Antibio Susceptibility, Phys/Chem Control, Host/Parasite Relationship

Question 1

What is MIC?

Answer 1

[minimum inhibitory], minimum needed antibiotic to prevent visible growth of B on/in lab media

Question 2

What is MBC?

Answer 2

[minimal bactericidal], minimum antibiotic needed to kill a defined percent of B when a mixture of B and antibiotic are incubated together

Question 3

What is measured and what are the categories in an agar disc diffusion susceptibility text?

Answer 3

resistant, intermediate, susceptible; measure distance from edge of disc to edge of growth

Question 4

What is the E test?

Answer 4

gradient diffusion, larger dose of AB further out on the strip

Question 5

what is the rapid AB susceptibility test?

Answer 5

swab on paper disc, wait for color change (colorimetric), impregnated with labeled Antibody to B lactam (or other) if color change it was hydrolyzed by B

Question 6

What is antiseptic?

Answer 6

chemical agent used to kill microorganisms on skin, mucus membranes, or other living tissue

Question 7

what is aseptic?

Answer 7

absence of microorganisms, usually applied to procedures in OR or micro labs which involve preventing microorganisms from reaching protected environment

Question 8

What is a bactericidal?

Answer 8

capable of killing bacteria

Question 9

What is bacteriostatic?

Answer 9

capable of inhibiting bacterial growth, multiplication resumes after removal

Question 10

What is a disinfectant?

Answer 10

substance used on inanimate objects to kill or inhibit growth of microorganisms; endospores and viruses may not be destroyed; reduce or inhibit growth, but don’t sterilize

Question 11

What is a germicide?

Answer 11

a chemical agent that kills microorganisms, bactericide, kills bacteria, sporicide kills endospores, fungicide kills fungi, virucide kills viruses and amebicide kills amoeba and protazoa

Question 12

What is septic or sepsis?

Answer 12

presence of unwanted microorgnaisms; usually pathogens on living tissue

Question 13

What is sterilization?

Answer 13

process of destroying all forms of microbial life (bacteria, endospores, viruses, fungi, etc) has to kill spores!!

Question 14

What are methods of action of physical and chemical agents for control of microbes?

Answer 14

membrane damage, protein denaturation and modification, and nucleic acid damage

Question 15

What are some physical controls?

Answer 15

heat (moist- 100C boiling some spores survive, autoclave 120C= sterile), filtration (liquids, air- HEPA 99.7% for <0.3micrometers), radiation (ionizing- xray, gamma, free radicals; nonionizing- UV thymine dimers; microwave- not sterile, heats water, spores survive)

Question 16

What are some chemical controls?

Answer 16

surfactants, phenol and phenolics, alcohols, heavy metals and their salts, halogens, iodine, chlorine gas, hydrogen peroxide, and alkylating agents

Question 17

what are some surfactants and how do they work?

Answer 17

soaps- ionize negative so kill, anionic detergents- bactericidal, cationic detergents- for surfaces, like quaternary ammonium, bactericidal, penetrate and puncture membrane

Question 18

Give examples of phenolics and how they work.

Answer 18

hexylresorcinol- mouth wash, works, 30 min more come back; hexachlorophene; chlorhexidine- keeps B down for a time but stains plaque; triclosan- membrane damage

Question 19

Give examples of alcohols and how they work.

Answer 19

ethyl- dissolve membranes, kill vegetative, evaporates fast; isopropyl- kills vegetative, evaporates, after 4-5 times should wash hands

Question 20

Give examples of heavy metals, their salts and how they work.

Answer 20

silver- prevent and treat infections, inhibits normal B function; copper- eye gtts, washes, dressings, catheters, tubing, and air handling

Question 21

What group does iodine belong to? Forms and uses?

Answer 21

halogen; interferes with protein structure by binding tyrosine, sporicidal, oxidizes sulfhydryls, tincture w/ potassium iodide in alcohol, iodophor (skin, longer its on more it kills)

Question 22

What group does chloride belong to? Forms and uses?

Answer 22

halogen; gas, sodium hypochlorite (bleach), chlorine dioxide (tent sterilization of building, use marker bacteria to ensure entire building covered), chloramine (drinking water, etc, kills fish)

Question 23

How is hydrogen peroxide used? effectiveness?

Answer 23

3% solution in home, 35% is sproicidal but can be explosive, time dependent killing; vapor- used in autoclaving room for heat sensitive instruments

Question 24

What group is aldehyde in? Forms, use, effectiveness?

Answer 24

alkylating; formaldehyde- disinfectant, sporicidal, preservative, but carcinogenic, covalently links amino groups, proteins can’t function; glutaraldehyde- disinfectant, heat sensitive instruments, endoscopes and bronchoscopes

Question 25

What group is ethylene glycol in? Forms, use, effectiveness?

Answer 25

alkylating; heat sensitive materials, used with nitrogens to make mixture used in sterilizer, sporicidal

Question 26

What is bacteremia?

Answer 26

presence of bacteria in the blood

Question 27

What is a carrier?

Answer 27

asymptomatic person harboring an infectious agent

Question 28

What is a communicable disease?

Answer 28

transferred from one person to another by some means other than direct inoculation

Question 29

What is endemic?

Answer 29

persistence of a disease at a low level in a defined population or geographical area

Question 30

What is an endotoxin?

Answer 30

lipopolysaccharide moiety of gram negative cell wall

Question 31

What is an enterotoxin?

