Campylobacter jejuni, Part 2; Virulence factors, sources, symptoms, treatment and complication
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This is the 2nd video
This is the 2nd video on Campylobacter jejuni and focuses on Virulence factors, sources, symptoms, treatment, and complications. The link to part 1 is:
Part 1: Campylobacter jejuni, Part 1; Introdu...
• The JlpA gene encodes JlpA of 372 amino acid residues with a molecular mass of 42.3 kDa, is C. jejuni lipoprotein adhesin virulence factor and mediates adherence of the bacterium to epithelial cells. The JlpA interacts with cell surface heat shock protein (Hsp) 90α and initiates signaling pathways leading to activation of NF‐κB, causing an inflammatory response. C. jejuni is also known to produce glycans [lipo-oligosaccharide (LOS) and glycoproteins] that can potentially be involved in the interaction with lectin-like host cell receptors. Another cell surface structure of Campylobacter that may also influence bacterial interaction with host cells is a Capsular Polysaccharide.
The only enterotoxin that seems to be encoded in the C. jejuni genome is the cytolethal distending toxin. It is believed that CDT initiates DNA degradation, which causes cells to arrest in G2 stage of the cell cycle and subsequently die by apoptosis. The death of these specialized cells is thought to lead to the loss of function and erosion of the protective intestinal epithelial layer thus producing the electrolyte disturbances and malabsorption associated with diarrhea. The cell death that accompanies this toxin is a reason for blood in the host’s diarrhea. Recent research has also acknowledged that C. jejuni has developed quorum sensing whereby chemical factors are used as communication signals with other bacterial species to coordinate infection. C. jejuni has the ability to form biofilms, which are monospecies or mixed-species bacterial communities encased in a matrix and attached to a surface.
The helical shape of the C. jejuni cell body and its amphitrichous flagella are postulated to contribute to the natural high velocity of motility observed in viscous environments. This motility facilitates colonization, spread and retention within mucous layers on intestinal epithelia for commensalism in animals and pathogenesis of diarrheal disease in humans.
The flagellum of C. jejuni is comprised of seven protofilaments consisting of FlaA and FlaB subunits, the flagellin protein (the major protein in the flagella) is heavily glycosylated. The flagella is capped at its distal end by the flagellar cap protein, termed as FliD (or HAP2). The flagellar fiber is anchored via a short hook filament structure to the flagellar motor complex in the bacterial membrane. This nanomachine drives the rotation of the flagella enabling movement of the bacteria. Besides its role in bacterial motility, the flagellar apparatus may act as a secretion machinery that exports proteins, Campylobacter invasion antigens, into the host cell cytosol. The flagella lack the TLR5 binding site. Bile and L-fucose are also positive chemotaxins for C. jejuni.
SOURCES/ Route of Transmission
a. All types of poultry and wild birds
b. Contaminated drinking water and unpasteurized milk
c. Contaminated food
d. Raw milk
e. Unchlorinated water.
f. The route of transmission is fecal-oral or ingestion of contaminated food and water
Symptoms
• Mild to severe diarrhea.
• Bloody diarrhea.
• Stomach pain.
• Cramps.
• Nausea and/or vomiting.
• Fever.
• Headache, and
• Muscle pain.
Important Diagnostic Tests
Rectal swabs are directly inoculated on Campylobacter Selective Agar and incubated at 42oC for 48-72 hours. Blood analysis is also helpful.
Treatment
Liquid and electrolyte replacement
Azithromycin therapy and Erythromycin are the antibiotics of choice. Its resistance remains low, and it can be used in pregnant women and children.
Complications
Reactive arthritis is a condition that causes redness and swelling (inflammation) in various joints in the body, especially the knees, feet, toes, hips and ankles.
It usually develops after you've had an infection of food poisoning.
The body's immune system seems to overreact to the infection and starts attacking healthy tissue, causing it to become inflamed. People who have a gene called HLA-B27 [A positive test means HLA-B27 is present and suggests a greater-than-average risk for developing or having certain autoimmune disorders] are much more likely to develop reactive arthritis than those who don't, but it's unclear why.
• Guillain-Barre Syndrome is a rare disorder in which your body's immune system attacks your nerves. Weakness and tingling in your extremities are usually the first symptoms. These sensations can quickly spread, eventually paralyzing your whole body.
• An important factor in contracting Guillians Barre syndrome from this pathogen is the sialic acid that is contained in its core oligosaccharide. This compound can resemble gangliosides [A ganglioside is a molecule composed of a glycosphingolipid with one or more sialic acids linked on the sugar chain] which can cause this neurological disease.
