Human Microbiomes (Normal Flora) PDF

Human microbiomes (Normal Flora)  Relationships between Organisms Symbiosis, is a permanent association between two different organisms. Commensalism: Two organisms living together, one is benefited and the other is not been affected. Mutualism: Two organisms living together, and...

Human microbiomes (Normal Flora)  Relationships between Organisms Symbiosis, is a permanent association between two different organisms. Commensalism: Two organisms living together, one is benefited and the other is not been affected. Mutualism: Two organisms living together, and both benefit from that. Parasitism: Two organisms living together, one is benefited ‘’called parasite’’ and the other is harmed ‘’called host’’. Neutralism: Two organisms living together, and neither is affected.  Microbiomes (Normal flora) Also known as microflora or microbiota. Normal flora defined as the mixture of microorganisms (bacteria and fungi) that are regularly found on body surfaces contact with outside environment (skin & mucosa). By other words, normal flora refers to the population of microorganism that inhabit in the skin and mucous membranes of healthy normal person.  How the human microbiome is acquired Microbial populations begin to establish before birth (in utero). Placental microbiome consists of only few different bacteria. Just before a woman gives birth, lactobacilli in her vagina multiply rapidly, and they become the predominant in newborn’s intestine. More microorganisms are introduced to the newborn’s body from the environment when breathing and feeding start. An individual’s microbiome changes rapidly during the first three years. After birth, E. coli and other bacteria acquired from foods, people, and pets begin to inhabit the large intestine. An estimated 4 x 1013 bacterial cells (around 100 trillion) in human body. More cells than the human body; up to 2 kg of mass There are two groups of microbiota: a/ Permanent residents (Escherichia coli in colon), consist of a fixed types of microorganisms regularly found in a given area at a given age. b/ Transient residents (Acinetobacter in urethra), which colonizes the superficial layers of the skin, is easily to be remove by routine hand hygiene. Microflora contributes to health: I. Protective role (host defense) by: (1)maintaining pH, so other organism may not grow. (2) Occupying the host surface receptor, thereby preventing binding of pathogen. II. Serves nutritional function by synthesizing: K and B vitamins.  Microflora can cause infection: Normal flora causes opportunistic infection in one of the following conditions: I. If misplaced, fecal flora to urinary tract or abdominal cavity or skin flora to catheter. II. Reduction of immune system, such as immunocompromised person(AIDs/or under immunosuppression). III. Imbalance of normal flora, for example, antibiotics can reduce the normal colonic flora that allows Clostridium difficile, which is resistant to the antibiotics, to overgrow and cause pseudomembranous colitis. Sites of the normal flora Representative Normal Microbiota by Body Region Representative Normal Microbiota by Body Region https://www.cdc.gov/drugresistance/p df/arsi-microbiome-infographic-2017. pdf Thank You