Enterobacteriaceae & Salmonella Flashcards
All Enterobacteriaceae are:
Gram stain?
Shape?
Catalase positive or negative?
Oxidase positive or negative?
Gram -
Rod shaped
Catalase positive
Oxidase negative
Enterobacteriaceae hide their cell wall (CW) by _____ _____
outer membrane
Enterobacteriaceae has ____ genera with a total of ____ species
68, 355
What can be seen here?
Enterobacteriaceae
Medically important eight bacterial genera
within Enterobacteriaceae include:
CEEK group is also called coliform bacteria b/c they ferment lactose.
The CEEK group are _______ fermentors
Which members of CEEK are Lactose positive?
lactose
Citrobacter, Enterobacter, Kiebsiella
SPY-Sh group are __________ ___-______.
Which members of SPY-Sh are Lactose negative?
lactose non-fermentors
Salomonella, yersinia, proteus
IMViC test mostly used in enterobac group. This is an abbreviation for the Indole test uses trytophan amino acid.
VP = ketone bodies, such as acetone
Which tests will help us determine the presence of Enterobacteriaceae?
Test for the presence of Lactose fermentation on MacConkey Agar.
Tests help us determine which bacteria cause disease in animals. These tests are:
1. Lactose fermentation (+/-)
2. H2S, CO2, or no as on TSA agar
3. Urease - if positive, they are proteins, if negative they are salmonella
If produce gas = citrobacter
If your MacConkey Agar turns pink, what does that mean?
Positive = pink colonies –> coliform bacteria
Which Enterobacteriaceae are considered to be “fast”?
Klebsiella, Enterobacter
Which Enterobacteriaceae are considered to be “slow”?
Citrobacter
If your MacConkey Agar turns pale, what does that mean?
Negative = pale colonies –> highly pathogenic bacteria.
You then test for H2S production on triple sugar iron (TSI).
Proteus and Salmonella are positive for?
H2S on triple sugar iron (TSI)
Proteus is Urease positive or negative?
positive
Salmonella is urease positive or negative?
negative
Yersinia is negative for ____ and _____, but positive for?
H2S, CO2, Ureas
Lactose positive bacteria are also called?
Coliform bacteria
Which Enterobacteriaceae are Indole positive?
Citrobacter
Which Enterobacteriaceae are Indole negative?
Klebsiella, Enterobacter, Salmonella, Yersinia, Proteus
Which bacteria are Voges-proskauer negative?
Citrobacter, Salmonella, Yersinia, Proteus (glucose)
Which bacteria are Voges-proskauer positive?
Klebsiella, enterobacter (acetoin)
Which Enterobacteriaceae are Citrate positive?
Yersinia
Proteus
Which Enterobacteriaceae are Citrate negative?
Salmonella
Klebsiella
Enterobacter
Citrobacter
Which Enterobacteriaceae are Urease negative?
Salmonella, enterobacter
Which Enterobacteriaceae are Urease positive
yersinia, proteus, klebsiella, citrobacter
Which Enterobacteriaceae produce H2S gas (black)?
Salmonella
Proteus
Citrobacter
Which Enterobacteriaceae produce CO2 gas (yellow) ?
Enterobacter
Klebsiella
Yersinia produces NO gas but is yellow in color.
All
Enterobacteriaceae are _______ anaerobic
* Non- ______
* Non- _____ forming
* Grow on bile containing media (?)
* Almost all are motile by flagella except the following:
?
Facultative, fastidious, spore, MacConkey agar, 1. Klebsiella
2. Shigella
The habitat of
Enterobacteriaceae
They love small and large intestine
Live inside large and small intestine
SEEK group in proteus live in the mouth, vulva area, teats of females
Enterobacteriaceae
oral-fecal transmission route
Entry – almost all of them by oral route by ingestion of contaminated food/feed & water (except Y. pestis: by flea bite)
Exit – feces, urine, milk, nasal discharge
Enterobacteriaceae
Commensal of digestive tract
Opportunistic diseases
Diarrhea
Urinary tract infection
Septicemia
Pneumonia
Meningitis
The greatest impact of
Enterobacteriaceae in humans
& animals
- Major cause of gastro-intestinal infection (diarrhea & dehydration)
- Major cause of liver abscess
- 70% of urinary tract infection
- 33% of bacteremia &
septicemia is caused by
Enterobacteriaceae - Major cause of meningitis
- Major cause of mastitis originated from environmental
source in female animals
Enterobacteriaceae causes _______
diarrhea
____/____ and ______ disturbance in diarrhea causes morbidities
and mortalities.
