Hazard of Fungal Origin

8/8/2019 Hazard of Fungal Origin

1/5

Hazard of fungal origin

Introduction

A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as

yeasts and molds as well as the more familiar mushrooms.

Feed can become contaminated by fungiduring production, storage, processing and transportationwhen temperature and humidity conditions are suitable.fungi and their metabolites (mycotoxins) can pre-

sent a major risk and animal health. Hundreds of fungi species of more than twelve genera produce more

than three hundreds identified mycotoxins whichcan pose a threat to health of all mammalian species.Onesurvey indicated that 25 % of global agricultural commodities is contaminated with mycotoxins.

Hazard come from mycotoxin and their effects

Aflatoxins

These are group of toxins produced by certain fungi mainly Aspergillus flavus and A. parasiticus. Maize,groundnut meal and cottonseed meal are more prone to be contaminated. There are four aflatoxin viz. B1,

B2, G1, and G2.These are knlwn for liver toxicity, kidney toxicity and suppression of immunity. Theimportant sign are less feed intake, reduce body weight gain, feed utilization efficiency, listlessness,

lameness, jaundice.

Ochratoxins

The ochreatoxins are produced by fungi aspergillus alutaceus, A. ochraceus. The primary toxins under

this group are ochratoxin A and B. The ingredients maize, wheat, barley, oats and rye are generallycontaminated with these toxins producing fungi. The sign are dehydration, emaciation, dry gizzard,

bleeding in mucosa of proventriculus and catarrhal enteritis in young chicks.It causes polyuria,depression, decreased weight gain, low specific gravity of urine and dehydration but it is rapidly degraded

inthe rumen and thus thought to be of little consequencefor ruminants.

Zearalenone(F-2 toxin)

It produce by fungi Fusarium moniliformin, F. oxysporium, F. roseum and F. tricutum. It is the natural

contaminat of maize and other cereals. This toxin have estrogenic properties.It is associated with

abortion in cattle, vaginitis, vaginal secretion, poor reproductive performance and mammary glandenlargement.

Citrinin

It is found in wheat, barley, and oats and it causes kidney damage. The important sign of citrinin toxicity

is dramatic increase in consumption and excretion of water.

Terichothecenes( T-2 toxin)

Terichothecenes are produced by the fungus Fusarium tricincutum. Four types of trichothecenes havebeen detected so far as natural contaminants are deoxynivalinol-DON, diacetoxy scirpenol, nivalinol and

T-2. These are immunosuppressive.These are associated with reduced feed consumption, decreased milk


2/5

production, absence of estrous cycle, production losses, gastroenteritis, intestinal haemorrhages and

necrosis.

Fumonosins

Fumonisin B1 is the most prevalent member of a family of toxins produced by Fusarium verticillioides

as well as by Fusarium proliferratum. Fumonosin B1 is the most prevalent in nature and occurs in maizeand maize based products. It iscarcinogenic and causes liver damage, lower milkproduction and reducedfeed consumption in dairycattle. Dairy cattle may be more sensitive to fumonosins than beef cattle due togreater production stress.

Ergot alkaloids, including fescue toxicity

One of the earliest recognized mycotoxicoses is ergotism caused by a group of ergot alkaloids. They are

produce by several pecies ofClaviceps, Ergotism primarilycausesa gangrenous or nervous condition in animals.Symptoms are directly related to dietary concentrations and include reduced weight, lameness, lower milk production, agalactia and immune suppression.

PR toxin

PR toxin is one of the several toxin produce by Penicillium molds. PR toxin caused acute toxicity in cats

by increasing capillary permeability resulting in direct damage to the lungs, heart, liver and kidneys.

Patulin

Patulin is produced by Penicillium, Aspergillus and Byssochlamys. Patulin is most likely to occur inmoldy fruits but also found in grain especially wet graiand silage. Patulin reduce VFA production, fiberdigestion.

Mycotoxins and their effects on buffaloes and cows

Mycotoxin Effect

Aflatoxin, trichothecene Immune suppression

Aflatoxin, fumonosin Hepatotoxicity

Aflatoxin, fumonosin Carcinogenicity

Ochratoxin Nephrotoxicity

Trichothecene Neurotoxicity

Aflatoxin,trichothecene, zearalenone Decreased performance


3/5

Trichothecene Hematopoiticity

Trichothecene Dermal effects

Aflatoxin, zearalenone Teratogenic effects

Aflatoxin, trichothecene Gastrointestinal effects

Facial eczema

This disease is produce by fungus Pithomyces chartarum produces a hepatotoxic agent, sporidesmin. The

fungus is commonly associated with ryegrass pastures. The clinical sign include lethargy, anorexia,jaundice and photosensitive dermatitis. Affected cows lick area of mild chronic irritation.

