Border Color Location
  Extracellular
  Cell membrane
  Cytoplasm
  Organelle
  Bacterial membrane or virus envelope
  Other
Backgound Color Node Shape Object Type
  Box Protein or gene
  Box Protein of gene complex
  Ellipse Pathway or action
  Box Eukaryotic cell or cell component
  Box Microorganism or its component
  Box Microbe-host cell complex

Phinet Name: Burkholderia mallei

Phinet Information
Pathogen Name: Burkholderia mallei
Pathogen NIAID Category: NIAID Category B
Bio-objects
Bio-object 1: B. mallei cell spread and persistence
  • Type: Pathway or action
  • Location: Extracellular
  • Description: There is little information about pathologic findings in humans infected with B. mallei. The bacteria tend to localize at the site of entry (skin, nasal or laryngeal mucosa) and induce formation of nodules that ultimately ulcerate, resulting in lymphangitis and lymphadenopathy. When the B. mallei bacteria are spread systemically, many tissues can be seeded. These tissues include skin, skeletal muscle, bone, joints, less commonly brain, and rarely nasal or ocular. The lungs, liver, and spleen are often affected. In the subacute course of infection, the encapsulated forms of B. mallei parasitized mainly in the cells of the system of mononuclear phagocytes in the liver, the spleen and the lungs. The capsule formed by B. mallei is the factor facilitating its persistence in the host.(<a href="#reference5242">Fritz et al., 2000</a>)(<a href="#reference5246">Popov et al., 2000</a>)
Bio-object 2: Burkholderia mallei bacterium
  • Type: Microorganism or its component
  • Location: Extracellular
  • Function: Infection
  • Description: Burkholderia mallei is a gram-negative, nonmotile, oxidase-positive bacterium responsible for a disease known as glanders in equines (horses, mules and donkeys) and occasionally in humans. The factors involved in the pathogenesis of Burkholderia mallei (B. mallei) infection remain relatively poorly defined at the molecular level. As a result, very little is known about the basic mechanism of B. mallei pathogenesis.(<a href="#reference5239">Burtnick et al., 2002</a>)(<a href="#reference5240">DeShazer et al., 2001</a>)(<a href="#reference5241">Anuntagool et al., 2002</a>)
Bio-object 3: Extracellular polysaccharide capsule
  • Type: Microorganism or its component
  • Location: Extracellular
  • Description: Little is known about the virulence factors of B. mallei. The only virulence factor definitively shown to be essential for the pathogenicity of this bacterium is an extracellular polysaccharide capsule. The structure of B. mallei O-polysaccharide (probably component of LPS) is described as 3)-beta-D-glucopyranose-(1,3)-6-deoxy-alfa-L-talopyranose-(1-, in which the talose residue contains 2-O-methyl or 2-O-acetyl substituents.It should be noted that the R-type strains of B. mallei may be isolated as frequently as the S-type strains(<a href="#reference5239">Burtnick et al., 2002</a>)(<a href="#reference5240">DeShazer et al., 2001</a>)(<a href="#reference5241">Anuntagool et al., 2002</a>)(<a href="#reference5242">Fritz et al., 2000</a>)
Bio-object 4: Host cell necrosis
  • Type: Pathway or action
  • Location: Cytoplasm
  • Description: Infection of the lungs by B. mallei is resulted in foci of acute inflammation and necrosis. Necrosis of the tracheobronchial tree and pustular skin lesions characterize acute infection with B. mallei.(<a href="#reference5245">Lopez et al., 2003</a>)(<a href="#reference5247">Lehavi et al., 2002</a>)(<a href="#reference5248">Lever et al., 2003</a>)
Bio-object 5: The virulence factors
  • Type: Protein or gene complex
  • Location: Other
