click below
click below
Normal Size Small Size show me how
normal flora
Question | Answer |
---|---|
bacteria that have an established niche at a body site or sites. occupy sites for extended periods or indefinitely | residents |
are usually excluded from the host by competition from the residents. establish themselves briefly in the host when they are acquired | transients |
these potentially pathogenic organisms can be resident or transients | carrier state |
significance of normal flora:protects against these | invading pathogens. if normal flora is occupying host "space" there is less room for pathogens to take up residence |
significance of normal flora:thought to influence human anatomy and physiology | influence priming of immune system, production of vitamins,lifespan |
role of probiotics | restore balance of normal flora. imbalance leads to disease states. |
axilla,perineum and toe webs | highest concentration of normal flora cuz there is more moisture here. |
hands, face, trunk | lower concentration of normal flora. lowest concentration is on arms/legs. |
gram ? are the predominant type of normal flora because skin is relatively dry and gram ? is more susceptible to drying out | (gram +). gram neg is prone to dessication because of their outer membrane |
these gram + are predominant normal flora of skin (4 genuses) | Staph(Epidermidis/Aureus);Micrococcus; Propionibacterium; Clostridium |
true or false : aerobes predominate in the respiratory tract | false: there are 10-100 times more anaerobes in mouth, nasopharynx, oropharynx |
Steptococcus, Haemophilis, Neisseria species are common aerobic bacteria of | mouth, oropharynx,nasopharnyx |
Streptococcus mutans | oral flora involved in the development of biofilms(plaque) |
3 species involved in periodontal disease: | Veillonella,Fusobacterium,Actinomyces |
HACEK group bacteria gram-negative normal flora are associated with what disease state: | subacute endocarditis |
substance which inhibits bacterial growth in the eyes | lysozyme in tears. there are a few important residents though: Staph epidermidis, Haemophilus, Corynebacterium, Moraxella |
property of normal flora of stomach | must survive at low pH. Helicobacter,Lactobacillus and Strep are known to colonize |
Most bacteria located in this part of GI tract are anaerobes | small intestine |
what is blind loop syndrome? | an obstruction of the GI tract where passage of baceria is prevented thus they proliferate and colonize the obstructed region |
This body organ has the largest number of normal flora | colon. Include Bacteroides, Bifidobacterium, Clostridium, Enterococcus |
this member of Enterobacteriaceae is particularly prevalent in large intestine | E.coli |
a method of altering normal gut flora | the use of antibiotics: leads to overgrowth of bacteria normally present at low numbers |
altering normal gut flora: relationship to pseudomembranous colitis | caused by overgrowth of Clostridium dificile after use of certain antibiotics. note: Staph aureus can also cause pseudomem colitis |
the only anatomic areas permanently colonized with bacteria | anterior urethra and vagina. |
Lactobacillus begins to colonize the vaginal epithelium of baby girls during first? weeks | six |
3 factors influencing flora of vagina | age, hormonal levels (especially estrogens),and pH |
when does Lactobacillus decrease in the vaginal epithelium? | after menopause |
Following metabolism of estrogens, these 3 species predominate in the vagina: | Staph, Strep, Enterobacteriaceae |
after menarche, vagina is dominated by Lactobacillus and a variety of gram ??? | gram negative/positive anaerobes and facultative anaerobes |
fecal bacteria such as members of Enterobacteriaceae and Enterococcus present in anterior urethra will cause: | UTI's (urinary tract infections) E. coli is a common culprit. |
method of urine culture | requires a "clean catch" specimen. lots! of bacteria are initially in the urethra, must catch urine midstream |
3 main categories of vaginitis | yeast, bacterial (BV), Trichomonas vaginalis |
Lactobacillus are thought to mainatain an acid pH in vagina by the metabolism of: | glucose. in patients with BV, Lactobacillus are replaced with G.vaginalis and other anaerobic flora |
increased prevalence and concentration in patients with BV, but is not a sole etiologic agent. | Gardnerella vaginalis (gram +) |
This bacteria is more prevalent in women in women with BV and does not gram stain | Mycoplasma hominis |
gram + ;obligate anaerobe; bacterial vaginosis | Mobiluncus |
gram - ;obligate anaerobe; bacterial vaginosis | Fusobacterium |
hydrogen peroxide(produced by some Lactobacillus strains) and production of lactic acid inhibit growth of these kind of BV organisms: | anaerobes. most anaerobes lack catalase(cannot eliminate toxic H202) |
pathogenesis in BV: these bacterial products may play a role in BV | endotoxin,collagenases,proteases, malic acid production (Mobiluncus spp.) |
pathogegesis in BV: transmission route | sexual transmission |
-vaginal fluid with a pH greater than 4.5; fishy odor on addition of 10% potassium hydroxide to discharge ;"clue cells" on a saline wet mount | clinical diagnosis of BV--Tx: metronidazole |
-pelvic inflammatory disease-pre-term birth-postpartum endometriosis | complications of BV |