Test 2- Burkholderia Flashcards
Genus Burkholderia
Gram negative
Aerobic
Rods
Catalase positive
- Taxonomically not yet very clear
- Many new description of species
- Mostly environmental bacteria:
• Pathogenic species:
• B. mallei: glanders
- B. pseudomallei: melioidosis
- B. cepacia (humans, frequently in cystic fibrosis patients)
• Plant pathogens
B. mallei: glanders
general
• BSL3 agent
- Has been used in WW I
- Primarily Equine pathogen
————-Also infects felines, dogs, humans,…
• When diagnosed: has to be declared
————- Now mainly in Asia and South America
B. mallei: glanders
• Symptoms
• Nodules and ulcers, pyogranulomatous
- Orchitis
- Skin respiratory tract
- Great variability in severity
Virulence factors for B. Malleli
Virulence factors; non specific
- Capsule
- LPS
B. mallei: glanders
Transmission
• Ingestion: feed, water
- Inhalation
- wounds
B. mallei: glanders Pathogenesis
- Chronic
- Debilitating
Entry– Pharynx, skin
Spread- via lymphatic and blood
Nodular lesions in lymph nodes, lung, liver, spleen, nose and skin
B. mallei: glanders Pathology
Suppurative lesions
- Nodular:
neutrophils, fibrin, red blood cells - Granulomatous:
Central: necrotic granulomatous
Surrounded by
epithelial cells, giant cells
lymphocytes embedded in granulation tissue- CAN MAKE TX HARD
B. mallei: glanders Symptoms
• Acute infection
• Fever
- Nasal discharge
- Lymphadenitis (head & neck)
• Frequently fatal (2 weeks)
B. mallei: glanders Symptoms
Chronic
• You should not see this (declaration at acute phase)
- Fever & respiratory problems
- Skin abscesses (cranial lymph nodes)
Is B. mallei zoonotic?
YES!
B. mallei: glanders
B. mallei: glanders Diagnosis
• Isolation and identification
• Serology: Care for false positives
• Difficult
• Few laboratories do it
• Cross reactions (false positive)
—–Environmental group of bacteria
• CFT, ELISA, HAI
• Horses CFT is official test, but creates sometimes false positives
• Intradermo test (mallein test)
- Type IV hypersensitivity
- Cellular
B. Mallei Prevention:
- No vaccination available
- Screening and culling of positive animals
- After outbreak: bedding, feed should be disinfected (burned)
• Avoid contact with horses from endemic areas
Treatment of B. mallei
• Outbreak should be notified to competent authorities
• Culling of positive animals
Burkholderia pseudomallei, Melioidosis
• Melioidosis
• pyogranulomatous infections • Reportable disease
• Real saprophyte- JUST IN NATURE NOT CONTAGIOUS
• In water rich environments
• Frequently infections after flooding’s, heavy rain fall • Swampy terrain
• Rice paddies
- Melioidosis
- pyogranulomatous infections • Reportable disease
- Real saprophyte
- In water rich environments
- Frequently infections after flooding’s, heavy rain fall
- Swampy terrain
- Rice paddies
• Endosymbiont of environmental amoeba
• Wide host range: large dissemination possibilities
- Mammalians
- Mainlysheep&goat
- Rodents: reservoir in endemic regions (Tropical and subtropical)
• Avian (rather rare)
• Reservoir in Amoeba
Burkholderia pseudomallei, Melioidosis
• Transmission
• Ingestion
- Wound infection
- Airborne
- Arthropod bites (wound infection like)
Burkholderia pseudomallei, Melioidosis
• Virulence factors
• Adhesins-flagella
- Capsule
- T3SS and T4SS- Needle that injects factor proteins into the cell
• Not all is known
Burkholderia pseudomallei, Melioidosis
• Human infection
- Highly variable disease symptoms
- Subclinical (asymptomatic) to acute and fatal (sepsis)
• Pneumonia
Burkholderia pseudomallei, Melioidosis
species
Dogs
• Febrile diseases with localizing suppurative foci
• Very important in military dogs during war in Vietnam
Equine
• Mimics glanders: pseudoglanders- this is what makes it reportable- because it’s so similar to B. Mallei
Cattle
• Acute to chronic
• lungs, joints and uterus
Sheep
• Arthritis and lymphadenitis
Goat
• Loss of condition, respiratory and central nervous system disturbances, arthritis, and mastitis
Swine
• Loss of condition, respiratory and central nervous system disturbances, arthritis, mastitis, abortion and diarrhea
- more backyard swine
Burkholderia pseudomallei, Melioidosis Diagnosis
- BSL3
- Samples
-Purulent content
• Cultivation
-Blood agar or McConkey
Serology: Care for false positives
• CFT, ELISA, HAI
• Horses CFT is official test, but creates sometimes false positives
- Intradermo test (mallein test) • Type IV hypersensitivity
- Cellular
• PCR
Burkholderia pseudomallei, Melioidosis
Treatment and control
Prevention
• No vaccination
• Difficulty: water & soil contact is common
Therapy
- Outbreak should be notified to competent authorities
- Drainage of abscesses
• Antimicrobials (susceptibility profile!)
-Fluoroquinolones, tetracyclines, anti-pseudomonas β-lactams
Burkholderia mallei and pseudomallei differentiation
- Isolation and identification
- Blood or glycerol agar, glycerol-potatoe, chocolate agar and MacConkey agar
- B.pseudomalleigrowsfasterthanB.mallei<48h
- B.pseudomalleigrowson2%NaCl
- B.pseudomalleioxidizeslactose,norB.malleiorP.aeruginosado
- B.pseudomalleiandP.aeruginosacangrowat42°C.B.malleican’t • B.pseudomalleiismotile,B.malleiisnon-motile
- Use of Selective media aids in mixed infections • Ashdown’s selective medium for B. pseudomallei
- PCR
