Difference between revisions of "Systemic Mycoses"

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#REDIRECT[[:Category:Systemic Mycoses]]
 
 
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==Adiaspiromycosis==
 
 
 
*Haplomycosis
 
 
 
*''Emmonsia crescens''
 
**Does not proliferate within the animal body
 
**Each spore develops into a thick-walled spherule called an '''adiaspore'''
 
 
 
*''Chrysosporium parvum, C. crescens''
 
 
 
*Non-contageous, pulmonary mycosis
 
 
 
*Worldwide
 
 
 
*Found in soil
 
 
 
*Affects burrowing rodents and small animals
 
 
 
*Respiratory infection
 
 
 
*Spetate hyphae with large numbers of small, round conidia either singly or in groups on the ends of the short conidiospores can be seen
 
 
 
*Dimorphic
 
 
 
*Grows on Sabauraud's Dextrose agar and Blood agar
 
==Aspergillosis==
 
 
 
*''Aspergillus fumigatus'' causes [[Nasal Cavity Inflammatory - Pathology#Infectious causes of rhinitis|rhinitis]] and in [[Respiratory Fungal Infections - Pathology#|respiratory tract inflammation]], also [[Paranasal Sinuses Inflammatory - Pathology#Infectious causes of sinusitis|sinusitis]], [[Guttural Pouches Inflammatory - Pathology|guttural pouch mycosis]]
 
*Sometimes appears on [[Nasal Cavity Hyperplastic and Neoplastic - Pathology#Progressive ethmoidal haematoma|lesions of ethmoidal haematoma]]
 
 
 
*May cause [[Bronchi and Bronchioles Inflammatory - Pathology#Chronic obstructive pulmonary disease (COPD)|COPD]]
 
 
 
==Blastomycosis==
 
 
 
*North America
 
**Most common in the North-Central and South-Eastern states
 
 
 
*Caused by ''Blastomyces dermatitidis''
 
 
 
*Widespread in soil
 
 
 
*Respiratory infection
 
 
 
*Lesions start in the [[Lungs - Anatomy & Physiology|lungs]]
 
**Haematogenous dissemination
 
**Can be found in lesions in the eyes, brain, bones and genitalia
 
**Fatal if not treated
 
 
 
*Lesions are also found on the skin
 
*These may ulcerate
 
 
 
*Granulomatous nodules
 
 
 
*Affects mainly dogs (and humans)
 
**Can affect cats, horses, dolphins, ferrets and sealions but is rare in these species
 
 
 
*Microscopically:
 
**Large, spherical, thick-walled cells
 
**Single buds connected to a mother cell by a wide base
 
**Double contoured effect of cells
 
 
 
*Grows on Sabauraud's Dextrose and Blood agar
 
**On Sabauraud's Dextrose colonies appear moist and grey with a white cotton-like mycelium which turns tan, brown and then black
 
***Septate hyphae
 
***Small, oval/pyriform conidia
 
***Older cultures have thickened walls
 
**On Blood agar colonies are creamy in colour, waxy and wrinkled
 
***Thick-walled budding yeast cells can be seen
 
 
 
*Diagnosis:
 
**Complement fixation test
 
**Falling antibody titres indicate a poor prognosis
 
**ELISA and counterimmunoelectrophoresis can also be used
 
 
 
*Treatment:
 
**[[Antifungal Drugs#Polyene Antifungals|Amphotericin B]]
 
**[[Antifungal Drugs#The Azoles|Imidazoles]]
 
 
 
==Coccidioidomycosis==
 
 
 
*''Coccidioides immitis''
 
 
 
*Ocurs in the soil
 
**Respiratory infections
 
**Most commonly seen following dust storms
 
 
 
*Occurs in arid regions
 
**E.g. South West USA and Mexico
 
 
 
*Non-contageous, systemic mycosis
 
 
 
*Affects dogs, cattle, sheep and humans
 
 
 
*Mainly affects the [[Lungs - Anatomy & Physiology|lungs]]
 
**Dissemination can occur to other organs
 
 
 
*Causes nodule or granuloma formation
 
**Localised
 
**Gross lesions resemble [[Mycobacteria spp.#Bovine tuberculosis|Tb]] in cattle as are usually seen in the bronchial and mediastinal [[Lymph Nodes - Anatomy & Physiology|lymph nodes]] and occasionally [[Lungs - Anatomy & Physiology|lungs]]
 
**Dissemination can occur, especially in primates and dogs, to the [[Lungs - Anatomy & Physiology|lungs]], [[Liver - Anatomy & Physiology|liver]], [[Spleen - Anatomy & Physiology|spleen]], [[Nervous System - CNS - Anatomy & Physiology|brain]] and [[Bones and Cartilage - Anatomy & Physiology|bones]]
 
 
 
*Thick-walled spherules in tissue
 
**Large sporangia burst leaving 'ghost' spherules
 
 
 
*Saprophytic phase consists of coarse, septate, branching hyphae which fragment into thick-walled, barrel-shaped arthrospores which alternate with empty cells
 
**Stained by Lactose Phenol Cotton Blue
 
 
 
*Grows on Sabouraud's Dextrose agar and Blood agar
 
**Flat, moist colonies which develop a coarse, cotton-like aerial mycelium which varies from white to brown in colour
 
 
 
*Complement fixation test, latex agglutination and immunodiffusion tests can all be used
 
**A positive skin test indicates exposure
 
 
 
==Entomophthoromycisus==
 
 
 
*Basidiobolmycosis
 
 
 
*Caused by ''Basidiobolus'' and ''Conidiobulus'' fungi
 
 
 
*Causes ulcerative granulomas in subcutaneous tissue
 
 
 
*Affects the oral and nasal mucous membranes
 
 
 
