BACTE MODULE 3

• CAMPYLOBACTER

  • These organisms are major

  causes of gastrointestinal

  infections in human, dogs and

  cats with diarrhea.

  • These are short, curved rods.

  • They are found in the

  reproductive and alimentary

  tracts of humans and animals.
• Species of Campylobacter associated with animal infections

  • Campylobacter fetus subsp.

  venerealis (Cattle)

  • C. jejuni

  • C. coli

  • C. consicus

  • C. helveticus

  • C. hyointestinalis

  • C. mucosalis

  • C. lari
• Lawsonia spp. associated with Campylobacter?

  L. intracellularis
• Morphology, staining features and cellular composition of Campylobacter and Lawsonia

  • Campylobacter spp. and Lawsonia

  spp. are Gram-negative, slender

  curved short rods.

  • Two or more bacterial cells that

  are placed together form S or a gull-

  winged shapes.

  • These organisms possess cell wall,

  capsule and flagella.
• Growth characteristics of Campylobacter and lawsonia

  • These organisms are microaerophilic and require

  an atmosphere containing 3 to 15% oxygen.

  • Their growth does not require fermentation or

  oxidation of carbohydrates as their energy

  requirement is reportedly obtained from oxidation

  of amino acids.

  • Lawsonia intracellularis has not reportedly been

  grown in artificial media.
• Reservoir of infection of Campy

  •Milk

  •Poultry carcass and intestinal tracts

  of infected animals

  •Feces of infected pigs

  (L. intracellularis) and preputial crypts

  of the bull (C. fetus sp. venerealis)

  Transmission

  •Feco-oral route

  •Artificial insemination and coitus

  •Direct or indirect contact
• Campylobacter infection in Dogs and Cats

  Etiologic agent: C. jejuni

  • Infection is marked by diarrhea and

  gastroenteritis

  • Pathogen invades the distal segments of the

  small intestines

  • The mucosal epithelium is destroyed, destroy

  arachidonic acid pathway, produces

  prostaglandins and leukotrienes and elevation

  of cAMP

  • Diarrheic feces contain cell debris and mucus

  that irritates epithelium and renders feces

  bloody

  • L. intracellularis causes necrotic enteritis,

  regional ileitis and proliferative hemorrhagis

  enteropathy
• Campylobacter infections in Cattle

  Etiologic agent: C. fetus subsp. venerealis

  • The disease is marked by infertility and

  abortions and cattle are healthy shedders of

  Campylobacter infections
• Campylobacter infections in Sheep and birds

  Etiologic agent: C. fetus subsp. fetus

  • The disease is marked by abortion in sheep

  and birds
• Campylobacter infections in Swine

  Etiologic agents: C. hyointestinalis and

  C. mucosalis

  • The disease is marked by proliferative

  enteritis
• Virulence factors of

  Campylobacter

  (cellular product of Lawsonia spp. in

  presently unknown)

  • Toxin similar to cholera toxin

  • Heat-labile toxin (LT, increases

  intracellular levels of CAMP)

  • Toxin with cytotonic and

  cytotoxic activity

  • Cyto-lethal distending toxin

  • Hemolysin

  • Hepatotoxin

  • Mannose resistant adhesin

  • Survival in mononuclear

  phagocytes
• Laboratory diagnosis of Campy

  Samples: Feces and intestinal scrapings,

  preputial samples and smegma and

  stomach contents

  Preferred culture media: Blood and Thiol agar

  Agent Identification

  • Microscopic examination of wet mounts

  (Tumbling motility)

  • Staining of bacterial smears in Romanovsky

  stain (curved rods) and Warthin-Starry

  (modified acid-fast stain)

  • Bacterial cultivation and isolation (Campy-CVA

  medium)

