Aspergillus niger is the most common pathogenic fungus , familiar to us from the frightening name “black mold”. You can discover whole colonies of this amazing adaptive organism right at home - in the basement, in a dark dank corner, in an old book.
Morphology and physiology of Aspergillus niger
What kind of Aspergillus niger mushrooms? They are able to take root and grow into a colony even at temperatures above +40 0 . The rate of ripening of mushrooms during the capture of significant territories is simply unique - within three days. Darkening, acquiring a characteristic dark gray or black color, the fungi as the conidia mature - microscopic formations at the apex of the thickened conidial head of the parasitic organism.
The morphology of Aspergillus niger implies several strains of black mold, choosing premises, food products or even the human body as their habitat.
Favorable environment for black mold
Mold spores are present everywhere, they are not present only in an environment of complete sterility or vacuum. Particles that have separated from the mycelium, are in the air and begin to multiply actively wherever the spore can catch and go unnoticed.
The mold unit itself is formed of two filamentous bodies, one of which creates a vegetative formation, and the other stretches up and, ripening, gives life to new disputes.
Favorable factors contributing to the good survival of Aspergillus niger:
- lack of inflow and outflow of fresh air; this creates a sultry atmosphere saturated with vapors, which is ideal for the emergence of multiple mold colonies;
- humidity close to 100% is one of the most common conditions under which Aspergillus niger can be detected;
- sharp temperature jumps, leading to the formation of steam and condensate;
In addition, one of the factors is the lack of tightness of food packages.
Strains Aspergillus niger
No type of mold is similar to another, if we examine the structure of fungi under a microscope. The expressive and frightening appearance of black mold noticeably distinguishes it from the light fluffy balls of Aspergillus of another variety, which seem less dangerous, but this is a delusion. Black can be the mycelium of several strains at once, depending on the periods of maturation of the fungus, the type of surface covered, and the speed of propagation of the colony.
There are such strains of Aspergillus niger:
- The color of the mycelium is light, only mature spores are black. Such a fungus lives in the dark damp corners of residential and non-residential premises and is the cause of aspergillosis disease.
- Phoma - refers to the 4th group of pathogenicity. In their case, on the contrary, the vegetative body is a black blot with a white edge of matured spores.
- The next look always has a rich dark color. Separated spores readily settle in the human digestive tract and cause intoxication and a pronounced allergic reaction.
- There is a kind of awesome dark color and with rare survivability, but at the same time almost not dangerous to human health.
- Among the varieties of black mold are penicillin mushrooms, which are often grown in difficult adaptive conditions to obtain a valuable substance, on the basis of which antibiotics are made.
- The mycelium of the following species resembles spots of slimy plaque that occur on long-lying vegetables, fruits, nuts.
So Aspergillus nigeria is not only a substance of deep mourning color that is familiar to us. An ominous fungus can hide under a completely harmless white cannon.
Infection with human Aspergillus niger fungi
Aspergillosis is a consequence of a person inhaling black mold spores freely moving in the air. Most often, fungus attacks are carried out by people whose professional activities are related to conditions in which mold feels most comfortable. These are grain processing, bakery, aging workshops for finished cheeses, weaving and spinning mills.
A healthy person can breathe air affected by spores without danger to himself, but weakened immune defenses, past or current diseases of the bronchi, lungs, and nasopharyngeal sinuses make the body vulnerable. Based on the initial strain of the fungus, which has settled in the moist environment of the body, a specific type of aspergillosis also develops.
Aspergillus niger infection can occur in other ways:
- through food;
- through wounds, microcracks on the epidermis or mucous membranes.
Sometimes successful penetration of the fungus into the human body is facilitated by radiation therapy and prolonged antibiotic therapy.
Symptoms
Despite the fact that fungal spores are able to gain a foothold on any organ, the most frequent area of their damage is oxygen-rich lung tissue. An infected person experiences all the symptoms of acute bronchitis:
- severe cough with expectoration of sputum off-white in color, sometimes with bloody clots;
- constant fatigue, weakness, general decrease in activity;
- weight loss.
Treatment that does not correspond to the elimination of the cause of the disease leads to the development of pulmonary mycosis. This stage of lung damage is characterized by a worsening of the patient's condition. Appear:
- severe wet cough with stable sputum;
- chills;
- chest pain;
- dyspnea;
If at this stage of the disease to study the biological material (sputum), then Aspergillus spores are found in the secretions.
Aspergillosis of the organs of hearing and nasopharynx can resemble rhinitis, sinusitis, otitis media, pharyngitis, tonsillitis according to the algorithm of the course. The hallmarks of affection of the ENT organs with a fungus are
- peeling of the external auditory canal and itching in this area;
- hearing impairment;
- hyperemia.
