Infections of the nervous system – III

What is the pathogen of cattle and sheep that causes septicemia, Thrombotic meningoencephalitis (TME)?

Histophilus somni

What causes Glasser’s disease in pigs?

Glaesserella (Haemophilus) parasuis

Glaesserella (Haemophilus) parasuis and Histophilus somni are gram- ___

negative

Haemophilus spp. does NOT grow on

MacConkey agar

Fastidious in growth

H. parasuis and Avibacterium paragallinarum require growth factor V (NAD)

TME and Glasser’s disease occur ____ due to predisposing factors.

opportunistically

Virulence factors of H. somni

Endotoxin

Phase variation of its lipo-oligosaccharide (LOS)

Production of transferrin-binding proteins (Tbps)

Immunoglobulin-binding proteins

Diagnostic Procedures for H. somni

Either chocolate agar or blood agar inoculated with a streak of S. aureus, incubated in 5-10% CO2 at 37oC for 2 to 3 days in moist atmosphere, is used for isolation

PCR

Disease associated with H. somni in cattle

Septicemia and thrombotic meningoencephalitis

Disease associated with Glaesserella (Haemophilus) parasuis in pigs?

Glasser’s disease

Clinical signs of infections caused by H. somni in cattle

Septicemia

Thrombotic meningoencephalitis (TME)

dead, high fever, depression, blindness, lameness, & ataxia

Sudden death due to myocarditis

Arthritis

What is Thrombotic meningoencephalitis (TME) ?

Common consequence of septicemia, is encountered sporadically in young cattle recently introduced to feedlots due to infection in cattle caused by H. somni

What pathogen is commonly isolated from the enzootic calf pnemonia complex?

Histophilus somni

Diagnosis of Infection caused by H. somni in cattle

Severe neurological signs

Multiple foci of hemorrhagic necrosis,

Cattle affected by H. somni should be

isolated

Treatment of infection by H. somni in cattle?

Oxytetracycline is used for therapy

Healthy sheep may carry __ __ of H. somni in prepuce or vagina

ovine strains

What does H. somni cause in young rams?

epididymitis

What does H. somni cause in ewes?

Vulvitis, mastitis and reduced reproductive performance

What does H. somni cause in (lambs)

Meningitis

Septicemia

Glasser’s Disease manifests as

polyserositis and leptomeningitis

Who does Glasser’s Disease affect?

s pigs from weaning up to 12 weeks of age

How do piglets acquire infection of Glasser’s Disease?

by direct contact or aerosols from sows shortly after birth

Diagnosis of Glasser’s Disease

Isolation and identification of G. parasuis from joint fluid, heart blood, CSF, post-mortem tissues of a recently dead pig are confirmatory

Post-mortem findings of pigs with Glasser’s Disease includes:

polyserositis, polyarthritis and meningitis

Treatment of Glasser’s disease includes

Antimicrobial drugs as tetracycline, penicillin and potentiated sulfonamides administered early in the course of disease are effective

What is the causative agent of Cryptococcosis?

Cryptococcus neoformans, a capsulated yeast. NOT a dimorphic fungus

Cryptococcosis is most common in

cats

Reservoir for Cryptococcosis is

Soil especially associated with pigeon excreta

Clinical signs of Cryptococcosis in Cats

Hard, nodular skin swellings, most often over the bridge of the nose

Distortion of the nasal cavity as a result of bone invasion

Neurologic abnormalities

Eye disorders

Cryptococcus neoformans remain in what forms in the environment and host?

yeast form in both

What is the most primary site of infection from Cryptococcosis?

Nasal mucosa

Treatment of Cryptococcosis

Surgical intervention; cryotherapy.

Antifungals – azoles derivatives.

Diagnosis of Cryptococcosis

Clinical signs

Impression smears of exudate or granulomatous tissue

Culture