micro sheet # 2 - Amira Almahasneh

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micro sheet # 2 - Amira Almahasneh

Post by Shadi Jarrar on 19/2/2011, 8:14 pm

بسم الله الرحمن الرحيم


micro .doc



*We must understand the basic structure of the fungi, as we said its divided into major group , one group is called filamentous fungi ,in relation to the presence of filaments and in association of spores which considered as the root of this filaments!

*To give u example about the type of filamentous fungi as we see in the slides its orange, we can see a type of filamentous fungi called Aspergillous flaves.

*Aspergillus flavus in relation to the color, we have a species of these Aspirgillous flavus which produce a highly toxic material which is called flava toxin and this can be associated with foods which contain high amount of nutrients .

*We have many species of aspirgillous ,some of these aspirgillous are widely distributed in nature and often contaminate our food or skin etc… most type of aspirgillous are non- toxogenic but we have at least one known type called 'aspirgillous flavas' and some of these strains or subtypes produce a very toxic material known as afflatoxin in relation to flavaous and afflatoxin usually once reach intestinal tract it will be absorbed and later reach our liver.
within our liver they produce their toxic effect in form of cirrhosis, but the very intensive form which might resulted in amount of afflatoxins result in sever cirrhosis and death in a period of time of one weak or more, that depend on amount of toxin absorbed.
- This type of aspirgillous flavous which not toxogenic and found in fruits.
other type in relation to penuts, rice, milk…etc, so, therefore in our country, they look always to investigate all imported food especially milk products, powder milk, penuts …etc, all may have afflatoxin.
Because if there is few amount of aspirgillous flavous that produce afflatoxin!, it shouldn't be allowed to be consumed by population.
- If we take few amount from the surface and place it in special medium, and allow it to grow as we see in the plate that we will have within 48 hrs, the presence of such type of growth, spread over the surface.
if we take one single colony "small colony" and look for the presence of morphological structure of this colony, you will find the following :-
1- you will see a large number of spores in colonies, and this is for as we see distributed over the vesicle "the head" of the filaments or hyphea, as we see, vertical hyphea.
we use certain terms, in relation to these filamentous fungi , we have spores , these spores called "microconidia" in relation that these spores are small ,
If the spores large , called macroconidia

2- second important feature that you have seen on the surface of cultured medium ,which projected over the surface of the medium called
Aeral Mycelium → means the spores and filaments are projected over the surface of the medium.
-whereas , the second type of filaments which are responsible of absorption of nutrients and you cant see during presence of food articles ,called (vegetative mycelium).
vegetative mycelium its from vegetation and it means the filaments are responsible for absorption of nutrients and water and which support later production of spores.

Another picture here , we have special type of fungi which might found in our skin and it might develop to skin infection which is called dermatophytosis by certain dermatophytes ,a type of fungi which grow slowly and which can be associated with Aeral Mycelium, vegetative mycelium , but on the other hand might be associated with a special type of small dispersed spores which considered as microconidia .

also, we see in other form of candid called macroconidia → large structure , and these structure if you look exactly , in each of these structures ,there is a comportment (أجزاء )and according in number of compartment , y3ni , how much it has deputation within these of each macroconidia , for example we have 4,6,8,12...etc , such type of fungi which associated with these microconidia related to certain dermatophytes , which produce skin infection or hair or nail infection.

