pseudomonas & burkholderia

Pseudomonas

• Gram-negative rods

P. aeruginosa

Most veterinary diseases are caused by

Burkholderia mallei

Previously names pseudomonads of veterinary importance have been reclassified:

• Pseudomonas malle →

Burkholderia pseudomallei

Previously names pseudomonads of veterinary importance have been reclassified:

• Pseudomonas pseudomallei →

Pseudomonas & Burkholderia

• Medium sized, straight or slight curved Gram-negative rods

• Strict aerobes

• Non-spore forming

• Oxidative

• Catalase-positive

P. oryzihabitans and P. luteola

Pseudomonas & Burkholderia

• oxidase positive except

B. mallei

Pseudomonas & Burkholderia

• Mostly motile by one or several polar flagella except

soluble pigments

Pseudomonas & Burkholderia

• Some zpecies produce ______

• water, soil, plants, fruits, and vegetables

• Have predilectiom for aqueous environment

Environmental microorganisms (worldwide distribution)

Opportunistic pathogens

_________ of:

• animals

• Humans

• Plants

• disinfectants

• Ointments

• Soaps

• Eye drops

• Irrigation fluids and equipments

• Aerators

• Traps of sinks

Pseudomonas aeruginosa

• potential sources

Resistant

Pseudomonas aeruginosa

• ________ to many antimicrobials

  • Frequently causes infection in animals undergoing antibiotic treatment or immunocompromised hosts.

• skin

• Mucous membranes (GI tact)

Pseudomonas aeruginosa

• sometimes found as microbial flora of healthy animals

• trauma to tissue (burns and wounds)

• Debilitation due to malignancy or immunodeficiency

• Transplant recipients

Pseudomonas aeruginosa

• rarely involved in primary disease

• Predisposing cuases:

  • _____

• infection occur at “moist sites”

• Due to intrinsic and acquired resistance

• Formation of biofilms

Pseudomonas aeruginosa

• treTment is often difficult

• Pneumonia in farmed mink and pigs

• Otitis, pneumonia, sepsis and sudden death in chinchillas

• Sepsis in poultry

• Mastitis in ruminants

• Otitis externa in dog

Pseudomonas aeruginosa

• Can infect many species, at a variety of anatomical sites

• Some presentations associated with this organism include:

Otitis externa and pyoderma

Pseudomonas aeruginosa

• isolated from compromised aeruginosa

• Isolated from compromised animals

  • _______ - following roudns of therapy

• ulcerative keratitis

• Cause of “melting ulcers” in horses

Pseudomonas aeruginosa

• infecting corneal tissues

P. aeruginosa

Melting ulcers

• Left - horse

• Right - dog

P. aeruginosa

Melting ulcer in a dog. Note, the green colour here is a result of fluoroscein dye used to visualize the ulcer not due to P. aeruginosa pigments

• ability to quorum sense

• Elastase

• Siderophores

• Type III secretion systems

• Alginate biofilms

P. aeruginosa virulence factors

Ability to quorum sense

involved in different phases of infection (biofilm maturation, motility etc.)

Elastase

damage to blood vessels and lung tissues, disrupts neutrophil function

Siderophores

pigmented iron scavenging molecules pyoverdine (green), pyocyanin (blue) – Results in characteristic color

Type III secretion systems

secretion of effector molecules to damage host tissues or other bacteria

Alginate biofilm

slimy matrix produced by some strains which prevents phagocytosis

Burkholderia mallei

• Obligate parasite with restricted host range

• Cannot survive in environment for more than 2 weeks

• Easily killed by desiccation, sunlight and common disinfectants

• Once had worldwide distribution

  • Now, mainly seen in China and Mongolia

  • Reports of infection in India, Iraq, Turkey and Philippin

Equids

Burkholderia mallei

• primarily affects _____

• Humans and cats are also susceptible

• Transmission by ingestion of food water contaminated by nasal discharges

B. mallei

_______ is a facultative intracellular parasite and spread between cells in a manner similar to L. monocytogenes

• pulmonary infection

• Septicemia

• Farcy

Burkholderia mallei

• 3 forms of disease

Pulmonary infection

Burkholderia mallei

• inhalation causes severe

  • pneumonia,

  • lung abscess and

  • chest pain

Septicemia

Burkholderia mallei

• rapidly fatal systemic infection

  • Bacteria enters the bloodstream

  • Causes widespread pustules and abscesses in internal organs

Farcy

Burkholderia mallei

• cutaneous

  • Bacteria enters through skin abrasions or wounds

  • Nodules which may ulcerate are seen along tracks of lymphatics on skin

donkeys and mules than horses

Burkholderia mallei

• Acute disease more common in ______

• Begins with pyrexia, depression and anorexia

• Watery discharge from nostril (often unilateral), coughing

• Nodules and ulcers develop on septum and discharge becomes thicker (copious yellow mucopurulent discharge)

