Thesis Abstract

Abstract
Fungal colonization on human body surfaces is a complex and dynamic phenomenon that plays a significant role in human health and disease. Fungi are ubiquitous in the environment and can colonize various body sites, including the skin, oral cavity, respiratory tract, gastrointestinal tract, and genitourinary tract. The interaction between fungi and the human host is influenced by a variety of factors, including the host immune response, the composition of the microbiota, and environmental factors. The skin is the largest organ of the human body and is constantly exposed to a variety of fungi from the environment. Fungal colonization of the skin can be influenced by factors such as moisture, temperature, and sebum production. Certain fungal species are part of the normal skin microbiota, while others can cause infections under certain conditions. Fungal skin infections are common and can range from mild conditions such as athlete's foot to more severe infections like invasive candidiasis. In the oral cavity, fungi are a normal part of the microbiota, with Candida species being the most common fungi found in this environment. Under certain conditions, such as immunosuppression or antibiotic use, Candida species can overgrow and cause oral infections such as thrush. Fungal infections of the oral cavity can also occur in individuals with poorly fitting dentures or those undergoing chemotherapy. In the respiratory tract, fungi can colonize the upper airways and sinuses, with Aspergillus species being commonly implicated in respiratory infections. In individuals with compromised immune systems, such as those with HIV/AIDS or undergoing organ transplantation, invasive fungal infections of the respiratory tract can occur, leading to serious complications. In the gastrointestinal tract, fungi play a role in maintaining the balance of the gut microbiota. Disruption of this balance, such as through the use of antibiotics or a high-sugar diet, can lead to fungal overgrowth and the development of conditions such as candidiasis. Fungal infections of the gastrointestinal tract can also occur in individuals with conditions such as inflammatory bowel disease or HIV/AIDS. In the genitourinary tract, fungal infections such as vaginal yeast infections are common, particularly in women. Factors such as hormonal changes, pregnancy, and the use of certain medications can increase the risk of developing these infections. In men, fungal infections of the genital area can occur, particularly in individuals with compromised immune systems. Overall, fungal colonization on human body surfaces is a complex interplay between the host, the environment, and the fungi themselves. Understanding the factors that influence fungal colonization can help in the development of strategies to prevent and treat fungal infections in humans.

Thesis Overview

                      INTRODUCTION

Fungi are a major group of living things, originally considered plants lacking chlorophyll, leaves, true stems, roots and reproducing by spores, but now treated as the separate kingdom fungi.
They occur in all environments on the planet and include important decomposers and parasites. Parasitic fungi infect animals including human, other animals, birds, and insects with consequences varying from mild itching to death, in general, humans have a high level of inmate immunity to fungi and most of the infections they cause are mild and self limiting (Adeleke, 2006).
Fungi are contacted during our everyday routines, some which are potentially pathogenic to human and other not human could be exposed simply by walking by a construction areas were the oil has been disturbed and scattered into the wind by the machinery, also can be exposed while jogging, hiking, hunting and fishing. The study of fungi as animal and human pathogen is called mycology (Emmons 1979)
Also, they are eukaryotic, unicellular, or multi-cellular organisms that, because they lack chlorophyll, are dependent upon external food sources. They are ubiquitous in all environments and play a vital role in the Earth’s ecology by decomposing organic matter. Familiar fungi includes yeasts, rusts, smuts, mushrooms, puffballs, and bracket fungi. Many species of fungi live as commensal organisms in or on the surfaces of the human body. “Mold” is the common term for multicellular fungi that growths as a material of intertwined microscopic filaments (hyphae).  Exposure of molds and other fungi and their spores is unavoidable except when the most stringent of air filtration, isolation, and environmental sanitation measures are observed, e.g in organ transplant isolation units.

Molds and other fungi may adversely affect human health through three processes. (1) allergy (2) infection and (3) toxicity. One can estimate that about 10% of the population has allergic antibodies to fungal antigens. Only half of these, or 5%, would be expected to show clinical illness. Furthermore, outdoor molds are generally more abundant and important in airway allergic disease than indoor molds leaving the latter with an important, but minor over all role in allergic airway disease.