Microbiology Questions, Essay Example

The dentist is describing the bacterium that causes dental caries to a patient and uses the following: aerotolerant, mesophilic, facultatively halophilic bacillus. Can you clarify to the patient by describing the organism in terms they will understand?

What the dentist is trying to say is that tooth decay, or what we call dental caries, is caused by a type of bacteria that lives in your mouth. Bacteria are microscopic, singe celled organisms that are naturally present in your mouth. Some kinds of bacteria are helpful and useful, and others have no effect either good nor bad. There are certain kinds, however, that can have adverse effects when the population reaches a sufficient number. The bacteria that causes dental caries is perfectly adapted to the warm, moist, low oxygen environment of your mouth and thrives there, especially when there is plenty of food available, as there is when you eat and food molecules stick to your teeth. The bacteria is even adapted to survive super saline conditions, so even eating salty foods, which can kill other types of bacteria that can’t live in saline conditions, won’t kill it!  The two types of bacteria that cause tooth carries are  Streptococcus mutans and Lactobacillus. When these organisms come into contact with the food you eat, especially starches and carbohydrates, it consumes them via a fermentation process that, as a byproduct, releases lactic acid which corrodes the surface of the teeth. This process is what causes the effect of tooth decay.

You work in a dentist’s office as a dental assistant. You are working on a patient that has numerous dental caries that need to be repaired. You know from your microbiology course that the likely cause is Streptococcus mutans. You need to explain to the patient why this bacteria is so common in human mouths. Make sure to include a description of the structure found on this organism that allows it to take up residence in his or her mouth.

One of the most common prevalent diseases among people living today is dental caries, or tooth decay, caused by the bacteria Streptococcus mutans. This bacteria, which thrives in the warm, low oxygen environment of the human mouth, is perfectly adapted to to its environment. It can tolerate a low oxygen  environment and even survives in highly saline conditions.  S. mutans also thrives in the human mouth because here it has an unlimited food supply. Whenever you eat, small particles of food inevitably stay in your mouth. S. mutans digests carbohydrates and sugars, including glucose, fructose and lactose, using a fermentation process by which it releases lactic acid as an end product. In addition, the bacteria form a thin, sticky film to stick to each other and to teeth by attaching to each other using a sticky polysaccharides that they produce using sucrose that is in the various foods that you eat. These films, known as plaque, cover the teeth. Once on, plaque films can build up, layer by layer, ever hardening and becoming very difficult to remove. It is a combination of the plaque films and the lactic acid produced by the bacteria that cause tooth decay.

One of the natural defenses your body has for counteracting the acidic effects of S. mutans is the production of saliva. When you eat, your body naturally produces saliva which has a low pH that causes it to neutralize the lactic acid created by the bacteria. However, substances that cause “cotton mouth” such as smoking cigarettes, marijuana and many over the counter and prescription medications, inhibit the formation of saliva allowing the lactic acid to spend more time on your teeth, causing a faster rate of decay.

Terms and Definitions

Aerotolerant: An organism that is able to live and thrive in low oxygen conditions.

Facultatively halophilic bacillus: A type of bacteria that is capable of living in highly saline environments.

Mesophilic A mesophilic organism grows well in moderate temperatures, typically between 25º and 40º C.

Polysaccharides: A class of carbohydrates that includes starch and cellulose formed by polymer molecules that are long chains of either monosaccharide or disaccharide units.

Streptococcus mutans: S. mutans is a gram positive bacteria commonly found in the human mouth. It is facultatively anaerobic.

Sucrose: The chemical name of common table sugar, sucrose is an organic molecule that is common in many processed foods and drinks.

Clinical Experience

One of the most common conditions encountered in dental patients is dental caries caused by Streptococcus mutans and Lactobacillus. From the time tardar begins to build up on the tooth to the point at which serious caries have been formed, actions of  Streptococcus mutans and Lactobacillus are typically at hand. As a dental practitioner, it is thus extremely important to be aware of how this disease functions and how it affects patients. Being able to communicate this information to patients in a way that they can understand is useful on a daily basis. A good example of this is when a young child comes in with his first cavity. He may be scared and not understand how this painful thing happened to him. Explaining to the child how the bacteria works and what steps they can take in their daily routine to inhibit more damage from occurring could help prevent that child change his dental hygiene habits and help keep him from getting another cavity.