Answer 31

exotoxin which causes GI symptoms

Question 32

What is an epidemic?

Answer 32

increased occurrence of disease

Question 33

What is an exotoxin?

Answer 33

protein toxin produced intracellularly and subsequently secreted by certain pathogenic bacteria

Question 34

What is a fomite?

Answer 34

an inanimate object that may be involved in disease transmission

Question 35

What is an infectious dose?

Answer 35

number of organism required to cause a disease

Question 36

What is a latent infection?

Answer 36

infection in which infecting organism is quiescent, but may reactivate

Question 37

What is an opportunistic pathogen?

Answer 37

a normally nonpathogenic bacterium capable of causing infection only under the most favorable conditions (immunosuppression)

Question 38

What is a pandemic?

Answer 38

epidemic on a world wide basis

Question 39

What is pathogenicity?

Answer 39

ability of microorganism to cause disease

Question 40

What is pyemia?

Answer 40

septicemia due to pyogenic organisms which are causing multiple abscesses in the body

Question 41

What does pyogenic mean?

Answer 41

pus-forming

Question 42

What does pyrogenic mean?

Answer 42

capable of inducing fever

Question 43

What is septicemia?

Answer 43

bacterial sepsis, systemic disease in which microorganisms multiply in the blood stream, producing clinical signs and symptoms

Question 44

What is a superinfection?

Answer 44

an infection superimposed on an already existing infection or occurring after the primary pathogen is under control

Question 45

What is a toxoid?

Answer 45

modified endotoxin treated to destroy it's toxicity but to retains its immunogenicity

Question 46

What is a zoonosis?

Answer 46

disease having an animal reservoir

Question 47

What cell types make exotoxins? features of production, secretion and action?

Answer 47

gram + and -, secretion, not pyrogenic by itself not causing fever but can accompany it, super antigens can cause it, protein, heat labile (e. coli and staph), induces antitoxin, can be converted to toxoid, high potent toxicity, high specificity, no shock

Question 48

What cell types make endotoxins? features of production, secretion and action?

Answer 48

gram -, cell must lyse to release, pyrogenic, LPS, Not heat labile, no induce antitoxin, cant be converted to toxoid, low toxicity and specificity, yes shock

Question 49

what is a super antigen?

Answer 49

molecules that stimulate a large number of T cells by binding MHC class II and outside variable region of T cell receptor, resulting in non-specific polyclonal T cell activation

Question 50

What bacteria toxin utilizes inactivation of EF2 by ADP ribosylation? disease?

Answer 50

corynebacterium diptheraie (dpitheria) and pseudomonas aeruginosa (abscesses)

Question 51

What bacteria's toxin blocks release of ACh? disease?

Answer 51

clostridium botulinum; botulism

Question 52

How does E.Coli's toxin cause diarrhea (ETEC)?

Answer 52

LT: elevation of cAMP, ST: elevation of cGMP

Question 53

What bacterias have AB toxins? What do the subunits do?

Answer 53

A= active, B= binding; diphtheria, botulism, shiga toxin of shigella and E. Coli, and anthrax

Question 54

What are the different invasive features?

Answer 54

adhesion (pili, cell wall proteins, sIgA protease), resistance to phagocytosis (capsules, cell wall proteins, etc), survival within phagocytes (obligates need it, facultative can be both, listeria, mycobacterium, legionella, salmonella, Shigella) and extracellular enzymes (protease, collagenase, lipase, collagenase, leukocidins)

Question 55

What is a microbiome? importance of them?

Answer 55

collective genomes of all microbes on/in human body; protective barrier, nutrition, disease (prevention), and immunity (innate, modulation and regulation)

Question 56

What are the major bacterial and fungal microbiota on the skin and ear?

Answer 56

staph epidermis, proprionibacterium acnes, staph aureus

Question 57

What are the major bacterial and fungal microbiota on the eye (conjunctiva)?

Answer 57

haemophilus, streptococcus

Question 58

What are the major bacterial and fungal microbiota in the mouth?

Answer 58

strep mutans, strep sallivarius, actinomyces, porphyromonas, prevotella, fusobacterium, and candida albicans

Question 59

What are the major bacterial and fungal microbiota in the nose and nasopharynx?

Answer 59

staph aureus, strep pneumonia, haemophilus, Neisseria, staph epidermis, mycoplasma, anaerobes

Question 60

What are the major bacterial and fungal microbiota in the stomach?

Answer 60

H pylori

Question 61

What are the major bacterial and fungal microbiota in the small intestine?

Answer 61

bacteroides

Question 62

What are the major bacterial and fungal microbiota in the colon?

Answer 62

bacteroides, clostridium, enterococcus faecalis, streptococcus, anaerobes, peptostreptococcus, fusobacterium, enterobacteriaceae (E. coli, Proteus, enterobacter), candida

Question 63

What are the major bacterial and fungal microbiota in the vagina?

Answer 63

lactobacillus, E. coli, streptococcus agalactiae, gardnerella, anaerobes, mycoplasmas, candida

Question 64

What are the major bacterial and fungal microbiota in the urethra?

Answer 64

E. coli, Staph. epidermis

Question 65

What are some main cuases of disease by normal microbiota?

Answer 65

immunosuppression (cancer, transplant), extracorporeal devices (dialysis), cauterization, antibiotics, surgery, other diseases (AIDS, diabetes), trauma, possibly related to birth disorders