  • Amplification of campylobacter DNA through

  PCR
• Treatment with antibiotics of campy

  • Tetracyclines

  • Erythromycin

  • Tylosin

  • Quinolones

  Control and prevention

  • Adherence to hygienic measures and

  disinfection protocols
• PSEUDOMONAS

  ➢ Microbes are rarely involved

  with a primary disease

  ➢ Difficult to eliminate when they

  contaminate a compromised site

  ➢ Produce grapelike and/or

  ammoniacal odors

  ➢ Replace the normal flora after

  antibiotic therapy (resistance

  to some antibiotics
• Species associated with animal

  infections

  ➢P. mallei

  ➢P. pseudomallei

  ➢P. aeruginosa

  ➢P. maltophilia
• Morphology, staining features and cellular composition of Pseudomonas

  ➢ Gram-negative aerobes

  ➢ Capsules may be produced

  ➢ Motile (polar flagella)

  ➢ Piliated in some forms

  ➢ Form many protein exotoxins (A, S),

  elastase, bacteriocins (Pyocins),

  pigments (pyocyanins), siderophores,

  pyochelins and pyoverdin
• Growth characteristics of Pseudomonas

  ➢ Growth is hastened by blood

  agar

  ➢ Grow on all common media

  that contain glycerol and

  blood over a wide range of

  temperature (4-41C)

  ➢ ferments glucose
• Reservoir of infection

  • Soil
  • Infected water
  • Infected hosts Transmission
  • Environment
  • Endogenous exposure
  • Contaminated feeds, water and fomites
  • Ingestion of the pathogen
  • Bacterial entry through wound infections
• Glanders in horses

  Etiologic agent: P. mallei

  (Burkholderia mallei)

  ➢ Systemic pyo-granulomatous infection of horses

  ➢ Entry through the pharynx

  ➢ Penetration of the nasopharyngeal (nasal form)

  ➢ Invades the regional lymphatics and spreads to various sites

  ➢ Bacteria produce nodular lesions on the way to lymph nodes and blood stream

  ➢ Marked by thick nodules and ulcers in the mucus membranes of upper respiratory tract

  ➢ Metastatic lesion form in the lungs and skin
• Clinical signs of glanders

  ➢ Nasal discharges

  ➢ Lymphadenitis of the head and neck

  ➢ Swellings along the upper respiratory

  tract (Pulmonary form)

  ➢ Pain in muscle

  ➢ Dermal abscesses (Cutaneous/Farcy)

  ➢ Nodular induration of cranial lymph

  nodes

  3 forms of glanders

  • Pulmonary

  • Nasal

  • Skin (farcy)
• Melioidosis in humans

  (mimic disease)

  ➢ (Pseudomonas pseudomallei or

  Burkholderia pseudomallei)

  ➢ Suppurative foci or granulomas

  systemically
• Other Pathogenic Entities

  (Pseudomonas aeruginosa)

  ➢Green Wool Infection

  (Sheep)

  ➢Ear infections (Dogs and

  cats)
• Virulence factors of Pseudomonas

  ➢ Exotoxin A (inhibits protein

  synthesis)

  ➢ Extracellular slime

  (antiphagocytic action and

  facilitates penetration of

  pathogen in the tissue)

  ➢ Elastase (destroys the lung

  parenchyma, pneumonia cases)

  ➢ Bacteriocins and pigments

  ➢ Pyocyanin and siderophores
• Laboratory diagnosis of Pseudomonas

  Samples: Nodules from the nasal

  passages, lymph nodes,

  blood

  Agent Identification

  ➢ Bacterial cultivation (glycerol-enriched or

  other selective media)

  ➢ Mallein Test

  (Subcutaneous, ophthalmic and intra-

  palpebral)

  ➢ Bacteriocin typing (pyocin kills other

  strains of the same species of bacteria)

  ➢ Phage typing (spotting of known phages on

  the overlay of test strains suggestive of

  lysis patterns, kills other Pseudomonas

  except P. aeruginosa)
• Treatment of Pseudomonas

  ➢ Gentamycin

  ➢ Carbenicillin

  ➢ Tobramycin

  ➢ Ciprofloxacin

  ➢ Ticarcillin

  ➢ Cluvanilic acid

  ➢ Enrofloxacin

  ➢ Neomycin

  Prevention and control

  ➢ Early diagnosis and elimination of

  reacting animals

  ➢ Culling/ elimination of infected animals
• BORDETELLA

  ➢Coccobacillary forms of

  bacteria

  ➢Invaders of ciliated

  respiratory epithelia
• Species of associated with animal infections of Bordetella

