Food Microbiology and Specified Risk Material

Question 1

What is microbiology?

Answer 1

• Specialized area of biology dealing with organisms too small to be seen
• Includes bacteria, fungus, viruses, and parasites
• Food microbiology is concerned with the desirable and undesirable effects of microbes on food products

Question 2

What are bacteria?

Answer 2

• Small single-celled organisms too small to be seen that form groups or colonies on food sources

Question 3

What are fungi? What are two different classes of fungi?

Answer 3

• Mold: multicellular organisms forming branching filamentous structures microscopically. Appear colorful, furry, or downy on food surfaces. Reproduce by spores and passed in air currents
• Yeast: single cellular appearing slimy or creamy white, can also spread via air currents. Reproduce by budding

Question 4

What are parasites?

Answer 4

• Organisms that derive nourishment and protection from host organisms
• Reproduce in host tissue
• Transmitted through infested food and water

Question 5

What are viruses?

Answer 5

• Very small microbes that infect hosts by interfering with genetic material

Question 6

What are some of the most common foodborne illnesses?

Answer 6

• Bacteria such as Salmonella, Clostridium perfringens, Campylobacter, Bacillus cereus, Listeria (has own sets of regulations), Staph aureus, Clostridium botulinum, E. coli O157:H7 and non-O157, Shiga toxin producing E. coli (O26, O103, O111, O121, O145)

Question 7

What is the purpose of spore produciton? What bacteria produce these?

Answer 7

• Survival in unfavorable conditions
• C. botilinum and C. perfringens will produce these
• Very difficult to clean

Question 8

How do bacteria reproduce?

Answer 8

Binary fission

Question 9

What is the first phase of bacterial growth?

Answer 9

Lag phase

• Bacteria are adjusting to environment, slow growth
• Phase time length depends on environmental conditions

Question 10

What is the second phase of bacterial growth?

Answer 10

Log phase

- Bacteria multiply rapidly in new environment due to high resources. Exponential growth is seen

Question 11

What is the third phase of bacterial growth?

Answer 11

Stationary phase

- Bacterial growth is equal to bacterial death due to decreased resources and increased waste production

Question 12

What is the fourth phase of bacterial growth?

Answer 12

Death phase

- Bacterial death outnumbers growth due to low resources and high waste products

Question 13

What factors affect bacterial growth? What is an acronym to remember this?

Answer 13

FATTOM
Food: nutrients available to the microbes. Most important factor for growth

Acid: most microbes survive in neutral or slight acidid pH, most bacteria cannot grow below 4.6, meat typically lives around 6-6.4, where bacterial growth is active and spoilage may occur

Temperature: Microbes begin to die over 140 F, reproduction is slowed under 40 F, danger zone is between 40-140 F

Time: Time for microbes to adapt to environment, doubling time for bacteria is usually 10-30 minutes, rate is slowed if handled properly

Oxygen: availability determines microbe activity. Molds are aerobic, most yeast are facultative aerobes, bacteria causing spoilage are aerobes, bacteria causing food-borne illness are anaerobic

Moisture: water is necessary to put nutrients in a soluble form. Bacteria have highest requirement, molds have lowest, yeast are somewhere in between

Question 14

Where are microbes located in establishment?

Answer 14

• GI tract, upper respiratory tract, lower urinary tract are typically dirty
• Muscle is usually sterile
• Soil, hides, feathers, people, equipment, pests/ vermin can contaminate product

Question 15

What is a biofilm?

Answer 15

• A protective matrix formed by bacteria that makes them very difficult to sanitize

Question 16

What are two fundamental ways to control microbes?

Answer 16

1. Reducing microbe entering processing environment and contacting products
2. Making the environment as inhospitable as possible to reduce numbers and growths

** it’s impossible to eliminate all microbes in the environment

Question 17

What practices can be used to reduce contamination with microbes?

Answer 17

• Good manufacturing practices (GMPs), appropriate sanitation, procedures for employee hygiene

Question 18

What are some examples of foodborne parasites?

Answer 18

• Giardia duodenalis, Cryptosporidium parvum, Cyclospora cayetanesis, Trichinella spiralis (pork roundworm), Taenia saginata (beef tapeworm), Taenia solium (pork tapewor),

Question 19

What does SRM stand for?

Answer 19

• Specified Risk Materials

- Includes product that may be infected with prion diseases such as BSE (mad cow) or vCJD

Question 20

What tissue are SRM in cattle of all ages? What Regulation governs this?

Answer 20

• Tonsils and distal ileum (80 in of small intestine, this is due to peyers patches absorbs the prion protein)
• Regulation 310.22 (a)(2)

Question 21

What tissue are SRM in cattle 30 months or older? What Regulation governs this?

Answer 21

• Skull, brain, eyes, spinal cord, trigeminal ganglia, dorsal root ganglia, vertebral column excluding tail vertebrae, transverse process of thoracic and lumbar vertebrae, and wings of sacrum
• Regulation 310.22 (a)(1)

Question 22

What regulation states that establishments must have written procedures and HACCP plans for SRM?

Answer 22

9 CFR 310.22 (e)(1)