Lab Practical II, Expiraments: 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 23, 24, 27
College: First year, College: Second year, College: Third year, College: Fourth year
HYDROLYSIS OF STARCH (EX. 11)
WHAT ENZYME IS CAUSING THE HYDROLYSIS OF STARCH?
AMYLASE
HYDROLYSIS OF STARCH
WHAT IS THE END PRODUCT OF STARCH HYDROLYSIS?
GLUCOSE
HYDROLYSIS OF STARCH
WHAT REAGENT IS ADDED POST INCUBATION TO INTERPRET THIS TEST?
IODINE
HYDROLYSIS OF STARCH
IN A POSITIVE STARCH HYDROLYSIS TEST, THE AGAR:
A) TURNS DARK BLUE
B) REMAINS IODINE COLOR (NO COLOR CHANGE)
C) TURNS RED
REMAINS IODINE COLOR (NO COLOR CHANGE)
HYDROLYSIS OF STARCH
IN A NEGATIVE STARCH HYDROLYSIS TEST, THE AGAR TURNS
A DARK PURPLE COLOR AROUND THE STREAK LINE
HYDROLYSIS OF GELATIN (EX. 12)
WHAT ENZYME DOES BACTERIA PRODUCE TO HYDROLYZE GELATIN?
GELATINASE
HYDROLYSIS OF GELATIN
WHAT ARE THE END PRODUCTS OF GELATIN HYDROLYSIS?
AMINO ACID
HYDROLYSIS OF GELATIN
HOW CAN YOU TELL WHICH TUBE IS POSITIVE FOR GELATIN HYDROLYSIS?
THE GELATIN IS IN LIQUID FORM
HYDROLYSIS OF GELATIN
WHY MUST YOU READ THE RESULTS OF THIS TEST AT ROOM TEMPERATURE?
GELATIN WILL MELT AT TEMPERATURES EXCEEDING 25°C, WHICH IS ROOM TEMPERATURE, AND IT WOULD GIVE A FALSE POSITIVE.
HYDROLYSIS OF GELATIN
HOW CAN YOU TELL WHICH TUBE IS NEGATIVE FOR GELATIN HYDROLYSIS?
THE GELATIN REMAINS SOLID
FERMENTATION OF CARBOHYDRATES (EX. 13)
THESE CARBOHYDRATE BROTH TUBES CONTAIN GLUCOSE, PROTEIN AND A pH INDICATOR CALLED
PHENOL RED
FERMENTATION OF CARBOHYDRATES
AN INVERTED TUBE CALLED A(N)
DURHAM
FERMENTATION OF CARBOHYDRATES
WHAT IS THE PURPOSE OF THIS INVERTED TUBE?
COLLECT GAS
FERMENTATION OF CARBOHYDRATES
WHAT COLOR DOES THE pH INDICATOR TURN UNDER ACIDIC CONDITIONS?
YELLOW
FERMENTATION OF CARBOHYDRATES
HOW CAN YOU TELL WICH TUBE GIVES THE FOLLOWING RESULTS: A/G+ (ACID/GAS (+))
THE TUBE WILL BE YELLOW W/BUBBLES
FERMENTATION OF CARBOHYDRATES
CONSIDERING THE INGREDIENTS OF A CARBOHYDRATE FERMENTATION BROTH TUBE, WHY IS IT MANDATORY THAT YOU READ THE RESULTS WITHIN 24 TO 48 HOURS (BE SPECIFIC)?
YOU MIGHT GET A FALSE NEGATIVE BECAUSE THE BACTERIA CAN FERMENT ALL OF THE CARBOHYDRATES WITHIN 48 HOURS AND THEN BREAKDOWN PROTEIN WHICH WILL CHANGE THE pH BACK TO BASIC.
FERMENTATION OF CARBOHYDRATES
B/G- (BASE/GAS (-))
RED (BASIC)
FERMENTATION OF CARBOHYDRATES
A/G- (ACID/GAS (-))
YELLOW W/O BUBBLES
PRODUCTION OF DECARBOXYLASE (EX. 16)
THE ABILITY OF BACTERIA TO DECARBOXYLATE (REMOVE THE CARBOXYL GROUP FROM AN AMINO ACID) IS MOST OFTEN DEMONSTRATED WITH WHICH 3 AMINO ACIDS?
1. LYSINE
2. ARGANINE
3. ORNITHINE
PRODUCTION OF DECARBOXYLASE
WHICH pH INDICATOR IS IN THE MEDIA?
