Module 3 (Spiral And Curved Bacteria) Flashcards
• 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.
Compylobacter
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
Species of Lawsonia associated with animal infections
L. intracellularis
• 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.
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.
Compylobacter
It has not reportedly been
grown in artificial media.
Lawsonia intercellularis
Reservoir of infection from Compylobacter
• 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 of Compylobacter
•Feco-oral route
•Artificial insemination and coitus
•Direct or indirect contact
Diseases associated with Campylobacter
- Campylobacter infection in Dogs and Cats
- Campylobacter infections in Cattle
- Campylobacter infections in Sheep and birds
- Campylobacter infections in Swine
• 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 infection in Dogs and Cats
• 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 Cattle
• Etiologic agent: C. fetus subsp. fetus
• The disease is marked by abortion in sheep
and birds
Campylobacter infections in Sheep and birds
• Etiologic agents: C. hyointestinalis and C. mucosalis
• The disease is marked by proliferative enteritis
Campylobacter infections in Swine
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 Compylobacter
SAMPLES: Feces and intestinal scrapings,
preputial samples and smegma and
stomach contents
PREFERRED CULTURE MEDIA: Blood and Thiol agar
Agent Identification for Compylobacter
• 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
for Compylobacter
• Tetracyclines
• Erythromycin
• Tylosin
• Quinolones
Control and prevention for Compylobacter
• Adherence to hygienic measures and
disinfection protocols
• Gram negative aerobes
• 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
PSEUDOMONAS
Species associated with animal
infections for Pseudomonas
➢P. mallei
➢P. pseudomallei
➢P. aeruginosa
➢P. maltophilia
➢ 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
Pseudomonas
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 (4-41C)
➢ ferments glucose
Reservoir of infection Pseudomonas
• Soil
• Infected water
• Infected hosts
Transmission of Pseudomonas
➢ Environment
➢ Endogenous exposure
➢ Contaminated feeds, water
and fomites
➢ Ingestion of the pathogen
➢ Bacterial entry through
wound infections
Diseases associated with Pseudomonas
- Glanders in horses
- Melioidosis in Humans (mimic disease
- Green Wool Infection (Sheep)
4.Ear infections (Dogs and cats)
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
Glanders in Horses