Microbiology 2051 Lab Final (LSU)
Study Guide Exam with Actual
Detailed Answers.
Staphylococcus aureus - Answer -Gram (+) cocci in clusters**
-Catalase (+)**
-Produces Coagulase (fibrin clot)**
-Produces beta hemolysin**
-Ferments mannitol**
-Yellow on MSA plate**
-Part of normal microbiota
-Capable of causing sever illness
-Can produce virulence factors & is considered a pathogen
-Produces enterotoxin responsible for gastroenteritis (diarrhea) & food poisoning
-Produces toxin that causes Toxic Shock Syndrome
-Common infections = Styes, pimples, boils
-Responsible for high % of nosocomial infections
-Salt tolerant
Staphylococcus epidermis - Answer -Gram (+) staphylococci**
-Catalase (+)**
-Pale on MSA plate**
-Does not ferment mannitol**
-Does not produce coagulase**
-Carbohydrate Test Results**:
---Glucose = Growth, Acid production, no gas production
---Lactose = Growth, Acid production, no gas production
---Sucrose = Growth, Acid production, no gas production
-Facultative anaerobes
-Found on most skin and produce few virulence factors
-However, can cause disease if it enters the body
-Frequent cause of nosocomial infections following cardiac surgery
-Commensalistic relationship with Clostridium sporogenes
-Salt tolerant
,Micrococcus - Answer -Catalase (+)**
-Use Oxygen for respiration
Lactobacillus - Answer -Gram (+)**
-Catalase (-)**
-Produce lactic acid in fermentation from sugars and is used commercially to produce yogurt &
cottage cheese from milk
-Aerotolerant anaerobes = Can grow in presence of O2, but doesn't need it)
-Colony morphology on MRS plate = Irregular, filamentous, flat, opaque, shiny & white
-Grows with pH <6.0
Lactococcus lactis - Answer -Gram (+)
-Produces lactic acid
-Homofermentative metabolism
-Importnat for manufacturing dairy products
Saccharomyces cerevisiae - Answer -Yeast that produces CO2 and ethyl alcohol from sugar
(i.e. beer, wine)
Bacillus cereus - Answer -Carbohydrate Test Results**:
---Glucose = Growth, Acid production, NO Gas production
---Lactose = Growth, NO Acid production, NO gas production
---Sucrose = Growth, Acid growth, NO gas production
Streptococcus mutans - Answer -Gram (+) usually in chains, normal microbiota of humans*
-Catalase (-)
-In mucous membranes and intestines of humans
-Some are pathogens which cause strep throat, scarlet fever, & other serious illnesses
-Facultative anaerobe
-Produces lactic acid in Fermentation from sugars and is used commercially to produce yogurt
and cottage cheese from milk
Streptococcus pyogenes - Answer -Gram (+), usually in chains**
-Catalase (-)**
-Produces a beta hemolysin = Complete destruction of RBC**
, -In mucous membranes and intestines of humans
-Some are pathogens which cause strep throat, scarlet fever, and several other illnesses
Enterococcus - Answer -Catalase (-)**
Pseudomonas putida - Answer -Oxidase (+)
Eshcerichia coli - Answer -Oxidase (-)**
-Amylase (-)**
-Catalase (-)**
-Gelatinase (-)**
-Cysteine desulfhydride (-)**
-Carbohydrate Test Results**:
---Glucose = NO Growth, Acid production, Gas production
---Lactose = NO growth, Acid production, Gas production
---Sucrose = Growth, NO Acid production, NO gas production
-IMViC Results**:
---Indole (+)
---MR (+)
---VP (-)
---Citrate (-)
-NO2 present, so it's reduced to NO3
Bacillus subtilis - Answer -Amylase (+)**
---Makes yellow/orange zone of hydrolysis when iodine is added**
-Caseinase (+)**
---Makes a clear, transparent area around colony
-Gelatinase (+)**
---Makes a clear, transparent area around colony when acid is added (The rest of the agar is
cloudy)
Cytophaga huntchinsonii - Answer -Isolated originally from sugarcane piles
-Breaks down the cellulose-containing sugarcane to use the simple sugars as carbon and energy
sources
-Degrades cellulose aerobically
Study Guide Exam with Actual
Detailed Answers.
