CHAPTER 23 and 24: Pathogenicity of Enteric gram-negative bacteria Flashcards
_________ is the most common type of E. coli isolated from patients with neonatal meningitis and septicaemia.
E. coli K1
These are facultatively anaerobic Gram-negative bacilli that are easily cultured, reduce nitrate and ferment glucose
Enterobacteriaceae
________ possesses a capsule or Vi (virulence) antigen and a vaccine containing the Vi antigen is protective against typhoid
Salmonella typhi
The ___________molecule consists of a central lipid
A and oligosaccharide core, and a long straight or branched polysaccharide ‘O’ antigen.
Lipopolysaccharide (LPS)
________ 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
Lipid A
Toxin of E. coli O157 which causes Haemolytic uraemic Syndrome
Verotoxin
Infection with _______ allows calcium and phosphates to precipitate, with the formation of renal stones due to it’s urease that lowers pH
Proteus spp
E. coli that express _________ fimbrae are associated with lower urinary tract infections and cystitis
Mannose-binding
E. coli that express _______ fimbriae are associated
with pyelonephritis and septicaemia
P
______ produce LT and ST toxins that act on the enterocyte to stimulate fluid secretion, resulting in diarrhoea.
Enterotoxigenic E. coli (ETEC)
______, which is heat labile, shares 70% homology with
cholera toxin and, like cholera toxin, increases local cyclic adenosine monophosphate (cAMP) in the enteric cell.
LT toxin
______ is heat stable and stimulates cyclic guanyl monophosphate (cGMP).
ST toxin
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
Enteroaggregative E. coli (EAggEC)
_____________ cause disease by colonizing the epithelial lining of the small intestine and injecting effector proteins that cause effacement of microvilli and intimate adherence
Enteropathogenic E. coli (EPEC)
E. coli strains produce a verotoxin named because of its in vitro activity on ‘vero’ cells causing haemorrhagic diarrhea
Enterohaemorrhagic E. coli (EHEC)
Series of connected genes for pathogenicity determinants
Pathogenicity Islands
Two Salmonella species that account for the majority of
human and animal infections:
S. enterica and S. bongori
Enteric fever (typhoid) is caused by ________ serotype Typhi or Paratyphi
Salmonella enterica
Classical rash of enteric fever
Rose spots on the abdomen
______ production by Proteus is the most important virulence determinant in urinary infection, lowering pH and precipitating stone formation.
Urease
_____________ is an important complication for patients with sickle cell disease or AIDS
Salmonella osteomyelitis or septic arthritis
_____________ are used in the treatment of typhoid.
Ceftriaxone and ciprofloxacin
In urinary tract infections of Enterobacterioceae, ________ are the first-choice antibiotics
Cefalexin, ampicillin, nitrofurantoin or trimethoprim
Klebsiella infection associated with chronic
bronchiectasis.
K. ozanae
Klebsiella infection that causes a progressive granulomatous infection of the nasal passages
and surrounding mucous membranes.
K. rhinoscleromatis
