Final Mirco Lab Test

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1

Coliforms

Gram negative, aerobic or faculative anaerobic, non-sporing bacilli that ferment lactose with gas within 24-48 hours at 35C.

2

Enterbacteriacea family

Escheria coli

Enterobacter aerogenes

3

Standard Water Analysis

1) Done to narrow the identification of E. coli

2) Rule out false-positive indicator organisim such as E. aerogenes

test is divided into 3 parts

4

3 Parts of Standard Water Analysis

Presumptive

Confirmed

Completed

5

Presumptive

Large Durham tube containg double-strength phenol red lactose broth. Turns

6

Positive Presumptive tests

Any tubes showing acid and gas production.

Coliform bacteria ferment lactose and produce gas. Thus, if this is a coliform bacteria is present we will see a color change to yellow and an air bubble in the Durham tube.

-Still not sure if E.coli is present

7

Confirmed Test

Using an EMB Agar Plate (Eosin Methylene Blue) agar plate.

Use streak-plate method. A positive test confirms the presense of E. coli : A green metallic sheen .

8

Estimated cells per ml

# colonies (colony-forming units) * dilution factor

ex:

99* 10,000 = 990,000 cells/ml

9

Succesive dillutions for milke plate

We do successive dilutions in order to get a milk plate with an adequate number of colonies < 30 Colony Formning Units eqauls too few > 300 CFU equals to many.

10

Bacteria Plate Count

Indicator of quality of milk sample

11

A diesease in milk that all forms of pasturization kills

Mycobacterium bovis

12

Fomites

...

13

Vectors

Direct Methods of transmission

personal contact with someone who has the disease

14

Vectors

Indirect Method of transmission

consuming contaminted food and contact with fomites

15

Fomites

inanimate objects that carry organisms that can cause a disease. ie hospital bedding

16

Vector

Mechanical

organism carried on legs or othe body parts of arthropod vector

17

Vector

Biological

arthropod itself is infected and orgnaism becomes part of its life cycle.

18

Arthropod

indirect transmission method

hinge or joint- footed animal

ex: insects

19

Vectors

Organisim which carries diease agent from one host to the next.

20

Fungi

heterotrophic

eukaryotes

non-photosynthetic

- many are decomposers and break down dead, organic matter

21

Fungi taxonomy

Kingdom fungi

22

Heterotrophic

Must ingest carbon mollecules

23

Zygomycota

Conjugation Fungi

Sexual: zygospores

Asexual: sporangiospores

zygospores form where plus and minus strands meet

Hyphae produce diploid

Sporangiospores in sacs called sporangia

Some are human pathogens / opportunists (take advantage of immunocompromised hosts)

Ex: Rhizopus stolonifer (black bread mold) , Mucor

24

Ascomycota

Sac Fungi

Sexual: Ascospores (in sacs - ascus)

Asexual: Conidiospores (not in sacs - naked)

Includes non-pathogens, opportunits and pathogens

Ex:

1) Candida albicans (oral thrush, vaginal yeast infection, systemic candidiasis)

2) Saccharomyces cerevisiae: yeast used to make bread and alcohol

3) Penicillium notatum: Penicillin

4) Aspergillus niger

25

Basidiomycetes

club fungi

many mushroom

sexual: basidiospores

asexual: most do not have asexual stage

found underside of mushroom cap (in the gills)

26

Deuteromycetes

Fungi imperfecti

No sexual stage

many fungi previously placed in group have been moved to another group.

27

Septate hyphae

hyphae that have cross-walls / septa

28

aspetate

no cross-walls / septa

29

Vegatative hyphae

grow along substrate

(ex: soil)