  • Description: The virulence factors and pathogenesis of the disease caused by B. mallei are distinctive, still elusive, and remain to be investigated. The losing of the capsule appears to decrease in virulence, suggesting that capsule is an important virulence factor for B. mallei, as it is for other pathogenic bacteria. B. mallei can survive in the presence of 30% normal human serum (NHS) over the course of 18 h while the strains lacking O-polysaccharide are completely killed following 2-h incubation in 30% NHS. These results suggest that B. mallet O-polysaccharide plays a crucial role in the serum resistance of this organism. The TTSS plays an essential role in the virulence of B. mallei and is required for intracellular replication within murine macrophage-like cells.(<a href="#reference5239">Burtnick et al., 2002</a>)(<a href="#reference5242">Fritz et al., 2000</a>)(<a href="#reference5244">Ulrich et al., 2004</a>)(<a href="#reference5245">Lopez et al., 2003</a>)
Bio-object 6: Type III Secretion System
  • Type: Protein or gene complex
  • Location: Cell membrane
  • Function: Transporter
  • Description: Type III secretion systems (TTSS) are implicated in the pathogenicity of several gram-negative bacterial pathogens. The B. mallei TTSS encodes 30 open reading frames (ORFs) and shares genetic similarity to some gram-negative bacteria. Mutagenesis analysis demonstrated that a functional TTSS was required for the full pathogenicity of B. mallei in the experimental animal models. It is not clear yet what secreted effector molecules (virulence factors) are involved in translocation process from B. mallei bacteria to the host cells. Further studies will be needed to identify putative effectors and decipher the complex molecular mechanisms associated with this TTSS.(<a href="#reference5243">Rainbow et al., 2002</a>)(<a href="#reference5244">Ulrich et al., 2004</a>)
Interactions
Interaction 1: I1
  • Input Objects: Burkholderia mallei bacterium
  • Output Objects: Extracellular polysaccharide capsule
  • GO Evidence Code: Inferred from Direct Assay
  • Description: B. mallei extracellular polysaccharide capsule.(<a href="#reference5239">Burtnick et al., 2002</a>)(<a href="#reference5240">DeShazer et al., 2001</a>)(<a href="#reference5241">Anuntagool et al., 2002</a>)(<a href="#reference5242">Fritz et al., 2000</a>)
Interaction 2: I2
  • Input Objects: Burkholderia mallei bacterium
  • Output Objects: Type III Secretion System
  • GO Evidence Code: Inferred from Direct Assay
  • Description: B. mallei type III secretion system.(<a href="#reference5243">Rainbow et al., 2002</a>)(<a href="#reference5244">Ulrich et al., 2004</a>)
Interaction 3: I3
  • Input Objects: Extracellular polysaccharide capsule, Type III Secretion System
  • Output Objects: The virulence factors
  • GO Evidence Code: Inferred from Direct Assay
  • Description: Extracellular polysaccharide capsule is involved in pathogenesis of B. mallei.Type III secretion system (a virulence factor delivery system) is essential for the pathogenicity of B. mallei.(<a href="#reference5239">Burtnick et al., 2002</a>)(<a href="#reference5242">Fritz et al., 2000</a>)(<a href="#reference5244">Ulrich et al., 2004</a>)(<a href="#reference5245">Lopez et al., 2003</a>)
Interaction 4: I4
  • Input Objects: The virulence factors
  • Output Objects: B. mallei cell spread and persistence
  • GO Evidence Code: Inferred from Direct Assay
  • Description: The encapsulated forms of B. mallei bacteria are spread systemically and persistent mainly in the cells of the system of mononuclear phagocytes in the liver, the spleen and the lungs.(<a href="#reference5242">Fritz et al., 2000</a>)(<a href="#reference5246">Popov et al., 2000</a>)
Interaction 5: I5
  • Input Objects: B. mallei cell spread and persistence
  • Output Objects: Host cell necrosis
  • GO Evidence Code: Inferred from Direct Assay
  • Description: B. mallei infection leads to acute inflammation and necrosis of some host tissues.(<a href="#reference5245">Lopez et al., 2003</a>)(<a href="#reference5247">Lehavi et al., 2002</a>)(<a href="#reference5248">Lever et al., 2003</a>)
Pathways