  ➢B. bronchiseptica

  ➢B. avium

  ➢B. pertussis

  ➢B. parapertussis
• Morphology, staining features and cellular composition of Bordetella

  ➢ Gram-negative coccobacilli

  ➢ Small, blue-gray colonies on the surface

  of blood agar

  ➢ Piliated and show bipolar staining

  ➢ Pleomorphic with capsulated envelope (B.

  bronchiseptica)

  ➢ Motile by means of peritrichous flagella

  ➢ Some forms possess surface covering of

  fibrils

  ➢ Heat-labile and heat-stable K antigens
• Growth characteristics of Bordetella

  ➢ Aerobic

  ➢ Utilize citrate as source of carbon

  ➢ Derive energy from oxidation of

  amino acids

  ➢ Facultative intracellular parasite

  (living within phago-lysosomes of

  phagocytic cells (B. bronchiseptica)
• Reservoir of Infection of Bordetella

  ➢ Wild and domestic carnivores

  ➢ Nasopharynx of healthy animals

  ➢ Carrier sows

  Transmission

  ➢ Airborne

  ➢ Water
• Swine atrophic rhinitis

  (Dystrophic rhinitis, Infectious rhinitis,

  Rhinitis atrophic deformans, sniffles,

  sneezing sickness, schniffel crankheit)

  • Etiologic agent : B. bronchiseptica

  • Ciliated respiratory epithelium

  • Cilial paralysis and inflammation

  • Nasal irritation

  • Turbinates irritated by

  dermonecrotic toxin

  • Depressed respiratory clearance

  and secondary bacterial infections
• Clinical Signs of Swine atrophic rhinitis

  ➢ Sneezing and coughing

  ➢ Atrophy of the turbinate

  bones

  ➢ Distortion of nasal septum

  ➢ Shortening and twisting of

  upper jaw
• Kennel cough

  (Canine infectious tracheobronchitis

  of dogs)

  Etiologic agent : B. bronchiseptica

  • Marked by hacking cough
• Rhinotracheitis in turkeys

  Etiologic agent : B. avium

  • Marked by sinusitis and air

  sacculitis

  • Nasal exudates,

  conjunctivitis, rales and

  dyspnea
• Acute coryza in turkeys

  Etiologic agent : B. avium

  • Obstruction of ciliated

  respiratory epithelium
• Pneumonia in sheep

  Etiologic agent: B. parapertussis
• Whooping cough in man

  (B. parapertussis)
• Virulence Factors of Bordetella

  ➢ Siderophores

  ➢ Histamine-like scrutinizing factor

  ➢ Adhesins

  ➢ Oxidase

  ➢ Urease

  ➢ Catalase

  ➢ Adenylate cyclase

  ➢ Fibrillar material

  ➢ Dermonecrotic toxin

  ➢ Proteases

  ➢ Hemolysins

  ➢ Hemagglutinins

  ➢ Tracheal cytotoxins
• Laboratory diagnosis of Bordetella

  Samples: Tracheal aspirates,

  nasal swabs,tissues [taken

  after transverse section of

  the head at the level of pre-

  molar teeth]

  Agent identification

  ➢ Bacterial cultivation

  (Bordet-Gengou agar, Blood agar, Brain

  Heart infusion broth)

  ➢ Serodiagnosis
• Treatment of Bordetella

  ➢ Erythromycin

  ➢ Nitrofurantoin

  ➢ Tetracycline

  Prevention and control

  ➢Disinfection and sanitation

  ➢Fumigation of kennels

  ➢Elimination of carrier

  animals

  ➢Isolation of infected dogs