Nasal passageway

Description of Nasal Passageway

Location of the Nasal Passageway

The main entry to the nasal passageway is through the nostrils, inside the nose, which is located on the face. From there, the passageway extends...

Physical Conditions of the Nasal Passageway

What are the conditions in your niche? Temperature, pressure, pH, moisture, etc.

Normal: The temperature of the normal passageway should be around 31 degrees Celcius. The pressure of the normal passageway should be around 1 atm. The nasal passageway walls are layered with respiratory mucous membranes secreted by goblet cells. These membranes have many small hair-like cells, known as cilia, that move mucus in waves toward the throat area. Bacteria, along with dust and other particles inhaled from the outside environment are snared by the nasal mucus, carried back out, and dripped into the gastric juices to destroy any possible pathogens. The mucus contains lysozymes that dissolve and kill the bacteria, although most bacteria are not killed by it.

Diseased:

Influence by Adjacent Communities

Is your niche close to another niche or influenced by another community of organisms?

Throat: The throat is connected to the nasal passageway and contains aerobic, gram-positive bacteria which are characterized by hemolysis. An example of a pathogenic bacteria in the throat is Streptococcus pyogenes, which can infect when the immune system is down and cause diseases such as scarlet fever and pharyngitis (strep throat) among others. An example of nonpathogenic bacteria in the throat is Streptococcus salivarius which may enter the bloodstream and may cause diseases such as septicemia although not very often. These diseases mostly affect the throat, but may move upwards to cause nasal passageway infections.

Sinuses: The diseased maxillary and ethmoid sinuses are most commonly associated with affecting the nasal passages by causing inflammation and congestion.

Conditions under which the environment changes

Do any of the physical conditions change? Are there chemicals, other organisms, nutrients, etc. that might change the community of your niche.

Anything that might irritate a human's nose, like air pollution, pesticides, etc., may cause swelling and blockage of the nasal passageways which will lead to bacterial growth and infection. The trapped mucus within the nasal will create a breeding ground for bacteria.

The temperature of the air will also affect the nasal cavity. The cold air will stimulate an increase in mucus production and thicken the mucus.

Who lives in the Nasal Passageway?

Which microbes are present in the Nasal Passageway?

You may refer to organisms by genus or by genus and species, depending upon how detailed the your information might be. If there is already a microbewiki page describing that organism, make a link to it.

Even though we cannot see them with our naked eye, microscopic organisms are living inside our nasal passageways. Although most of these bacteria are non-pathogenic, some may induce illness if they successfully break through the bodies defense systems. Some examples of these non-pathogenic bacteria are Streptococcus, Neisseria, Haemophilus, and Micrococcus. Some of the pathogenic examples include Staphylococcus aureus, Corynebacterium diphtheriae, Streptococcus pneumoniae, and Haemophilus influenzae.

Normal:

Staphylococcus epidermidis with Corynebacteria predominantly colonizes the upper respiratory tract, especially the nostrils. S. epidermidis covers 90%-100% staphylococci from the nasal cavity when S. aureus is not present.

Corynebacterium is a Gram-positive normal flora in the nose. Most species of Corynebacterium will not cause diseases in humans; however, there is a specific species that is highly infectious. The Corynebacterium diptheriae causes infection in the upper respiratory tract, and can be deadly if untreated. (2)

Another Gram-positive bacterium that lives in the human nose is the Staphylococcus aureus, often referred to as staph. It is carried either on the skin or in the nose of healthy people, but 25% - 30% of the population is populated in the nose. Well Staph is growing, it will not cause any infection, until the bacteria can enter a wound.

Micrococcus luteus is an obligate aerobe, Gram positive, spherical, bacterium that also resides in the nose as well as the mouth, skin and upper resipratory tract. M. luteus is normally harmless except for those that have compromised immunities. M. luteus is resistant to reduced water potential that is found in mucus and can tolerate drying and high salt concentrations were the nasal cavity to dry up.