BROM CRESOL PURPLE
PRODUCTION OF DECARBOXYLASE
WHAT COLOR IS A POSITIVE APPEARANCE?
PURPLE
PRODUCTION OF DECARBOXYLASE
WHAT COLOR IS A NEGATIVE APPEARANCE?
YELLOW
PRODUCTION OF DECARBOXYLASE
THE MATERIAL ON TOP OF THE CULTURE IS?
MINERAL OIL
PRODUCTION OF DECARBOXYLASE
WHAT IS THE PURPOSE OF OVERLAYING THE CULTURE WITH MINERAL OIL?
TO CREATE AN ANAEROBIC ENVIRONMENT
PRODUCTION OF DECARBOXYLASE
THIS MEDIA IS USED TO TEST FOR THE ENZYME
DECARBOXYLASE
S I M REACTIONS: PRODUCTION OF HYDROGEN SULFIDE (EX. 18)
"S I M" ISAN ACRONYM FOR
SULFIDE
INDOLE
MOTILITY
S I M REACTIONS: PRODUCTION OF HYDROGEN SULFIDE
THE "S" TEST FOR THE PRODUCTION OF
HYDROGEN SULFIDE
S I M REACTIONS: PRODUCTION OF HYDROGEN SULFIDE
THE HYDROGEN SULFIDE REACTS WITH IRON SULFATE IN THE MEDIUM RESULTING IN THE FORMATION OF
BLACK PERCIPITANT (IRON SULFIDE)
S I M REACTIONS: PRODUCTION OF HYDROGEN SULFIDE
THE AMINO ACID WITH SULFUR IN ITS R-GROUP, WHICH IS INCLUDED IN THE S I M MEDIA IS
CYSTEINE
S I M REACTIONS: PRODUCTION OF HYDROGEN SULFIDE
WHAT COLOR IS A POSITIVE TEST FOR HYDROGEN SULFIDE?
BLACK PERCIPITATE
S I M REACTIONS: PRODUCTION OF HYDROGEN SULFIDE
WHAT COLOR IS A NEGATIVE TEST FOR HYDROGEN SULFIDE?
YELLOW (NO CHANGE)
S I M REACTIONS: PRODUCTION OF INDOLE
WHAT AMINO ACID IS HYDROLYZED FORMING THE PRODUCT INDOLE?
TRYPTOPHAN
S I M REACTIONS: PRODUCTION OF INDOLE
THE PRESENCE OF INDOLE IS INDICATED BY A SIMPLE COLORMETRIC TEST IN WHICH ONE ADDS WHAT REAGENT?
KOVAC'S
S I M REACTIONS: PRODUCTION OF INDOLE
WHAT COLOR IS A POSITIVE TEST FOR INDOLE?
RED LAYER
S I M REACTIONS: PRODUCTION OF INDOLE
WHAT COLOR IS A NEGATIVE TEST FOR INDOLE?
YELLOW (NO CHANGE)
S I M REACTIONS: PRODUCTION OF INDOLE
IS THIS A POSITIVE OR NEGATIVE TEST FOR MOTILITY?
OBSERVE THE STAB LINE & SURFACE OF DEEP FOR EVIDENCE OF MOTILITY:
1. POSITIVE = CLOUDY (MOTILE)
2. NEGATIVE = NOT CLOUDY (NON-MOTILE)
MR-VP REACTIONS (EX. 19)
MR-VP IS THE ACRONYM FOR WHICH TWO TESTS?
1. METHYL RED
2. VOGES PROSKAUER
MR-VP REACTIONS
WHAT REAGENT IS USED IN THE MR TEST?
METHYL RED
MR-VP REACTIONS
THIS IS A TEST TO DETERMINE WHETHER OR NOT A MICROBE CAN FERMENT _________ AND PRODUCE PREDOMINANTLY ACID END PRODUCTS TO THE DEGREE THAT THE pH OF THE MEDIA WILL BE LOWERED, PRODUCING AN ACID COLOR.
GLUCOSE
MR-VP REACTIONS
WHAT IS THE pH INDICATOR USED IN THE MR TEST?
METHYL RED
MR-VP REACTIONS
UNDER ACID CONDITIONS WHAT COLOR DOES METHYL RED TURN?
RED
MR-VP REACTIONS
UNDER BASIC CONDITIONS WHAT COLOR DOES METHYL RED TURN?
YELLOW
MR-VP REACTIONS
WHAT IS THE END PRODUCT OF THE VP TEST?
ACETYL METHYL CARBINAL (AMC)
MR-VP REACTIONS
WHAT SPECIAL PRECAUTION MUST BE PRACTICED IN THE ANALYSIS FOR THE PRODUCTS OF THE VP TEST?