*''Basidiobolus'' causes large lesions which may involve skin on the head, neck and chest
 
**Fistulous tracts
 
**Extends to [[Lymph Nodes - Anatomy & Physiology|lymph nodes]]
 
 
 
*Produce flat, waxy colonies which become white and fizzy over time
 
 
 
*Microscopically:
 
**Septate hyphae
 
 
 
*Treatment:
 
**Surgical excision
 
**[[Antifungal Drugs#Polyene Antifungals|Amphotericin B]] or [[Antifungal Drugs#The Azoles|Ketoconazole]]
 
 
 
==Histoplasmosis==
 
 
 
*''Histoplasma capsulatum''
 
 
 
*Non-contageous, systemic mycosis
 
 
 
*Commonly pulmonary infections occur
 
**Other organs can be involved
 
**Involves the reticuloendothelial system
 
**Intestinal form can also occur
 
 
 
*Acute and chronic disease can occur
 
 
 
*Endemic to the USA
 
**Isolated cases have been reported in Europe
 
 
 
*Respiratory infection
 
**Infection via ingestion can also occur
 
 
 
*Affects dogs, cats, cattle, horses and humans
 
 
 
*Found in soil contaminated by bird droppings, decaying vegetation and in caves inhabited by bats
 
 
 
*Fine, branching, septate hyphae with smooth-walled pyriform to spherical microconidia and large, thick-walled tuberculate macroconidia on simple conidiophores
 
 
 
*Dimorphic fungi
 
 
 
*Hard to demonstrate in smears as the organisms is very small
 
**Stain with Giemsa or Wright and examine under oil immersion lens
 
 
 
*Present intracellularly in [[Macrophages - WikiBlood|macrophages]] as oval yeast cells with few buds
 
**Clear halo is seen around the darker staining central material
 
 
 
*Grows on Sabouraud's Dextrose agar
 
**Creamy white colonies, turning tan coloured and then brown
 
 
 
*Also grows on Blood agar
 
**Small, white yeast-like colonies
 
 
 
*Test using immunodiffusion, complement fixation and counterimmunoelectrophoresis
 
**Skin test of little value as it only indicates exposure
 
 
 
*Treatment with [[Antifungal Drugs#Polyene Antifungals|Amphotericin B]]
 
**If [[Antifungal Drugs#Polyene Antifungals|Amphotericin B]] is contra-indicated, [[Antifungal Drugs#Imidazoles|imidazoles]] can be given orally
 
 
 
*The prognosis is poor in acute and disseminated cases
 
 
 
==Zygomycosis==
 
 
 
*Also known as mucormycosis, hyphomycosis and phycomycosis
 
 
 
*Caused by strains of ''Mucor, Absidia, Rhizopus'' and ''Mortierella''
 
**''Mucor circinelloides''(rare), ''Rhizomucor pusillus'' and ''R. meihi''
 
**''Absidia corymbifera'' often causes zygomycosis in cattle and pigs
 
**''Rhizopus arrhizus, R. microsporus'' and ''R. rhizopodormis''
 
**''Mortierella wolfi'' implicated in bovine abortion (mycotic placentitis), ''M. hygrophila'' in fowl and ''M.polycephala'' in cattle
 
 
 
*Occurs widely in nature
 
 
 
*Infection is by inhalation and ingestion
 
 
 
*Infects [[Lymph Nodes - Anatomy & Physiology|lymph nodes]] of the [[Cardiorespiratory System - Anatomy & Physiology|respiratory]] and [[Alimentary - Anatomy & Physiology|alimentary tract]]
 
**[[Lymph Nodes - Anatomy & Physiology|Lymph nodes]] enlarge and become caseous
 
**Can cause [[Alimentary - Anatomy & Physiology#Stomach|stomach]] and [[Small Intestine - Anatomy & Physiology|intestinal]] ulcers
 
 
 
*Granulomatous lesions which can ulcerate
 
 
 
*Mostly localised lesions but can be generalised
 
 
 
*Pigs
 
**Mediastinal and submandibular [[Lymph Nodes - Anatomy & Physiology|lymph nodes]] lesions
 
**Embolic tumours in the [[Liver - Anatomy & Physiology|liver]] and [[Lungs - Anatomy & Physiology|lungs]]
 
**Can also be present in gastric ulcers
 
 
 
*Cattle
 
**Bronchial, mesenteric and mediastinal [[Lymph Nodes - Anatomy & Physiology|lymph nodes]] lesions
 
**Ulcers of the [[Nasal cavity - Anatomy & Physiology|nasal cavity]] and [[The Abomasum - Anatomy & Physiology|abomasum]] also occur
 
**Often contaminate the [[Gestation -Placenta - Anatomy & Physiology|placenta]]
 
 
 
*Horses, dogs, cats, sheep, mink, guinea-pigs and mice can also be infected
 
 
 
*Microscopically:
 
**Fragments of non-septate hyphae which are branched and coarse
 
**''Rhizomucor'' produce a thick, grey mycelium and have short, black, spherical sporangia
 
**''Mucor'' produce thick, colourless mycelium with no rhizoids. Globose spoangia with small spores are present and sporagiospores are simple or branched.
 
**''Absidia'' resemble ''Rhizopus'' grossly
 
**''Mortierella'' produce white, velvet colonies on Sabouraud's Dextrose and Blood agar
 
 
 
*Grows on Sabauraud's Dextrose agar
 
**Common contaminants
 
 
 
*Treatment is with [[Antifungal Drugs#Polyene Antifungals|Amphotericin B]]
 
**Surgery is also an option in treatment
 
 
 
==Further Links==
 
 
 
*[[Antifungal Drugs]]
 

Latest revision as of 13:47, 29 April 2010