Microbio PT, EE, ME

Which group of microorganisms is characterized by their thick peptidoglycan layer and appears blue or purple after Gram staining?

Gram positive bacteria

Food process that Louis Paster developed to prevent spoilage and reduce the risk of disease by heating beverages like wine and milk to destroy bacteria

Pasteurization

Why is endospore staining important

Helps in identifying the important genera that produce endospores

Ernst August Friedrich Ruska invented the first

Electron microscope

In plating, which method is designed to isolate pure cultures of bacteria or colonies from mixed populations by simple mechanical separation?

Streak plating

Group of microorganisms that cannot reproduce on their own and require a host cell for replication

Virus

Microorganism that requires oxygen at lower concentrations than are present in the atmosphere

Microaerophile

Group of microorganisms characterized by their thin peptidoglycan layer and an outer membrane causing it to appear pink or red after gram staining

Gram negative bacteria

According to Codex, the max level of aflatoxin allowed for peanuts intended for further processing is

15 ppb

Which type of microorganism typically reproduces by binary fission

Bacteria

Microorganism linked to multiple foodborne outbreaks associated with peanut butter

Salmonella

Unit used to report results in the multiple fermentation test for the detection of E. Coli in a milk sample

MPN/mL

Pathogen commonly associated with food poisoning symptoms such as diarrhea, abdominal cramps, and vomiting within 1-6 hours after consumption

Staphylococcus aureus

Which of the following is least likely to be contaminated with L. Monocytogenes

Evaporated milk

Which is most likely to be contaminated by E. coli O158:H7

Bean sprouts

The following culture media are used for identification of Bacillus spp. in common food products except:

A. Mannitol egg yolk polymyxin medium

B. Chromogenic agar

C. Polymyxin pyruvate egg yolk mannitol bromothymol blue agar

D. Cycloserine-cefoxitin-fructose-egg yolk agar

D. Cycloserine-cefoxitin-fructose-egg yolk agar

Based on guidleines for microbiological requirements, which is not a reference criteria for kesong puti?

A. LAB

B. E. coli

C. Listeria monocytogenes

D. Salmonella

A. LAB

The following are Salmonella reactions on TSI and LIA tubes, except

A. Produce both acid (yellow) slants and butts or have a slight red slant (SRS) with the balance of the tube yellow

B. Produce alkaline (purple) slants and butts with hydrogen sulfide (black)

C. Produce alkaline (red) slants and acid (yellow) butts with hydrogen sulfide (black)

D. Produce alkaline (blue) slants and butts with hydrogen sulfide (black)

D. Produce alkaline (blue) slants and butts with hydrogen sulfide (black)

The following are common symptoms of C. jejuni food poisoning except:

Vomiting, abdominal cramps, fever, bloody stool

Vomiting

The presence of purple-red colonies that are 0.5mm or larger in diameter and surrounded by a zone of precipitated bile acids on Violet red bile agar (VRBA) indicates the presence of?

Coliforms

Which does not denote a positive result for e. coli in the IMViC test?

A. Yellow in Voges-Proskauer

B. Blue in citrate

C. Red in methyl red

D. Red in indole

B. Blue in citrate

Pregnant women and immunocompromised individuals should avoid the following foods to prevent listeriosis, except

A. Cereals

B. Cold cuts

C. Unpasteurized milk

D. Soft serve ice cream

A. Cereals

Maximum allowable number of canned meat samples that may test positive for commercial sterility

0

Which is least likely to explain the emergence of botulism?

A. Honey mixed with baby food

B. Vacuum packed fish left at room temperature for several hours

C. Pre packed deli meats left at room temperature

D. Canned product thermally processed for 12log reduction of C. botulinum

D. Canned product thermally processed for 12log reduction of C. botulinum

Used in the presumptive test for coliforms, fecal coliforms, and E. coli

Lauryl tryptose broth (LST)

The following hurdle technologies are usually employed in the production of shelf-stable sous vide pasta except

A. Vacuum sealing

B. Addition of pesto sauce

C. Refrigeration

D. Addition of antimycotics

B. Addition of pesto sauce

The following types of culture media are used for the identification of e. coli in common food products except

A. Eosin methylene blue agar

B. Tryptic soy broth

C. MacConkey agar

D. Xylose lysine dextrose agar

D. Xylose lysine dextrose agar

IMViC test result for Salmonella enterica serovar Typhi

A. + + - -

B. - - + +

C. - + - +

D. + - + -

Maximum allowable number of marginally acceptable samples for butter tested for S. Aureus

A. 3

B. 0

C. 2

D. 1

C. 2

Reference organism for pasteurized milk

Aerobic plate count, coliforms

Microorganism primarily responsible for fermenting sugars into alcohol during the production of wine

Yeast

Bacteria typically associated with RTE foods such as hotdogs, cold cuts, and other deli style meat and poultry products

Listeria monocytogenes

How many plates recommended for the enumeration of yeasts and molds

3

Least essential hurdle needed for shelf stable longganisa

A. Vacuum packaging

B. Refrigeration

C. Addition of preservatives

D. Addition of salt and sugar

B. Refrigeration

Which of the following is least likely to cause botulism

A. Canned lemon

B. Canned corn

C. Vacuum packed fish

D. Canned green beans

A. Canned lemon

Using MPN method, the population of S. aureus in a cheese sample is reported in which unit?

MPN/g

Reference microorganism for frozen fruits

E. Coli

Incubation temperate for APC and YMC in a milk sample

32C, 25C

How many plates recommended for the enumeration of S aureus using Baird Parker agar

3

The following indicate a positive result for Salmonella except

A. Purple butt in lysine iron agar

B. Agglutination (somatic flagellar test)

C. Agglutination (somatic flagellar test)

D. Yellow and/or gas production in phenol red lactose broth

D. Yellow and/or gas production in phenol red lactose broth

Which does not indicate a negative reaction for Salmonella?

A. Growth in KCN broth

B. Yellow color and/or gas production in phenol red lactose broth

C. No agglutination in polyvalent flagellar test

D. Purple color in lysine decarboxylase broth

The following characterize S aureus except

A. Glucose fermentation positive

B. Coagulase positive

C. Catalase negative

D. Thermonuclease positive

C. Catalase negative

A color change to red indicates a positive result in all IMViC tests except

Citrate test

Medium used in the completed test to confirm the presence of E. Coli

Eosin methylene blue agar

Salmonella typically gives positive results in the following except

A. Methyl red test

B. Polyvalent flagellar test

C. Polyvalent somatic test

D. Phenol red test

D. Phenol red test

Recommended incubation period for APC in food samples

48h at 35C

Broth used for the confirmed test for coliforms

Brilliant green lactose bile broth