Introduction

Classification

Taxonomy

• Phylum: Proteobacteria.
• Order: Burkholderiales.
• Family: Burkholderiaceae.
• Genus: Burkholderia.
• Species: pseudomallei.

Etymology

• Previously known as Pseudomonas pseudomallei, Malleomyces pseudomallei, Loefflerella pseudomallei, Pfeiferella pseudomallei.
• Burkholderia: named after W H Burkholder, an American bacteriologist who discovered the etiological agent of sour skin disease in onions.

Active Forms

Clinical Effects

Epidemiology

Habitat

• Saprophyte that is found in soils and in standing water in tropical and subtropical regions worldwide.

Transmission

Pathological effects

• B. pseudomallei is a facultative intracellular organism.
• Various types of infection, including:
  • Mild, or inapparent infections.
  • Localized, cutaneous ulcers.
  • Abscess and granuloma formation in the subcutis and internal organs.
  • Pneumonia and pulmonary abscessation.
  • Septicemia.
  • Encephalomyelitis.
• Generalized clinical signs of melioidosis in dogs include:
  • Fever.
  • Lethargy, malaise and anorexia.
  • Pale mucous membranes.
  • Purulent discharge from cutaneous lesions and wounds.
  • Multiple subcutaneous abscesses.
  • Testicular and scrotal swelling and pain.
  • Myalgia.

Control

Control via animal

• Surgical debridement and drainage of skin abscesses (for precautions see Isolation).

Control via chemotherapies

• Treatment of melioidosis may be prolonged and is often unsuccessful.
• B. pseudomallei is reported to be susceptible in vitro to the following antibiotics:
  • Trimethoprim-sulphonamide Trimethoprim.
  • Clavulanate-potentiated amoxicillin Amoxicillin, ticarcillin Ticarcillin.
  • Quinolones.
  • Tetracyclines Tetracycline.
  • Third generation cephalosporins.
  • Chloramphenicol Chloramphenicol.
  • Carbapenems.
• The antibiotic of choice in humans is ceftazidime Ceftazidime, often used in combination with meropenem or potentiated sulphonamides.
• Robust evidence for clinical efficacy and choice of antimicrobials in dogs in not available.
• B. pseudomallei is generally resistant to penicillin G, aminopenicillins, early generation cephalosporins, gentamicin and other aminoglycosides, macrolides, and rifampicin.

Control via environment

• Reduction of exposure to organisms in endemic areas is not really feasible since the organism is widespread in the environment.
• There is often a spike in human cases following severe flooding, strong winds and monsoonal conditions, so minimizing outdoor activities during these times, if possible, would seem prudent.
• Burkholderia pseudomallei is susceptible to various disinfectants, eg:
  • Benzalkonium chloride Benzalkonium chloride.
  • Iodine.
  • Mercuric chloride.
  • Potassium permanganate.
  • 1% sodium hypochlorite.
  • 70% ethanol.
  • 2% glutaraldehyde.
• B. pseudomallei is effectively killed by commercial disinfectants, Perasafe® and Virkon®.

Vaccination

• There is no vaccine available.

Other countermeasures

• Euthanasia Euthanasia should be considered in seriously ill dogs.

Diagnosis

Further Reading

Publications

Refereed Papers

• Recent references from PubMed and VetMedResource.
• Khrongsee P, Lueangthuwapranit C, Ingkasri T, Sretrirutchai S, Kaewrakmuk J, Saechan V, Tuanyok A (2019) Successful Treatments and Management of A Case of Canine Melioidosis. Vet Sci 23,6(4), 76 Full Article.
• Ryan C W, Bishop K, Blaney D D, Britton SJ, Cantone F, Egan C, Elrod M G, Frye C W, Maxted A M, Perkins G (2018) Public health response to an imported case of canine melioidosis. Zoonoses Public Health 65(4), 420-424 PubMed.
• Peacock S J, Schweizer H P, Dance D A B, Smith T L, Gee J E, Wuthiekanun V et al (2008) Management of accidental laboratory exposure to Burkholderia pseudomallei and B. mallei.  Emerging Infectious Diseases 14(7), e2 1080-6059 PubMed.

Other sources of information

• O’Brien C R, Malik R (2012) Miscellaneous bacterial infections. In: Infectious Diseases of the Dog and Cat, Greene CE (editor) Elsevier 4^th edn, ISBN: 978-1-4160-6130-4. pp 465-469.