Virus della salmonella

Typhoid fever and enteric fevers should be treated with antibiotics. Antibiotic therapy of non-typhoidal salmonellosis should be reserved for the septicemic, enteric fever, and focal infection syndromes. Antibiotics are not recommended for uncomplicated Salmonella gastroenteritis because they do not shorten the illness and they significantly prolong the fecal excretion of the organisms and increase the number of antibiotic-resistant strains.

Turn recording back on. National Center for Biotechnology Information , U. Show details Baron S, editor. Search term. Chapter 21 Salmonella Ralph A.

General Concepts Clinical Manifestations Salmonellosis ranges clinically from the common Salmonella gastroenteritis diarrhea, abdominal cramps, and fever to enteric fevers including typhoid fever which are life-threatening febrile systemic illness requiring prompt antibiotic therapy.

Structure, Classification, and Antigenic Types Salmonella species are Gram-negative, flagellated facultatively anaerobic bacilli characterized by O, H, and Vi antigens. Pathogenesis Pathogenic salmonellae ingested in food survive passage through the gastric acid barrier and invade the mucosa of the small and large intestine and produce toxins. Host Defenses Both nonspecific and specific host defenses are active. Epidemiology Non-typhoidal salmonellosis is a worldwide disease of humans and animals.

Diagnosis Salmonellosis should be considered in any acute diarrheal or febrile illness without obvious cause. Control Effective vaccines exist for typhoid fever but not for non-typhoidal salmonellosis. Introduction Salmonellae are ubiquitous human and animal pathogens, and salmonellosis, a disease that affects an estimated 2 million Americans each year, is common throughout the world.

Clinical Manifestations Some infectious disease texts recognize three clinical forms of salmonellosis: 1 gastroenteritis, 2 septicemia, and 3 enteric fevers.

Structure, Classification, and Antigenic Types Salmonellae are Gram-negative, flagellated, facultatively anaerobic bacilli possessing three major antigens: H or flagellar antigen; O or somatic antigen; and Vi antigen possessed by only a few serovars. Table Ecologic Classification of Salmonellae. Pathogenesis Salmonellosis includes several syndromes gastroenteritis, enteric fevers, septicemia, focal infections, and an asymptomatic carrier state Fig. Figure Pathogenesis of salmonellosis.

Figure Scheme of the Pathogenesis of Salmonella enterocolitis and diarrhea. Figure Invasion of intestinal mucosa by Salmonella. Figure Electron photomicrograph demonstrating invasion of guinea pig ileal epithelial cells by Salmonella typhimurium.

Host Defenses Various host defenses are important in resisting intestinal colonization and invasion by Salmonella Table 2. Table Host Defenses Against Salmonellae. Table Factors Increasing Susceptibility to Salmonellosis. Epidemiology Contaminated food is the major mode of transmission for non-typhoidal salmonellae because salmonellosis is a zoonosis and has an enormous animal reservoir. Diagnosis The diagnosis of salmonellosis requires bacteriologic isolation of the organisms from appropriate clinical specimens.

Control Salmonellae are difficult to eradicate from the environment. Salmonellosis—a review of some unusual aspects. N Engl J Med. Microb Pathogen. Epithelial cell surfaces induce Salmonella proteins required for bacterial adherence and invasion.

Salmonella interactions with the epithelial cell. A model to study the biology of intracellular parasitism. ASM News. Galan JE, Curtiss R. Cloning and molecular characterization of genes whose products allow Salmonella typhimurium to penetrate tissue culture cells. Giannella RA. Importance of the intestinal inflammatory reaction in Salmonella-mediated intestinal secretion.

Infect Immune. Influence of gastric acidity on bacterial and parasitic enteric infections: A perspective. Ann Intern Med. Pathogenesis of salmonellosis. Studies of fluid secretion, mucosal invasion, and morphologic reaction in the rabbit ileum. J Clin Invest. Pathogenesis of Salmonella-mediated intestinal fluid secretion: activation of adenylate cyclase and inhibition by indomethacin.

