Normal Flora Flashcards
What two microbiota are found in the GI tract?
Bacteroidetes and Firmicutes
What is microbiota?
also known as normal flora, colonizes every surface of the human body exposed to external environment.
What is the term dysbiosis?
it is microbiota disruption has been proposed to contribute to obesity, cardiovascular disease, colon cancer and other conditions
the firmicutes?
The Firmicutes are a phylum of bacteria, most of which have Gram-positive cell wall structure. A few, however, such as
The Proteobacteria?
The Proteobacteria are a major group of Gram-negative bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, Yersinia, and many other notable genera.
Are probiotics approved for clinical use by the FDA?
No, they are recognized as GRAS generally recognized as safe but are not approved for clinical use.
What is the rule when recommending probiotics to your future patients?
Always use reasoning, is the patient immunocomprised?
What features should the ideal probiatic have?
Should survive stomach acid and intestinal bile, multiply within the human intestine, attach to human epithelial cells, produce antimicrobial substances.
Lactobacillus GG has been chosen for probiotic intervention because it has these features and prevent adherence of E.coli 0157 H:7 and produces a substance effective against some pathogenic bacteria.
What are some examples of complications after probiotic use?
the supplementation with Lactobacillus rhamnosus GG has been associated with the development of sepsis with a cause effect relationship in six newborns and children being treated for necrotizing enterocolitis.
Where are a large number of microorganisms found?
The large intestines contain a large amount of microorganisms.
what bacteria is found in high osmotic pressure in salty sweat?
Staphylococci
What is meant by habitat filter?
a collection of resources and conditions that allow for the growth of some microbes but not others resulting in selection of microbial traits that permit survival and growth in the host
what is meant but the human body and its symbionts?
can be viewed as communities of interacting cells.
where does Propionibacterium acnes predominates?
, the sebaceous glands of the face, scalp, chest and back produce large amount of oily sebum and are the sites where the lipophilic anaerobe propionibacterium predominates
…..
Streptococci are rarely seen on normal skin because of the presence of lipid on the skin which is lethal to
What are the normal flora of the skin?
Corynebacterium, Propionibacterium, Staphylococcus epidermidis,Staphylococcus aureus
What are characterisitcs of corynebacerium? what disease is associated with?
( Gram +) [ Salt tolerant, some lipophilic, obtain nutrients from sweat]
Gas Gangrene
What are characteristics of Propionibacterium? what disease is associated with?
- ( Gram +) [Lipophilic, produced propionic acid, acid lover, hair follicles= low O2}
acne and rarely infect orthopedic or cariovascular prostheses
what are characteristics of staphylococcus epidermidis?
what disease is associated with?
- ( Gram +) [Lipophilic, Salt tolerant, facultative anaerobe]
infect orthopedic or cardiovascular prostheses
what are characterisitcs of staphylococcus aureus? what disease is associated with?
( Gram +) [Lipophilic. Salt tolerant, facultative anaerobe]
toxic shock syndrome food poisoning and abscesses and more
The oral flora are primarily ____
anaerobes
What is so special about Veilonella ?
A gram - anerobic cocci that loves acid and maintains normal ph of the mouth by consuming acid from other organisms in the mout
what bacteria is associated with initation of cavity formation?
S. mutants by acid production
What types of organisms are seen in the nasal cavity?
The nasal microbiota is more similar to the skin. Skin has a wide variety of microenvironments that vary in conditions including the nasal cavity.
What types of organisms are seen in the oral cavity cavity?
There are predominantly anaerobes and many more species compose the oropharynx than the nasal cavity and Gram -
what diseases associated with Haemophilus influenze?
meningitis and respiratory tract infections in children
what diseases associated with Moraxella catarrhalis?
bronchitis , pneumonia, sinusitis, otitis media and conjunctivitis
Describe the ph environment and bacteria that live throughout the gi tract starting with the stomach?
stomach (acidic), Acid tolerant ex lactobacillus and streptoccous spp small number of bacteria.
Small intestine (neutral , anaerobic) because of the facultative anaerobes suck all the O2. ex Peptosreptococcus spp , Porphyromonas spp and Prevotella spp
Large intestine (Alkaline, Anaerobic) Bifidobacterium, Bacteroides spp
what is the obligate anerobe most common anaerobe responsible for intra abdominal disease?
Bacteroides fragilis
The vaginal flora changes overime , explain this?
from birth to 6 weeks lactobacilli predominate, then after 6 weeeks of age the vaginal flora changes to include staphylococi , streptococci, and enterobacteriaceae.. then at puberty estrogen levels rise and Lactobacilli reemerge as the predominate organism
How does Lactobacilli protect newborn girls?
by making the vaginal flora acidic and making it an inhabitable environment.
What organisms avoid phagocytosis?
Mycobacterium species, Chlamydia, and Rickttsia, shigella, and Listeria
