CHAPTER 23 and 24: Pathogenicity of Enteric gram-negative bacteria

Question 1

_________ is the most common type of E. coli isolated from patients with neonatal meningitis and septicaemia.

Answer 1

E. coli K1

Question 2

These are facultatively anaerobic Gram-negative bacilli that are easily cultured, reduce nitrate and ferment glucose

Answer 2

Enterobacteriaceae

Question 3

________ possesses a capsule or Vi (virulence) antigen and a vaccine containing the Vi antigen is protective against typhoid

Answer 3

Salmonella typhi

Question 4

The ___________molecule consists of a central lipid

A and oligosaccharide core, and a long straight or branched polysaccharide ‘O’ antigen.

Answer 4

Lipopolysaccharide (LPS)

Question 5

________ stimulates host macrophages to produce cytokines, such as interleukin-1 and tumor necrosis factor (TNF), which mediate the fever, shock and metabolic acidosis associated with severe sepsis

Answer 5

Lipid A

Question 6

Toxin of E. coli O157 which causes Haemolytic uraemic Syndrome

Answer 6

Verotoxin

Question 7

Infection with _______ allows calcium and phosphates to precipitate, with the formation of renal stones due to it’s urease that lowers pH

Answer 7

Proteus spp

Question 8

E. coli that express _________ fimbrae are associated with lower urinary tract infections and cystitis

Answer 8

Mannose-binding

Question 9

E. coli that express _______ fimbriae are associated

with pyelonephritis and septicaemia

Answer 9

P

Question 10

______ produce LT and ST toxins that act on the enterocyte to stimulate fluid secretion, resulting in diarrhoea.

Answer 10

Enterotoxigenic E. coli (ETEC)

Question 11

______, which is heat labile, shares 70% homology with

cholera toxin and, like cholera toxin, increases local cyclic adenosine monophosphate (cAMP) in the enteric cell.

Answer 11

LT toxin

Question 12

______ is heat stable and stimulates cyclic guanyl monophosphate (cGMP).

Answer 12

ST toxin

Question 13

Some strains of E. coli, which are known as _________, secrete plasmid-encoded toxin, a serine protease that binds α-fodrin and causes disruption of the actin cytoskeleton, and are able to cause chronic diarrhoea

Answer 13

Enteroaggregative E. coli (EAggEC)

Question 14

_____________ cause disease by colonizing the epithelial lining of the small intestine and injecting effector proteins that cause effacement of microvilli and intimate adherence

Answer 14

Enteropathogenic E. coli (EPEC)

Question 15

E. coli strains produce a verotoxin named because of its in vitro activity on ‘vero’ cells causing haemorrhagic diarrhea

Answer 15

Enterohaemorrhagic E. coli (EHEC)

Question 16

Series of connected genes for pathogenicity determinants

Answer 16

Pathogenicity Islands

Question 17

Two Salmonella species that account for the majority of

human and animal infections:

Answer 17

S. enterica and S. bongori

Question 18

Enteric fever (typhoid) is caused by ________ serotype Typhi or Paratyphi

Answer 18

Salmonella enterica

Question 19

Classical rash of enteric fever

Answer 19

Rose spots on the abdomen

Question 20

______ production by Proteus is the most important virulence determinant in urinary infection, lowering pH and precipitating stone formation.

Answer 20

Urease

Question 21

_____________ is an important complication for patients with sickle cell disease or AIDS

Answer 21

Salmonella osteomyelitis or septic arthritis

Question 22

_____________ are used in the treatment of typhoid.

Answer 22

Ceftriaxone and ciprofloxacin

Question 23

In urinary tract infections of Enterobacterioceae, ________ are the first-choice antibiotics

Answer 23

Cefalexin, ampicillin, nitrofurantoin or trimethoprim

Question 24

Klebsiella infection associated with chronic

bronchiectasis.

Answer 24

K. ozanae

Question 25

Klebsiella infection that causes a progressive granulomatous infection of the nasal passages
and surrounding mucous membranes.

Answer 25

K. rhinoscleromatis