Introduction
Salmonella
Salmonella is a Gram-negative facultative rod-shaped bacterium, motile bacteria live in the intestinal tracts of warm and cold blooded animals. Is the most complex genus in the family Entero bacteriaceae. lactose non-fermenters motile (with a few exceptions), facultatively anaerobic, produce acid from glucose usually production of gas, and are oxidase negative Most produce hydrogen sulphide except Salmonella Typhi and Salmonella Paratyphi A, which are a weak producer. Not produce urease. Common symptoms including diarrhea, fever, and cramps usually last 4 to 7 days. This is salmonella attacking human cells. Most people recover without treatment, but some cases be more serious. Salmonella is a bacterium that causes foodborne illness. It resides in the intestines of animals and is transmitted through animal foods. Salmonella is considered a very common infection and second most common foodborne infection after norovirus. While salmonella itself is not typically a severe disease, it is still a leading cause of death from foodborne diseases, accounting for around 400 deaths per year in the USA the most common sources of salmonella are raw or undercooked eggs also carry a risk of salmonella, as the inside part of the egg can be contaminated. Other meats are also common.
Symptoms of salmonella
Symptoms
typically start within 6 hours of ingesting the bacteria. Diarrhea, often
mucoid or bloody, is the most common symptoms, accompanied by abdominal cramps
and nausea. Vomiting is also common, especially in children, and fever is
frequently observed with salmonella infections. Symptoms generally last for 4-7
days. In some individuals, especially the immunocompromised, the infection can
become severe, requiring immediate medical attention.
Subspecies enterica
1. Typhoidal (typhoid fever and paratyphoid fever). Also called enteric fever. Salmonella
enterica serovars Typhi & Paratyphi A, B, C.
2. Non-typhoidal Salmonella (NTS). All other S. enterica sub species enterica are cause of NTS infecting or colonizing a broad range of vertebrate animals including mammals, reptiles, birds, and insects.
1. Typhoid or enteric fever:
Caused by salmonella
typhi and salmonella paratyphi. Lives only in humans, the transmission is
fecal-oral route. Most people in developed countries pick up tyhoid bacteria
while they are traveling and they can spread it to others through the
fecal-oral route. If you eat food that has been handled by someone who has
typhoid fever and who hasn’t washed carefully after using the toilet, you can
become infected. Also transmission can be direct contact or indirect contact
via contaminated food/water. Symptoms include high fever, weakness, stomach
pain, and can lead to complications. Chronic carriers (people carrying the
bacteria after recovery) are common. Vaccines are available for prevention,
especially for travelers to high-risk regions.
2. Nontyphoidal salmonella:
Can cause a range of
gastroenteritis- related illnesses. Infects a wide range of animals and can be
transmitted to humans through contaminated food, water, or contact with
infected animals. Symptoms include diarrhea, abdominal cramps, nausea, and
fever, varying in severity. Chronic carries are rare, and most people clear the
infection without becoming carriers. No specific vaccine, prevention focuses on
proper food handling and hygiene.
Pathogenesis
& Clinical Findings
- Salmonellosis includes several syndromes:
- Enteric fever: S typhi, S paratyphi-A
- Septicemia or focal infections: S. choleraesuis
- Gastroenteritis: S typhimurium and S. enteritidis, however, any serotype can produce any of the syndromes.
Enterocolitis
Is the most common
manifestation of salmonella infection, mainly caused by S. typhimurium and
S. enteritidis, but can be caused by any of group I serotypes of
salmonellathe stools may contain, blood, and mucus.
Epidemiology
Contaminated
food is the major
mode of transmission for non-typhoidal salmonellae. salmonellosis is a
zoonosis and has an enormous animal
reservoir (chickens, pigs, and cows etc.). Typhoid fever and other
enteric fevers primarily involves person-to-person spread because these
organisms lack a significant animal reservoir. Contamination with human feces
is the major mode of spread, and the usual vehicle is contaminated water.
Asymptomatic human carrier state exists for the agents of either form of the
disease. 3% of persons infected with S.
typhi and 0.1% of infected with non-typhoidal salmonellae become
chronic carriers.
Haw to
treatment salmonella
First-line
treatment is rehydration. For infants, frequent breast milk or formula milk is
recommended. Older children and adults should take oral rehydration solution.
Ciprofloxacin, ampicillin, tetracycline, trimethoprim -sulfamethoxazole and
chloramphenicol.
Prevention of salmonella
Sanitary control
of water, food, and milk, Proper sewage disposal, Disinfection of excreta and Early
detection and treatment of carriers: e.g : Food handlers.
Conclusion
Salmonella
is an important genus of Gram-negative bacteria that causes a wide range of
diseases in humans and animals, ranging from mild gastroenteritis to severe
systemic infections such as typhoid and paratyphoid fever. Transmission usually
occurs through contaminated food, water, or direct contact with infected
animals. Because of its public health importance, prevention depends on proper
hygiene, safe food handling, vaccination (for typhoid), and surveillance
systems. Overall, Salmonella remains a major global pathogen of medical and
veterinary concern.
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