Bacterial Infections of the Digestive System

One of the common symptoms produced by bacterial disease is diarrhea. Diarrhea, the occurrence of more than three liquid or very loose bowel movements per day, is a common gastrointestinal disease symptom. Its causes may be bacterial, viral, fungal, or parasitic. An enterotoxin, a toxin released by certain viral and bacterial pathogens that specifically targets the intestines, can frequently be a cause of diarrhea. Acute diarrhea is an occurrence of more than three liquid or very loose bowel movements each day over a period of two days to two weeks. It is often caused by a viral infection such as rotavirus and norovirus or by bacteria such as E. coli, Shigella, Staphylococcus, and Salmonella. Acute diarrhea is commonly referred to as food poisoning. The causative agents of acute diarrhea are often transmitted by food, and disease can occur when the contaminated food transports the virus or bacteria into the body. These diseases can also be transmitted by infected individuals who do not properly wash their hands. Shigella, one cause of acute diarrhea, causes a disease called dysentery, which is a condition characterized by severe diarrhea and stomach cramps with blood or mucus in the feces and is often resolved within a few days. Recovery from acute diarrhea typically occurs within a week, even in the absence of medical intervention. Chronic diarrhea is an occurrence of more than three liquid or very loose bowel movements each day over a period of two to four weeks or longer. Chronic diarrhea can be caused by an infection or by other inflammatory states, such as irritable bowel syndrome, ulcerative colitis, and food allergy or sensitivity, and as a side effect of some medications. Bacterial causes of chronic diarrhea include Clostridium spp. and Vibrio cholera. Clostridium spp. is a common organism transmitted in hospitals to patients taking antibiotics, while V. cholera is transmitted by contaminated water. Regardless of the cause of diarrhea, dehydration is a major side effect. Dehydration can lead to side effects affecting organs throughout the body that are not receiving adequate amounts of water to function properly. Fluid replacement of water and electrolytes is important in the recovery from acute or chronic diarrhea. Dental caries, also known as a cavity, is an area of permanent tooth decay and is another common disease of the digestive system. Dental caries can be caused by acid that breaks down the tooth enamel. The acid is formed when bacteria in the mouth attach to the teeth and produce acid, which destroys the enamel and the tooth underneath. Dental caries are repaired by clearing out the diseased area of the tooth and replacing it with a filling, usually a plug made of a silver alloy containing silver, tin, zinc, and copper.

The bacterium Streptococcus mutans is the primary cause of tooth cavities. S. mutans grows rapidly and produces biofilms in the presence of sugar. The biofilm is a protective layer, and if not removed it will harden through the addition of calcium in the process of calcification, producing tartar. Several other bacteria participate in the progression of decay started by S. mutans, including species of Lactobacillus and Actinomyces. When the buildup of tartar is not removed through regular oral hygiene, the gums become irritated and inflamed (gingivitis), resulting in bleeding and a condition known as periodontal disease. The bacteria associated with periodontal diseases are predominantly anaerobic bacteria and cause the erosion of the enamel and bone surrounding the teeth. Proper hygiene is suggested to prevent the development of cavities, including regular dental cleanings, flossing and brushing at least twice per day, and use of a strong antibiotic mouthwash to kill any remaining bacteria.