Mycoplasma pneumoniae

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Erika J Ryan
May 18th, 2010

Abstract: Pneumonia is a respiratory infection cause by either a bacterium or a virus, and in this case, caused by the bacterium Mycoplasma pneumoniae. It is an inflammation of the lungs the begins in either the nose or the mouth of the person infected, usually by respiratory droplets. The pneumonia infection can also be transmitted by blood from an initial site of infection, found elsewhere in the body and into the lungs of the infected individual. Furthermore, I studied specifically M. pneumoniae, which is a common form of community-acquired pneumonia. However, this bacterium lacks a cell wall and has the ability to fuse with its host's cells, making it very difficult to treat. I also researched studies done that tested and proved the presence of drug-resistant strains of M. pneumoniae.

I wanted to research the respiratory infection, Pneumonia because I believe that many respiratory infections are vastly overlooked. Many individuals go through great risks to eat healthy, maintain a healthy body weight, and avoid any type of cardiac complications. While many individuals in America die every year from heart attacks and strokes, pneumonia is a disease that can infect any human, healthy or not, via respiratory droplets. Pneumonia, whether it be chronic, terminal or temporary forms of infection, do not discriminate between the healthy and the weak. With more knowledge about the risks and greater understanding about the dangerous outcomes of untreated pneumonia, we can lower the death rate cause by this infectious disease.

Another reason this subject is of great importance to be is because my cousin passed away from a terminal respiratory genetic disease called Cystic Fibrosis. Due to the fact that someone else is researching this subject, I could not fully conduct research on this subject. However, there are many short-term, similar characteristics between Cystic Fibrosis and Pneumonia are similar, ignoring the fact that one is temporary and one is terminal and without a cure. Understanding the importance of the health of your lungs could later lead to a decrease in the number of deaths due to pneumonia and a cure for Cystic Fibrosis.

Pneumonia is the sixth leading cause of death, infecting 1.2 million people annually. Specifically, Mycoplasma pneumoniae infects 300,000 individuals in the United States annually. These statistics show that pneumonia plays a significant role in the health and well-being of Americans. However, most will die because of this disease due to the fact that they are:

  1. Too old or too young
  2. Weakened immune systems
  3. Leave the symptoms untreated for too long due to the lack of knowledge about pneumonia

Symptoms of Pneumonia:

  • Fever
  • Chills
  • Cough
  • Rapid breathing with wheezing
  • Chest pain
  • Vomiting
  • Decreased appetite

In some extreme cases, a bluish color will form in an individuals lips or nails.

Mycoplasma Pneumoniae

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Specifically, Mycoplasma pneumoniae bacterium is a member of the class Mollicutes, and is a common type of infection that causes pneumonia. What makes this bacterium special is it's complete lack of cell walls and ability to invade its host's cells, making it more difficult to treat without proper diagnosis.

Mycoplasma pneumoniae is a common and yet special type of pneumonia. Like all forms pneumonia, the infection itself is not fatal if treated within a specific amount of time. However, if the symptoms of pneumonia are left untreated, it may lead to more severe symptoms and eventually death.

Mycoplasma pneumoniae completely lacks a cell wall. Most of the antibiotics used to treat pneumonia attack the cell walls of the infectious bacterium, but in the case of Mycoplasma pneumoniae, these antibiotics are used to no prevail. Another interesting characteristic of Mycoplasma pneumoniae is that it has the ability to fuse together with the host's cells, allowing it to be practically untraceable by the host's immune response.


  • antibiotics

M. Pneumoniae contriutes to other respiratory infections
As researchers study the genome of M. pneumoniae, they discover that pneumonia may not be the only infectious disease its proteins cause. Research done in 2009 shows that M. pneumoniae may play a significant role in other respiratory infections, such as chronic asthma and wheezing syndromes. MPN372, a 591-amino-acid protein that was just recently discovered through its ability to bind to human surfactant protein A. Human surfactant protein A is the major glycoprotein component of pulmonary suractant. Surfactant is a fluid found in your lungs that lessens the friction in your lungs when inhaling and exhaling.

Case Studies and Applications

Recently, studys have been conducted to trace M. pneumoniae, and to test whether this bacterium has mutated and become resistant to existing antibiotics. This is a perfect example of evolution and the microbial level.
Three familial cases of drug-resistant Mycoplasma pneumoniae infectionby Shintaro Kamizono, Hitomi Ohya, Sadanobu Higuchi, Norio Okazaki, Mitsuo Narita

A study was done in Japan in November of 2009, claiming that there are 3 intrafamilial cases of drug-resistant M. pneumoniae. In this study, these researchers claim that an infection caused by a "defective host immune response" rather than an actual obstruction to the host's cells (Kamizono). This study is conducted between three family members. Patient 1, Patient 2 and Patient 3 were a cousin to an older sister and a younger sister, respectively. All were young children. Each were cultured with a pharyngeal swab, and another swab was taken for a "routine bacterial culture"(Kamizono, p. 723). The conclusion of the study is that there is a mutation in the domain V of 23S rRna in each of the three strains. The mutation was A2063G, which is the dominant type of drug-resistant strains found in Japan(Kamizono, p. 724).

Occurrence of macrolide-resistant Mycoplasma pneumoniae strains in Germany
by R. Dumke, H. von Baum, P.C. Luck and E. Jacobs
A study was conducted in Germany in September of 2009, to test for the presence of drug-resistant M. pneumoniae. Using PCR and real-time PCR, 167 adult outpatients were cultured. Researchers found a number of interesting facts about M. pneumoniae. Different mutations cause either high resistance in the bacterium or low resistance in the bacterium, based on where the mutation occurred. These mutations were found in the 23S rRna gene as well. If the mutation were an A to G/C transition at position 2063 or 2064, it resulted in high drug-resistance(Dumke, p.613). If the mutation occurred as a C to G or C to A at position 2617, it resulted in a lower-level resistance to antibiotics. Overall, out of the 167 outpatients cultured, only 1.2% of them were found to have been infected by the mutated M. pneumoniae (Dumke, p. 615).

Dundon, William. Malicious Microbes. Gamlingay, Sandy: Authors OnLine Ltd, 2007.

Dumke, R. , H. von Baum, P.C. Luck, and E. Jacobs. Clinical Microbiology and Infection. 16. Ulm, Germany: Journal Compilation, 2009. 613-16. Print.

Howard, Katherine J. "M. Pneumoniae "The Mystery Bug"" Index of / M. Pneumoniae. Web. 16 May 2010. <>.

Kamizono, Shintaro, Hitomi Ohya, Sadanobu Higuchi, Norio Okazaki, and Mitsuo Narita. "Three Familial Cases of Drug-resistant Mycoplasma Pneumoniae Infection." European Journal of Pediatrics 169.6 (2010): 721-26. Print.

Pakhomova, Olga N., Aleander B. Taylor, Argentina Becker, Stephen P. Holloway, T.R. Kannan, Joel B. Baseman, and P. John Hart. "Crystallization of Community-acquired Respiratory Distress Syndrome Toxin from Mycoplasma Pneumoniae." Acta Crystallographica Section F Structural Biology and Crystallization Communications 66 (2010): 294-96. Print.

Tortora, Gerard J., Berdell R. Funke, and Christine L. Case. Microbiology: an Introduction. San Francisco, CA: Pearson Benjamin Cummings, 2010. Print.