Epizootic lymphangitis

Epizootic lymphangitis is a contagious, chronic disease of horses, mules and donkeys.The causativeagent, Histoplasma capsulatum var. farciminosum, is a thermally dimorphic fungus. The disease ischaracterised clinically by a suppurative, ulcerating, and spreading pyogranulomatous, multifocal

dermatitis andlymphangitis. It is seen most commonly in the extremities, chest wall and the neck, but itcan also be present asan ulcerating conjunctivitis of the palpebral conjunctiva, or rarely as a multifocal

pneumonia.

Mycotic Abortion

Abortions are typically sporadic, and occur from 4 months to term. The incidence, in cold climates, ishighest in the winter months. Severe infection of the placenta, characterized by a leathery thickening of

the areas in between the cotyledons, is a common finding.Inabout 25% of the cases the fungus invades the

fetus and red or white ring-wormlike lesions can be seen in thefetal skin.Leathery, thickened placental tissue isobserved in both Brucella andCampylobacter abortion, but inneithercase is the thickening as severe as withmycotic infection.

Dermatophytosis

Dermatophytosis (ringworm) is a common cosmopolitan disease. It is most commonly caused byTrichophyton verrucosum,and less frequently by T.mentagrophytes, T. equinum,Microsporumgypseum, M. canis, and M. nanum. In temperate climates the disease is most common in fall and winter,

especially in confined animals. There are no apparent breed or sex predilections, and young

animals (less than one year old) are most commonly affected.Lesions can occur anywhere, but are most common on the face,head, pinnae, neck, rump, tail, and

perineum.Bovine dermatophytosis is a zoonosis.

Aspergillosis


4/5

Fungal placentitis results in skin lesions on aborted fetuses; lesions can be widespread or localized;

annular,grayish, felt-like plaques; or yellow-white, dry plaques; especially Aspergillus fumigatus; cultureand dermatohistopathology.

Pythiosis

Rare; South America and southeastern United States; prolonged exposure to water; Pythium insidiosum;nodules, ulcers, draining tracts; especially distal legs; dermatohistopathology, immunohistochemistry,culture.

Phaeohyphomycosis

Very rare and cosmopolitan; multiple ulcerated, oozing nodules over rump and thighs (Dreschlera

rostrata);multiple nodules on pinnae, tail, vulva, and thighs (D. spicifera); culture anddermatohistopathology.

Malassezia otitis externa

Common and perhaps geographically-restricted (South America); ceruminous to suppurative otitisexterna;predominantly Malassezia sympodialis in summer, and M. globosa in winter.

Malassezia Dermatitis

Malassezia dermatitis is probably an uncommon, cosmopolitandisease. Inadequate nutrition and disease-related debilitation appear to be predisposing factors.There are no apparent breed, sex, or age

predilections.Lesions begin multifocally over the back and trunk, becomefairly generalized and tend tospare the head and legs.

Cryptococcosis

Cryptococcosis is infection caused by the fungus Cryptococcus neoformans, Very rare; solitaryerythematous nodule on nostril; solitary ulcerated plaque on top of head.

Referance


5/5

a) N. Sultana and N. Q. Hanif,Mycotoxin Contamination In Cattle Feed And Feed Ingredients,Pakistan Vet. J., 2009, 29(4): 211-213Romer Labs, Rawalpindi, Pakistan,

b) B. Kobbe,Mold toxins:Hazard to animal and human health,california agriculture, novemberdecember 1979

c) A.J. Feuell,Toxic Factors of Mould Origin,Canad. Med. Ass. J. Mar. 19, 1966, vol. 94d) M. Basalan, S.E. Hismiogullari, A.A. hismiogullari and A. Filazi,Fungi and aflatoxin B1 in horse

and dog feeds in Western Turkey,Revue Md. Vt., 2004, 156, 5, 248-252

e) A.B.Mandal,A.S.Yadav,Nutrition and disease management of poultry,first edition 2004,international book distributing Co, page137-145

f) D.W. Scott Color atlas of fram animal dermatology,Blackwell 2007 page 17,111,157g) R.W.Blowey.A.D.Weaver,A Colour atlas of disease and disorder of cattle page 214

Hazard of Fungal Origin

Documents

Transcript of Hazard of Fungal Origin