A) READ BEFORE 20 MINUTES HAVE ELAPSED
B) WAIT A MINIMUM OF 10-20 MINUTES FOR THE
FINAL READING
C) ADD THE POTASSIUM HYDROXIDE FIRST
D) INCUBATE AT ROOM TEMPERATURE
E) NONE OF THE ABOVE
NONE OF THE ABOVE
***YOU MUST ALLOW THE SAMPLE TO STAND FOR A MINIMUM OF 20-30 MINUTES (PG. 99).
MR-VP REACTIONS
WHAT COLOR INDICATES A POSITIVE VP REACTION?
RED
MR-VP REACTIONS
WHAT COLOR INDICATES A NEGATIVE VP REACTION?
YELLOW
MANNITOL SALT AGAR (EX. 22)
THIS IS A SELECTIVE AND DIFFERENTIAL MEDIA FOR THE ISOLATION OF WHAT GENERA OF BACTERIA?
STAPHYLOCOCCUS
MANNITOL SALT AGAR
THE MEDIA TURNS YELLOW BECAUSE THE MICROBE FERMENTS WHAT SUGAR?
MANNITOL
MANNITOL SALT AGAR
WHAT INGREDIENT INCORPORATED INTO A MSA PLATE MAKES THE MEDIA SELECTIVE?
7.5% SALT
MANNITOL SALT AGAR
WHAT TWO INGREDIENTS INCORPORATED INTO A MSA PLATE MAKES THE MEDIA DIFFERENTIAL?
1. MANNITOL
2. PHENYL RED
MANNITOL SALT AGAR
WHEN STAPHYLOCOCCUS AUREUS FERMENTS MANNITOL, WHAT COLOR DOES THE pH INDICATOR (PHENOL RED) CHANGE TO?
YELLOW
REDUCTION OF NITRATES (EX. 14)
A TUBE OF NITRATE BROTH WAS INOCULATED WITH BACILLUS SPIZIZZENII AND INCUBATED FOR 4 DAYS AT 37°C. AFTER INOCULATION AND INCUBATION, SULFANIC ACID AND DIMETHYL-α-NAPHTHYLAMINE (DAN) WAS ADDED AND THE SOLUTION TURNED RED. THIS INDICATES WHAT TYPE OF REACTION FOR NITRATE REDUCTION:
A) POSITIVE FOR NITRATE REDUCTION
B) NEGATIVE FOR NITRATE REDUCTION
C) INDETERMINATE FOR NITRATE REDUCTION
D) POSITIVE FOR NITRITE REDUCTION
POSITIVE FOR NITRATE REDUCTION
REDUCTION OF NITRATES
AFTER INCUBATING AN INOCULATED TUBE OF NITRATE BROTH, SUFANILIC ACID AND DAN WERE ADDED AND THE SOLUTION DID NOT CHANGE COLOR. AT THIS POINT, THE TEST IS INTERPRETED AS:
A) POSITIVE FOR NITRATE REDUCTION
B) NEGATIVE FOR NITRATE REDUCTION
C) INDETERMINATE FOR NITRATE REDUCTION
D) POSITIVE FOR NITRITE REDUCTION
INDETERMINATE FOR NITRATE REDUCTION
REDUCTION OF NITRATES
WHAT DO YOU ADD TO THE NITRATE BROTH TUBE AFTER YOU HAVE ADDED THE TWO REAGENTS AND NO COLOR CHANGE OCCURRED?
ZINC
A) IF THE NITRATE BROTH TURNS RED AFTER THE ZINC
IS ADDED THEN THE RESULTS ARE NEGATIVE.
B) IF THE NITRATE BROTH STAYS THE SAME COLOR AFTER
THE ZINC IS ADDED THEN THE RESULTS ARE
POSITIVE.
REDUCTION OF NITRATES
MANY MICROORGANISMS CAN REDUCE NITRATE COMPOUNDS TO NITRITE COMPOUNDS UNDER ANAEROBIC CONDITIONS (ANAEROBIC RESPIRATION). IN THIS PROCESS THE NITRATE TAKES THE PLACE OF OXYGEN AS THE FINAL _________ ACCEPTOR.
ELECTRON
REDUCTION OF NITRATES
WAS THERE A TEST PERFORMED IN THE REDUCTION OF NITRATES?
NO
CATALASE TEST (EX. 15)
WHAT REAGENT IS ADDED TO BACTERIAL GROWTH TO DETECT THE PRESENCE OF CATALASE?
