Sample Essay On Microbiology Week 7: Essay 1 & 2

{Author Name [first-name middle-name-initials last-name]}
{Institution Affiliation [name of Author’s institute]}

Essay 1

Respiratory tract infections are categorized into various types on the basis of organ affected causes and the pattern of symptoms:
Obstructive respiratory condition: This condition develops on narrowing the bronchial tubes which makes the inhale and exhale process difficult. Example: bronchitis, asthma and

Emphysema.

Restrictive respiratory condition: It is an interstitial lung problem that makes lungs stiff to expand during respiration. Example: fibrosis and sarcoidosis.
Vascular conditions: When pulmonary vessels are affected due to infection. Example: pulmonary embolism and edema.
Respiratory tract infections: Infections developed in the parts of respiratory tract due to pathogenic activities. It is further divided into two types:
Upper respiratory tract infection: It is the most common type of infection that impacts the upper part of the tract including throat, nose, trachea and larynx. For example, common cold, tonsillitis, sinusitis, laryngitis and pharyngitis.
Lower respiratory tract infection: Lower respiratory tract infection impacts the lower part of the tract including alveoli, bronchioles and bronchi. This type of infection is caused by bacteria. Apart from bacteria fungi and viruses are also found responsible for developing such infections like pneumonia or ruthless acute respiratory syndrome and Bronchitis (Emedicinehealth.com).
The causes of such infections may be environmental as well as allergic reactions to pollutants, weather or infectious pathogens transmitted from infected individual. All of the respiratory tract infections illustrate symptoms of coughing, stuffy nose or excessive fluid running from nasal cavities. The microbes present in the air enter the respiration machinery and cause inflammation, so the infections of respiratory tract are very common. The infections of upper tract are very infectious and usual, but the infections of lower tract are more serious. Upper respiratory tract infections are caused by gram-positive bacteria, such as Streptococci and Staphylococci. In the case of lower tract infection the pathogens vary and several more perilous pathogens are involved. That’s why the infection of upper tract infection is milder that lower tract infections. Symptoms of lower tract infection are mucus or phlegm generation, and congested feeling in the lungs, breathlessness and wheezing. Several infections of lower tract are persistent such as tuberculosis.
The most preventive way to avoid upper tract infections is keeping an eye on hygiene and regular hand washing. For flu like symptoms of upper tract antibiotic and vaccines can be suggested. For common cold no any chemotherapeutic agents are found accurate. Decongestants and antihistamines are recommended for relieving symptoms. To ease the upper way irritation several corticosteroid as medications are prescribed (Bartlett, 1997).
For lower tract infection hand washing and avoiding contact with infected people is good practice. , Home based treatments as gargles, steam inhalation, Deep breathing exercises and lots of rest can be considered as primary care. Some OTC medications like anti-inflammatories, Ibuprofen, Steroidal medicines, antiviral and antibiotics, expectorants and nasal steroids can relieve the symptoms. If the condition worsens with pneumonia or bronchitis the medical management involves tetracyclines, fluoroquinones agents. Respiratory tract exposure to pathogens makes bodies’ immune system combat the foreign pathogens and defend itself. Cytokines, Macrophages, antibodies (immunoglobulins or Ig) and lymphocytes (B & T cells) are the explicit factors of our immune system that is involved in preventing the infectious agents out of the lungs. This defence involves three steps: recognising the foreign pathogen, directly attacking and killing the pathogen and finally remembering the pathogen and keeping its record for future through recovering from it (Gordon & Read, 2002).

Essay 2

Enteric Pathogen
Enteric Pathogens directly invade and irritate the gastrointestinal path of the host through producing toxins and interfering with the intestinal absorptive and barrier functioning. The symptom of enteric disease is the unformed or diarrheal stools more than thrice a day.
Members of Enterobacteriaceae are facultative anaerobes that lives into gut and intestinal part of the host and can ferment sugars into lactic acid. Anaerobic organisms are not visible in a routine fecal cultures or specimens because such types of routine cultures are developed under the aerobic conditions. Thus, the selection of proper media and a fast recognition method is necessary for the detection of enterohemorrhagic microbe.
The lactose fermenters enteric bacteria are identified through IMViC reaction. The term IMViC denotes indole, methyl red, Voges-Proskauer and citrate tests.
1: Indole Test: Several bacteria have ability to break tryptophan into alanine and indole. The produced indole reacts with paradimethylaminobenzaldehyde in Kovac's reagent resulting red color. This red color verifies the release of indole.
2: Methyl Red Test. This test is based on the high acidity of the culture that can turn the color of methyl red reagent to a distinctive red color. Yellow color indicates negative.
3: Voges-Proskauer Test. The production of acetylmethylcarbinol from dextrose resulting in a pink red color shows the positive results for the Voges-Proskauer test. Yellow indicates negative.
4: Citrate Test. The positive result of this test illustrates the ability of bacteria to consume sodium citrate as a source of carbon in a chemically distinct medium. For this test a little amount of Simmons' citrate agar slightly goes through inoculation process. Positive result or growth is identified through an alkaline reaction that also turn the color from green to deep blue. No change indicates absence of coliforms (Farmer, 1995).

Flowchart for the isolation and identification of specific enteric bacteria from fecal samples.

Urea
TSI Agar

References

Bartlett, J. G. (1997). Management of respiratory tract infections. Williams & Wilkins.
Emedicinehealth.com,. (2015). eMedicineHealth - experts in everyday emergencies, first aid and
health information. Retrieved 24 January 2015, from
http://www.emedicinehealth.com/script/main/srchcont_em.asp?searchwhat=1&src=respir
atory+infection&submitimg.x=0&submitimg.y=0
Farmer, J. J. (1995). Enterobacteriaceae: introduction and identification.
Manual of clinical microbiology, 438-449.
Gordon, S. B., & Read, R. C. (2002). Macrophage defences against respiratory tract infections
The immunology of childhood respiratory infections. British medical bulletin, 61(1), 45-
61.