5.6 Gram Negative Non-Lactose Fermenting Aerobic Rods

Question 1

how does diarrhea from Salmonellosis differ from E. coli

Answer 1

Salmonellosis causes mucoid, necrotic, watery, bloody diarrhea whereas E. coli causes watery, sometimes haemorrhagic diarrhea

Question 2

how would you culture a bacteria from diarrhea to differentiate E. coli from Salmonella

Answer 2

1) selective media (ex. MacConkey agar)
2) enrichment culture
3) lactose fermentation test

Question 3

what laboratory testing would you order to diagnose salmonellosis

Answer 3

• PCR
• serology
• typing of isolates

Question 4

how do the intestines of an animal infected with salmonellosis look (3)

Answer 4

• inflammed mucosa
• fibrin
• pseudomembranes

Question 5

what is the main species of Salmonella in veterinary medicine? How many subspecies? What subspecies causes the most clinical infections?

Answer 5

Salmonella enterica; 6 subspecies; Salmonella enterica subsp. enterica

Question 6

where does salmonella live in animals? is this normal or not?

Answer 6

colon; should NOT normally be there (not normal flora except in reptiles)

Question 7

what is unique about the multiplication of salmonella

Answer 7

can multiply not only in the host but also in the environment and in food

Question 8

how do we further classify the subspecies of S. enterica

Answer 8

into serovars (over 2500) via serotyping using slide agglutination for O and H antigens

Question 9

what is unique about the flagella of salmonella

Answer 9

biphasic

Question 10

how can we FURTHER classify serovars of salmonella

Answer 10

into subtypes (phage types, pulsotypes, sequence types, etc.)

Question 11

T/F animals can be carriers of salmonella

Answer 11

T

Question 12

what are the 2 major types of disease caused by salmonella enterica

Answer 12

diarrhea (severe and inflammatory) and septicemia (shock, abortion, death)

Question 13

what are the 2 broad categories of salmonella serotypes and how do they differ in the type of disease caused

Answer 13

host-adapted: cause systemic infection and septicemia

non host-adapted: cause gastroenteritis +/- septicemia if predisposed

Question 14

what two serovars of Salmonella are non host-adapted

Answer 14

Salmonella enterica subsp. enterica serovar Indiana and Salmonella enterica subsp. enterica serovar Enteritidis

Question 15

T/F Salmonella enterica is zoonotic

Answer 15

T

Question 16

what are pathogenicity islands and what bacteria are they involved with

Answer 16

involved with Salmonella enterica; two types (SPI-1 and SPI-2) that are involved in the invasiveness of Salmonella

Question 17

what is the difference between SPI-1 and SPI-2 (in regards to salmonella); what is the similarity between them?

Answer 17

SPI-1: involved in uptake by enterocytes, apoptosis, inflammation, diarrhea

SPI-2: involved in survival in macrophages

Both SPI-1 and SPI-2 use a Type III secretion system

Question 18

(host-adapted/non host-adapted) S. enterica contain virulence _________ that contain ______ genes

Answer 18

host-adapted; plasmids; spv

Question 19

what are spv genes involved in

Answer 19

intracellular multiplication and survival, resistance, fimbriae

Question 20

what does LPS on salmonella do

Answer 20

causes inflammatory enteritis with secretory diarrhea

Question 21

how does Salmonella enterica cause septicemia

Answer 21

migrates through the intestines and survives in macrophages, where it is then systemically distributed

Question 22

how are neutrophils involved in salmonella enterica gastroenteritis

Answer 22

when salmonella invades epithelial cells (via SPI-1) it promotes recruitment and diapedesis of a large number of neutrophils; this in turn causes an increase in vascular permeability; neutrophils induce tissue injury, causing fluid accumulation; eventually a large number of neutrophils and fluid fill the intestinal lumen, creating pseudomembranes and diarrhea

Question 23

if you were to look at the intestines of an animal that died from salmonellosis histologically, what would you see?

Answer 23

tons of neutrophils in the intestinal lumen

Question 24

what are some factors that influence whether or not salmonellosis will develop

Answer 24

1) dose
2) virulence
3) host (genetics, age, immunity, nutrition)
4) gastric acidity
5) environment (infectious load, hygeine)

Question 25

what is the major reservoir of salmonellosis for humans

Answer 25

poultry (chicken and turkey)

Question 26

in what species is salmonellosis uncommon

Answer 26

dogs and cats

Question 27

immunization against salmonella targets what type of immunity

Answer 27

cell-mediated immunity

Question 28

for what species is there an oral samonella vaccine

Answer 28

chickens

Question 29

salmonella infections are usually ___________, so antibiotics are warranted only when ___________

Answer 29

self-limiting; severe/septicemia (aka host-specific)

Question 30

T/F multidrug resistance is a problem with salmonella

Answer 30

T

Question 31

what serovars of salmonella enterica subsp. enterica are multidrug resistant

Answer 31

S. Dublin, S. Typhimurium, S. Newport, S. Heidelberg

Question 32

salmonella can multiply at temperatures of

Answer 32

20-45C

Question 33

T/F intensification of food animal production promotes salmonellosis, but control programs seem to be helping

Answer 33

T

Question 34

what caused the bubonic plague

Answer 34

Yersinia pestis

Question 35

what is present in pig tonsils and pork

Answer 35

Yersinia enterocolitica

Question 36

what bacteria is commonly seen as an opportunistic pathogen in cases of otitis externa (along with S. pseudointermedius)

Answer 36

P. mirabilis

Question 37

is P. mirabilis susceptible to antibiotics

Answer 37

yes