HYDROGEN PEROXIDE
CATALASE TEST
WHAT GAS IS PRODUCED IN A CATALASE REACTION?
OXYGEN
CATALASE TEST
DESCRIBE A NEGATIVE CATALASE REACTION
NO BUBBLES
CATALASE TEST
DESCRIBE A POSITIVE CATALASE REACTION
BUBBLES
CATALASE TEST
WHY WOULD YOU NOT WANT TO PERFORM A CATALASE TEST ON COLONIES GROWING ON A SHEEP BLOOD AGAR PLATE?
IT WILL GIVE YOU A FALSE POSITIVE BECAUSE BLOOD CONTAINS CATALASE.
CATALASE TEST
WHAT TWO GENERA MENTIONED IN CLASS, CAN THE CATALASE TEST BE USED TO DISTINGUISH?
1. GENERA: STAPHYLOCOCCUS
CATALASE REACTION: + (POSITIVE)
2. GENERA: STREPTOCOCCUS
CATALASE REACTION: - (NEGATIVE)
HYDROLYSIS OF UREA (EX. 17)
WHAT ENZYME IS RESPONSIBLE FOR THE HYROLYSIS OF UREA?
UREASE
HYDROLYSIS OF UREA
WHAT IS THE DETECTABLE PRODUCT OF UREA HYDROLYSIS?
AMMONIA
HYDROLYSIS OF UREA
THIS DETECTABLE PRODUCT CAUSES THE MEDIA TO TURN (ACID OR BASIC)?
BASIC
HYDROLYSIS OF UREA
WHAT IS THE pH INDICATORIN UREA BROTH?
PHENYL RED
HYDROLYSIS OF UREA
WHAT IS THE COLOR INDICATOR WITH AN ACIDIC SUBSTANCE?
ORANGE/PEACH
HYDROLYSIS OF UREA
WHAT IS THE COLOR INDICATOR WITH A VERY BASIC SUBSTANCE?
HOT PINK
HYDROLYSIS OF UREA
WHICH OF THE FOLLOWING REAGENTS IS ADDED AFTER INCUBATION TO PERFORM A UREA HYDROLYSIS TEST?
A) SULFANILIC ACID
B) METHYL RED
C) DAN
D) UREASE
E) NO REAGENT IS REQUIRED
NO REAGENT IS REQUIRED
HYDROLYSIS OF UREA
WHAT COLOR IS A POSITIVE TEST?
HOT PINK
HYDROLYSIS OF UREA
WHAT COLOR IS A NEGATIVE TEST?
ORANGE/PEACH
COAGULASE PRODUCTION (EX. 23)
WHAT IS THE NAME OF THE VIRULENCE FACTOR THAT ALL STAPHYLOCOCCUS AUREUS PRODUCE?
COAGULASE
COAGULASE PRODUCTION
HOW DOES COAGULASE AID IN THE VIRULENCY OF S. AUREUS?
THE COAGULASE PROTECTS S. AUREUS FROM PHAGOCYTOSIS BY INACTIVATING THE SODIUM CITRATE WHICH CONTAINS CLOTTING FACTORS, THEREBY CAUSING THE PLASMA TO CLOT.
COAGULASE PRODUCTION
WHAT IS THE CHARACTERISTIC OF A POSITIVE TEST FOR COAGULASE?
SOLID (CLOT)
COAGULASE PRODUCTION
WHAT IS THE CHARACTERISTIC OF A NEGATIVE TEST FOR COAGULASE?
LIQUID (NO CLOT)
COAGULASE PRODUCTION
WHAT IS THE MEDIA USED IN THE COAGULASE TEST?
RABBIT PLASMA
COAGULASE PRODUCTION
WHAT IS THE POSSIBLE IDENTITY (GENUS & SPECIES) OF THE ORGANISM IN A POSITIVE COAGULASE TEST?
S. AUREUS
COAGULASE PRODUCTION
WHAT IS THE POSSIBILE IDENTITY (GENUS & SPECIES) OF THE BACTERIA IN A NEGATIVE COAGULASE TEST?
S. EPIDERMIDIS
SIMMONS CITRATE (EX. 20)
THE MEDIUM USED IN THIS TEST DETERMINES WHETHER OR NOT A BACTERIUM CAN UTILIZE ________ AS ITS SOLE SOURCE OF ______.
CITRATE, CARBON
SIMMONS CITRATE
THE pH INDICATOR IN THIS MEDIA IS ________ AND WILL TURN A ________ COLOR IF THE TEST IS POSITIVE
BROMTHYMOL BLUE, DEEP PRUSSIAN BLUE
SIMMONS CITRATE
IF THE TEST IS NEGATIVE, THE pH IN BROMTHYMOL BLUE WILL ___________.
