Normal flora of the respiratory tract is usually same as the normal flora of the mouth. A wide spectrum of organisms colonizes the nose, throat and mouth, but the lower bronchi and alveoli typically contain few, if any, organisms. The nose is colonized by variety of streptococcal and staphylococcal species, the most significant of which is the pathogen staphylococcus aureus. Occasional outbreaks due to this organism, particularly in newborn nursery, can be traced to nasal, skin, or perianal carriage by personnel.
The throat contains a mixture of viridans streptococci, Neisseria species, and streptococci epidermidis. These nonpathogens occupy attachment sites on the pharyngeal mucosa and inhibit the growth of the pathogens streptococcus pyogenes, neisseria meningitiids and staphylococcus aureus respectively.
In the mouth, viridans streptococci make up about half of the bacteria. Streptococcus mutans, a member of the viridans group is of special interest since it is found in large numbers in dental plaque, the precursor of caries. The plaque on the enamel surface is composed of gelatinous, high molecular weight glucans secreted by bacteria.
The throat contains a mixture of viridans streptococci, Neisseria species, and streptococci epidermidis. These nonpathogens occupy attachment sites on the pharyngeal mucosa and inhibit the growth of the pathogens streptococcus pyogenes, neisseria meningitiids and staphylococcus aureus respectively.
In the mouth, viridans streptococci make up about half of the bacteria. Streptococcus mutans, a member of the viridans group is of special interest since it is found in large numbers in dental plaque, the precursor of caries. The plaque on the enamel surface is composed of gelatinous, high molecular weight glucans secreted by bacteria.
0 comments:
Post a Comment