|MadSci Network: Microbiology|
A baby's mouth have fewer bacteria than an adolescent. Babies acquire their first flora from the mother. Oral bacteria from mother can be transmitted to the fetus during pregnancy, during the birth process and from mother to child after birth during breast feeding, by example. After teeth emerge, the number of attachment sites for bacteria and potential bacterial niches increases significantly. The type of oral colonization is different between individuals already when they are babies; variable bacterial load in saliva of closely related persons and other close contacts and how often the baby is exposed to these bacteria may partly account for individual differences. In addition, the exposure of a baby to antibiotics affects the quality of colonizing bacteria. acquisition. At birth the oral cavity is relatively sterile (without bacteria) but rapidly becomes colonized from the environment, particularly from the mother in the first feeding. In the mouth of the baby, only mucosal (soft) surfaces are available. The bacteria Streptococcus salivarius is dominant and may make up 98% of the total oral flora until the appearance of the teeth (6 - 9 months). The eruption of the teeth during the first year leads to colonization by S. mutans and S. sanguis. These bacteria require a nondesquamating (nonepithelial = teeth) surface in order to colonize. They will persist as long as teeth remain. Other types of streptococci adhere strongly to the gums and cheeks but not to the teeth. The creation of the gingival crevice area (supporting structures of the teeth) increases the habitat for the variety of anaerobic (live under low oxygen content) types of bacteria found. The complexity of the oral flora continues to increase with time, and bacteria Bacteroides and spirochetes colonize around puberty (teenagers).
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