Typhoid fever is an illness caused by the bacterium Salmonella Typhi (S. Typhi).
It infects your small intestines (gut) and causes high fever, stomach pain and other symptoms.
Typhoid fever is also called enteric fever.
Salmonella is a gram negative rods genus belonging to the Enterobacteriaceae family.
Within 2 species, Salmonella bongori and Salmonella enterica, over 2500 different serotypes or serovars have been identified to date.
Gram-negative rods
Do not ferment lactose
Antigens of Salmonella species
Cell wall O antigen
Flagellar H antigen
Capsular Vi (virulence) antigen)
Salmonella bacteria are widely distributed in domestic and wild animals.
They are prevalent in food animals such as poultry, pigs, and cattle; and in pets, including cats, dogs, birds, and reptiles such as turtles.
Person-to-person transmission can also occur through the faecal-oral route.
Incubation Period: 7 to 23 days (average 10 to 14 days)
Aerobic or facultative anaerobes
Optimal temperature 37°C
Optimal pH
Nutrient broth: Uniform turbidity
Blood agar: Colonies 2 to 3 mm, circular, low convex, smooth, translucent, and non-hemolytic
MacConkey agar: Non- lactose fermenter ( colorless colonies)
Deoxycholate Citrate Agar (DCA): Non-lactose fermenter colonies
Wilson and Blair bismuth sulfite medium: Jet black colonies with a sheen
Principle:
The strip consists of 20 microtubes containing dehydrated substrates. The tests are inoculated with bacterial suspensions that reconstitutes the media. During incubation, specific bacterial metabolites are produced that can be detected via color changes. Based on this information, bacterial identification is often possible.
3. What is Typhoid fever?
• Typhoid fever is an illness caused by the
bacterium Salmonella Typhi (S. Typhi).
• It infects your small intestines (gut) and
causes high fever, stomach pain and
other symptoms.
• Typhoid fever is also called enteric fever.
4. • Salmonella is a gram negative
rods genus belonging to the
Enterobacteriaceae family.
• Within 2 species, Salmonella
bongori and Salmonella enterica,
over 2500 different serotypes or
serovars have been identified to
date.
5.
6. Important properties of Salmonella
species
• Gram-negative rods
• Do not ferment lactose
• Antigens of Salmonella species
Cell wall O antigen
Flagellar H antigen
Capsular Vi (virulence) antigen)
7.
8. Sources and transmission
• Salmonella bacteria are widely distributed in
domestic and wild animals.
• They are prevalent in food animals such as
poultry, pigs, and cattle; and in pets, including
cats, dogs, birds, and reptiles such as turtles.
• Person-to-person transmission can also occur
through the faecal-oral route.
16. API (Analytical Profile Index) 20E
Principle:
The strip consists of 20 microtubes containing
dehydrated substrates. The tests are inoculated with
bacterial suspensions that reconstitutes the media.
During incubation, specific bacterial metabolites are
produced that can be detected via color changes. Based
on this information, bacterial identification is often
possible.