So that we should study these slides in order to understand that in relation to mycology, we depend on pathology in order to identify these types of fungi .
Firstly we look for the growth pattern of fungi , and how these fungi grow in the verto ( in lab ) if this fungi begin to grow as unicellular cells , as we call it (yeast ).
other produce psuedohyphea (not exactly true hyphea.
second the temperature of growth,
Does it grow at cold temperature or in range between
(00-250) or prefer to grow at a high temp. or at body temp. 370 or more ….etc .
In general , most type of fungi cause pathogenesis, which affects our hair can grow at wide range of temperature in range between (00-370).
there are certain fungi that grow only at high temperature ( but generally those affect our body , grow at wide range of temperature so it can survive in nature and we are always susceptible to be infected with one or other fungi ).
Second we relay on the :
-type of spores, is it microconidia or macrocanidia.
-the color of conidia.
-arrangement of conidia.
-arrangement of filament , is it septated or non-septateal & all these together can help us in the diagnosis of most type of fungi.
Note :
For the bread , we must use backer yeast with dough , in fact its not pathogenic & its useful &its called Saccharomyces cerevisiae
, and it ferments sugar which present in the dough , and the end product is production of (CO2) as a gas and this allow maturation of the bread.
this (Saccharomyces cerevisiae),these cant produce psuedohyphea , and any filaments which associated with inflammation reaction , in the mucosa of our body …etc .
only its useful for production of very important kinds of vitamins,protiens , and can be used in genetic engendering to manipulate yeast chromosomes and production of variety of products.
Also, they have used Saccharomyces cerevisiae for production of certain drugs and vacancies , interferon …etc.
in relation to cell wall, the cell wall of most fungi either yeast or filamentous fungi, is the same, no big difference, we have 3 important chemical compounds which considered as main component of the cell structure which called chitin which is long chain of polymers of N-acytl glycosomine, has part of the chemical compound in bacterial cell wall, because the bacterial cell wall composed of N-acytl glycosomine and N-acytl glucomic acid, and we have another two important sugars known as plant sugar (mannan and glucan
- fungi cell wall structure also have specific proteins, this is can also explain why it's not easily to produce specific antibodies against cell wall of fungi.
- Immunological reaction, our human body produce very similar antibody similar to all type of what we call fungi wall, so it can't be(the presence of (*) of anti antibody) used to recognize the infection of one or other type of fungi.
- but bacteria always have different specific antigen, some is somatic antigen, H-antigen , K-antigen…etc, and these usually (inserted!) a different type of Antibody which can be used to recognize presence of infection due to salmonella, prucella or other infection.

But In relation to fungi, its not easily, they have similar type of antigen, but they have recently discovered in relation to candid, there is certain types of sugars which might be important in recognition of infection related to candidiasis bcoz candidiasis is very important and common positive agents in clinical medicine especially in (*), as we will see a lot of oral candidiasis and they usually should be treated and investigated to know exactly why this patients develop more than one type of (*).

Another last hints about general morphological structure of fungi in relation to yeast, we have already mentioned that yeast multiply by asexual means, by budding, and there are kind of yeast which may reproduce by sexual means, which is positive and negative interaction.

Dermatitis means : presence of fungal infection.
Clinically when we use the term mycosis ,that mean patient suffer from a type of fungal infection whether filamentous or non-filamentous (yeast), and this should be considered in relation to the part of the body because mycosis is divided into :
1-superficial mycosis which affect superficial parts of our skin.
2- coetaneous mycosis, and that means any infection related first to skin, second to hair and nails.

So the presence of any infection of these parts of our body means we have persons suffer from superficial mycosis.
This superficial mycosis divided according to type of causative agent of the fungi.
Within filamentous fungi ,we have special group called dermatophytes.
Dermis of our skin, but it includes presence of any part of body when we have keratin in our body, and dermaophytes can be also in relation to disease, called " dermatophtosis.
Dermatophtosis originates from dermatophytes and they are filamentous fungi. These dermatophytes is widely found as spores in the environment and small segments of filaments and it can survive in association with dust, in soil, on surface of flower..etc.
It survive for long time so its not easily to be killed.
These spores once reach our skin it might lodge , fixed on the surface in epidermis layer,,,if our body doesn't respond to the presence of these spores , y3ni can't eliminate these spores, and It might results in developing of infection.

