Micro 3

Gram Negative

Rods

Will grow on MacConkey Agar with fermentation of lactose being shown as colored colonies

REMEMBER: All species of Enterobacteriacae will grow on MacConkey Agar

A gram negative organism that appears as rods in culture

WIll grow on MacConkey Agar, and because it ferments lactose, the colonies that show up will be colored

Urinary Tract Infections
Neonatal Sepsis
Neonatal Meningitis
Diarrhea

Ecoli is referred to as the king of urinary tract infections

The organism typically enters the urethra and will ascend through the urinary tract into the bladder, causing cystitis

REMEMBER: Ecoli is a gram negative rod that will grow on MacKonkey agar showing colored colonies due the fermentraiton of lactose

Vertical transmission during birth via the birth canal may infect the newborn and cause neonatal sepsis and meningitis

This particular strain of Ecoli has a K1 capsule (K=Kindergarten, Summer Camp)

The strain of ecoli that is associated with vertical transmission during the birthing process.

Associated with Neonatal sepsis and meningitis

REMEMBER: Ecoli is a gram negative, rod shaped organism that will grow on MacConkey agar, showing colored colonies due to the fermentaiton of lactose

Ecoli K1 (Neonatal Sepsis and Meningitis)
ETEC (Travelers Diahrrea)
EHEC (Hemorrhage in the diharrea)
EPEC (pathologic in the hospital nursery)
EIEC (Blood diahrrea and pus)

The strain of Ecoli that is associated with travelers diahrrea.

Associated with a heat labile toxin that stimulates cAMP and therefore increases the sodium, chloride, and water loos in the GI Tract

This is usually a self limiting disease and therefore does not require treatment

Associated to Ecoli strain ETEC

REMEMBERL: ETEC is the strain is ecoli that is associated with traveler's diharrea. This specific toxin increases levels of cAMP, which will result in increased water, sodium, and chloride exretion in the GI tract

The strain of ecoli that is associated with the production of VEROTOXIN. This toxin will inhibit protein synthesis and result in hemorrhage of the GI tract

Presents with bloody diharrea without fever of PMNS in the stool

May cause hemolytic uremic syndrome

The toxin that is associated with the EHEC strain of ecoli

This disease commonly presents with bloody diharrea in the absence of PMNS in the stool and fever. If untreated, may progress to hemolytic uremic syndrome

EHEC

The strain of Ecoli that is associated with watery diharrea in hospital nursuries.

Will present with water diharrea and fever in the absence of blood and PMNs in the Stool

EPEC

A stain of Ecoli that is associated with bloody diharrea, fever, and PMNs in the stool

EIEC

EHEC
Shigella

REMEMBER: EHEC is the strain of bacteria that causes bloody diharrea in the absence of fever and PMNs in the stool. This pathology is caused by the VEROTOXIN, which is produced by this strain of bacteria.

Cipro
TMP/SMX
2nd and 3rd generation Cephalosporans

ETEC

REMEMBER: This disease is mediate by LT. This toxin increasses levels of cAMP, causing an increase in NA, CL, and water excretion in the GI tract.

EHEC

REMEMBER: This process is mediated by VEROTOXIN. It may also eventually culminate in Hemolytic Uremic Syndrome

EPEC

REMEMBER: This strain of ecoli will cause diharrea in the hospital nursuries

EIEC

Shigella
Salmonela
EIEC
Enterabiasis Hemolyticus
Campolbacter Jejuni

Gram Negative

Rod

Because Salmonella Typhi does not ferment lactose, Salmonella Typhi will grow colorless colonies on the MacConkey Agar

Salmonella Typhi will also grow on SS agar and will produce black colonies

A gram negative rod that, like all members of the enterobacteriaciae family, will grow on the MacConkey agar. Because it is a non-lactose fermenter, Salmonella Typhi will produce clear colonies on the MacConkey Agar.

Salmonella Typhi will also grow on SS agar, producing black colonies.

Salmonella Typhi

Typhoid Fever

High Fever
Rose spot rash on abdomen
Perforation of the intestinal wall
rupture of the spleen

Salmonella Typhi

Salmonella Typhi is an organism that is found in the human GI tract exclusive and is therefore shed in the stool, either from the direct shedding from the intestinal wall or from the infection of the gallbladder and release of the organism in the bile

Those patients that are asymptomatic and are carriers of this organism are the most dangerous, because they unknowngly can spread the disease.

