Bacteriological Analysisof Normal Flora of Skin,Nasal and Ear Specimens Sonia Akhtar, Xia Mujahid, Sobia Ishaque and Fareeha 26 April, 2012
Introduction: The human microbiome (or human microbiota) is the aggregate of microorganisms that reside on the surface and in deep layers of skin, ear, in the saliva and oral mucosa, in the conjunctiva, and in the gastrointestinal tracts. They include bacteria, fungi, and protozoa. Some of these organisms perform tasks that are useful for the human host. Those that are expected to be present, and that under normal circumstances do not cause disease, but instead participate in maintaining health, are soul members of the normal flora.
It is estimated that 500 to 1000 species of bacteria live in the human gut and a roughly similar number on the skin.Bacterial cells are much smaller than human cells, and there are at least ten times as many bacteria as human cells in the body (approximately 1014 versus 1013).Though members of the flora are found on all surfaces exposed to the environment (on the skin and eyes, in the mouth, nose).
Different harmless microorganisms establish as commensals or mutualistic with the host. Normal flora can be divided into two groups, residential flora and temporary flora. The normal flora as well as host immune status both do not allow to infect the host. The environmental conditions like pH, temperature, availability of oxygen, presence of moisture etc also influence their presence.
Aim: The basic aim of this studywas to analyze the normal flora of Skin, Nose and Ear
Materials and Methods: Samples of nose , ear & skin were collected by the normal healthy individuals by the help of swabs in aseptic conditions. Media: which were used are nutrient agar, sheep blood agar, MacConkey agar, Manitol salt agar, Muller Hinton Agar and Salt Indol Motility agar.
RESULTS: The Ear specimens 1 and 2 were identified as Streptococcus viridans and Staphylococcus aureus Nasal specimens 1 and 2 were identified as Niesseria spp.and Klebsiella pneumoniae Nasal specimens 1 and 2 were identified as Niesseria sp Non of the isolated organisms showed sensitivity against antibiotics
DISCUSSION: The varied environment of the skin results in locally dense or sparse populations, with Gram-positive organisms (e.g., staphylococci, micrococci, diphtheroids) usually predominating. S. epidermidis is a major inhabitant of the skin, and in some areas it makes up more than 90 percent of the resident aerobic flora.
Streptococci, especially β-hemolytic streptococci, are rarely seen on normal skin. The paucity of β- hemolytic streptococci on the skin is attributed at least in part to the presence of lipids on the skin, as these lipids are lethal to streptococci. Gram-negative bacteria make up a small proportion of the skin flora.Gram-negative bacteria, is more common in the moist intertriginous areas.
• The nose and perineum are the most common sites for S. aureus colonization, which is present in 10 percent to more than 40 percent of normal adults. S. aureus is prevalent (67 percent) on vulvar skin. Its occurrence in the nasal passages varies with age, being greater in the newborn, less in adults. S. aureus is extremely common (80 to 100 percent) on the skin of patients with certain dermatologic diseases such as atopic dermatitis, but the reason for this finding is unclear.