Dermatophytosis is widely recognized in all ages weather young or old. It affect any superficial layer of our body.
The outer layer cause of dermatophtosis is still not well recognized, for example , why there is some people susceptible to develop skin dermatophytosis where other not, even between the members of the same family.
But generally according to new research , there are certain underlying causes that allow dermatophytosis to develop infection. In general they have recognized dermatophytosis in association with stress condition ,in some cases there will be increase in some hormones ,these factors contribute to develop dermatophytosis in any part of our body .
Second, it might to be related to lack of certain vitamins in body or disposing to certain chemicals ,sun light, so there are a lot of factors contribute for developing of skin infection ,due to these dermatophytes.
We have most common causative agent of dermatophtosis , 3 genera each of these composed of many species:
1- Dermatophytes.
2- Microsporium
3- Epidermophyton species.
These 3 majors causative agents associated with infection in skin or hair or nail.
Each of these types of fungi can be isolated and classified in lab require certain experience to know exactly the species but its not so difficult.
Lets begin with the first part of body which is skin to consider the infection related to this form of mycosis.

Tinea corpus ,corpus mean body, it affect many parts of the body weather face , legs hands…etc.

Here, we have 2 major causative agents, one related to yeast and the second related to dermatophytes.
The one related to yeast called tinea versicolor, and versicolor indicate the change in color of skin produce infection in our skin especially face and neck ,hands are most common ,also there will be circled dark spots, so that the most causative agent of these spots due to (warts!), as they have use (*) in their (*) in order to identify presence of skin infection, but later they discovered there is no (warts!), the causative agent isn’t related to type of yeast or type of filamentous fungi.

Sometimes this according to the type ,it might produce change in color ,allergic reaction ,this can be easily recognized and often this is not a serious form of dermatophytes or skin infection and require no treatment and this is recognized in relation to persons who are under stress condition, many cases related to (*),the majority recognize presence of tienea versicolor caused by a special yeast called Pityriasis versicolor which considered yeast form found normally in our skin but no body know why this person develop this form of infection and others not.
Generally, the mild form of infection require no treatment , maybe its type of yeast called (lipophilic!) yeast and often can disappear within 2-3 weeks without using any type of treatment.
The Mild form of under certain condition might come chronic form, here we need treatment with certain antifungal ,but many dermatologist they prefer not to give special antifungal ,they give supportive treatment to relieve allergic reaction related to complication which might be associated with presence of lipophilic (*) or causative agent but bcoz of the diseases of other types of bacteria where found in our hair follicles and our skin, so it will add secondary inflammatory reaction if the inflammation not related to this yeast, but related bacteria which considered part of skin flora ,which responsible for inflammation and in such a case we might use anti bacterial drug in addition to (*)drug, which relieve you from feature of allergy or hypersensitivity to the presence of yeast.

Note : always dermatophytosis or fungal infection of skin, begin in change of color of skin in form of spots and this can only be one spot or many, if you manipulate this spot with your finger ( y3ni bet7ekha) it might resulted in inflammation reaction in epidermis and produce redness ,might associated with inflammation but the agent of this inflammation isn’t due to presence of filaments or yeast but due to presence of bacteria which cooperate of this type of fungi and develop this type of reaction.

soOo keep in mind always any change in color of skin might be mild and require no treatment, only relaxation, and later will disappear and its very low among our ages and children.

Discoloration of skin might be enhanced by presence of certain factors especially in relation to exposing to sunlight or uv-light and chemical or using of certain detergent ..etc, it might produce more intensive reaction.
In general, these are harmless skin infection but sometimes this skin infection might be more aggressive form of dermatophytes and might produce chronic infection, depend on causative agent and this tenia versicolor which caused by yeast (Malassezia furfur
)cant be cultured ,infact we can identify yeast only if we take a specimen from the surface of skin and lack from presence of yeast.
Culture is very difficult and not easily can be done.
Another form of infection recognized in children especially from( 3-13) years of age ,in infection of hair with Tinea capitis.
When infection begin in the hair follicles by presence of spores from any type of dermatophtes which is Trichophyton or Microsporium and less Epidermophyton bcoz its more related to skin not to the hair.