Clear Colonies on MacConkey Agar
Black Colonies of SS Agar
Widal Test

Will need to obtain cultures of both the blood and the stool because Salmonella Typhi may disseminate into the blood (this is the mechanism through which the gal bladder becomes infected)

Must ALWAYS treat this conditon as it has shown to be fatal

Can use Ampicillian because it will be elminated in the bile

1-2 days

Gram Negative

Because it is a non-lactose fermenter, salmonella eteritidis will grow in white colonies on the MacConkey Agar

WIll grow in black colonies on the SS Agar

humans AND animals

REMEMBER: Salmonella Typhi is only found in the GI tract of humans, it is NOT found in the GI tract of other animals

To have a clinically significant infection, there will need to be a high innoculation of bacteria in the body

A gram negative, rod shaped organism that will grow in white colonies on the MacConkey Agar because it does not ferment lactose and as black colonies on the SS agar.

It is found in the digestive tract of BOTH animals AND humans and therefore can be transmitted via animal hosts as well, unlike Salmonella Typhi which can only be transmitted via human carriers.

To get a clinically significant infection, there will need to be exposure to a large number of bacterial organisms

Will cause food posioning

An incubation period of 1-2 days

Results in bloody diharrea with PMNs in the stool and a fever (this is the same as EIEC)

No treatment may be needed as it can be a self limiting disease.

If treatment is needed, you can used TMP/SMX or 3rd generation cephalosporins

Gram Negative

Because it is a non lactose fermenter, it will produce clear colonies on the MacConkey Agar

It will also produce clear colonies on SS Agar

REMEMBER: Salmonella enteritidis and salmonells typhi will produce black colonies on the SS Agar and therefore this is one way that the bacteria can be differentiated.

Shiga Toxin

REMEMBER: Shigella is a gram negative, rod shaped organism that will grow clear on BOTH the MacConkey agar and SS agar. Becasue this a very virulent organism, it only requires a small innoculation dose (unlike salmonella)

A very virulent organism, therefore it only requires a small infectious dose

REMEMBER: This is different from salmonella, which require a high innoculation dose

The organism will invade the GI tract and produce the Shiga toxin.

The shiga toxin will kill GI epithelial cells and endothelial cells of the capillaries, resulting in bloody diharrea with pus in the stool as well as a fever

REMEMBER: EIEC, Salmonella Eteritidis, Camplobacter jejuni, and enteroboasis hemolyticus are all other organisms that have the ability to cause these symptoms

Both of these organisms are gram negative, rod shaped organisms that will produce clear colonies on the MacConkey agar because it is a non lactose fermenter. They will both result in bloody diharrea, fever, and PMNs in the stool

Differences include
Salmonells is a motile organism that will produce black colonies on the SS agar and will require a high innoculation dose

Shigella is a non motile organism that will produce clear colonies on the SS agar and will require only a SMALL innoculation dose.

EK!
Ecoli
Klebsiella

REMEMBER: A lactose positive will ferment lactose on the MacConkey agar and therefore produce colored colonies

PPSS!
Proteus
Psudomonas
Shigella
Salmonella

REMEMBER: These organsims, because they do not ferment lactose, will grow as colorless colonies on the MacConkey Agar.

Gram Negative

Comma Shaped

Gram negative comma shaped organisms that produce a cholera toxin

REMEMBER: The cholera toxin attaches to the interstinal mucosa an produces the cholera enterotoxin, which prevents absorption in the GI tract

Cholera: Explosive watery diharrea

After infection of the GI tract by cholera vibrio, the organism will produce the cholera enterotoxin. This enterotoxin will prevent absorption in the GI tract, resulting in rice water stools.

Because of the massive loss of water and electrolytes, metabolic acidosis may develop due the the massive loss of bicarbonate

Metabolic Acidosis due to the massive loss of bicarbonate

REMEMBER: The cholera enterotoxin will prevent absopriton of water and electroytes in the GI tract resulting in rice water stools.

Purely based in clinical observations

Observations will include rice water stools, evidence of a metabolic acidosis

Antibiotic therapy does not affect the disease process once the bacteria has attatched the the GI mucosa. Treatment is entirely supportive, treating the severe dehydration and metabolic acidosis.

Gram Negative

Rod, comma shaped organisms

Does not grow on either MacConkey or SS agars.

This organism however will grow on Skirrows agar

infection wil result in bloody diharrea associated with fever and PMNs in the stool

The most common caused of infectious diharrea

Guillan-Barre Syndrome

REMEMBER: Guillan-Barre syndrome is an ascedning paralysis that will occue 4 days to 4 weeks after infection with Camplobacter Jejuni.

