Microbiology

Microbiology Study Guide

Escherichia Coli Infections These infections are caused by the gram-negative rod bacteria, Escherichia coli . This bacterium causes infections in humans by invading the tissues and producing toxins. One of the common infections caused by these bacteria is travelers’ diarrhea, which has been observed among the people travelling to Caribbean and Central American nations. The bacteria even possess the ability to infect infants, causing diarrhea and unitary tract infections. In extreme cases, this infection can cause hemorrhage in the kidneys. Campylobacteriosis Campylobacteriosis is caused by the curved gram-negative rod bacteria campylobacter jejuni . The infection is transmitted through contaminated milk. Major symptoms include diarrhea with bleeding, fever, and pain in the abdomen. The bacteria have the ability to limit it, but faster recovery is possible through taking the antibiotic drug, Erythromycin. Gastric Ulcers Disease/Helicobacter Pylori Disease The gram-negative rod bacteria Helicobacter Pylori is responsible for causing gastric ulcers. The organism takes its position in the lining of the stomach where it produces enzymes that convert urea to ammonia. The outcome of this infection is the elevation of pH levels in the body followed by deep penetration of the stomach wall’s mucosa. The infection can be treated with an antibiotic therapy of tetracycline. Shigellosis Popularly known as bacillary dysentery, Shigellosis is caused by gram-negative rod bacteria from the species of Shigella, S. dysenteriae, S. boydii, S. sonnei , and S. flexneri. The worst victims of this disease are young children in whom the infection is transmitted through fecal passageways. The bacteria generate a Shagalike toxin that affect the health of individuals. Major symptoms include lesions and inflammation of the intestinal lining, followed by blood and mucus formation in stool. In extreme cases, dehydration becomes fatal and calls for urgent rehydration. The treatment of the disease is antimicrobial drugs like quinolones. Botulism Caused by the gram-positive rod Clostridium botulinum , botulism is transmitted through food. The bacterium generally transmits and reproduces through food in a vacuum sealed anaerobic environment and produces dangerous exotoxins that cause infection. Toxins produced by these bacteria infect the acetylcholine released by the human body in between the nerve and muscle cells. Symptoms include paralysis and arrest in the respiratory system, which may cause death. The disease is highly fatal and long-term treatment with antitoxin botulism can prevent death; however, no vaccination or drugs are otherwise available to prevent the disease. Staphylococcal Food Poisoning One of the most common types of food poisoning in the United States is Staphylococcal food poisoning, caused by the species Staphylococcusaureus . The microorganism produces an enterotoxin, which is

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