Question

A 44 yr old woman presents to the office for evaluation of skin growths on her right arm. She reports that a few weeks ago she developed some small, red bumbs on her right palm. This then ulcerated, but it never was painful. She has been putting topical antibiotics on the area with little effect. Recently she noticed new growths extending up her forearm that appear similar to the original lesion. She is employed as a florist and has been for the last few years.

1. What fungal pathogen might you suspect the patient is suffering from?

2. A microscopic examination of the biopsy from the lesion would most likely reveal what characteristic forms

3. If a culture was performed, how might the characteristic forms detected be different?

4. How do you differentiate this group of fungi from other fungi? (Hint: Temperature, growth rate, color, hyphae, others)

Answer 1

1. A maculopapular rash is made of both flat and raised skin lesions. The name is a blend of the words “macule,” which are flat discolored skin lesions, and “papule,” which are small raised bumps. These skin lesions are usually red and can merge together. Macules that are bigger than 1 centimeter are considered patches, while papules that are merged together are considered plaques.

A maculopapular rash is a marker for many diseases, allergic reactions, and infections. Most of the time, the cause is a viral infection. See a doctor if you have a maculopapular rash. The rash could indicate a serious disease.

Contact dermatitis is an allergic skin reaction that produces an itchy, red skin rash. The rash may consist of raised, red bumps that ooze, drain, or crust. ... Keratosis pilaris is a skin condition marked by an overgrowth of a protein called keratin. It causes small bumps around hair follicles on the body.

2. A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle aspiration biopsy. Biopsies are most commonly performed for insight into possible cancerous or inflammatory conditions.

Most skin lesions are benign; however, some concern has caused the patient to make an inquiry, and a correct diagnosis is important. The plethora of dermatologic conditions makes a correct diagnosis challenging. To combat this, the clinician must approach the evaluation of the lesion in a systematic way. In addition to the physical characteristics of the lesion, the patient’s demographics, presence of associated symptoms, related systemic disorders, and location and growth patterns of the lesion all give clues to adequately diagnose and treat.

The accurate diagnosis of any skin lesions can be made by histologic examination of a skin biopsy. However, clinicians must gain the clinical acumen to correctly identify common benign skin lesions and to distinguish those skin conditions that do need a biopsy and possible further treatment.

3. Study of cultural characteristics of microorganism is done with a purpose to distinguish different microorganisms into various taxonomic groups. So the objective of this experiment is to understand different characteristics of microorganisms and to classify them into various groups basing on their characteristics.

Culture and Sensitivity. A culture is a test to find germs (such as bacteria or a fungus) that can cause an infection. A sensitivity test checks to see what kind of medicine, such as an antibiotic, will work best to treat the illness or infection.

During a bacteria culture test, a sample will be taken from your blood, urine, skin, or other part of your body. The type of sample depends on the location of the suspected infection. The cells in your sample will be taken to a lab and put in a special environment in a lab to encourage cell growth.

4.hypha consists of one or more cells surrounded by a tubular cell wall. In most fungi, hyphae are divided into cells by internal cross-walls called "septa" (singular septum). Septa are usually perforated by pores large enough for ribosomes, mitochondria and sometimes nuclei to flow between cells.

Fungi have well-defined characteristics that set them apart from other organisms. Most multicellular fungal bodies, commonly called molds, are made up of filaments called hyphae. Hyphae can form a tangled network called a mycelium and form the thallus (body) of fleshy fungi. Hyphae that have walls between the cells are called septate hyphae; hyphae that lack walls and cell membranes between the cells are called nonseptate or coenocytic hyphae)

In contrast to molds, yeasts are unicellular fungi. The budding yeasts reproduce asexually by budding off a smaller daughter cell; the resulting cells may sometimes stick together as a short chain or pseudohypha . Candida albicans is a common yeast that forms pseudohyphae; it is associated with various infections in humans, including vaginal yeast infections, oral thrush, and candidiasis of the skin.

Some fungi are dimorphic, having more than one appearance during their life cycle. These dimorphic fungi may be able to appear as yeasts or molds, which can be important for infectivity. They are capable of changing their appearance in response to environmental changes such as nutrient availability or fluctuations in temperature, growing as a mold, for example, at 25 °C (77 °F), and as yeast cells at 37 °C (98.6 °F). This ability helps dimorphic fungi to survive in diverse environments. Histoplasma capsulatum, the pathogen that causes histoplasmosis, a lung infection, is an example of a dimorphic fungus .