Gram + rods listeria, erysipelothrix Flashcards
Whats a good way to get yourself infected with listeria?
unpasteurized foods and lunch meat.
Crosses placenta!
What are some details about listeria?
Small, Gram + facultative anaerobic rods
What temperature range does listeria grow in?
4-44oC
Where in animals is listeria usually found?
GI Tract
How thriving is Listeria?
it is resistant to harsh environmental conditions, Ubiquitous in the environment, especially temperate zones.
how common is listeria?
it is a sporadic disease in a variety of animals including man
What does monocytogenes mean?
Can survive in macrophages
What is the most frequent Listeria species?
Listeria monocytogenes- associated with all forms of disease in multiple hosts including humans
occasionally this species of listeria is seen associated with ruminant abortion?
Listeria ivanovii
Listeria species rarely seen that is reported from CNS in ruminants?
listeria innocua
what time of year does this disease mainly affect?
Winter spring of feedlots or housed ruminants
Outbreaks of listeria usually happen when?
after feeding poor-quality silage.
Why is this disease important?
MONEY always money with seasonal occurance (winter months)
how is Listeria taken up by a host?
Ingestion or inhalation> septicemia, abortion, and latent infection.
where does listeria affect animals when absorbed through buccal cavity?
Trigeminal nerver and then brain stem
What is a poultry infection of listeria called?
septicemic listeriosis
What is the pathogenesis of Listeria?
Invasive ( direct invasion of epithelial cells) enters blood steram
Facultative intracellular bacteria: persit in macrophages
Intracellular growth leads to cell death and focal microabscesses.
How does the disease present?
Encephalitis- most common presentation in ruminants. bacteria invade oral mucosa and travel along trigeminal nerve to brainstem.
Abortion- hematogenous spread to gravid uterus, organisms penetrate the placenta and spread to fetal liver resulting in focal hepatic necrosis.
Speticemia; common in monogastrics, intracellular replication in macrophages, multifocal miliary abscess in spleen. liver. mainly occurs in neonates as a continuation of the fetal infection
What are the virulence factors of listeria?
Internalin ( gain entry to macrophages). listeriolysin O (hemolysin): required for intracellular multiplication facilitate bacterial release from phagosomes Act A: Intracellular movement (one cell to another)
L. monocytogenes uses what to travel between cells and evade antibodes?
Host actin filaments
What diseases are associated with Listeria?
Neurologic symptoms: dullness, turning or twisting of head to one side, walking in circles (circling disease)
Unilateral facial nerve paralysis with drooping of eylid and ear, drooling to pharyngeal paralyis, strabismus, nystagmus, hemiparesis, head pressing, decreased rumen motility.
Purulent endophthalmitis, usually unilateral
What lesions are associated with listeria?
Microabscesses and glial nodules infiltrated by neutrophils and gitter cells that may contain bacteria.
Acute vascular fibrinoid necrosis secondary to drainage into virchow-robin space
Leptomeningitis and densly cellular perivascular cuffs composed of lymphocytes and histiocytes with fewer neutrophils and eosinophils
neuronal necrosis
Crainial nerves may have intrafasicular and perineural accumulations of inflammatory cells (Lymphocytes, macrophages, plasma cells, and neutrophils)
what are the DDx of listeria?
pregnancy toxemia in ewes ketosis in cattle BSE thrombotic meningoencephalitis polioencephalomalacia-(thymine difficiency) sporadic bovine encephalomyelitis lead poisoning Rabies Parasitic infections Vestibular disease
How does the clinician diagnose listeria ante-mortem?
CNS disease Presumptive Dx from symptoms Listeria enrichment culture Gram stained CSF sediment short intracellular and extracellular Gram + bacteria Septicemia culture of liver and spleen
how does the clinician diagnose listeria Post mortem?
No Gross lesions, Histopathology, culture of brainstem
immunohistochemical staining
how do you treat listeria?