Acid/base, electrolyte
________ children die each day globally from. ___% of them will die due to diarrhea = _______ child deaths from diarrhea each year
2,195, 10, 801,000
Virulence factors of
Enterobacteriaceae
* Surface structures (3)
- Capsule
- Flagella, fimbriae, adhesins and invesins
- Lipopolysaccharide is → endotoxin → pyrogenic/fever
Intestinal adhesion,
colonization,
inflammation,
fever,
damage blood vessels; hence, causes ischemic necrosis
Virulence factors of
Enterobacteriaceae
* Enzymes (2)
- Catalase
- superoxide dismutase
both = detoxify free radicals
Virulence factors of
Enterobacteriaceae
* Toxins and secreted substances (3)
- Hemolysins – kills host cells to make iron available for bacteria
- Siderophores/Enterobactin - Rob iron from the host cell
- Pathogenicity island on their genome encoding toxins,
enzymes, and type three secretion systems (T3SS)
Type 3 secretion system (T3SS) = syringe-like apparatus on
their cell wall to directly
inject bacterial enzymes,
toxins,
cytokine inhibitors into the host cells (a smart attacking
method).
Gram-positives do not
have such a syringe-
like apparatus.
Enterobacteriaceae enjoys antigenic diversity
using its lipopolysaccharide (O), flagella (H) & capsule (K) whilst attacking the
host using lipid A part of its LPS.
Enterobacteriaceae have wide _______ diversity (antigenic
heterogeneity) within a species due to?
serotype, 1. somatic lipopolysaccharide (O) antigen
2. flagella (H) antigens
3. capsular (K) antigen
Notes from images on this slide.
Culture media for isolation, identification,
and growth of
Enterobacteriaceae
1. ______ agar
2. ________ agar (Most Gram ______ bacteria
cannot grow on this media as it has ?, except _______)
3. ______ ______ _____ (___) agar
4. _____ ______ _____ (____) agar
Blood, MacConkey, positive, bile salt
and crystal violet, Enterococcus, Eosin Methylene Blue (EMB), Triple Sugar Iron (TSI)
Enterobacteriaceae is a global threat due to
_______ issue by contributing ____ genera to _______
AMR, 3, ESKAPE
Salmonella shares all characteristics that we
described for _________
Enterobacteriaceae
Salmonella is
Gram ________ ____
* Unique characteristics
______ non-_____
______ negative
Produce ______ _____ (___) gas that is a special tests
Salmonella; H2S
production (_______ ___ smell and providing _____ colonies)
All motile by _____ flagella (except ?)
no _____ = gamma hemolysis on ___ agar
negative, rods, Lactose, fermenter, Urease, hydrogen sulfide, H2S, rotten egg, black, peritrichous, S. Gallinarum and S. Pullorum, hemolysis, blood
Widely used culture media for isolation ofSalmonella
- MacConkey agar,
- Eosin methylene blue
- Selective culture media
- Brilliant green agar
- Salmonella and Shigella agar
Selective enrichment growth media for isolation and identification of
Salmonella
Salmonella habitat
Normal digestive tracts flora of:
Mammals (humans, primates, domestic and wild herbivores,
carnivores, rodents)
Birds (chickens, turkeys, ducks, geese, pigeons, psittacines
(parrots), sparrows, starlings, pheasants, quail, guinea fowl,
partridges, peacocks)
Reptiles (turtles, tortoises, snakes, lizards, chameleons, and
iguanas)
amphibians
Fish
Invertebrates (insects, flies)
__________ is normal flora of reptile and amphibian skin
S. Typhimurium
Salmonella Transmission routes – entry vs. exit
Oral-fecal transmission route for entry and
exit, respectively
* Entry
Infection occurs from ingestion of
bacteria with:
water
feed or
food (eggs, milk, meat, fish)
* Exit
feces
One exception: Trans-ovarian
transmission to next generation in poultry
is possible e.g.
Salmonella Pullorum
Salmonella has ____ species comprising of
about ______ serotypes
two, 2500
All species of salmonella are motile with 5-10 peritrichous flagella
S. Gallinarum and
S. Pullorum are non-
motile (no flagella = no H antigen)
Salmonella has about 2500 serotypes based on:
lipopolysaccharide (O) = 45-60 serotypes
flagella protein (H) = 85 serotypes
Over 2500
Salmonella serotypes by
combining 85 H x 45-60 O antigens
The 2500 serotypes of
Salmonella are classified into
two species…
S. enterica and
S. Bongori
Clinically relevant
Salmonella belongs to
__________, which consists of ___ _______.
S.
enterica, 6 subspecies
What are the 6 subspecies of Salmonella enterica
Salmonella is among the 7 priority diseases of the
_______ ______ ______ _____ (_____) in the USA
National Poultry Improvement Plan, NPIP
- The goal is to ban any shipment from a poultry farm or hatchery if they are positive
to the above pathogens. - Thus, before any shipment, be tested & free of the above pathogens as per USDA
inspection service to ensure the interstate “clean” shipment program
Salmonella Outbreak Linked to _____ _______
Wild Songbirds
- Birds can carry germs like ________ while looking _____ and _____.
