Lab Quiz 3: Acid-Fast Stain, Bacterial Motility, Protozoa, and Fungal Slide Culture (Bio 286 - Microbiology)

Question 1

(Kinyoun) acid-fast stain

Answer 1

differential stain; differentiates acid-fast bacteria (pink) from non-acid-fast bacteria (blue)

Question 2

Kinyoun acid-fast stain process

Answer 2

1. primary stain - basic fuchsin… 2. mordant - phenol… 3. decolorizer - acid alcohol… 4. secondary stain - methylene blue

Question 3

(Kinyoun) primary stain/mordant

Answer 3

basic fuchsin - phenol (15 minutes)

Question 4

(Kinyoun) decolorizer

Answer 4

acid alcohol (10 seconds)

Question 5

(Kinyoun) secondary stain

Answer 5

methylene blue (1 minute)

Question 6

appearance of acid-fast cells after basic fuchsin / phenol

Answer 6

colorless -> red

Question 7

appearance of acid-fast cells after acid alcohol

Answer 7

red

Question 8

appearance of acid-fast cells after methylene blue

Answer 8

RED

Question 9

appearance of non-acid fast cells after basic fuchsin / phenol

Answer 9

red

Question 10

appearance of non-acid fast cells after acid alcohol

Answer 10

colorless

Question 11

appearance of non-acid fast cells after methylene blue

Answer 11

BLUE

Question 12

Kinyoun technique

Answer 12

a method of acid-fast staining that does not use heat; “cold” method of staining

Question 13

mycobacterium

Answer 13

tuberculosis (TB) and leprae (leprosy); smegmatis (nonpathogenic, normal microbiota of skin)

Question 14

mycolic acids (wax)

Answer 14

prevents most stains from binding, so acid-fast staining procedure is utilized

Question 15

flagella

Answer 15

external bacterial structures that enable motility in liquid media; moving cells by rapidly rotating and providing thrust; structures that are very thin and fragile

Question 16

monotrichous flagella

Answer 16

single flagellum at one end

Question 17

amphitrichous flagella

Answer 17

two flagella with one at each end

Question 18

peritrichous flagella

Answer 18

flagella that cover the surface of a cell

Question 19

lophotrichous flagella

Answer 19

multiple flagella at one end

Question 20

motility

Answer 20

flagella are thin “electric motors” that spin; need to be “thickened” like eyelashes with mascara to be viewed

Question 21

swarming motility

Answer 21

coordinated propulsion involving a group of bacteria moving together via flagella

Question 22

protozoa

Answer 22

single-celled, non-photosynthetic, primarily free-living organisms… do not posses a cell wall, but are covered with a pellicle

Question 23

pellicle

Answer 23

series of flexible protein strips that maintains the protozoan cell’s shape and provides strength while remaining flexible

Question 24

polymorphic

Answer 24

protozoan life cycle has more than one stage

Question 25

cyst

Answer 25

infective form/resting form of a pathogenic protozoa; is resistant to heat, acid, and drying (but less so than an endospore)

Question 26

trophozoite

Answer 26

the active form of a pathogenic protozoa once its cyst form is ingested; the stage in which it will grow and reproduce and form cysts under unfavorable conditions

Question 27

pleomorphic

Answer 27

protozoa have more than one trophozoite form

Question 28

polyphyletic

Answer 28

the protozoa are split amongst many different groups that are only distantly related genetically, as in the past they were classified based on their mechanism of motility (amoeba, ciliates, flagellates, and nonmotile)

Question 29

amoebozoa

Answer 29

organisms that move using pseudopodia ("false feet"), namely the amoeba; reproduce by binary fission and feed by engulfing their prey with their pseudopodia; pathogenic sarcodine: entamoeba histolytica

Question 30

cercozoa

Answer 30

group of amoeba that differs by having a calcium carbonate shell (called a test)

Question 31

plasmodial slime molds

Answer 31

related to amoeba

Question 32

alveolata

Answer 32

organisms possessing a complex cortical structure containing alveoli, extrusomes, and a microtubule framework

Question 33

ciliphora

Answer 33

alveolata organisms that move using cilia ("eyelashes"); most are free living (inclduing Paramceium and Didinium) which are common inhabitants of pond water; reproduce asexually by longitudinal binary fission; contain two nuclei -- macronucleus containing several active copies of chromosomes (used for growth and metabolism) and micronucleus containing one quiescent copy of chromosomes (used during genetic exchange); in sexual reproduction the two ciliates fuse in a process called conjugation where micronuclei are exchanged; only parasitic ciliate: balantidium coli (largest protozoan found in gut)

Question 34

apicomplexans

Answer 34

alveolata organisms; nonmotile protozoa; obligate parasites; characterized by several organelles at one tip of cell; includes Plasmodium (causative agent of malaria) and toxoplasma and sarcocystis

