Enterobacteriacea Introduction

Question 1

All Enterobacteriaceae are:

§_______
§______ fermenters
§______ negative
§ All reduce nitrates to nitrites except: (4)

Answer 1

Facultative anaerobe, non-spore-former

Glucose

Cytochrome oxidase

Erwinia
Pantoea agglomerans
Photorhabdus
Xenorhabdus

Question 2

All members are motile or non motile?

Answer 2

Motile

Question 3

All members are motile except:

Answer 3

§ Klebsiella
§ Shigella
§ Yersinia
Generally are NM @370C, but M at RT

Question 4

Motile members have_____ flagella except:
§ Tatumella ptyseos which has____ flagella

Answer 4

peritrichous

polar

Question 5

__and sometimes___
produce mucoid colonies

Answer 5

Klebsiella

Enterobacter

Question 6

T or F

Beta-hemolysis is seen in some strains

Answer 6

True

Question 7

All are____ positive except for one group of Shigella species and Xenorhabdus.

Answer 7

catalase

Question 8

§ Primary culture media used in the presumptive identification of enteric organisms in the laboratory.

§ EMB, MAC, XLD, HEA, SSA

Answer 8

Selective and Differential Media

Question 9

– a serologic test that determines
species/subtypes of bacteria based on the antigens present on its surface.

Answer 9

Serotyping

Question 10

– substances (proteins) that react with specific antibodies

– proteins that react to antigens.

Answer 10

Antigens

Antibodies (anti-sera)

Question 11

– refers to the variations in the antigenic structures of antigens

Answer 11

Antigenic variations

Question 12

(3) species may look the same under
the microscope, but they can be separated into different many
serotypes according to the variations of the antigens found on their
surface.

Answer 12

Salmonella/Escherichia/Shigella

Question 13

Serotyping is determined by the agglutination of bacteria with
specific antisera to identify variants of (2) antigens

Answer 13

O and H antigens

Question 14

• flagellar antigen
  • An antigen found in the flagellum of motile members
  • Protein in nature
  • Heat____
  • Used in the serotyping between species of Salmonella and other
  motile bacteria.

Answer 14

H antigen

labile

Question 15

• somatic antigen
  • Heat____, located in the____
  • Lipopolysaccharide of the cell wall composing the____ portion

Answer 15

O antigen

stable

cell wall

endotoxin

Question 16

• There are over_____ types of O antigen for E.coli and specific types are associated with diseases.

• Shigella have been grouped into four serotypes based on the O antigen: serotypes (4)

•____ types of O antigens exists for Salmonella

Answer 16

160

A, B, C, and D

60

Question 17

• capsular antigen/envelope antigen
  • Heat_____ polysaccharide found in
  encapsulated strains.

• Covers the O antigen (must be removed to detect the O antigen!!)

• To remove the antigen - the organism must be______.

Answer 17

K antigen

labile

boiled for 30 minutes

Question 18

(3) have K antigens.

•____ antigen for Salmonella is categorized as K antigens.

Answer 18

• Klebsiella, Salmonella, and E.coli

Vi

Question 19

Common types of infections include:
•

Answer 19

UTI, Gastroenteritis, Septicemia