- Salmonella germs can spread ________ birds, to ____, and to ______.
- _____ ____ can carry Salmonella and make people sick.
- Always take steps to stay healthy around _____ ____ and ____ ____
Salmonella, healthy, clean, between, pets, people, Wild birds, wild birds, bird feeders
Salmonella pathogenicity island (SPI)-1, SPI-2 and other SPIs are present on the Virulence _____ or _______ of Salmonella. Both DNAs encoding Type ___
secretion systems (T3SS) and other dangerous toxins.
plasmid, Genome, 3
see slide 35
Identify the 3 broad virulence factors for pathogenicity for Salmonella
A. Body structures for adhesion & binding
- Fimbriae (pili)
- Has 5-10 flagella
- Capsule (vi)
- Lipopolysaccharide (endotoxin)
Salmonella possess Fimbriae (pili) which are used for - ______ & ______ of __ and _______ for ______ gene transfer/sharing
adhesion, invasion, gut, conjugation, horizontal
Salmonella possess ___-____ flagella which are used for?
5-10 flagella - motility, adhesion and flagella (H) antigenic variation
Salmonella possess a capsule (___) which is used for?
adhesion, shield/protect Salmonella from antibodies, complement, & phagocytes
Salmonella possess Lipopolysaccharide (endotoxin) which are used for?
Lipid A - adherence, intestinal colonization, induce
inflammation, fever, damage endothelium of blood vessels; hence causes ischemic necrosis (e.g.
gangrene in S. Dublin).
The 3 broad virulence factors for pathogenicity
B. Enzymes for invasins
- catalase
- superoxide dismutase
- Siderophores - rob iron from host cell and transport it to bacteria
Salmonella contain the enzymes catalase and superoxide dismutase which are used to protect against?
host reactive oxygen species (ROS).
Salmonella contain the enzyme Siderophores which function to rob _____ from ___ cells and transport it to bacteria.
iron, host
The 3 broad virulence factors for pathogenicity
C. Toxins
Steps/processes of
Salmonella infection & pathogenesis
Virulence factors expressed for host cell invasion
and intracellular survival and multiplication
Salmonella is an ______ pathogen with uptake into the ________ cells of the ____ _____ being required for pathogenesis.
intracellular, epithelial, GI tract
Salmonella primarily affects the ______ and ______ ______ in adults, leading to _________ with limited systemic transloocation.
cecum, proximal colon, enterocolitis
Once ingested how long is the incubation period for Salmonella?
7-14 days
What cell types does Salmonella encounter once it reaches the submucosa?
Dendritic cells, MQs, enterocytes
After reaching the submucosa, Salmonella bacteria travel to four different parts of the body - name these parts.
What happens after it reaches these parts of the body?
Peyers patches
Mesenterial lymph nodes
Reticulo-endothelial system
Blood stream
After it reaches the blood stream –> secondary infection.
Secondary infection due to Salmonella affects which parts of the body?
Bone marrow
Liver
Spleen
Gallbladder = chronic reservoir
This leads to reinfection via bile excretion.
What are the complications of Salmonella infection (gastroenteritis)?
- Toxic encephalopathy with myocarditis and hemodynamic shock
- Necrosis of Peyer’s patches with peritonitis and sepsis.
The three forms of
Salmonella infection in farm animals,
pets, and poultry:
(a) silent, (b) enteritis & (c) systemic forms
The silent form of Salmonella is also called the ____ (_____) form and causes _______ (______), _________, _______ and Salmonella shedding in the ______.
gut, enteric, enteritis, colic, dehydration, feces
The vast majority of farm animals, pets, and poultry harbor Salmonella in a chronic carrier state in which parts of the body?
How is Salmonella then spread to other hosts?
Gallblader, mesenteric lymph nodes, tonsils, MQs, fibroblasts.
They shed it silently in their feces for months or years to infect others or relapse (common).
Eneteric/colic diseases (acidosis, diarrhea, &
dehydration) + systemic disease + abortion
How is Salmonella diagnosed?
Diagnosed by fecal culture followed by different biochemical tests.
List and describe the steps of diagnosing Salmonella.
- Take sample and mix with ________ broth medium (___-_____ media).
- Transfer some of sample into _______ broth and ______ ________ broth.
- Transfer sample mixed with tretrathionate broth & selenite cyteine and mix with ______ _____ agar media and ______ and ______ media.
Lactose, non-selective, tetrathionate, selenite cyteine, brilliant green, salmonella, shigella
How do you serotype for Salmonella?
Serotype using O and H antisera.
Treatment with antimicrobials is controversial but
all agree on supportive fluid and electrolyte therapy
The control and prevention of
Salmonella is
mainly linked to
control of fecal contamination
List the ways to control and prevent salmonella (1)
List the ways to control and prevent salmonella (2)