Question 35

discicristata or euglenozoa

Answer 35

members of mastigophora - organisms that move using a flagellum ("whip"); reproduce by lateral binary fission or a complex sexual cycle involving two different hosts; have a deep oral groove and possess disk-shaped mitochondria; hemoflagellates affect circulatory system of infected humans (including Trypanosoma and Leishmania); sexual cycles of these parasites occurs in an insect or arthropod vector so when a carrier bites a human the blood stream is infected

Question 36

excavata

Answer 36

organisms that do not have mitochondria; including important pathogens such as giardia lamblia; normally infects through ingestion of infective cysts where the trophozoite form will emerge and reproduce once the cysts reach the intestine, causing diarrhea; during growth some cells re-cyst and are passed back into environment with feces (while few living trophozoites remaining in fecal matter quickly dying upon removal from intestine); trichomonas vaginalis causes vaginal infections (with no cyst stage, directly transmitted trophozoite through physical contact)

Question 37

microsporidia (opisthokonta)

Answer 37

non-motile protozoa; potential pathogens lack both microtubules and mitochondria; thought to be more related to fungi rather than protists (like oomycetes)

Question 38

protozoa characteristics

Answer 38

aquatic organisms; apex predators; single cell; no cell wall; motile

Question 39

Entamoeba histolytica

Answer 39

of Sarcodina; Causative agent of amoebic dysentery, a severe diarrheal disease associated with ingestion of contaminated food or water; viewed on 100x magnification

Question 40

Balantidium coli

Answer 40

of Ciliophora; The only ciliate human pathogen, these cells are transmitted by fecal contamination; viewed on 4x/10x magnification

Question 41

Trichomonas vaginalis

Answer 41

of Mastigophora; only has Trophozoite form;Causes vaginitis and is an example of a sexually transmitted protozoan; viewed on 40x magnification

Question 42

Giardia lamblia

Answer 42

of Excavata; Giardia has a much reduced (nearly absent) (lost) mitochondria. Causes diarrheal diseases; viewed on 100x magnification

Question 43

Plasmodium falciparum

Answer 43

of Apicomplexans; The ring stage trophozoite can be seen in some red blood cells of malaria infected organisms; viewed on 40x magnification

Question 44

fungi

Answer 44

group of eukaryotic microbes that can exist as single-celled or multicellular forms; cell wall is composed of chitin (type of polysaccharide); fungal membrane uses ergosterol (reinforcing agent)

Question 45

yeast

Answer 45

single celled fungi

Question 46

molds, mildews, mushrooms

Answer 46

multicellular fungi forms

Question 47

saprophytes

Answer 47

vast majority of fungi live by decomposing dead organisms; secrete exoenzymes to break down larger molecules before transporting smaller subunits into cells

Question 48

mycoses

Answer 48

fungi that can cause infections, but usually limited to skin infections (systemic infections are rare but usually fatal)

Question 49

kingdom fungi divisions

Answer 49

chytridomycota, zygomycota, ascomycota, basidiomycota

Question 50

mycologists

Answer 50

scientists who study fungi

Question 51

hyphae

Answer 51

filamentous structure of multicellular fungi; main mode of vegetative growth; collectively called a mycelium

Question 52

septate

Answer 52

hyphae that are divided into cells by internal cross walls; usually perforated by pores large enough for organelles to flow between cells

Question 53

coenocytic

Answer 53

aseptate hyphae; hyphae are not partitioned by septa internal cross walls

Question 54

fungi characteristics

Answer 54

terrestrial; single celled (yeast) or multicellular (mold); cell wall is made of chitin; cell membrane contains sterol called ergosterol

Question 55

lactophenol cotton blue

Answer 55

stains fungal cell walls blue

Question 56

Fusarium verticillioides

Answer 56

member of the class Ascomycetes and has septate hyphae; filamentous fungus widely distributed on plants and in the soil; “football-shaped” macroconidia; may cause various infections in humans -- opportunistic mycoses.

Question 57

Penicillium chrysogenum

Answer 57

member of the class Ascomycetes and has septate hyphae; filamentous fungus that is widespread -- it can be found in soil, decaying vegetation, and the air; conidia form on finger-like projections; may cause infections, particularly in immunocompromised hosts; fungus that produces the antibiotic penicillin.

Question 58

Rhizopus stolonifer

Answer 58

member of the class Zygomycetes and has coenocytic hyphae; cosmopolitan filamentous fungus found in soil, decaying fruit and vegetables, animal feces, and old bread (black bread mold); common contaminants, but can also cause occasional serious (and often fatal) infections in humans; some species are plant pathogens.

Question 59

Syncephalastrum racemosum

Answer 59

member of the class Zygomycetes and has coenocytic hyphae; filamentous fungus that is commonly isolated from soil and animal feces particularly in tropical and subtropical areas; heterothallic fungus that requires a mating strain to produce zygospores; commonly considered as a contaminant and very rarely associated with human disease.