilus spp. Small, gram-negative rods. Often includes H. influenzae.
Bacteroides spp. Small, gram-negative rods. Strict anaerobes.
Streptococcus spp. Gram-positive streptococci in chains. Often includes S. pneumoniae.
H. influenzae
Bacteroides fragilis
Streptococcus spp.
Microflora of the Oral CavityMicroflora of the Oral Cavity Provides great shelter and nutrients
for many species of microbes. Flourish in gum margins, crevices
between teeth, and deep fold of the tonsils.
Bacteria feed on food particles and dead epithelial cells.
Poor hygiene can lead to periodontal diseases.
Most common microbes are species of alpha-hemolytic streptococci.
anatomy.med.umich.edu
Gastrointestinal TractGastrointestinal Tract
Digestion of food, absorption of nutrients, and elimination of undigested material.
Includes: Oral cavity and throat (already
discussed) Esophagus Stomach Small intestines Large intestines Anus
www.giconsults.com
Microflora of the Gastrointestinal TractMicroflora of the Gastrointestinal Tract Stomach
Acidic environment prevents much growth. Exception – Helicobacter pylori – found in some people causes ulcers.
Small Intestine Upper part of small intestine (duodenum) – little growth due to bile. Lower portion of small intestine (jejunum and ileum) – more
microbial growth present. Large intestine (colon)
Contains the largest number and variety of microbes. 500-600 species. Anaerobic environment. Contains obligate anaerobes, aerotolerants, and facultatives. Many are opportunistic pathogens if enter other areas of the body.
Genitourinary TractGenitourinary TractUrinary Tract
Kidneys Ureters Urinary bladder Urethra
Male and Female Reproductive Systems
www.pvurology.org
Microflora of the Genitourinary TractMicroflora of the Genitourinary Tract Healthy kidneys, ureters, and urinary bladder are
sterile. Urethra harbors many microbes (i.e. yeasts, bacteria, and
viruses). Usually don’t invade bladder due to acidic nature of urine. UTI (urinary tract infections) occur when microbes travel up
the urethra and multiply.
Male and female reproductive systems are sterile with the exception of the vagina.
Type of growth depends on stage of sexual development. pH of vagina changes throughout sexual development
providing different environments for different organisms.
The EndThe End