Term
| Microorganisms have specialized ecological niches in and on the body. This is due to 5 reasons. What are they? |
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Definition
1. specific receptor sites on host cells
2. nutritional needs
3. presence or lack of certain inhibitory substances produced by host
4. competition of other flora and environmental conditions |
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Term
| What are the three predominant skin flora? |
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Definition
1. coagulase-negative staphylococci
2. propioibacteria
3. dipththeroids |
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Term
| Predominant flora of the mouth (4) |
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Definition
1. gram + streptococci especially a-hemolytic strep
2. Facultative anaerobes (ex. eikenella corrodens causes of bite wound infections)
3. Anaerobes
spirochetes -gingival crevices
porphyromas gingivalis - gingival crevices
prevotella intermedia
4. yeasts |
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Term
| Predominant flora of the oropharynx, nasopharynx (4) |
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Definition
1. gram +, especially a-hemolytic streptococci
2. gram - cocci that resemble Neisseria meningitides
3. nontypeable Haemophilus influenzae (NTHi)
4. transient flora |
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Term
| Transient flora of oropharynx and nasopharynx |
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Definition
1. Streptococcus pneumoniae (sinusitis, otitis, pneumonia)
2. Gram - rods
3. Haemophilus influenzae, type b
4. Neisseria meningitides (bacterial meningitis)
5. Strep pyogenes
6. Coagulase-positive Staphylococcus |
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Term
| flora of esophagus and stomach: |
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Definition
| few organisms, mostly from saliva. most are killed by acidity of stomach. |
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Term
| flora of duodenum and jejunum: |
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Definition
sparse concentrations
ileum - organisms qualitatively similar to those in the lg intestine |
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Term
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Definition
>100 species, mostly anaerobes
1. Bacteroids & Bifidobacterium - in colonic mucosal
2. Clostridium perfringens A &C
3. Coliforms - gram - rods, facultative anerobes. indicate fecal contamination in food
4. yeasts - Candida
Feces is 20% bacteria
NF of gut are stable after solid food diet is introduced. Only severe situations can alter NF changes in gut. |
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Term
flora of vagina and ectocerix:
(8) |
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Definition
mostly anaerobic
1. Lactobacillus - predominant, important in maintaining a low pH
2. Group B streptococci - Strep agalactiae, can be both NF and have pathogenic potential
3. Gardnerella vaginalis - bacterial vaginosis
4. Mobiluncus - bacterial vaginosis
5. Mycoplasma & Ureaplasma - can be sexually transmitted and passed to neonates.
6. Staph aureus - toxic shock syndrome
7. Candida - vaginitis
8. Veillonella - resembles Neisseria gonorrhea |
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Term
| what portions of the vagina are normally sterile? |
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Definition
-distal portion of the endocervix
-uterus
cervical mucous plus prevents entry of microbes into the uterus |
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Term
In a normal immunocompetent person what is normally sterile (does not have NF)?
(7)
*KNOW |
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Definition
1. blood
2. spinal fluid
3. synovial fluid
4. bladder urine
5. lower respiratory tract
6. uterus
7. internal organs/tissues |
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Term
| Discuss how NF can stimulate the innate immune response: |
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Definition
1. Lactobacilli in vaginal mucosa produce H2O2 that reacts w/ cel myeloperoxidase to produce HOCL- which inhibits/kills other bacteria.
