Causes, Effects, and Prevention of Pneumonia

The microbe

Bacteria are among the first forms of life that appeared on Earth billions of years ago. They are believed to have helped shape and change the planet's environment by creating atmospheric oxygen that enabled other more complex life forms to develop. Bacteria are prokaryotic unicellular organisms without a true nucleus. They grow to a fixed size and then reproduce through binary fission, a form of asexual reproduction. Under optimal conditions, they can grow and divide extremely rapidly. Bacteria range from 0.5 -5micrometres in length. There are numerous species of bacteria, but most occur in one of three different shapes namely: round (coccus), rod (bacillus), or tightly coiled spirochetes.

Gram reaction

The wide variety of shapes is determined by the bacterial cell wall made up of peptidoglycan. Some bacteria have a single cell wall and retain a purple color when stained with a dye known as crystal violet; these bacteria are known as Gram-positive. Other bacteria have double cell walls, with a thin inner wall of peptidoglycan and an outer wall of carbohydrates, proteins, and lipids. Such bacteria are pink with the application of crystal violet and are known as Gram-negative. The cell wall and the gram stain are important in identifying and classifying bacteria. Identification of bacteria is particularly relevant in medicine because correct treatments are determined by the bacterial species causing an infection.

Habitat and Nutrition

Bacteria can be found virtually everywhere. They are in the air, the soil, water, and in and on plants and animals, including humans. During unfavorable conditions, some bacteria are capable of forming highly resistant, dormant structures called endospores. These enable them to survive extreme physical and chemical stresses, such as high levels of radiation, disinfectants, heat, freezing, and so on. In this dormant state, these organisms may remain viable for millions of years.

Bacteria have a wide range of environmental and nutritive requirements. Most bacteria may be placed into aerobic, anaerobic and facultative anaerobes based on their response to gaseous oxygen. Some bacteria can make their own food from sunlight while others absorb food from the material they live in.

Roles of bacteria

Bacteria are very important in not only maintaining the atmosphere/ecosystem but also in helping to digest food, destroy disease-causing cells, and give the body vitamins. Although bacteria play an important role in the body in the global ecosystem, they also invade the human body; give off chemicals called toxins, which can damage tissue and cause diseases or infections such as pneumonia.

The disease

Pneumonia is a major cause of morbidity and mortality throughout the world, despite continuing improvements in medical management. It results from an inflammatory response in the lungs' air sac after the entry of microbial agents into the lower respiratory tract. Other microbes aside from bacteria can equally cause pneumonia; however, bacterial pneumonia will be discussed in this paper.

Etiology

Some of the many bacteria which can cause pneumonia are Streptococcus pneumonia, Legionella pneumophila, mycoplasma and Chlamydophila pneumonia. The most common bacterial pneumonia is Streptococcus pneumonia. This bacterium is a gram positive coccus and a normal inhabitant of the oropharynx in most adults. The organism has a polysaccharide capsule that protects the bacterium from phagocytosis and therefore is an important factor in its virulence. A streptococcal infection usually occurs after a viral upper respiratory tract infection such as the flu.

Pneumonia is often commonly acquired in two major ways. The first is by inhalation, whereby organisms are carried in small droplets that are inhaled into the tracheobronchial tree. The second is by aspiration, whereby sections from the oropharynx pass through the larynx and into tracheobronchial tree. Aspiration usually is thought of as a process occurring in individuals unable to protect their airways from secretions by glottic closure and coughing. However, everyone is subject to aspirating small amount of oropharyngeal secretions particularly during sleeping.

Patient Susceptibility

Pneumonia can vary from mild to severe. The type of microbe, age, and overall health of an individual affect how serious pneumonia can be. Young children, older adults ( > 65 years ), people who have other health