Microbiology Unit 3 – Flashcards
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| all microbes that reside on or within a healthy person Includes: bacteria, fungi, protozoa, viruses |
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| indigenous/normal flora/microbiota |
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| normal flora varies in response to life - these factors: |
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| age, size, activities, environment, hormones in body |
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| normal flora can become parasitic and pathogenic, but have low virulence - T or F |
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| TRUE |
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| normal flora can become parasitic and pathogenic, but have low virulence - T or F |
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| TRUE |
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| how many body cells do you have compared to bacterial cells? |
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| 10 trillion compared to 100 trillion |
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| normal flora that is present on your body temporarily, can be washed away or dies in competition with other flora |
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| transient micro flora |
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| persistent survival of organisms on the surface of the human body |
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| colonization |
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| why is knowledge of normal flora important? |
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| in diagnostic microbiology for determining clinical significance of organisms isolated from patient specimens |
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| during processing, collection or may be causative agent |
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| how flora discovered |
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| normal flora always there in body sites connected to ____ |
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| outside |
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| benefits of normal flora NUTRIENTS IRRITANTS ANTIBIOTIC PRODUCTION OCCUPIES SPACE |
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| Nutrients: Vit K, B12, Pantothenic acid, Biotin Irritant - stimulate immune system |
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| skin microflora includes species __ and __; and bacteria and fungi HOW RID BODY OF THIS? |
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| staphylococcus and streptococcus HANDWASHING with soap and water |
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| streptococci and staphylococci in the MOUTH are usually beneficial; can be __; Can be aerobes or anaerobes |
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| potentially pathogenic opportunists |
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| sterile parts of ear |
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| middle and inner ear |
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| outer ear and auditory canal contain same kind of microorgs that are in ___ |
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| nose and mouth |
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| what can cause microbes to be carried along Eustach tube and into middle ear where they can cause infection |
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| coughing, sneezing, blowing the nose |
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| ear infections can also occur when Eustach tube does not open and close properly to maintain ___ |
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| correct air pressure within ear |
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| ear infections can also occur when Eustach tube does not open and close properly to maintain ___ |
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| correct air pressure within ear |
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| Tears contain ___ that ____ |
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| Lysozyme that destroys bacteria |
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| eye microflora found where? |
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| conjunctiva of eye that lines eye and tears, external openings of eye |
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| respiratory tract flora usually found where? and not where? |
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| nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli NOT larynx or below |
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| where are flora in urogenital tract? |
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| distal urethra or external genitalia |
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| why doesn't stomach tend to house flora? |
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| acidic environment |
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| what inhibits flora in duodenum? |
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| bile |
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| what flora found in lower part of small intestine? |
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| staphlyo, lactobacillus, streptobacillus, coccos |
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| where are the largest # bacteria foundHow many species theremany flora here are _____ |
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| large intestine; 400 opportunists - only cause disease if dislodged or when imbalance present |
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| sterile areas of the body |
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| blood, lymph, spinal fluid, joint fluid, most internal tissues and organs (lungs, liver, heart, brain, etc) |
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| why might infection NOT occur? |
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| land in wrong place and be unable to multiply, may not have specific receptor sites to attach to, antimicrobial factors at site where it lands, immunity from previous infection or vaccination, phagocytes may engulf it |
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| subjective changes in body fx not apparent to observer |
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| symptoms |
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| objective changes that can be observed or measured |
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| signs |
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| group of signs and symptoms that accompany particular disease |
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| syndrome |
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| prolonged use of ___ may destroy intestinal microflora, causing diarr and making body more susceptible to 2 invaders |
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| antibiotics |
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| fever, septicemia, microbes in tissue fluid, swollen lymph nodes, antibodies in serum |
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| common signs |
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| chills, pains, ache, stiffness, nausea, itching, headache, cramps, sore throat, lack of appetite |
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| ex of symptoms |
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| how do lysozyme in tears, saliva and perspiration help fight infection? |
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| they destroy or inhibit growth of microbes if pathogen lies at that site |
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| infectious disease that can be transmitted from person to person by direct contact ex. HIV, gonorrhea, diphtheria |
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| communicable disease |
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| communicable disease easily passed ex. droplets in air, measles, chixpox |
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| contagious disease |
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| predisposing factors contributing to disease susceptibility |
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| gender age nutrition fatigue climate and weather genetics age, habits, chemotherapy, pre-existing conditions, stress, lifestyle |
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| 1. org enters host 2. attaches to tissue 3. multiplies 4. invades into deeper tissue 5. causes damage to tissue |
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| dev of infectious disease |
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| some pathogens can cause disease even though they can't attach, some cause disease without burrowing deeper into tissue |
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| two exceptions to sequence of dev of infectious disease in body |
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| occurs when bodies primary defenses lose battle with pathogen |
