Case 3 2nd Post

Possible Micro-organism	Microscopy	Culture	Biochemical Tests	Antibiotics Sensitivity Testing	Treatment
Escherichia Coli	Gram negative bacilli	Mac Conkey: Lactose Fermenting(Pink) Sheep Blood Agar: β-hemolytic	TSI: acidic slant/ acidic deep Oxidase Test: Negative IMViC: ++-- Urease Test: Negative	Sensitive to amoxillin, cephalosporins, carbapenems, aztreonam, trimethoprim-sulfamethoxazole, ciprofloxacin, nitrofurantoin, aminoglycosides	No drug is normally needed. Amoxillin used when needed.
Proteus spp.	Gram negative bacilli	Mac Conkey: Non-Lactose Fermenting(colourless) Sheep Blood Agar: Spreading Growth	TSI: alkaline slant with black ppt Oxidase Test: Negative IMViC: ++-+* Urease Test: Positive	Resistance to tetracycline, first generation cephalosporins and ampicillins	Most antibiotics can be used other then the 3 that it is resistant to.
Klebsiella spp.	Gram negative bacilli	Mac Conkey: Lactose Fermenting(Red) Growth in areobic and anareobic condition	TSI: alkaline slant/ acidic deep Oxidase Test: Negative IMViC: --++ Urease Test: Negative	Susceptible to aminoglycosides cephalosporin, gentamicin Resistance to carbenicillin, ampicillin, quinolones, and increasingly to ceftazidime	Genamicin
Serratia	Gram negative bacilli	Mac Conkey: Non-Lactose Fermenting(Colourless)	TSI: acid slant/ acid deep Oxidase Test: Negative IMViC: +-++ Urease Test: Negative	Suceptible to anitbiotics carbapenems, cephalosporin, amikacin Resistant to gentamicin and tobramycin	Carbapenems, cephalosporin, amikancin
Pseudomonas	Gram positive bacilli	Mac Conkey: Non-Lactose Fermenting(colourless)	TSI: alkaline slant/ alkaline deep Oxidase Test: Positive Catalase Test: Positive	Susceptible to piperacillin, imipenem, tobramycin, ciprolorxacin Resistant to penicillin	Tobramycin
Enterococcus	Gram positive cocci	Mac Conkey: Lactose Fermenting(Pink) Sheep Blood Agar: No Haemolysis	Catalase test: Negative	Resistant to Quinupristin, ampicillin and vancomycin	Vancomycin

*Mostly Proteus strain positive except P. mirabilis negative.

Urease Test: Positive - Pink, Negative - Orange

Oxidase Test: Positive - Dark Maroon to Black, Negative - Slight pink colouration or no colouration

IMViC: Indole Test, Methyl Red, Voges-Proskauer, Citrate test. Done when oxidase test is negative.

Indole Test: converts tryptophan into indole, ammonia and pyruvic acid. Bacterial culture grown in tryptophan or peptone for 24 to 48 hours before adding kovac reagent. Positive-Red, Negative- Yellow

Methyl Red Test: If the organism uses the mixed acid fermentation pathway and produces stable acidic end-products, the acids will overcome the buffers in the medium and produce an acidic environment in the medium. When methyl red is added, if acidic end products are present, the methyl red will stay red.

Voges-Proskauer: When the VP reagents are added to MR-VP broth that has been inoculated with an organism that uses the butylene glycol pathway, the acetoin end product is oxidized in the presence of potassium hydroxide (KOH) to diacetyl. Creatine is also present in the reagent as a catalyst. Diacetyl then reacts to produce a red color. Therefore, red is a positive result. If, after the reagents have been added, a copper color is present, the result is negative.

Citrate Test: To see if bacteria is able to use only citrate as carbon and energy source. Positive-Blue, Negative- Green.

Reference:

http://www.wikepedia.com/

Douglas
0503224H
TG01