Penicillin (drug of choice)
ceftiofur, erythromycin, TMPS
High doses required because of difficulty achieving minimum bactericidal concentrations in the brain
Listeria and zoonosis and theres a lot
mild flu like symptoms, febrile gastroenteritis to meningitis and or meningoencephalitis
occurs in pregnant women, neonates, the elderly and immunocompromised individuals. healthy individuals may also be affected
meningitis, frequently accompanied by septicemia
fetal infection and abortion, stillbirth, or delivery of an acutely ill infant.
Listeria disease outcome depends on?
number of organisms exposed to
route of exposure
virulence of strain
immune status of host
Are there vaccines for listeria?
Nope, cell-mediated immunity important
How does one protect themselves from listeria disease?
avoid high risk foods
- poor quality silage, ph>5.5
- unpasteurized dairy products
- processed meats
- undercooked vegetables
Minimize aerosol exposure in areas where microbe is present
precautions for pregnant and immunocompromised animals
What are the details of Erysipelothrix?
Small, non-sporeforming gram+ rods
What is the common species of Erysipelothrix?
E. rheusiopathiae- most common in pigs and birds but also seen in many other species including humans (serotypes 1a, 1b and 2 common in pigs)
what erysipelothrix species is avirulent in pigs but virulent in dogs?
E. tonsillarum
Swine bacterial infection and navle!!!
Erysipelothrix
facultative anaerobe bacillus
swine are most important reservoir
what percentage of swine harbor erysipelothrix?
30-50% in tonsils or other lymphoid tissue.
What age of swine are most susceptible to erysipelothrix?
3 months to 1 year of age and pregnant sows.
disease manifestations of erysipelotrhix include?
septicemia, polyarthritis, and endocarditis
What is the transmission and virulence factors of erysipelothrix?
primarily oral, infection of palatine tonsil or GALT
Can enter through skin abrasion
Neuraminidase= adherence to endothelial cells
Heat labile capsule= resists phagocytosis by neutrophils
what is the sign of all signs on pigs with erysipelothrix infection?
rhomboid shaped patches on the skin
What acute diseases does erysipelothrix cause?
septicemia, common (pigs, birds other)
Abortion, rare (pigs)
cutaneous cellulitis/ utricaria, occasional (pigs birds man)
what subacute diseases does erysipelothrix cause?
vegetative (valvular) endocarditis, occasional ( pigs, birds, humans, others) Idk what others is?
What chronic disease does erysipelothrix cause?
arthritis, common (pigs, birds)
what is the DDx for erysipelothrix?
salmonella choleraesuis
classical swine fever virus (porcine pestivirus)
Dermatitis and nephropathy syndrome of pigs (cutaneous and systemic necrotizing vasculitits)
Erysipelothrix in lambs/ sheep?
fivrinopurulent polyarthritis and osteomyelitis; cutaneous lesions occasionally, usually happens without history of contact wit swine
erysipelothrix in turkeys
with acute disease- septicemia, cyanotic combs, hemorrhage (breast and leg muscles), splenomegaly; with chronic disease- polyarthritis and endocarditis. Adult toms most commonly affected
Marine mammals and erysipelothrix
acute septicemia or similar skin lesion to SE
Calves and erysipelothrix
poly arthritis
humans and erysipelothrix
erysipeloid. usually a localized skin lesion but may rarely be systemic
what causes human erysipelas?
Group A beta-hemolytic streptococci
which type of morphology is usually the virulent type?
Short rod form
smooth colony type
How is erysipelothrix diagnosed?
culture
what is the treatment of erysipelothrix?
Penicillin tetracycline
how do you control erysipelothrix?
treat and isolate infected animals
cull chronically affected animals
good hygiene practices
Vaccination of erysipelothrix?
Pigs and turkeys
(live attenuated + Bacterin (killed preparation of bacteria used for vaccination))
surface proteins
