Vibrio, Campylobacter, Helicobacter, Aeromonas & Plesiomonas Flashcards
Vibrios
• Natural habitants of seawater (Halophilic)
Except:?????
Vibrio cholerae
Vibrio mimicus
Vibrios
• Mode of Transmission:
• Isolated from…
Drinking contaminated water or seafood
Gastrointestinal tract (for patients with Gastritis), blood and wound infections
Vibrios
• Motile (______flagellum), Gram-Negative bacteria; comma-shaped; or curved rods
In______, they may lose the bended shape, and retain a straight morphology
single polar
prolonged culture
Vibrios
• aerobic condition???
• Oxidase (+), EXCEPT:???
• Fermentative → Carbohydrate metabolism
Facultative anaerobes or aerobic
Vibrio metschnikoii (oxidase negative)
Vibrios Culture Media
• media used????
• Incubate at ______ hours for ____C
→ Subculture to _______???
• Initial pH of______, for initial isolation
Alkaline Peptone Water (enrichment media)
5-8 hours at 35 degrees Celsius
Thiosulfate-citate-bile salts-sucrose (TCBS) agar
8.4
• Thiosulfate-citate-bile salts-sucrose (TCBS) agar
Components????
• Important in inhibiting gram positive bacteria and lactose fermenting gram negative bacteria
• Sucrose
• oxgall (derivative of bile salt)
• sodium citrate
• bromothymol blue
• thymol blue
Vibrios
•______- High pH enhances growth of Vibrios, they cannot grow in an acidic environment / killed by acids
• Smooth Yellow color for Sucrose fermenters
pH (8.6)
Vibrios
Sucrose Positive
Vibrio cholerae
Vibrio alginolyticus
Vibrio fluvialis
Vibrio furnissii
Vibrios
Sucrose Negative
Vibrio parahaemolyticus
Vibrio vulnificus
Vibrio mimicus
• Causative agent of CHOLERA
Vibrio cholerae
Vibrios
• GIT infection characterized by severe diarrhea
• Death may occur as a result of severe dehydration
V. cholerae
Vibrios
• Mode of Transmission: Ingestion of contaminated seafoods, undercooked shellfish, and drinking contaminated water
Halotolerant, non-halophilic
Ferments sucrose
V. cholerae
Vibrio cholerae
ANTIGENIC STRUCTURE AND BIOLOGIC
CLASSIFICATION
__________
• Poorly immunogenic
__________- serologically specific
• O1 strain (causes epidemic and pandemic)
• Non-O1 straint (cholera-like disease)
• 130-139 serologic groups of the O antigen
» there may be different O antigens, but they share the same H antigen
• Flagellar (H) antigen
• Somatic (O) Antigen
V cholerae
•________ strain (causes epidemic and pandemic)
•_______ strain (cholera-like disease)
• ________ (how many) serologic groups of the O antigen
» there may be different O antigens, but they share the same H antigen
O1 strain
Non-O1 strain
130-139
Vibrio cholerae serotype 01 (3 serogroups)
• - isolated in India
• - from the Philippines
• - from Japan
Ogawa
Inaba
Hikojima
• Epidemic strain → categorized into 2 biotypes: (2)
_______ is responsible for the recent pandemics
Classical & El Tor
El Tor
Classic vs El Tor
RBC Hemolysis
Vogues-Proskauer
Polymyxin B (50 U)
Classic vs El Tor
Nonhemolytic | Beta-hemolytic
Negative | Positive Susceptible | Resistant
Classic vs El Tor
Agglutination of chicken RBC
Clinical Significance
Negative | Positive
-Cholera (First 6 Pandemics = 1817, 1829, 1846, 1863, 1881, 1899)
———————————
-Cholera Seventh Pandemic 1961
Vibrio cholerae O139(last) is very similar to Vibrio cholerae O1 _______ biotype
• To differentiate: perform?????
El Tor
Antigen detection or detect the polysaccharide capsule
Vibrio cholerae
O1 Antigen | Polysaccharide capsule
Negative
Positive
Vibrio cholerae
O1 Antigen | Polysaccharide capsule
Vibr cholerae O1
Positive | Negative
________Pathology and Pathogenesis
• Pathogenic only for humans.
• Normal gastric acidity
Vibrio cholerae
ID = >10^10 or more Vibrio cholerae in water for infection to occur
=<10^2 - 10^4 organism in food for infection to occur
Vibrio cholerae PATHOGENESIS
• Severe diarrhea = ________
→ bowel mucosa → outpouring of water and electrolytes (rice-watery stool) → severe dehydration → severe muscle cramping and anuria → death
• Vibrio cholerae produces heat labile enterotoxin (___&____subunits)
• A subunit causes I level of cAMP (increased cAMP levels usually leads to hypersecretion of water and electrolytes into the lumen)
choleragen (potent enterotoxin)
A & B
SPECIMEN: stool, rectal swab (accepted usually in the acute phase)
• Specimen Transport is done with_____
Vibrio cholerae DIAGNOSIS
Cary-Blair
• SMEAR: ????