Diseased:

The nasal passages, being as large as it is (from a microbe's standpoint), can be harbor many types of bacteria, viruses, and fungi which can often lead to infection. One very commonly found gram-positive bacteria is the Staphylococcus epidermidis which colonizes in the anterior naris. (The Sinuses book) Their grape-like appearance when viewed under the microscope only measures approximately 1 micrometer in diameter. This bacteria, if environmental conditions are optimal, will form biofilms to aggregate more securely. A three stage process of The exopolysaccharide casing of the biofilm provides excellent protection against the environment and phagocytosis by their host's immune system as they seek to mature and eventually dissolute from the colony. The slim (biofilm), mainly composed of teichoic acid and typically found on the cell wall of these microbes can also protect them against antibiotics making them very difficult to treat. This unique ability of the Staphylococcus epidermidis to form a biofilm in the nasal passages may be the reason for their strong virulence. (The Internet Journal of Microbiology)

The Streptococcus pneumoniae bacteria is another Gram-positive bacteria that is commonly found in the nasal passages, primarily in a patient with acute sinusitis. This lancet-shaped bacteria, approximately 0.5 - 1.25 micrometers in diameter, is one of the primary causes of pneumonia. Although they are also found in the upper respiratory tract of healthy individuals, they are usually the cause of sinus infection when a small amount of this bacteria is lodged in the sinus cavities such as the ethmoid or maxillarysinuses, typically by the force of a sneeze or the blowing of the nose. Its capsule, composed of polysaccharides prevents phagocytosis of the bacteria. The pili structures on some strains of S. pneumoniae have been identified in the involvement of colonization in the nasal passages. This allows them to gain a strong attachment to epithelial cells and sometimes leads to a challenging problem if left untreated.

Are there any other non-microbes present?

Plants? Animals? Fungi? etc.

Normal: Hopefully, no plants, animals, or fungi live in the normal nasal passageway.

Do the microbes that are present interact with each other?

Describe any negative (competition) or positive (symbiosis) behavior

The reason only 25% - 30% of the nasal passageway is populated by the Staph. aureus is beacuse Staph. epidermidis and Corynebacterium have a negative symbiosis behavior with the Staph. aureus. Some possible reasons for the decrease in Staph. aureus may be the synthesis of bactericidal exoprotiens by the Staph. epidermidis or the competition of specific attachment to epithelial cells, which Corynebacterium has a higher affinity for mucus than Staph. aureus. Although Stap. epidermidis has a negative impact on Staph. aureus, Staph. aureus has a higher affinity for mucus than does Staph. epidermidis. (1)

Do the microbes change their environment?

Do they alter pH, attach to surfaces, secrete anything, etc. etc.

Do the microbes carry out any metabolism that affects their environment?

Do they ferment sugars to produce acid, break down large molecules, fix nitrogen, etc. etc.

Current Research

Enter summaries of the most recent research. You may find it more appropriate to include this as a subsection under several of your other sections rather than separately here at the end. You should include at least FOUR topics of research and summarize each in terms of the question being asked, the results so far, and the topics for future study. (more will be expected from larger groups than from smaller groups)

As previously mentioned, Staphylococcus aureus is commonly found in the nose. Researchers from the University of Washington were interested in finding out why this bacterium is able to survive the human's natural production of nitric oxide in the nasal passages. This production of nitric oxide in the nose and nasal passages usually protects against disease causing bacteria by preventing their respiration process. These researchers found out that Staph aureus produces lactic acid in the presence of nitric oxide,making a chemical balance, allowing it to continue to grow in this type of environment. The researchers then found a way to remove the lactic acid production by Staphylococcus aureus and found that it was then not able to survive in the presence of nitric oxide. This was tested in mice and the researchers also found that there were no diseases caused by the modified bacterium. The researchers hope to use this type of modification to find new ways to prevent the survival of such bacteria without the use of antibiotics.

(Not sure if this is an ok summary for current research, let me know if I should find something else or try to add more to it.- Naty)

References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

1. Lina, G., Boutite, F., Tristan, A., Bes, M., Etienne, J., Vandenesch, F., "Bacterial Competition for Human Nasal Cavity Colonization: Role of Staphylococcal agr Alleles". "Applied and Environmental Microbiology". 2003. Vol. 69. No. 1. p. 18-23.

2. Santo-Pietro, Karen. "Microorganism of the Month: Corynebacterium species'". 'The Environmental Reporter: EMLAB'. 2007. Volume 5. Issue 5

3. Richardson, A., Libby,S., Fang,F."A nitric oxide Inducible Lactate Dehydrogenase Enables Staphylococcus aureus to Resist Innate Immunity". Science. 2008.Vol. 319. p. 1672-1676.

Edited by Jacinda Chen , Wayne Chen , Josephe Dalidi , Jennifer Hao , Rutu Kothari , Nidhi Patel , Natividad Rodriguez , Prudencio Sy, students of Rachel Larsen