Food Science #2 - Final: Part One Flashcards
(148 cards)
What is Salmonella?
- One of the leading pathogens/bacteria - naturally found on chicken and can be DESTROYED by cooking;
- Family= Enterobacteriaceae;
- Genus = Salmonella;
- Species = Enterica, bongori;
- > 2500 serotypes; S. enterica serovar Typhinimrium, S. enteritidis;
- Gram-negative, rod-shaped;
- Usually motile, pertricious (all over) flagella;
- Optimum growth temp 37C (body temp);
- Facultative anaerobic (no oxygen)
What is Gram-Negative?
-Thinner amount of peptadoglycan on the surface
What are the annual estimates of Salmonella?
- 1 million cases;
- 19,00 hospitalizations;
- 378 deaths;
- Estimated cost per case = $9000;
- *Leading cause of food borne ILLNESS and death!!
What are the leading Salmonella serotypes?
- Enteritidis = 22%;
- Newport = 14%;
- Tphimurium = `3%
What is the Salmonella-infectious dose?
- Generally 10^6 of cells;
- Some serotypes can be as low as 15-20cells
What is are the symptoms of of Human Salmonellosis?
- Gastroenteritis = abdominal pain, diarrhea, fever, nausea, vomiting, headache;
2 Systemic infection (all over the body) = arthritis, meningitis, bacteremia
What is the Treatment for Human Salmonellosis?
- Self-limiting, recover after 4-7 days with no antibiotics in HEALTHY individuals;
- Antibiotic lifesaving = Ciproflocicin and Ceftriaxone
What FOODS are reservoirs for Salmonella?
- Food animals (intestinal tracts of healthy animals) - cattle, chicken, turkey, pigs;
- Pet animals - reptiles, turtles
How is Salmonella transmitted?
- Animal feces (fecal-oral route);
2. Meat, poultry, eggs, milk, dairy (anything raw)
How can Salmonella be controlled?
- Reduced fecal contamination;
- Pasteurize eggs, milk, dairy;
- Competitive exclusion
What is Competitive Exclusion?
- Take feces from Salmonella-FREE birds and provide them to chicks through drinking water, spray inoculation;
- The competitive excision microflora establishes within hours and persists throughout life
What was the large Salmonella outbreak of 1985?
- Pasteurized milk mixed with raw milk, single plant (Illinois);
- S. enterica Typhinurium;
- 20,000 persons, 7 deaths
What was the large Salmonella outbreak of 1994?
- Ice cream mix (pasteurized) re-contaminated in tank truck used previously to ship liquid eggs;
- S. enterica Enteritidis;
- 200,000 persons in 21 states
What is E. Coli?
- Established in newborns gut in 4-12 months;
- Nearly 1% of gut bacteria, 10^6 cell per gram in human fecal matter;
- Most is BENIGN!
General characteristics of E. Coli?
- Enterobacteriacae;
- Straight, gram-neg, facultatively anaerobic, non-sporeforming rod;
- ~700 serotypes
E. Coli Pathotypes
- ETEC;
- EIEC;
- EAEC;
- EPEC;
- EHEC;
- STEC
ETEC
Enterotoxigenic = produces toxins in intestine
EIEC
Enteroinvasive = invades intestinal cells
EAEC
Enteroaggregative = forms clumps in intestine and produces toxins (non-invasive)
EPEC
Enteropathogenic = attaches to intestinal tract and causes inflammatory response
EHEC
Enterohemmorrhagic = produces toxins, can invade cells;
-Procudes Shiga Toxin = STEX
STEC
- Shiga toxin;
- O157:H7 — predominant in the US;
- *Major problem in the US;
- Over 100 STEC serotypes linked to human disease
How is E. Coli O157:H7 a problem in the US?
- An organism that has changed the US foot safety system;
- An emerging pathogen;
- 1992 = infected fast foods hamburgers lead to new laws for HACCP;
- Finding in new foods like produce;
- Zero tolerance in ground beef
What is the annual incidence of E. Coli O157:H7 in the US?
Estimated:
- 63,000 cases;
- 2, 000 hospitalizations;
- 20 deaths;
- $15,000 = cost per case