2. Production of lactic acid by lactobacilli and propionic acid by propionibacteria inhibits bacterial growth in vagina and on skin |
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Term
| Discuss how NF can stimulate the adaptive immune response: |
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Definition
1. NF can induce production of cross reacting Ab that can protect against pathogens. Ex. Ab induced by E. coli in gut protect against Haemophilus inflenzae
2. NF induced Ab are responsible for induction of isohemagluttinin (naturally occurring ABO blood group antibodies. |
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Term
| List 3 ways that NF can prevent colonization by pathogenic organisms: |
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Definition
1. competing for receptor sites
2. competing for nutrients
3. producing substances which inhibit or kill pathogens (lactobacilli in vagina produce H2O2) |
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Term
| What essential nutrients can be synthesized from NF? |
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Definition
Vit B and K
if pt is on broad spectrum antibiotics for a long time they can develope a nutritional deficiency |
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Term
Situations in which NF may become problematic:
(7) |
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Definition
1. damage to epi
2. presence of foreign body (catheters, prostheses)
3. transfer of bacteria to sites where they are not normally
4. suppression of immune system by drugs or radiation
5. impairment of host defenses due to infection
6. disruption of normal flora by antibiotics
7. unknown precipitating factor
8. unknown shift of normal flora in vagina
9. hospitalization or institutionalization |
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Term
| What are the periodontogpathogens? |
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Definition
Porphyromonas gingivalis
Prevotella intermedia
Eubacterium
Gingivitis and perio caused by oral NF leading to tooth loss can be trigged by increase flow of nutrient rich, Ab containing GCF due to an inflammatory response to accumulation of dental plaque. |
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Term
| How does hospitalization cause NF to become predominant? |
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Definition
1. NF of oropharynx and upper airways shift from gram + to gram -
2. skin increases colonization by enterococci and gram - bacteria
3. certain meds can slow peristalsis leading to sepsis
4. Prolong supine position, stomach hypoacidity can allow colonization of GI tract and oropharyngeal by lower GI flora. If aspirated can cause pneumonia
5. Catherization, intubation can cause nosocomial infections in urinary and respiratory tracts |
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Term
|
Definition
Use of living microorganisms to establish NF homeostasis w/ host. Prevents, treats, or cures some diseases.
Used in IBS, Crohns, food allergies.
Most contain mix of Lactobacillus and Bifodobacterium.
A great deal of fluctuation in the purity can exist. |
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Term
a-hemolytic strep
gram+ or gram - and where they are found |
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Definition
Gram + cocci in chains
Oropharynx
Cause serious disease when displaced from niche |
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Term
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Definition
gram - anaerobic rods
intestine
serious infections if displaced |
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Term
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Definition
Gram + anaerobic branching rod
symbiotic relationship w/ human intestine
aids in digestion
inhibits growth of bacteria and yeast
used in probiotics |
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Term
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Definition
gram + anaerobi rods
intestine
can cause food poisoning, pseudomembranous colitis |
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Term
| Coagulase negative staphylococci |
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Definition
gram + cocci in clusters
skin flora and vagina |
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Term
| Coagulase positive staphylococci |
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Definition
gram + cocci in clusters
nasal nares, skin, rectum, vagina
can cause skin and soft tissue infections and hospital acquired infections (nosocomial) |
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Term
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Definition
gram + curved rods (chinese character arrangements)
skin
rarely cause nosocomial or infections in immunocompromised |
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Term
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Definition
gram - pleiomorophic rods, facultatively anaerobic
oral flora
common cause of human bit wound infections |
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Term
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Definition
gram - rods
gut flora
causes sepsis, UTIs |
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Term
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Definition
gram - rods
oropharyngeal flora
may be pathogens
if capsule present can be serotyped (A, B, C...)
most NF are not capsulated (nontypeable H. influenzae) |
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Term
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Definition
gram + rods
beneficial to GI and vagina |
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Term
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Definition
no cell wall, no gram stain
pleiomorophic shape but tend to be flask shaped
ubiquitous in nature, colonizes |
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Term
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Definition
gram - diplococci
colonize mucosal surfaces
N. gonorrhoeae and N Meningitidis are pathogens |
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Term
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Definition
not truly gram reactive, visualized on darkfield microscopy
oral flora
associated w/ perio disease |
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Term
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Definition
gram - anaerobic rod
oral flora
may cause perio |
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Term
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Definition
gram - anaerobic rod
oral flora
may cause abscesses, perio |
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Term
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Definition
gram + rod, obligate anaerobe
skin, specifically the pilosebaceous gland
causative agent of acne and other infections |
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Term
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Definition
not bacteria but stain gram +
mucosal surfaces
opportunistic pathogens |
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