Bacterial Colonization On Human Skin

1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
A diverse microbial flora is associated with the skin and mucous membrane of every human being from shortly after birth until death. The human body which contains about 1013 cells routinely harbors about 1014 bacteria. This bacterial population constitutes the normal microbial flora. The normal microbial flora is relatively stable with specific genera populating various body regions during particular periods in an individual’s life. Tannock (1995).

Microorganisms of the normal flora may aid the host [By competing for micro-environment more effectively than such pathogens Salmonella Spp or by producing nutrients that the host can use. It may harm the host by causing dental caries, abscesses or other infectious diseases or it may exist as commercials by inhabiting the host for long periods without causing detectable harm or benefits. Even though most elements of the normal microbial flora inhabiting the human skin, nails, eyes, genitalia and gastrointestinal tract are harmless in healthy individuals, these organisms frequently cause disease in compromised hosts.

The normal flora in human usually develops in an orderly sequence, after birth leading to the stable populations of bacteria that made up the normal adult flora. The main factor determining the composition of the normal flora in a body region is the nature of the local environment which is determined by pH, temperature, redox potential, oxygen, water and nutrient levels. Other factors such as peristalsis, saliva hysozyme secretion and secretion of immunoglobulin also play roles in flora control. The local environment is like a concern to in which one principal instrument usually dominates. For example, an infact begins to contact organisms as it moves through the birth canal. A gram positive population [Bifido bacteria] predominates in the gastrointestinal tract early in life. If the infant is breast-fed. This bacterial population is reduced and displaced some what by a gram negative flora [Entero bacteriaceae] when the baby is bottle feel. The type of liquid diet provided to the infant is the principal instrument of this flora controls, immunoglobulins and perhaps other element is breast milk may also be important.

1.2 STATEMENT OF PROBLEM
The normal human skin is colonized by huge numbers of bacteria that live as commensals on its surface (Hay et al., 2004). At times bacteria not normally found there may colonize the epidermis and lead rapidly to disease. Apart from these pathogenic organisms, a wide range of bacteria land fortuitously on the skin, but are unable to multiply. Organisms not normally considered as skin flora may sometimes colonize it (Hay et al., 2004). When the skin is inflamed or abnormal, it is often difficult to determine whether an organism isolated is causing or contributing to the observed pathology. If the skin is damaged or the immune status of the subject impaired, bacteria usually regarded as non-pathogenic in body surface may assume the role of opportunist pathogens. Within a given species, there are also strain differences in virulence (Hay et al., 2004).
Some strains have a particular tendency to cause disease, perhaps due to greater adherence to epithelial cells or enzyme production (Hay et al., 2004). There are some studies investigating skin flora on healthy and ill population to find out any possible relation between disease and microbial flora of skin (Zell et al., 2008; Berlau et al., 1999). In this study, we planned to study the species of bacterial colonization on skin.

1.3 PURPOSE OF THE STUDY
The aim is to isolate and identify bacteria on human skin. The study will also explore the species of bacterial colonization on skin.

1.4 SIGNIFICANCE OF THE STUDY
Bacterial surface colonizers are subject to a variety of physical stresses. During the colonization of human epithelia such as on the skin or the intestinal mucosa, bacteria mainly have to withstand the mechanical stress of being removed by fluid flow, scraping, or epithelial turnover. To that end, they express a series of molecules to establish firm attachment to the epithelial surface, such as fibrillar protrusions (pili) and surface-anchored proteins that bind to human matrix proteins. In addition, some bacteria – in particular gut and urinary tract pathogens – use internalization by epithelial cells and other methods such as directed inhibition of epithelial turnover to ascertain continued association with the epithelial layer. Furthermore, many bacteria produce multi-layered agglomerations called biofilms with a sticky extracellular matrix, providing additional protection from removal. This study will give an overview over the mechanisms human bacterial colonizers have on the human skin. These findings will contribute to existing literature and also assist health professional in understanding the human bacterial colonizers and their ability to withstand physical stresses, bacterial adhesion and effect on the skin.