Study on Salmonella Typhimurium Bacteria: Report

Running head: Salmonella typhimurium 1
Salmonella typhimurium
Name
Institution of Affiliation

Salmonella typhimurium 2
Route of entry into the body
Salmonella typhimurium is a gram-negative bacteria that causes bacterial gastroenteritis.
The bacteria is toxic as a result of having a lipopolysaccharide layer on its outer membrane
protecting it from the external environment, (Arpaia et al., 2011) Gastroenteritis is characterized
by symptoms such as vomiting, abdominal cramps, and diarrhea. The onset of these symptoms
occurs 12 to 72 hours after a Salmonella typhimurium infection. Often this infection can spread
from the gastrointestinal tract to the bloodstream and consequently to other parts of the body
such as the liver and other parts to cause typhoid fever. However, for its infection to be
successful and be clinically manifested in an individual, salmonella has to surpass several
barriers in the body, (Onwuezobe et al., 2012).
Food poisoning is the main entry method for live salmonella into the body. It enters the
body through the mouth by consumption of contaminated food or water that contains the
bacteria. The bacteria then penetrate the intestinal wall, multiply by binary fission in lymphoid
tissue and thereafter it enters the systemic circulation causing Salmonellosis, (Krawiec et al.,
2014). This bacteria is present in polluted water. Animals will get infected by consuming
contaminated feed or water, direct contact with other animals, wild birds or through the grass.
When humans consume contaminated foods such as egg products, poultry, and beef products
they acquire the bacteria. In the kitchen, this bacteria can be cross transferred from raw to cooked
food by hands and contact with kitchen surfaces and equipment, (Varas et al., 2017). Humans
can be carriers as they could have and transmit salmonella without expressing any symptoms.
They do so by shedding the bacteria in their waste matter for up to one year. Salmonella can be
potentially be transferred to other individuals from persons having it up to several months as a
result of limited hand washing after toilet use, (Norton et al., 2012).

Salmonella typhimurium 3
Barriers that Salmonella Encounters
Salmonella typhimurium has to surpass several barriers in the body before causing a
successful infection. These barriers are the body's first line of defense that protects the body from
any external havoc. After ingestion into the body, the bacteria will encounter the acidic
environment of the stomach which it has to survive. Individuals like the old have a high gastric
pH hence there are more susceptible to the bacteria, (Hallstrom & McCormick, 2011). The
Salmonella also has to attach or to colonize intestinal walls of the gastrointestinal tract,
outcompete against the natural micro Bata of the gut. Another hurdle is surviving the body’s
defense mechanisms and crossing the epithelial barrier of the large intestine into the bloodstream
to successfully cause the disease
The Normal Flora that Salmonella has to Interact with
The indigenous intestinal microflora is suggested to interfere with the activity of
Salmonella typhimurium. The normal flora that the Salmonella has to interact with after being
ingested into the human body is mainly the gastrointestinal tract flora, (Swart & Hensel, 2012).
They include Bacteroides spp., Yersinia enterocolitica, Escherichia coli, Achromobacter spp.,
Actinomyces spp., Bacillus spp., Candida albicans, Enterococcus spp. and others. The natural
flora influences the physiology, anatomy, susceptibility to pathogens as well as morbidity of the
host (Gill et al., 2011). The micro-organisms in the stomach are transient and are only kept low
by the high acidity of the stomach. They include Helicobacter pylori which is a potential
pathogen of the stomach hence the Salmonella has to compete against the organism. In the ileum,
there is a moderately mixed flora. Flora of the large bowel is dense which constitutes largely of
anaerobes. The flora protects the body from pathogens such as the Salmonella mostly through
creating high competition for nutrients which starve the pathogens, forming a protective layer