If these spores of Trichophyton or Microsporium easily can be acquired from the dust or by contact with person who carry this organism it can produce infection if person not well clean, especially hair , bcoz during growth of hair there will be a secretion of heavy material, this material support growth of certain microspores or these spores of dermatophtes and allow spores to lodge in the hair follicle and there begin to grow and first produce sticky materials and if infected person doesn't continue to wash his hair without shampoo.

he will later begin to produce inflammatory reaction in the hair follicle and damage it and this damage can be permanent if not treated, bcoz sever damage due to presence of this type of dermatophytes in hair follicle in association of bacteria which found in the hair follicle, theretofore mostly children they are highly susceptible than adult, bcoz they have less certain hormone up to the age of 13 years which later after puberty they begin to produce sufficient amount of hormone and these hormones suppress the growth of these types of dermatophytes so rarely to recognize hair infection of tinea capitus in adults and if its present in adults its unusual and it should be investigated.
Now, within the hair tufts (5oslat elsha3ar) you might recognize an infection inside and outside the hair!
Y3ni, within each hair tufts u might recognize the presence of spores within the hair inside or outside , and in this relation we use special terms ,if the hair infected only within the hair inside hair tufts(5oslat elsha3ar) we call it endothrix ,this words means presence of spores inside them.
(hada 7akki el dr.!)
Whereas, if its outside and associated with sticky materials, we called it exothrix and its more sever and often can result in sever inflammatory reaction in the scalp and should be treated with anti fungal drugs and this is present in our country for example we have sometimes tinea capitus in schools where one student infected can infect the other students by spores.
Tinea unguium infection of nails ,fingrs, often infection begin at the tip of he nail and among females who work with hot water, washing clothes, detergents…etc, the nails start to produce crafts (tasha8o8at)..and this allow certain types of fungi to penetrate and begin to grow within nails.
for the leg nails there will be dissemination to the base of nails and might be associated with bacterial infection so we can recognize presence of 2 infection ,one related to the dermatophytes and the second related to bacteria .
the nail become fragile ,and when u try to cut them, it will not be sharp but it will produce small segments ,and the nails will be thick and discolored.
The thickness indicate infection even if there is no discoloration, but often there will be discoloration and that depend on type of fungi, it could be brownish, yellowish, black..etc.
Treatment of nails infected by fungi isn't easy, often require treatment for 3-6 months or the nail must be removed by surgical means, its not easily removed by topical means or antifungal.
Fungal nail is very common in certain type of working, such those who works with chemicals or with agriculture..
Also in certain immune deficiency, some persons who suffer from immune defect , they recognize this form of infection.
If we want to recognize the patterns of infection in relation to skin or to nails..etc , we have to take sample from the surface of skin and by using 10% of (KOH) in order to release presence of filaments and spores, and then by culturing them...and we can identify the presence of filaments by using special stains so it can be done easily.
So culturing is easy and we can isolate from skin , hair ,nail..etc, or special media, Here to give an example ,
If we have contaminant ( penicilinium) which might be on the surface of our skin, it grow within (24-72)hours and on special culture media, if we have a dermatophyte , usually we have to wait at least 4 weeks to recognize the presence of Aeral Mycelium, vegetative mycelium, and often there is special colors in association with macrocnidia, as well as there is release of (*), which contribute to identification of causative agent of dermatophytes, this is a type of dermatophytes which affect hair, nails skin in our country.

((I wanna say that I wrote every single word the dr. said, so im sorry if some paragraphs seem to be not very clear, and sorry 4 some missing words written like this (*) that I cant hear bcoz they r not clearrr at allll!,, and forgive me for being late !))

Done By : Amira Almahasneh.
Date of lect. : 9-2-2011..MONday

Last edited by Shadi Jarrar on 20/2/2011, 1:15 am; edited 1 time in total
Shadi Jarrar
مشرف عام

عدد المساهمات : 997
النشاط : 12
تاريخ التسجيل : 2009-08-28
العمر : 27
الموقع : Amman-Jordan


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