REMEMBER: Camplobacter Jejuni is one of 5 organisms that will cause watery diahreea associated with blood and PMNs in the stool as well as fever. The other 4 organisms include Shigella, Salmonella, EIEC, and Enterobius Hemolyticus. Shigella will be identidied as a gram negative rod shaped, non motile organism that will produce clear colonies on the MacConekey AND SS agar. Salmonella will be identified as a gram negative, rod shaped motile organism that will grow as clear colonieson the MacConkey agar and BLACK colonies on the SS Agar. EIEC will be identified as a gram negative rod shaped organism that will produce colored colonies on the MacConkey Agar

REMEMER: Colored colonies on the MacConkey Agar will mean that the organism is able to ferment lacotse

Camplobacter Jejuni

Growth on this agar will appear like a swarm of seagulls

Erythromycin
Ciprofloxacin

Gram Negative

Rod, curve shaped organisms

Urease Positive

A gream negative, rod shaped and curved motile organism that is urease positive

REMEMBER: A urease postive organism means that the organums is capable of splitting urea into ammonia, which will raise the pH of the stomach and is errosive to the stomach wall, which promotes ulcer formation

After ingestion, the organism will infect layers of the mucosal wall of the stomach. Here it will divide and produce urease, which will cleave urea in ammonia. The ammnia is caustic to the mucosa, and will result in subsequent inflammaiton and ulceraiton of the mucosa.

Busmuth Sulfate to coat the mucosa
Erythromycin
Metonidazole
Orneprazol to inhiit the proton pump and reduce acid secretion

Helicobacter Pylor

REMEMBER: Helicobacter pylori is a urease positve organism, meaning that urea will be cleaved into ammonia. The ammonia will buildup in the stomach, causing the breath to smell like ammonia. The ammonia will also cause irritation of the gastric mucosa.

Gram Negative

Because kelbsiella is a lactose fermenting organism, it will produce colored colonies on MacConkey agar

A carbohydrate antiphagocytic capsule

A gram negative lactose fermenting organism that produce an antiphagocytic carbohydrate capsule

Able to be partially identified as klebsiella as it will grow with colored colonies on the MacConkey agar

REMEMBER: Ecoli is the only other enterobacteria that will ferment lactose, and the differentiating factor between these two organisms the presence of the antiphagocytic capsule on the klebsiella organism

UTI in debilitated patients
Hemorrhagic lesions in the lung

Klebsiella Pneumoniae

part of the normal GI flora, and therefore can casue UTIs by introdution via a foley catheter or pneumonia due to aspiration of the normal flora of the respiratory tract

Klebsiella Infection

REMEMBER: Klebsiella is a gram negative, rod shaped, lactose fermenting organism that is associated with a carbohydrate antiphagocytic capsule. This organism is associated with urinary tract infections or hemorrhagic infections of the lungs

Ecoli
Proteus
Klebsiella
Pseudomonas

Gram Negative

Becasue proteus is non-lactose fermenting, it will grow as clear colonies on MacConkey Agar

The organism will have swarming motility on the agar

Urease Positive

Proteus

Sturvite Kidney stones that may be associated with sepsis

The struvite stones form due to the alkalinization of the urine that occurs in an individual infected with proteus.

REMEMBER: Struvite stones are commonly comprised of magnesium, ammonia, and phosphate. They will be translucent on xray or CT scan. These stones are minor stones in the population, with the majority of stones being comprised of calcium, oxalate, and phosphate. The COP stones will be radio-opaque

A test that can be utilized to diagnose infection with Proteus or Rickettsiae.

This is becasue the two organisms share some strains of antigenicity, and therefor when the two are mixed together, they will cause agglutination

Gram Negative

Becasue this is a non lactose fermenting organism, it will grow as clear colonies on the MacConkey Agar

The cultures will however smell like grap juice, and may appear as a blue-green due to pigment that is produced by the pseudomonas organism

Exotoxin that will inactivate EF-2
Antiphagocytic Capsule
Iron containing compounds that damage endothelial cells

Hospital Acquire Pneumonia
Pneumonia in CF patients
UTI
Wound infections in burn patients
Osteomyelitis in IV drug users
Swimmers Ear infection

This is a highly resistant organism, therefore multiple combinations of antibiotics may be needed to determine which ones will be effective against the particular organism causing the infection

May use ticarcillan and aminoglycosides or Cipro

REMEMBER: Aminoglycosides inhibit the 30S subunit, cipro will inhibit DNA Gyrase

Diptheria
Pseudomonas

Immune Compromised
Patients in the hospital

Gram Negative

The most abundant organism of the normal flora of the GI tract

Sepsis
Peritonitis
Abdomina Abcesses

These diseases typically are associated with bowel surgurey

Metronidazole

REMEMBER: The mechanism of action is primarily to inhibit energy production in the bacteria

Ecoli
Bacteriodes