REMAIN UNCHANGED (GREEN)
**EVEN THOUGH THE NAME IS BROMTHYMOL BLUE, IT IS THE COLOR GREEN AT NEUTRAL pH BUT TURNS BLUE ONLY ABOVE pH 7.6
WATER ANALYSIS (EX. 27)
IF 3 DIFFERENT COLIFORM TEST WERE PERFORMED ON 3 DIFFERENT TUBES, HOW CAN YOU TELL WHICH TUBE CONTAINS POSSIBLE COLIFORMS?
THE TUBE THAT IS A/G+ (YELLOW W/BUBBLES)
WATER ANALYSIS
WHAT IS THE SPECIFIC SUGAR INCORPRATED INTO THESE CARBOHYDRATE BROTH TUBES?
LACTOSE BROTH
WATER ANALYSIS
WHAT IS THE pH INDICATOR USED?
PHENOL RED
WATER ANALYSIS
ACCORING TO THE DEFINITION OF A COLIFORM AS DISCUSSED IN CLASS , NAME 4 CHARACTERITICS OF A COLIFORM:
1. GRAM (-)
2. NONENDOSPORE FORMING (ROD)
3. FERMENTS LACTOSE WITH ACID AND GAS
4. FACULTATIVE ANAEROBES OR AEROBES
WATER ANALYSIS
WHAT IS THE NAME OF THE TUBE INVERTED INSIDE THE CARBOHYDRATE BROTH?
DURHAM
WATER ANALYSIS
WHAT IS THE FUNCTION OF THIS INVERTED TUBE?
COLLECT GAS
WATER ANALYSIS
WHAT IS THE GENUS AND SPECIES OF THE INDICATOR ORGANISM WE ARE LOOKING FOR IN THESE TESTS?
E.COLI
WATER ANALYSIS
WHAT COLOR IS A POSITIVE TEST FOR THE COLIFORM, E.COLI, ON AN EMB PLATE?
GREEN METALLIC SHEEN
WATER ANALYSIS
WHAT DOES IT INDICATE?
FECAL CONTAMINATION
WATER ANALYSIS
AFTER A POSITIVE PRESUMPTIVE TEST, A CONFIRMED TEST IS DONE ON WHAT TYPE OF MEDIA?
(EMB) EOSIN METHYLENE BLUE PLATE
WATER ANALYSIS
THE BACTERIA THAT GROWS DURING THIS TEST IS PROBABLY
E. COLI
WATER ANALYSIS
WHAT TWO INGREDIENTS (DYES) MAKE THIS MEDIA SELECTIVE?
1. EOSIN
2. METHYLENE BLUE
WATER ANALYSIS
WHAT SUGAR IS USED IN THIS MEDIA TO MAKE IT DIFFERENTIAL?
LACTOSE
WATER ANALYSIS
THIS MEDIA IS SELECTIVE FOR __________ AND INHIBITORY TO ___________.
GRAM (-), GRAM (+)
HEMOLYSIS PRODUCTION (EX. 24)
WHICH SHEEP BLOOD AGAR PLATE DEMONSTRATES:
BETA HEMOLYSIS?
CLEAR ZONE (NO BLOOD IN THE AGAR)
HEMOLYSIS PRODUCTION
WHICH SHEEP BLOOD AGAR PLATE DEMONSTRATES:
ALPHA HEMOLYSIS?
GREENISH TINGE (W/SURFACE COLONIES)
HEMOLYSIS PRODUCTION
WHICH SHEEP BLOOD AGAR PLATE DEMONSTRATES:
GAMMA HEMOLYSIS?
THE AGAR REMAINS RED (NO CHANGE)
HEMOLYSIS PRODUCTION
WHAT IS AN EXAMPLE OF AN ORGANISM (GENUS AND SPECIES) CAPABLE OF CAUSING BETA HEMOLYSIS?
S. PYOGENES
HEMOLYSIS PRODUCTION
WHAT IS AN EXAMPLE OF AN ORGANISM (GENUS AND SPECIES) CAPABLE OF CAUSING ALPHA HEMOLYSIS?
S. PNEUMONIAE
HEMOLYSIS PRODUCTION
WHAT IS AN EXAMPLE OF AN ORGANISM (GENUS AND SPECIES) CAPABLE OF CAUSING GAMMA HEMOLYSIS?
E. FAECALIS