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| clinical disease |
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| ex. pimples, boils, abscesses disease remains localized to one site |
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| local or localized infection |
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| pathogens not stopped at localized level and carried to other parts of body by lymph, blood or perhaps phagocytes; infection spread thru body |
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| generalized or systemic infection |
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| mycobacterium tuberculosis may spread to many internal organs - then called |
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| miliary TB |
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| multiplication of bacteria in blood; characterized by fever, chills, extreme exhaustion |
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| septicemia |
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| toxins in blood |
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| toxemic |
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| viruses in blood; bacteria in blood |
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| viremia bacteremia |
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| can arise from infections in teeth, tonsils, or sinuses |
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| focal infections |
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| rapid onset, followed by relatively rapid recovery; org disappears after illness, usually immunity to re-infection occurs ex.- measles, mumps, influenza |
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| acute disease |
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| slow onset, lasts long time ex. TB, syphilis, leprosy |
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| chronic disease |
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| which disease is this: if not successfully tx, goes through - primary-secondary-latent-tertiary stages, affects nervous system, insanity results |
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| syphilis |
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| comes on more suddenly than chronic disease, but less suddenly than acute ex. mono, pneumonia |
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| subacute disease |
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| patient doesn't seek med attn for these kinds illnesses ex. cold, sliver in finger |
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| subclinical disease |
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| people with few or no disease symptoms; potential source of infection to others |
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| carrier |
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| disease that goes from being symptomatic to asymptomatic and back to being symptomatic |
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| latent infection |
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| latent infection involving cold sores, genital sores, virus always present but stress can trigger it |
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| herpes virus |
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| have disease as child, but virus stays in body, can dev shingles as adult |
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| chicken pox- varicella shingles - zoster (painful infection of nerves) |
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| phase of illness when pathogen multiplies, but patient is asymptomatic - req time for org to establish itself, overcome host defenses, multiply to infectious #'s - ave length of time is 1-2 wks |
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| incubation period |
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| phase of illness - patient feels out of sorts but doesn't have actual disease symptoms - 1-2 days *NOT ALL DISEASES HAVE THIS PERIOD |
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| prodromal period |
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| phase of illness - patient exper typical symptoms - may appear suddenly or over few days |
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| period of illness |
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| phase of illness - signs and symptoms subside, fever and malaise decrease |
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| period of decline |
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| during which phase of illness is body more susceptible to 2dry infection? |
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| period of decline |
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| phase of illness: symptoms disappear resulting in recovery, may have disability depending on organism and damage, can be quite long |
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| convalescent period |
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| how easily a pathogen can infect a host |
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| infectivity |
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| bacterial structures associated with virulence |
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| flagella - mvmt capsules - sticky pili - attachmt |
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| ability of organism to cause disease, damage or destruction |
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| pathogenicity |
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| msre of how easily org can cause disease and severity of disease |
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| virulence |
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| ability to get into host tissues, survive and multiply and spread (under virulence) |
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| invasiveness |
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| ability to produce toxins that will alter cell fx, destroy structures |
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| toxigenicity |
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| virulence factor - some pathogens excrete this to enable them to evade host defense mechanisms, invade or cause damage to body tissues |
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| enzymes |
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| enzyme secreted by organism to clot or coag plasma |
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| coagulase |
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| what specific organism secretes COAGULASE to clot plasma to form protective sticky coat around itself |
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| S. aureus |
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| pathogenic enzyme that dissolves clot, barriers that get in their way |
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| kinase |
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| what is a kinase produced by streptococci? |
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| streptokinase |
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| S. aureus produces which pathogenic enzymes? |
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| coagulase and kinase |
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| enables pathogen to spread thru connective tissues by breaking down hyaluronic acid |
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| hyaluronidase |
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| hyaluronidase produced by which pathogens? |
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| staphylo, strepto, clostridium |
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| pathogenic enzyme that breaks down collagen - a supportive protein in tendons, cartilage and bones; what pathogen secretes this? |
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| collagenase ex. Clostridium perfringens |
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| pathogenic enzyme that breaks down lecithin ex of pathogen that secretes this |
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| Lecithinase Clostridium perfringens |
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| major cause of gas gangrene |
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| clostridium perfringens |
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| what pathogenic enzyme is destructive to CELL MEMRANES of RBC's and other tissues |
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| lecithinase |
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| enzyme that causes damage to host's RBC |
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| hemolysin |
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| Streptococcus species can exhibit which types of hemolysis? |
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| all - alpha, beta and gamma |
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| beta-hemolytic alpha-hemolytic |
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| complete lysis; partial lysis |