Outbreaks of Salmonella enteritidis infections in the United States, J Infect Dis. Ciba Foundation Symposium Pitman Press, London, In: Baron S, editor.

Chapter In this Page. Related information. Similar articles in PubMed. Review Searching for Salmonella. Darby J, Sheorey H. Aust Fam Physician. Review Salmonella Infections in Childhood.

Adv Pediatr. Development of a Salmonella cross-protective vaccine for food animal production systems. Epub Nov Review [Salmonella gastroenteritis: causes, sequelae, therapeutic perspectives]. Desgrandchamps D, Altwegg M.

Schweiz Med Wochenschr. Patten RC. Am Fam Physician. Recent Activity. Clear Turn Off Turn On. Salmonella - Medical Microbiology. Clean habitats, toys, and pet supplies outside the house when possible.

Avoid cleaning these items in the kitchen or any other location where food is prepared, served, or stored. Pick the right pet for your family. Children under 5 years of age, adults aged 65 and older, and people with weakened immune systems are at a greater risk for serious illness.

Households with these people should consider a different pet. Educate customers and employees. Pet stores, breeders, or others that sell or display turtles should provide educational materials. Symptoms of Salmonella Infection. Most people infected with Salmonella develop diarrhea, fever, and stomach cramps 6 hours to 6 days after being exposed to the bacteria. The illness usually lasts 4 to 7 days, and most people recover without treatment.

In some people, the illness may be so severe that the patient needs to be hospitalized. Salmonella infection may spread from the intestines to the bloodstream and then to other places in the body.

Children younger than 5 years, adults 65 years and older, and people with weakened immune systems are more likely to have a severe illness.

For more information, see Symptoms of Salmonella Infection. January 9, CDC and public health officials in several states investigated a multistate outbreak of human Salmonella Oranienburg infections linked to contact with pet turtles. Investigation of the Outbreak Epidemiologic, laboratory, and traceback evidence indicate that contact with pet turtles was the likely source of this outbreak.

As of January 9, , this outbreak investigation is over. Outbreak By the Numbers. Related Links. Follow Salmonella. Links with this icon indicate that you are leaving the CDC website. Linking to a non-federal website does not constitute an endorsement by CDC or any of its employees of the sponsors or the information and products presented on the website. You will be subject to the destination website's privacy policy when you follow the link.

CDC is not responsible for Section compliance accessibility on other federal or private website. Most salmonella infections can be classified as stomach flu gastroenteritis. Possible signs and symptoms include:. Signs and symptoms of salmonella infection generally last two to seven days. Diarrhea may last up to 10 days, although it may take several months before bowels return to normal. A few varieties of salmonella bacteria result in typhoid fever, a sometimes deadly disease that is more common in developing countries.

Salmonella bacteria live in the intestines of people, animals and birds. Most people are infected with salmonella by eating foods that have been contaminated by feces. Commonly infected foods include:. The Food and Drug Administration also indicates that some salmonella outbreaks have been traced to contaminants in spices. The agency is seeking ways to increase the safety of spices. Many foods become contaminated when prepared by people who don't wash their hands thoroughly after using the toilet or changing a diaper.

Infection also can occur if you touch something that is contaminated, including pets, especially birds and reptiles, and then put your fingers in your mouth. Factors that may increase your risk of salmonella infection include activities that may bring you into closer contact with salmonella bacteria and health problems that may weaken your resistance to infection in general.

Your body has many natural defenses against salmonella infection. For example, strong stomach acid can kill many types of salmonella bacteria. But some medical problems or medications can short-circuit these natural defenses.

Examples include:. The following medical problems or medications appear to increase your risk of contracting salmonella by impairing your immune system. Salmonella infection usually isn't life-threatening. However, in certain people — especially infants and young children, older adults, transplant recipients, pregnant women, and people with weakened immune systems — the development of complications can be dangerous.

If you can't drink enough to replace the fluid you're losing from persistent diarrhea, you may become dehydrated.