INTRODUCTION
The primary function of intact skin is to control microbial population that live on the skin surface and to prevent underlying tissue from becoming colonized and invaded by potential pathogens (Ndip et. al., 2007). Exposure of subcutaneous tissue following a loss of skin integrity (i.e. wound) provides a moist, warm and nutritious environment that is conducive to microbial colonization and proliferation.
A wound is defined as any injury that damages the skin and therefore compromises its protective function. An acute wound is generally caused by external damage to the skin, including abrasions, minor cuts, lacerations, puncture wounds, bites, burns and surgical incisions. A wound is a breakdown in the protective function of the skin; the loss of continuity of epithelium, with or without loss of underlying connective tissue (Leaper and Harding, 1998). Wounds can be accidental, pathological or post operative. All wounds contain bacteria but majority of the wounds do no get infected. There are many variables that can promote wound infection when there is a discontinuity of skin barrier. This include both host and organism related factors like bacterial load and type, immune competence of host co-morbid like diabetes mellitus, etc (Mir et. al., 2012). An infection of this breach in continuity constitutes wound infection. Wound infection is thus the presence of pus in a lesion as well as the general or local features of sepsis such as pyrexia, pain and indurations.
Wound infections are one of the most common hospital acquired infections and are an important cause of morbidity and account for 70-80% mortality (Gottrup et al., 2005; Wilson et al., 2004). Wound infections can be caused by different groups of micro organisms like bacteria, fungi and protozoa. However, different micro organisms can exist in polymicrobial communities especially in the margins of wounds and in chronic wounds (Percevil and Bowler, 2001). Infection is one of the major causes of morbidity and mortality in hospitalized patients irrespective of the cause as it delays healing (Pondei et al., 2013). It also causes longer hospital stay and increased expenses. In order to recognise early signs and symptoms of infections in a wound, whether complicated or not, skilled and vigilant team of doctors and paramedical staff is required (Moore and Romanelli, 2006).
Wound infections have been a problem in the field of surgery for a long time. Advances in control of infections have not completely eradicated the problem because of development of resistance. Antimicrobial resistance can increase complications and costs associated with procedures and treatment. An infected wound complicates the postoperative course and results in prolonged stay in the hospital and delayed recovery. Most bacteria live on our skin, in the nasopharynx, gastrointestinal tract and other parts of the body with little potential for causing disease because of first line defence within the body. Surgical operation, trauma, burns, diseases, nutrition and other factors affect these defences. The skin barrier is disrupted by every skin incision, and microbial contamination is inevitable despite the best skin preparation.
Knowledge of the causative agents of wound infection in a specific geographic region will therefore will be useful in the selection of antimicrobial for empirical therapy. Antimicrobial resistance can increase complications and costs associated with procedures and treatment (Anguzu and Olila, 2007).