Specimen Collection: Processing and Handling

Colony counts are not valid more than 1 hour; Rapid doubling time of urinary tract pathogen.

Used for charcoal-impregnated swabs with glycerophosphate in medium; Good for most specimens esp. N. gonorrhea

Difficult in gram stain interpretation.

Modified Stuart's medium; replaced Glycerophosphate with balanced Salt Solution; retained charcoal but incorporated into mediums.

Similar to Stuart's but modified for FECAL SPECIMENS; pH increase from 7.4 - 8.4; removed charcoal from formula.

Designed for stool specimens only; good for mailing fecal specimen; high pH in favor for fecal pathogens.

Urine, fungal, mycobaterial and chlamydia

Wound, skin, and soft tissues.

CSF and other body fluids.

Best time to collect blood specimen.

Aseptically done blood collection

Blood and broth ratio

Young children blood-broth ration

adults blood-broth ration

Test that must be administered to patients taking penicillin; medication is hold for 2 week before reporting negative.

Indicators of positive blood culture.

An anticoagulant used in blood culture collection that also reduces the action of a protein called complement, which destroys bacteria, slows down phagocytosis (ingestion of bacteria by leukocytes), & reduces the activity of certain antibiotics.

Enhance growth of Neisseria meningitidis

Enhance growth of anaerobic organisms; anticoagulant

Inhibit activity of complement and lysosome; prevent phagocytosis; inactivates therapeutic concentration of aminoglycosides.

Inoculation period for blood culture

Incubation temperature for blood culture

Differential stain for primary identification of bacteria; based on cellular membranes of
bacteria.

Designed for bacteria who has mycolic acid on their cell walls; resistance to acid (acid fastness characteristic)

Hot method of acid fast staining

Coldmethod of acid fast staining

This staining method can be used to confirm the presence of bacteria in blood cultures when Gram stain results are difficult to interpret or when the presence of bacteria is highly suspected, but none are detected using light microscopy.

Waxy mycolic acids found in cell wall of Mycobacterium have affinity to A-R dye; the mycobacterial cells appear bright yellow or orange against a greenish background.

in which bacteria are grown that has specific characteristics, components, and function.

require specific and complicated growth requirements.

doesn't require complex media to grow.

Growth is indicated by its turbidity.

a combination of a solidifying agent added to the nutrients and water.

The most common solidifying agent

Weigh - dissolve - autoclave - dispense

Weigh - dissolve - dispense - autoclave

Support growth of most non-fastidious bacteria.
Ex. Nutrient Agar/broth; Trypticase Soy Agar/Broth

Contain nutrient supplement for fastidious bacteria.
EX. Blood Agar Plate ; Chocolate Agar Plate

Enhance the growth of an organism
EX. Selenite F, Alkaline Peptone Water

Select for growth of a particular organism; contains inhibitors
EX. THAYER MARTIN, MODIFIED THAYER MARTIN

Provides distinct colonial appearance of microorganisms to aid in their identification.
Ex. MAC agar plate

Inhibitors of gram + bacteria

Inhibitors of gram - bacteria

For isolation of Mycobacterium tuberculosis
INHIBITOR: Malachite Green

For isolation of Corynebacterium diphtheriae
INHIBITOR: Potassium Tellurite

nhibits growth of GramNegative bacteria; isolation medium for Gram-Positive bacteria

Selective-Differential Medium for Staphylococcus sp.; pH Indicator: PHENOL RED.

Selective for vibrios. High pH inhibits most bacteria. V. cholerae ferments sucrose and produces yellow colonies. V. parahaemolyticus and V. vulnificus don't ferment sucrose and usually produces blue-green colonies.

-Selective for gram-negative bacteria. Inhibits the grow of gram-positive bacteria and fungi
-*Differential for bacteria that ferments lactose. Lactose fermenters cause colonies to appear pink to red. Non-lactose fermenters cause colonies to appear colorless.

Selective-Differential Medium for Gram-Negative Enteric Bacilli

highly selective for salmonella and shigella and differentiates between them

Selective-Differential for Salmonella and Shigella.
Salmonella: NLF, H2S(+) - colorless with black center
Shigella: NLF, H2S (-) - colorless without black center

Isolation and differentiation of salmonella and shigella spp from other gram negative enteric bacilli

Inhibitor of Lowenstein-jensen

Inhibitor in Mueller-tellurite media

Inhibitors of media selective for N. gonorrhoreae

Used to detect Gonnorhea

For gram positive bacteria

For gram negative bacteria

for fungi and yeast

Prevents swarming of Proteus sp.

vancomycin, colistin, nystatin, trimethoprim
N. gonorrhoeae and N. meningiditis

Vancomycin + colistin + trimethoprim lactate + anisomycin

Vancomycin
Colistin
Trimethoprim lactate
Nystatin
N. gonorrhoeae only

Inhibits growth of fungi and yeast

pH indicator of MSA

pH indicator of TCBS

Carbohydrate in MAC and EMB

Inhibitors of MAC

Rapid lactose fermenter

Late lactose fermenter

Non lactose fermenter

H2S indicator of Salmonella-shigella agar

Serves as a transport enzyme that facilitates entry of lactose molecule across the bacterial plasma membrane

breaks down lactose into glucose and galactose

bacterial species that lacks betagalactosidase permease but possess beta-galactosidase

Differentiate members of Enterobacteriaciae, glucose fermenters from the aerobic pseudomonas and similar gram-negative bacteria.

determine the ability of microorganism to ferment a specific carbohydrate incorporated in
basal medium.

bacteria that produces several different acid (lactic acid, propionic acid, succinic acid)

Considered an initial step in the identification of Enterobacteriaciae.

H2S indicator of Triple sugar Iron agar

Sulfur source of Triple sugar iron agar

Detects the ability of microorganism to ferment carbohydrates, glucose
and lactose.

Can be used to determine the ability of the organism to deaminate lysine, decarboxylate lysine
and produce H2S.

pH indicator of LIA

H2S indicator in LIA

used to identify organisms that produce the enzyme catalase

Positive in catalase test

Cytochrome oxidase participate in Electron transport and nitrate metabolic pathways of some
bacteria.

Used for both g+ and g- bacteria producing enzyme hippuricase

Strep agalactiae, Gardnerella vaginalis, Campylobacter jejuni

Reagent for hippurate hydrolysis test

1. Purpose of test is to look for a particular ENZYME
a. L-PYRROLIDONYL ARYLAMIDASE
b. Used for identification of GROUP A STREPTOCOCCI (S. PYROGENES) and ENTEROCOCCI

Indole, Methyl Red, Voges-Proskauer, Citrate