Lecture 25 10/21/24

Question 1

What are the characteristics of Campylobacter jejuni?

Answer 1

-non-sporeforming
-gram negative rod
-curved to S-shaped morphology
-motile
-worldwide distribution

Question 2

What are the distribution and prevalence of Campylobacteriosis?

Answer 2

-most common in children under 5 and individuals aged 15-29
-highest rate in infants 6-12 months old
-seen in immunocompromised individuals
-can infect fetuses in utero and cause miscarriage/stillbirth

Question 3

What is the epidemiology of Campylobacteriosis?

Answer 3

-commonly found in GI tract of wild and domestic ruminants, swine, dogs, cats, fowl, and rodents
-surface water can cause infection when contaminated by birds or fecal run-off

Question 4

What are the characteristics of Campylobacter in birds?

Answer 4

-infection rates can be 90-100% due to bird’s higher body temp.
-resistance to antibiotics associated with use in poultry operations
-fluoroquinolones no longer used in poultry industry due to antibiotic resistance concerns

Question 5

What are the food sources of Campylobacter?

Answer 5

-improperly handled or undercooked poultry
-raw milk and cheeses from unpasteurized milk
-contaminated water

Question 6

How many Campylobacter cells are needed to cause infection?

Answer 6

500

Question 7

How does poultry become contaminated with Campylobacter?

Answer 7

-chickens with Campylobacter show no signs of illness
-bacteria spreads between birds via common water sources and fecal contact
-bacteria can transfer to meat at slaughter

Question 8

How does milk become contaminated with Campylobacter?

Answer 8

-cow has an udder infection
-milk is contaminated with manure

Question 9

What is the time-frame for a Campylobacter infection?

Answer 9

-incubation period of 2 to 5 days
-duration of 2 to 10 days
-typically self-limiting

Question 10

What are the clinical signs of Campylobacter infection?

Answer 10

-fever
-diarrhea
-abdominal pain/cramps
-vomiting
-nausea
-headache
-muscle pain

Question 11

How is Campylobacter diagnosed?

Answer 11

-isolation and culture under microaerophilic conditions
-inoculation of fecal samples directly onto selective or enriched media
-supplementation of media with blood and antimicrobial agents

Question 12

How is Campylobacter prevented?

Answer 12

-wash hands with soap
-prevent cross-contamination
-do not drink unpasteurized milk or untreated water
-cook poultry to 165 deg. F

Question 13

What are the characteristics of Coxiella burnetii?

Answer 13

-causes Q fever
-reservoirs are cattle, sheep, and goats
-environmentally stable
-low infectious dose; less than 10 bact.
-highly resistant to drying and heat
-infection occurs through inhalation and ingestion
-may survive LTH pasteurization, but not HTST

Question 14

Which animal secretions contain Coxiella burnetii?

Answer 14

-birth products (highest conc)
-urine
-feces
-milk

Question 15

What are the characteristics of Salmonella?

Answer 15

-rod shaped
-gram neg.
-non-sporeforming
-associated with feces
-growth in food not necessary
-zoonotic
-onset of symptoms within 8-72 hours

Question 16

What are the clinical signs of non-typhoidal Salmonella?

Answer 16

-nausea
-vomiting
-diarrhea
-cramps
-fever

Question 17

What are the clinical signs of typhoidal Salmonella?

Answer 17

-high fever
-diarrhea or constipation
-aches
-headache
-lethargy

Question 18

Which serotypes of Salmonella cause typhoidal illness?

Answer 18

-Typhi
-Paratyphi

Question 19

How can Salmonella contaminate food?

Answer 19

-contamination via fecal matter
-contaminated raw food that are not further processed
-vertical transmission into eggs
-cooked/prepared foods contaminated by equipment
-poor personal hygiene

Question 20

What are the steps to Salmonella control within the home?

Answer 20

-proper hygiene
-separate raw and cooked food
-store food at proper temp.
-cook food to proper temp.
-do not drink raw milk or eat cheese made from raw milk