• Enlargement of lymph nodes

• In animals that survive, nasal septum may be perforate

carnivores in zoos (large cats)

Burkholderia mallei

• Other species can also be affected

• Infections of ______ fed glanderous meat

• Camels are also susceptible

• infected animals,

• bodily fluids, or

• contaminated equipment

Burkholderia mallei

• is transmitted through direct contact with

Biological warfare

Burkholderia mallei

• possible agent of ________

• Thought to have been used by Germans in WW1

• Japanese in WW2

B. mallei

B. mallei

B. mallei

Burkholderia pseudomallei

• primarily found in tropical and subtropical regions

  • Rice-growing areas of Thailand, Vietnam and India

  • Found also in Northern Territory of Australia

Melioidosis

Burkholderia pseudomallei

• glanders like disease called

• Muddy water and humid soil

• Consumption of infected animals

• Exposure often occupational

• Laborers, cleaners, rice paddy workers

Burkholderia pseudomallei

• facultative intracellular pathogen

• Broad host range

• Contracted by contaminated food or water

Melioidosis

Burkholderia pseudomallei

• In people many infections are self-limiting flu like illnesses

• Typical lesions are abscesses which can occur anywhere in the body

  • In people the lungs and brain are the most common site

  • Infections can be latent and reactivate after years

• High rates of infection in US soldiers in the Vietnam war

• acute

• Subacute

• Chronic

Burkholderia pseudomallei

• 3 distinct forms

Acute

Burkholderia pseudomallei

• septicemia with metastatic lesions and abscesses

Subacute

Burkholderia pseudomallei

• “tuberculosis-like” oneumonia, lymphangitis

Chronic

Burkholderia pseudomallei

• localized chronic cellulitis

intrinsically resistant

Burkholderia pseudomallei

• _________ to many antimicrobials

• High mortality rate (95%) if untreated

• Mortality rates even high in developed countries among bacteremic patients (19%

• ruminants

• Pigs

• Horses

• Deer

• Camels

• Dogs

• Dolphins

• Koala

• Kangaroo

• Non-human primates

Burkholderia pseudomallei

• reported in numerous animal species

Fatal or subclinical

Burkholderia pseudomallei

• disease can be rapidly ________

Horses

Burkholderia pseudomallei

• _______ - may mimic glanders

Goats and pigs

Burkholderia pseudomallei

• _______ - respiratory and CNS infections, arthritis, and mastitis

Dogs

Burkholderia pseudomallei

• ______ - localized abscessations with pyrexia

B. pseudomallei

B. pseudomallei

Pseudomonas fluorescens

• Cause of septicemia primarily in high intensity aquaculture operations

  • Fish are lethargic

  • May have cutaneous lesions

• These organisms are ubiquitous within the environment

• More common in waters with organic pollutants

• Treatment is challenging due to intrinsic resistance

  • Drugs available for use in aquaculture not effectiv

P. fluorescens

Skin infection w _____ in CARP

P. fluorescens

• Strict safety precaution must be enforced (Biosafety Level 3)

• Collect discharges from lesions for culture

• Blood for serolog

Burkholderia specimen collection

• biosafety lvl 2

• Standard collection and transport

Pseudomonas - Specimen Collection

Mallein Test

Prescribed test to demonstrate hypersensitivity developed after infection with B. mallei

Mallein

• glycoprotein extracted from the bacterium

Subcutaneous test

results in swelling at the injection site and fever

Opthalmic test

inflammatory and purulent reaction in the eye

Intrapalpebral test

gives a localized, edematous swelling and purulent conjunctivitis

• medium-sized,

• Gram-negative rods with no other distinctive characteristics.

Direct microscopy from specimens is of little diagnostic use as Pseudomonas and Burkholderia are

Safety pin appearance

direct microscopy of Gram-stained smears with B. pseudomallei will often reveal small Gram negative bacilli with bipolar staining

• B. mallei and

• B. pseudomallei

A fluorescent antibody technique may be useful for

Readily grows on routine test media

Pseudomonas

B. mallei and pseudomallei

• Grows on blood and MacConkey agar

• Identified based on colony morphology

• PCR based assays

• Immunological tests helpful

• Serology (B. pseudomallei) cross reactivity between B. mallei and B.pseudomallei

Susceptibility testing

Pseudomonas and should be treated based on the results of _______

porin expression

Intrinsic resistance partially due to low level of _______ – drugs can’t get through the cell membrane