Part 1: Campylobacter jejuni, Part 1; Introdu...
• The JlpA gene encodes JlpA of 372 amino acid residues with a molecular mass of 42.3 kDa, is C. jejuni lipoprotein adhesin virulence factor and mediates adherence of the bacterium to epithelial cells. The JlpA interacts with cell surface heat shock protein (Hsp) 90α and initiates signaling pathways leading to activation of NF‐κB, causing an inflammatory response. C. jejuni is also known to produce glycans [lipo-oligosaccharide (LOS) and glycoproteins] that can potentially be involved in the interaction with lectin-like host cell receptors. Another cell surface structure of Campylobacter that may also influence bacterial interaction with host cells is a Capsular Polysaccharide.
The only enterotoxin that seems to be encoded in the C. jejuni genome is the cytolethal distending toxin. It is believed that CDT initiates DNA degradation, which causes cells to arrest in G2 stage of the cell cycle and subsequently die by apoptosis. The death of these specialized cells is thought to lead to the loss of function and erosion of the protective intestinal epithelial layer thus producing the electrolyte disturbances and malabsorption associated with diarrhea. The cell death that accompanies this toxin is a reason for blood in the host’s diarrhea. Recent research has also acknowledged that C. jejuni has developed quorum sensing whereby chemical factors are used as communication signals with other bacterial species to coordinate infection. C. jejuni has the ability to form biofilms, which are monospecies or mixed-species bacterial communities encased in a matrix and attached to a surface.
The helical shape of the C. jejuni cell body and its amphitrichous flagella are postulated to contribute to the natural high velocity of motility observed in viscous environments. This motility facilitates colonization, spread and retention within mucous layers on intestinal epithelia for commensalism in animals and pathogenesis of diarrheal disease in humans.
The flagellum of C. jejuni is comprised of seven protofilaments consisting of FlaA and FlaB subunits, the flagellin protein (the major protein in the flagella) is heavily glycosylated. The flagella is capped at its distal end by the flagellar cap protein, termed as FliD (or HAP2). The flagellar fiber is anchored via a short hook filament structure to the flagellar motor complex in the bacterial membrane. This nanomachine drives the rotation of the flagella enabling movement of the bacteria. Besides its role in bacterial motility, the flagellar apparatus may act as a secretion machinery that exports proteins, Campylobacter invasion antigens, into the host cell cytosol. The flagella lack the TLR5 binding site. Bile and L-fucose are also positive chemotaxins for C. jejuni.
SOURCES/ Route of Transmission
a. All types of poultry and wild birds
b. Contaminated drinking water and unpasteurized milk
c. Contaminated food
d. Raw milk
e. Unchlorinated water.
f. The route of transmission is fecal-oral or ingestion of contaminated food and water
Symptoms
• Mild to severe diarrhea.
• Bloody diarrhea.
• Stomach pain.
• Cramps.
• Nausea and/or vomiting.
• Fever.
• Headache, and
• Muscle pain.
Important Diagnostic Tests
Rectal swabs are directly inoculated on Campylobacter Selective Agar and incubated at 42oC for 48-72 hours. Blood analysis is also helpful.
Treatment
Liquid and electrolyte replacement
Azithromycin therapy and Erythromycin are the antibiotics of choice. Its resistance remains low, and it can be used in pregnant women and children.
Complications
Reactive arthritis is a condition that causes redness and swelling (inflammation) in various joints in the body, especially the knees, feet, toes, hips and ankles.
It usually develops after you've had an infection of food poisoning.
The body's immune system seems to overreact to the infection and starts attacking healthy tissue, causing it to become inflamed. People who have a gene called HLA-B27 [A positive test means HLA-B27 is present and suggests a greater-than-average risk for developing or having certain autoimmune disorders] are much more likely to develop reactive arthritis than those who don't, but it's unclear why.
• Guillain-Barre Syndrome is a rare disorder in which your body's immune system attacks your nerves. Weakness and tingling in your extremities are usually the first symptoms. These sensations can quickly spread, eventually paralyzing your whole body.
• An important factor in contracting Guillians Barre syndrome from this pathogen is the sialic acid that is contained in its core oligosaccharide. This compound can resemble gangliosides [A ganglioside is a molecule composed of a glycosphingolipid with one or more sialic acids linked on the sugar chain] which can cause this neurological disease.
4 سال پیش
در تاریخ 1399/09/10 منتشر شده
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