Difference between revisions of "Category:Actinomycetes"

Revision as of 12:22, 10 May 2010

Overview

Gram positive bacteria
Grow slowly on media and produce branching filaments
Opportunistic infections causing inflammatory responses and granulomatous reactions
Animal pathogens include Actinomyces, Arcanobacterium, Actinobaculum, Nocardia and Dermatophilus

Arcanobacterium, Actinomyces and Actinobaculum species

Non-motile, non-spore-forming bacteria
Anaerobic or facultative anaerobes
Grow on enriched media; non-acid fast
Colonise mucous membranes
Modified Ziehl-Neelson negative

<ncl style=compact maxdepth=2 headings=bullet headstart=2 showcats=1 showarts=1>Category:Actinomycetes</ncl> Arcanobacterium pyogenes

Actinomyces

Actinobaculum suis

Nocardia

Dermatophilus congolensis

Micropolyspora faeni and Thermactinomyces vulgaris in Bovine Farmers Lung
Thermactinomyces vulgaris may cause COPD

Subcategories

This category has the following 2 subcategories, out of 2 total.

A

► Actinomyces‎ (3 P)

N

► Nocardia species‎ (2 P)

Pages in category "Actinomycetes"

The following 5 pages are in this category, out of 5 total.

A

D

Dermatophilus congolensis

R

Renibacterium salmoninarum

@@ Line 28: / Line 28: @@
-===''Dermatophilus congolensis''===
+===''[[Dermatophilus congolensis]]''===
-*Filamentous, branching actinomycete
-*Aerobic
-*Produces motile zoospores
-*No growth on Sabouraud dextrose agar
-*Dermatophilosis most prevalent in tropical and subtropical regions
-*Organisms found in scabs and in foci in skin of carrier animals
-*Dormant zoospores become activated when moisture and temperature levels are favourable
-*Zoospores may survive 3 years in scabs
-*'''Pathogenicity''':
-**Does not usually invade healthy skin
-**Entrance after trauma or persistent wetting
-**Activated zoospores produce germ tubes which develop into filaments which invade the epidermis
-**Invasion causes an accute inflammatory response with many [[Neutrophils - WikiBlood|neutrophils]]
-**Microabscesses are formed in the skin
-**Raised crusts develop in the affected regions
-*[[Bacterial skin infections - Pathology#Dermatophilosis|'''Pathology''']]
-*'''Diagnosis''':
-**Giemsa-stained smears from scabs reveal branching filaments containing zoospores
-**Immunofluorescence
-**Scab material can be cultured on blood agar at 37 degrees centigrade, 2.5-10% carbon dioxide for 5 days
-**Zoospores can be cultured
-**After incubation, colonies are yellow and haemolytic (after 48 hours); they later become rough and yellow, and gain a mucoid appearance
-**No growth on Sabouraud dectrose agar
-*'''Clinical infections''':
-**Infection usually confined to epidermis
-**Dermatophilosis
-**Disease most prevalent in young animals
-**Damage to the skin predisposes to infection; blood-sucking insects also thought to be involved in transmission
-**Lesions after heavy rainfall predominantly affect dorsum of farm animals
-**Papules, serous, exudative matting of hair, raised crusty scabs
-**Scab formation more prominent in sheep and cattle than in horses
-**Lesions may resolve within weeks if dry weather, or may progress
-*'''Treatment''':
-**Parenteral antibiotics e.g oxytetracycline, pr penicillin-streptomycin combinations