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| catalase test - fx |
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| tests for catalase - enzyme that catalyzes breakdn of hydrogen peroxide to water and O2 |
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| Coagulase test |
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| coagulase causes bl clotting S. aureus is Coag+ |
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| toxin produced by LPS in gram neg cell walls as they die, associated with tissue and bl vsl damage, endotoxic shock, malfx of kidney/liver |
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| endotoxin |
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| toxins - proteins produced in cell and secreted by living pathogens - usually from Gram+ bacteria (usually part of plasmid) - often named for organs they target |
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| exotoxin |
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| most toxic exotoxin, affects CNS |
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| neurotoxins |
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| toxins that affect the GI tract, often cause diarr and sometimes vomiting (foodborne illness) |
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| enterotoxins |
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| toxins that destroy WBC, produced by some Staphylo and some Strepto species |
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| leukocidins |
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| some AVIRULENT strains may exist w/in species, depending on piliated or nonpiliated, etc |
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| TRUE |
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| pathogens that are highly infective but low in virulence produce a lot of ____; includes lots of opportunists in indigenous microflora |
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| carriers |
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| concerned with cause of disease |
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| etiology |
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| study of factors that determine occurrence of diseases in human populations |
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| epidemiology |
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| factors include: virulence of various pathogens overcrowding lack of immunizations nutritional status inadeq sanitation procedures modes of transmission |
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| factors epidemiology will study |
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| disease that is constantly present in low # in population or country - # of cases incr or decr but never dies out - ex. TB, HIV |
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| endemic |
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| greater than normal # cases of disease in particular region or w/in short amt of time |
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| epidemic |
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| # of cases incr to max then decr rapidly, # of exposed and susceptible is limited, may occur in communities not prev exposed to particular pathogen |
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| pattern of epidemics |
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| disease seen worldwide, epidemic of a specific disease, crosses continents ex. influenza, HIV, TB |
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| Pandemic disease |
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| ex of pandemics - |
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| influenza, HIV |
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| disease seen occasionally but can't predict it; examples |
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| Sporadic disease tetanus, botulism, gas gangrene, plague |
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| disease controlled as result of immunization and sanitation procedures; includes smallpox, poliomyelitis, and diphtheria |
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| nonendemic disease |
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| any site where pathogen can multiply or merely survive until transferred to a host |
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| reservoir |
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| living hosts (humans, animals), inanimate objects could be |
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| reservoirs |
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| animal disease that affects humans; acquired by direct contact, inhalation, ingestion, or injection |
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| zoonotic disease |
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| most prevalent zoonotic disease in US |
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| Lyme's disease |
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| 4 msrs to control zoonotic disease |
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| PPE proper use of pesticides isolation/destruction of infected animals proper disposal of animal carcasses and waste products |
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| orgs that can't survive long outside host, transferred person to person use ___ as reservoir |
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| humans |
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| staph, strepto, hep, STI, meningitis, diphtheria, dysentery |
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| ex of disease that need human reservoir |
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| carrier capable of transmitting pathogen during incubat period of particular infectious disease |
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| incubatory carrier |
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| carrier that harbors and transmits pathogen while recovering from disease |
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| convalescent carrier |
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| carrier that is completely recovered, but still harbors pathogen (i.e. strepto pyogenes) |
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| active carrier |
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| carries pathogen without ever having had disease |
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| passive carrier |
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| inanimate reservoirs for infection include |
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| air, water, soil, food, milk, fomites |
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| most highly contagious diseases include |
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| colds and influenza |
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| bacteria can't ___ in air, but can be transported via airborne particles to warm nutrient site for growth |
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| multiply |
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| person to person transmission |
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| direct transmission |
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| fomite transmission is type of |
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| indirect transmission |
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| transmission over short distances (<1m) via droplet nuclei |
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| Droplet transmission |
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| contamination with poorly treated or untreated sewage, i.e. cholera |
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| waterborne |
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| transmitted thru undercooked, raw foods, etc. |
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| foodborne |
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| larger than 5 microns, droplets that travel >1m, usually on dust particles, small enough to remain airborne for some time |
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| airborne transmission |
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| common vectors that transmit disease to humans |
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| arthropods, mice, ticks |
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| passive transmission on body parts of insect |
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| mechanical transmission |
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| complex process where microorg reproduces inside arthropod; human infected when bitten |
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| biological transmission |
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| mice and ticks transfer pathogen through |
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| bite to healthy individual |
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| pathogen from within patient (portal of entry) - normal flora in wrong site, etc |
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| endogenous source |
