MicroBio 16: Food Microbiology Flashcards
Three (3) effects of microorganisms on food:
- Beneficial
- Neutral
- Detrimental
- presence or growth of microbes
- do not harm or change nature of food
Neutral
- alter or improve flavor, taste and txture of food
- improve nutritive value of food
- others serve as food
Beneficial
- a food is considered spoiled when it losses its acceptable qualities
- spoilage occurs due to microbial growth in food, enzymes or both
Microbial Food Spoilage
Food contamination sources
- Raw materials
- Water
- Air/dust
- Soil
- Sewage
- Rodents
- Insects
- Animals and birds
9, Packaging materials - Food handlers/man
- some microbes may cause food spoilage
- others may cause food poisoning or food-borne illness
Detrimental
Classification of Foods Based on Ease of Spoilage
- Perishable
- Semi-perishable
- nonperishable
Foods that spoil quickly (in a matter of days) unless special preservative methods are used
e.g. milk, meats, fish poultry, fruits, vegetables
Perishable
If properly handled and stored, these remain unspoiled for relatively a long period (few weeks or months)
e.g. potatoes
Semi-perishable
Principles of Food Preservation
- Prevent the entrance of microorganisms into the food
- Remove microoorganisms in the food
- Inhibit the activity and growth of microorganisms in the food
- Kill the microorganisms in the food
(Prevent, Remove, Inhibit, Kill)
also called stable: foods that do not spoil unless handled carelessy; with a shell life of many months or years.
e.g. sugar, flour, dry beans
nonperishable
Microbial Foodborne DIsease may be divided into:
- Foodborne intoxication
- Foodborne infection
These result from the consumption of either food or water contaminated with viable pathogenic microorganisms or spores as in botulism, or food containing toxins produced by bacteria and molds
Microbial Foodborne Diseases
Occurs by ingesting food containing performed toxins
Foodborne intoxication
- caused by toxins of Staphylococcus aureus
- considered one of the most frequently occuring worldwide. - Some foods frequently implicated are hams, salami, bacon, salads, sauces, cheese, chicken and eggs.
- symptoms include salivation, nausea, vomiting, abdominal cramps and diarrhea
Staphylococcal intoxication
Mechanism of Staphylococcal Enterotoxins - Immune response
- Staphyloccocal penetrate the gut lining
- Activate local and systemic immune response
- Release inflammatory mediators
- Vomit
- Results from consumption of food containing botulin, the toxin produced by Clostridium botulinum
- very potent and requires small amount to produce symptoms and death due to respiratory failure
Botulism
True or False: Botulin is a gastrotoxic protein
False, it is a neurotoxic protein
- outbreaks associated with fruits and vegetables (low acid vegetables like green beans, corn, mushroom)
- Symptoms include nausea, vomiting, diarrhea, blurred or doubl vision, difficulty in swallowing, breathing and paralysis of involuntary muscles
Botulism
- most commonly caused by Clostridium perfringens
- bacteria gather in an injury or surgical wound that has no blood supply. The infection produces toxins that release gas and cause tissue death
- is a life-threatening condition
Gas gangrene
Results from ingesting food with toxins produced by molds
e.g. ergot from Claviceps purpurea
Mycotoxis
Also an example of Mycotxis from Aspergillus flavus (toxins detected in corn, wheat, barley, rice, beans, peas, peanuts
Aflatoxin
Occurs from consumption of food and water contaminated with pathogenic enteric bacteria (and protozoa such as amoeba)
Foodborne infections
- recognized as the major cause of all foodborne diseases since the 1950s
Salmonellosis
Salmonellosis is caused by ____ with 2 of the more than 200 serotypes namely _____ being __________ and _________ involved in higher frequencies
Salmonella enterica subsp. Enterica ; typhimurium and enteriditis
- caused by 4 species of Vibrio implicated are V. cholerae, V mimicus, V. parahaemolitycus and V. vulnificus
Gastroenteritis
- results from ingestion of the pathogen through food and water contaminated with feces of humans suffering the disease
- symptoms are onset of profuse watery diarrhea and vomiting causing dehydration
- severe cases include muscle cramps and clouded mental state
Cholera
- caused by Entamoeba histolytica
- symptoms include loss of appetite, stomach pains, cramping, nausea, vomiting, diarrhea, high fever
amoebic dysentery
Other term for amoebic dysentery
Amoebiasis
another example of foodborne infection (wa gihatag ang context lol)
- symptoms are hives, headache, losing your apetite, weakness, fatigue, jaundice, pain in the right side of the abdomen, dark urine, pale poop
Hepatitis B
