Unit 7C

Question 1

Describe salmonella

Answer 1

Gram negatice 
Rods 
Facultative anaerobes 
Motile (flagella) 
Non-lactose fermenting on MacConkeys 
Fastidious (strict growth requirements) (may need special transport media) 
Enteric, coliform 
Primary pathogen 
found in all animal species
Many strains

Present in very low numbers in intestines and feces but not considered normal flora (asymptomatic carriers)

Animal resevoirs are maintained by spreading and contaminated feeds

Question 2

What is salmonellosis and what are the 3 types if clinical disease

Answer 2

Diseases caused by salmonella enterica

Enteritis (secretory diarrhea)
Septicemia
Enteric fever

Pathology and clinical disease is similar in people and animals

Question 3

describe transmission of salmonella

Answer 3

Resevoirs (asymptomatic carriers)
Shedding when stressed

Fecal oral transmission
Food borne transmission (feces, egg, milks, meat)
Direct from pet reptiles/turtles to people

Question 4

Salmonellosis -enteritis

Most common clinicak presentation

Answer 4

Occurs 6-48 hours after minimum infectious dose

Nausea, fever, vomiting, cramps, secretory diarrhea

Bacteria infect celks and alter electrolyte absorption (minimal damage)

Lasts 2 days to 2 weeks (will resolve in healthy)

Maybcontijue to shed cor a long time after clinical stage resolves

Question 5

Salmonella zoonosis

Answer 5

One of the major causes of food born illness in people

Signs: Diarrhea, vomitting, fever, upset stomach

Question 6

What are the food borne sources of infection of salmonella

Answer 6

Contaminated poultry, eggs and dairy

Contaminated feces (especially in kids) from fecal oral transmission (especially from turtles and lizards)

Contamjnated water, rodents, wild fowl

Question 7

What are mycobacterium

Answer 7

Genus that contains a number of bacteria that cause serious disease (tuberculosis and leprosy)

Question 8

What do mycobacterium look like

Answer 8

Bacteria cell structure: very small rods, colonies form hyphae (fungi look like long thin threads)

Distinct cell wall (contain a lipid lyer and a wax layer (mycolic acids)

Question 9

What is acid fast stain

Answer 9

Mycobacterium need to be stained with acid fast technique to be able to penetrate wax layer because they do not stain with gram stain

Question 10

What does the wax layer of mycobacterium help with

Answer 10

Resistance: wax layer is protective, has lots of antibiotic drug resistnace, and resistant to pH changes, detergents and drying

Question 11

How is mycobacterium immunogenic

Answer 11

Great at activating inflammation

Purified cell wall is a component added to many vaccines to engance immune activity (called an adjuvant)

Question 12

Characteristics of mycobacterium

Answer 12

Aerobic
Non- spore forming 
Non motile 
Catalase positive
Very long generation time (fast growing species have visible colonies in 7 days, some take 2 years, compared to E. coli who takes minutes)

Question 13

Bovine tuberculosis

AKA: M. Bovis (mycobacterium)

Answer 13

Slow progressive lung disease which is eventually fatal

10% of infected aniamls develop clincal disease

90% are latent infections (hard to identify and can spread)

Resevoir in the wild (deer and elk)

Zoomotic

Common route of transmission: respiratory

Question 14

Diagnosis of bovine tuberculosis

Answer 14

Post mortem necrops (presence of tubercles and a culture)

Tuberculin testing

Question 15

describe tuberculin testing (CFIA certofied test)

Answer 15

Tuberculin (cell wall extract from bacteria is injected into the skin

Animals that have been infected for at least a month will reaponde to tuberculin and create an infmmatory lesion at injection site

Identifies silent carriers and clinically affected animals

Question 16

Bovine tuberculosis is a reportable disease, there is madatory testing in high risk areas and if the animal is found at slaughter, the whole herd will be tested by CFIA) how do you control the spread of it

Answer 16

Quarantine
Investigation
Euthanasia of all infected and exposed animals
Cleaning and disinfection
No restocking for that herd for 45 days (producers are compensated per head)

Question 17

What is mycoplasma

Answer 17

Smallest prokaryote (0.3-0.8 microns)

Structurally simple: no cell wall and pleiomorphic

Simple genome: 470-700 genes (limited genes= limited enzymes = limited functions that the cell is able to carry out on its own)

Complex nutritional requirements: lost fo essential amino acids and cofactors, requires external sources of sterols

Can hijack the host cell’s enzyme pathways

Question 18

Disease caused by mycoplasma are difficult to treat ___

Answer 18

Because its is variable where and what they infect and they have no cell wall and few enzymes to target with drugs

Question 19

What is mycoplasma anemia
AKA: mycoplasma haemofelis

Used to be called: hemobartonella felis

Answer 19

Disease infects RBCs (surface attachment), looks like small blue/pruole sots in the surface of RBCs

Can be seen with Diff-quick stains

Usually cocci, cab be ribg shaped or coccobacilli

Less often in cytoplasm

Question 20

What does mycoplasma anemia cause

Answer 20

Anemia: immune system sttacks RBCs that have mycoplasma

Initial diagnosis is usually on erythrocyte morphology

Species specific but disease is similar in cows, dogs, people and mice

Can soread via arthropd vectors (ticks, lice, mosquitoes)

Question 21

What is an endotoxin

Answer 21

membrane compounds of Gram-negative bacteria which elicit an inflammatory response in host

Question 22

What is an exotoxin

Answer 22

secreted proteins which act locally and at distance of bacterial colonization site

Question 23

What is an enterotoxin

Answer 23

toxin produced in or affecting the intestines

Question 24

What is a coliform

Answer 24

rod-shaped Gram-negative nonspore forming and motile or nonmotile bacteria that can ferment lactose with the production of acid and gas when incubated at 35–37°C. They are a commonly used indicator of sanitary quality of foods and water.