Staphylococcus aureus - Answer -Gram (+) cocci in clusters**
-Catalase (+)**
-Produces Coagulase (fibrin clot)**
-Produces beta hemolysin**
-Ferments mannitol**
-Yellow on MSA plate**
-Part of normal microbiota
-Capable of causing sever illness
-Can produce virulence factors & is considered a pathogen
-Produces enterotoxin responsible for gastroenteritis (diarrhea) & food poisoning
-Produces toxin that causes Toxic Shock Syndrome
-Common infections = Styes, pimples, boils
-Responsible for high % of nosocomial infections
-Salt tolerant
Staphylococcus epidermis - Answer -Gram (+) staphylococci**
-Catalase (+)**
-Pale on MSA plate**
-Does not ferment mannitol**
-Does not produce coagulase**
-Carbohydrate Test Results**:
---Glucose = Growth, Acid production, no gas production
---Lactose = Growth, Acid production, no gas production
---Sucrose = Growth, Acid production, no gas production
-Facultative anaerobes
-Found on most skin and produce few virulence factors
-However, can cause disease if it enters the body
-Frequent cause of nosocomial infections following cardiac surgery
-Commensalistic relationship with Clostridium sporogenes
-Salt tolerant
,Micrococcus - Answer -Catalase (+)**
-Use Oxygen for respiration
Lactobacillus - Answer -Gram (+)**
-Catalase (-)**
-Produce lactic acid in fermentation from sugars and is used commercially to produce yogurt &
cottage cheese from milk
-Aerotolerant anaerobes = Can grow in presence of O2, but doesn't need it)
-Colony morphology on MRS plate = Irregular, filamentous, flat, opaque, shiny & white
-Grows with pH <6.0
Lactococcus lactis - Answer -Gram (+)
-Produces lactic acid
-Homofermentative metabolism
-Importnat for manufacturing dairy products
Saccharomyces cerevisiae - Answer -Yeast that produces CO2 and ethyl alcohol from sugar
(i.e. beer, wine)
Bacillus cereus - Answer -Carbohydrate Test Results**:
---Glucose = Growth, Acid production, NO Gas production
---Lactose = Growth, NO Acid production, NO gas production
---Sucrose = Growth, Acid growth, NO gas production
Streptococcus mutans - Answer -Gram (+) usually in chains, normal microbiota of humans*
-Catalase (-)
-In mucous membranes and intestines of humans
-Some are pathogens which cause strep throat, scarlet fever, & other serious illnesses
-Facultative anaerobe
-Produces lactic acid in Fermentation from sugars and is used commercially to produce yogurt
and cottage cheese from milk
Streptococcus pyogenes - Answer -Gram (+), usually in chains**
-Catalase (-)**
-Produces a beta hemolysin = Complete destruction of RBC**
, -In mucous membranes and intestines of humans
-Some are pathogens which cause strep throat, scarlet fever, and several other illnesses
Enterococcus - Answer -Catalase (-)**
Pseudomonas putida - Answer -Oxidase (+)
Eshcerichia coli - Answer -Oxidase (-)**
-Amylase (-)**
-Catalase (-)**
-Gelatinase (-)**
-Cysteine desulfhydride (-)**
-Carbohydrate Test Results**:
---Glucose = NO Growth, Acid production, Gas production
---Lactose = NO growth, Acid production, Gas production
---Sucrose = Growth, NO Acid production, NO gas production
-IMViC Results**:
---Indole (+)
---MR (+)
---VP (-)
---Citrate (-)
-NO2 present, so it's reduced to NO3
Bacillus subtilis - Answer -Amylase (+)**
---Makes yellow/orange zone of hydrolysis when iodine is added**
-Caseinase (+)**
---Makes a clear, transparent area around colony
-Gelatinase (+)**
---Makes a clear, transparent area around colony when acid is added (The rest of the agar is
cloudy)
Cytophaga huntchinsonii - Answer -Isolated originally from sugarcane piles
-Breaks down the cellulose-containing sugarcane to use the simple sugars as carbon and energy
sources
-Degrades cellulose aerobically
