Clinical Bacteriology- Lecture and Laboratory | Doc Liwanag Final Notes #1

Basic Information, Culture Media, Unique Growth on Media, Unique Microscopic Morphology, other Unique Characteristics

Cell Wall

Part of the bacterial cell that determines gram positivity or gram negativity of an organism

Mycoplasma and Ureaplasma

considered Cell Wall-Less organisms

Cell Membrane

All bacteria have cell membrane, but usually no sterol.

Cell Wall-less but the Cell Membrane contains STEROL

Mycoplasma and Ureaplasma

Capsule

• Responsible for mucoid colonies

• Virulence factor that is anti-phagocytic

• stained using India ink or Mayer’s Mucicarmine

What virulence factor is anti-phagocytic?

Capsule

What stain is used for capsule?

India ink or Mayer’s Mucicarmine

How does capsule appear on gram staining?

Halo-like appearance

It can be a virulence factor that is used for adherence or attachment

Common Pili

Somatic Pili

Other term for Common Pili

The pili that is for gene conjugation

Sex Pili

What do inclusion bodies represent?

STORED FOOD

Much Granules

Inclusions in M. tuberculosis

Babes Ernst Bodies

Inclusions in C. diphtheriae

Loeffler’s Methylene Blue, Albert’s Stain, Neisser’s

stains that can demonstrate the Babes Ernst Bodies of C. diphtheriae

Genus Clostridium

SPORE-FORMING + GENERALLY ANAEROBE

Genus Bacillus

SPORE-FORMING + AEROBIC

“Mycoplasma” / “Mollicutes”

Genera Mycoplasma and Ureaplasma can be generally called as this

Clostridium tetani

terminally located swollen spores

Schaeffer and Fulton Method

Spore Stain

Malachite Green

Primary dye of Schaeffer and Fulton Method

Safranin

Counterstain of Schaeffer and Fulton Method

Green

appearance of spores in Schaeffer and Fulton Method

Red

appearance of other structures in Schaeffer and Fulton Method

Autoclaving

Sterilization that uses moist heat

Carried out at 121degC, 15psi, at 15 mins.

Autoclaving

132degC

Autoclaving can also be conducted with this temperature.

Oven

Sterilization using dry heat.

Steam under pressure.

Principle of Autoclaving

To sterilize used and unused media

purpose of autoclaving

Prions

they are not killed by autoclaving

infectious protein particles that can cause neurologic diseases

Prions

Mad Cow Disease, Bovine Spongiform Encephalopathy

Neurologic diseases caused by Prions

Most Resistant

Prions

Incineration

best way to destroy prions

not done due to being not environmentally friendly

incineration to destroy prions

Class II Biosafety Cabinet

• Type of BSC most commonly used in the Laboratory

• Also called Vertical Laminar Flow

BSC Class II

Least effective system because it is entirely open

BSC Class I

Commonly used type and is partly open and partly closed

BSC Class II

BSC Class III

Most effective system because it is entirely closed

Differential Stains

Acid-Fast Staining and Gram Staining

Counterstain in Gram Staining

Safranin

Crystal Violet

primary dye of gram staining

purple/violet

color of gram-positive organisms

red

color of gram-negative organisms

hot method

Ziehl-Neelsen Method

Heat / Steam

mordant of hot method

cold method

Kinyoun’s method

wetting agent like Tergitol

mordant of cold method

300 Fields

required number of fields to be examined in AFB smear before reporting a truly negative result in OIO

Carbol Fuchsin

Primary dye in AF staining in Ziehl Neelsen and Kinyoun’s

Methylene Blue

usual counterstain in AF staining in Ziehl Neelsen and Kinyoun’s

alternative for Methylene Blue in AF stain using Ziehl Neelsen and Kinyoun’s

Malachite Green

2 × 3 cm

size of AFB smear

red against blue background

color of AFB

Can use Class II

Type of BSC to be used when dealing with toxic chemicals, radioisotopes, and carcinogens

Sodium hypochlorite

best disinfectant

aka household bleach

zonrox, winrox, clorox = sodium hypochlorite

vinegar

substitute for bleach

Required dilution of bleach

1:10

iodophor

best antiseptic

iodine + neutral polymer

iodophor

detergent + iodine

iodophor

alcohol + iodine

tincture of iodine

tyndallization and inspissation

• fractional or intermittent methods of sterilization

• do not perform 1 time, but performed for 3 days

India Ink or Capsular Stain

Negative Stain

What does India ink or negative stain do?

It will color the background but not the organism.

What is the color of the organism on India ink/ Negative stain / Capsular Stain?

COLORLESS

Castaneda and HBT (Human Blood Bilayer Tween)

Biphasic Media

Both solid and liquid media

Biphasic Media

EMB, MaC, SSA

examples of solid media

SIM

example of semi-solid media

TSB, MRVP

examples of liquid media

5% SBA (Sheep’s Blood Agar)

routine isolation media for streptococci

CAP (chocolate agar plate= heated Blood Agar Plate)

routine isolation for Neisseria and Haemophilus

Thayer Martin, Martin Lewis, New York

media of Neisseria but only on textbooks 🙂 / not routinely used maniwala kay kay doc light pls

What grows best on HORSE BLOOD and RABBIT’s BLOOD but negative growth on SBA?

Haemophilus spp.

CTBA = Cystine Tellurite Blood Agar

On what media does Corynebacterium diphtheriae develop GRAY-BLACK COLONIES?

Tinsdale Media

On what media does Corynebacterium diphtheriae develop BLACK COLONIES with BROWN HALO?

Selective media for BACILLUS ANTHRACIS

PLET = Polymyxin Lysozyme EDTA Thallous Acetate

Media used for BACILLUS CEREUS

MEYP = Mannitol Egg Yolk Polymyxin B Agar (pag may kanin, may egg 🙂 )

Media used for Brucella spp.

Castaneda’s

Legionella spp.

agents of pneumonia

Buffered Charcoal Yeast Extract (BCYE)

media used for Legionella spp.

Media used for F. tularensis

BCGA = Blood Cystine Glucose Agar

Most recommended media for Bordetella but not routine

Regan Lowe

Routine media for Bordetella

Potato Blood Glycerol Agar

Cetrimide Agar

media used for Pseudomonas aeruginosa

Egg Yolk Agar

Plated media used to detect Lipase and Lecithinase production

Media used for C. difficile

Cycloserine Cefoxitin Fructose Agar

Media usually used for Yersinia enterocolitica

Cefsulodin-Irgasan-Novobiocin agar

All-purpose media

Thioglycollate media

Growth at bottom of Thioglycollate media means

anaerobes

Growth towards the surface of Thioglycollate media

means strict aerobes

Diffuse even growth all throughout the Thioglycollate media

means facultative anaerobe

APW = Alkaline Peptone Water

Enrichment media for Vibrio

Selenite Broth / Tetrathionate Broth

Enrichment media for Salmonella

Media for ANAEROBES

• Bacteroides Bile Esculin / BBE

• KVLB - Kanamycin Vancomycin Laked Blood

Egg-based media that is NON-SELECTIVE media for Mycobacterium

• Lowenstein Jensen

• Petragnani’s media

• Wallenstein media

• ATS- American Thoracic Society Media