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| most microorg have preferred portal of entry - T or F (only few types establish themselves as indigenous microflora) |
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| TRUE |
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| entry thru intact skin or mucus membranes; thru infusion or injection via contaminated needles or catheters; insect bites or punctures, wounds, surgery, cuts |
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| Parenteral portal of entry |
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| community-acquired infection is present or incubating at time of ____ |
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| admission |
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| community-acquired infection is present or incubating at time of admission - T or F |
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| TRUE |
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| infections as result of med or surg tx, caused by surgeons, physicians, etc |
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| Iatrogenic infections |
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| nosocomial infection contracted during patient care |
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| transmission based infection |
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| how many cases in US are nosocomial? |
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| 2 million |
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| factors contributing to nosocomial infections |
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| not using aseptic technique, inapprop use of broad spectrum antib, trusting antib too much, lengthy surgeries, overcrowding of hospitals/short-staffed, increased use of anti-inflamm and immunosuppressed agents, use of indwelling med devices |
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| presence of just ONE contrib factor to nosocom infections can cause problems...T or F |
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| TRUE |
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| orgs commonly indicated in nosocomial infections |
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| staph aureus, E. coli... |
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| most critical areas in hospital for disease transmission |
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| ER, OR, Delivery Room, Nursery, Central Supply Area |
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| most vulnerable patients |
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| preemies, newborns, women in L, surgical and burn patients, diabetic and cancer patients, patients receiving steroids, anticancer drugs, radiation, patients with deficient immune responses (AIDS), patients who are paralyzed or undergoing renal dialysis or catheterization (their normal defense mechanisms aren't working properly) |
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| two disease healthcare workers who handle bl and body fluids are at greatest risk for: |
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| Hep B and HIV |
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| bl infections most often transmitted thru inanimate vectors |
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| hep, syphilis, AIDS, malaria, systemic staph infections |
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| disposable apparatus are effective in preventing bl infections passed on to health workers - T or F? |
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| True |
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| modes of disease transmission in hospital |
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| airborne contact (direct or indirect) vector |
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| treat sick, immunize, isolate diseased persons, id and try to eliminate reservoirs, educate public about transmission and sanitation procedures - these are attempts at what? |
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| ways to control epidemic disease |
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| goal of infection control? |
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| prevent transmission of disease |
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| How is malaria and yellow fever - controlled/prevented? |
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| control source of transmission - mosquitoes |
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| when smallpox eradicated - how? |
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| 1967, thru isolation, immunization, detection |
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| good housekeeping includes: |
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| damp dusting, laundry, scrubbing |
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| who sets up specific guidelines for procedures based on aseptic technique? |
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| Infection Control Committee |
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| drying as important as washing to remove microorgs - T or F |
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| TRUE |
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| condition where living pathogens are absent, techniques used to achieve this depend on site, circumstance and environment |
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| asepsis |
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| clean technique; goal is to exclude all pathogens |
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| medical asepsis |
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| sterile technique - goal is to exclude all microorgs |
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| surgical asepsis |
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| wear this when contact with biohazardous material expected |
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| gowns |
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| what masks are used to filter out TB? |
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| HEPA or N95 masks |
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| types of precautions used on patients based on |
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| communicability of infection and possible routes or spread |
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| precautions that include: gloves, gown, handwashing, masks, and instructions for cleaning eqpmt, linens, sharps, etc |
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| standard precautions |
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| used in addition to standard precautions; req private room or cohorting |
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| transmission-based precautions |
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| used for microorgs transmitted by skin to skin contact with patient or indirect contact with environmental surfaces *req gloves, gowns |
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| contact precautions |
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| level of precautions mainly used for controlling spread of antibiotic resistant bacteria (MRSA and VRE), RSV, viral pneumonia in infants/small child, chickenpox, lice, scabies, congenital rubella, cutaneous diphtheria |
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| contact precautions |
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| precautions used for infectious microorgs transmitted by mucus droplets from upper airway; masks must be worn within 3 feet |
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| droplet precautions |
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| level of precautions used for influenza, meningitis, pneumonia, pharyngeal diphtheria, acute viral in infants and young child, 5th disease |
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| droplet precautions |
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| precautions to prevent dissemination of droplet nuclei or dust particles smaller than 5 microns |
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| airborne precautions |
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| level of precautions used for TB, zoster, measles, |
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| airborne precautions |
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| suspected TB patients must be in room with ___ air pressure, use ___ masks |
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| negative air pressure, N95 masks |
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| level of precautions for patients with burns, leukemia, transplant, radiation tx, leukopenic, preemies |
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| reverse isolation |
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| air is passed thru HEPA filter and room is under positive air pressure, visitors must wear gown and masks, proper handwashing - level of precautions |
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| reverse isolation |