With the progression of the disease, viewing the auditory canal will show the presence of a gray friable substance. Examination of the sample will give a positive result for the presence of parasitic mycelium.
Aspergillosis infection in the eyes is masked by:
- blepharitis;
- dacryocystitis;
- conjunctivitis.
The lack of proper treatment leads to complications in the form of partial or complete loss of vision.
So, it’s already approximately clear what kind of Aspergillus niger mushrooms are. On the hands (which is manifested primarily by damage to the nail plate), they can also settle. The signs of this infection are difficult to confuse with other types of disorders in the body. They are as follows:
- the appearance of dark scales;
- itching around the nail;
- infiltration;
- heavy smell coming from the nail.
Over time, if you do not use complex therapy, the color of the nail finally changes to yellow-brown or green-brown, the plate thickens and acquires a porous structure.
Diagnostics
Biological materials for the study in cases of suspected Aspergillus are samples taken from the suspected lesion area. In case of skin lesions, these are scrapings from the epithelium or nail, and in case of lung damage, sputum discharge. A clinical blood and urine test may also be required to determine the fungus.
Sometimes it is possible to isolate a culture only through serological tests and cultural research. It is possible that with severe lesions of the epidermis, the doctor will insist on conducting skin-allergic tests.
Only after confirming aspergillosis and establishing its form, the patient is referred to a narrow specialist to prescribe treatment.
Traditional treatment for aspergillosis
Local treatment of Aspergillus niger is carried out in combination with antifungal drugs: amphotericin B, voriconazole, flucytosine, itraconazole. The method of using the funds - by inhalation, intravenously or orally, is negotiated with the doctor based on the nature and degree of damage to the body.
Means for topical use are antiseptics and antifungal agents. Treatment of cutaneous aspergillosis is the most favorable according to forecasts, but only on the condition that the patient will undergo a full therapeutic course, lasting from a month to three.
Aspergillosis of the lungs in advanced or complex form gives a high mortality rate - up to 50%. A factor aggravating the patient's condition and worsening the prognosis is a weakened immunity.
A life-threatening form of the disease may require the patient to be in the hospital, but, as a rule, therapy is carried out at home with periodic control tests. Treatment of Aspergillus nigeria with folk remedies is unacceptable!
Aspergillosis in children
As in adults, Aspergillus niger in children develops in several forms:
- allergic bronchopulmonary aspergillosis;
- aspergillosis bronchitis;
- aspergillosis pneumonia.
Common symptoms with which aspirgellosis masquerades as bronchial and acute respiratory diseases are shortness of breath, cough with sputum discharge, and sternum pain. Sometimes symptoms are accompanied by fever.
Aspergillus is recognized by the nature of sputum, having a putrid or dirty gray color, in an advanced stage - with a blood admixture.
From a bouquet of signs addressed to the doctor in the form of a health complaint, the pediatrician should draw up a general kinetic picture and prescribe a diagnosis, which includes laboratory tests of blood and sputum, as well as skin tests. After confirming the presence of aspergillus in the biological material, clarifying examinations or tests may be needed to determine the degree of damage to the body:
- CT scan;
- spirometry;
- bronchoscopy;
- biopsy.
Examinations are carried out quickly to prevent the main complication - sepsis, in which fungi spread through the blood to healthy organs.
Treatment of aspergillosis in children
They hospitalize the child immediately after diagnosis. From the first day, antifungal drugs that inhibit the spread of aspergillus begin to be introduced into the patient's body. Reception of immunomodulators is an important point in the treatment of Aspergillus nigeria in children, since it is precisely the weakening in the protective reaction of the body that led to aspergillosis.
In rare cases, they resort to surgical treatment - when it is not possible to save the affected area of the lung and a decision is made to remove it. An indication for such a cardinal action is the onset of bleeding from a tumor that appeared during the formation of aspergilloma, a particularly complex form of aspergillosis.
Prevention
Black mold is most often found by residents of old houses or corner apartments in high-rise buildings, so in rooms of this type, walls should be inspected as carefully as possible. Aspergillus loves to hide behind lagging wallpaper, tiles, in clogged ventilation. At least once every three months, it is necessary to carry out a general cleaning of the sanitary unit using antibacterial agents and grouts.
It is impossible to prevent damp in the basement of the house, the appearance of deposits of rotting vegetables. Wooden shelves, floors in damp rooms are not allowed. If the house has a wall section regularly covered with mold, despite all measures, it is necessary to pay attention to the integrity of the wall in this place.