• CULTURE
•____; (rapid growth)
• Blood Agar Plate with pH 9
• TCBS Peptone agar; smooth, yellow coloines
Gram-negative bacteria; Comma-shaped
Peptone agar
Vibrios
• STRING TEST (______)
→ viscous string
• SEROTYPING
Serogroups _______→ cholera epidemics
• Biochemical reaction patterns
0.5% sodium deoxycholate
O1 and O39
Vibrio cholerae TREATMENT
• _________ replacement is very important
• Oral_______
Note: Some Vibrio cholerae acquired resistance already (Transmissible plasmids > jumping genes)
Perform Antimicrobial susceptibility testing
Water and electrolyte
tetracycline
Epidemic and pandemic cholera
“Asiatic cholera” first noted in India due to culture and practices
Vibrio cholerae
Gastroenteritis
(ingestion of contaminated food)
Most common agent of infections caused by eating contaminated seafoods
Vibrio parahaemolyticus
ABLE TO DEMONSTRATE A PHENOMENON where clinical isolates demonstrates hemolytic capacities on BAP, while those isolated from non-human sources are not hemolytic.
→ Kanagawa phenomenon →
Kanagawa toxin, a thermostable hemolysin seen only in HUMAN samples → Wagatsuma agar
Vibrio parahaemolyticus
Is a blood agar plate that contains high salt, mannitol concentrations
Wagatsuma agar
Septicemia and wound infection
Vibrio vulnificus
Gastroenteritis and ear infection (marine environment)
Vibrio mimicus
Wound and ear infection (marine environment)
Vibrio anginolyticus
Gastroenteritis and diarrhea (marine environment)
Vibrio fluvialis
Vibrio furnissii
• Found in both fresh and seawater
Awromonas
• Causes diseases in cold-blooded animals
Aeromonas
• Lab Diagnosis:
• Mac, Eosin-Methylene Blue, SSA, CIN medium
• Perform oxidase test
• Fermentation of glucose and indole
production
• Motile: monotrichous
Aeromonas
Aeromonas
Most common human isolate
Heat labile enterotoxin and heat stable cytotoxic enterotoxin
Produce protease, lipase, and nuclease enzymes
Aeromonas hydrophilia
Motile, straight, round Gram-negative bacteria
Now categorized as enteric bacteria
Previously belonged to the Vibrionaceae family together with Aeromonas, but currently they are categorized as Enteric bacteria
Plesiomonas
Important in tropical and subtropical countries, and in Japan
Plesiomonas shigelloides
Infection: gastroenteritis
• Mild with no blood or mucus in stool
Mode of Transmission: Ingestion of contaminated food
Plesiomonas shigelloides
Plesiomonas shigelloides
• Lab Diagnosis:
BAP, NLF on MacConkey & EMB
Oxidase and Indole (+)
Gelatin test
Who’s negative?
Plesiomonas
Who has growth on TCBS agar
Vibrio
Positive for NaCl requirement
Vibrio
Who ferments inositol
Pleisiomonas
Campylobacter
19 species, but most significant is…
Campylobacter jejuni
• Campylobacter coli - accounts for____ of infections in humans
5-10%
Campylobacter
• Substitute______ when performing gram staining
Disease: Gastroenteritis and diarhea
Campylobacter coli
carbolfuchsin
Motile, microaerophilic and capnophilic
Catalase and oxidase (+)
Does not oxidize and ferment CHO
Gram-negative bacilli with comma, S, or “gull-wing” shapes
Campylobacter
• Characteristic darting motility (fast movement); best demonstrated when using darkfield microscope
• Single, polar flagellum
Campylobacter
Guillain-Barré syndrome
Campylobacter
• An autoimmune disorder resulting from cross-reactivity of Campylobacter antibodies with the nerve ganglia
Guillain-Barré syndrome
• Virulence factor:
• Able to produce Cytotoxin, cytotoxic factor and enterotoxin
• Organism multiplies in the Small intestine → invades the epithelium → inflammation
→ appearance of blood cells in stool
Campylobacter
• Specimen: Stool
• Smear: “Gull-wing” shaped rods (gram-negative)
Campylobacter
• CULTURE
• Campylobacter blood agar (SELECTIVE
due to the presence of Vancomycin, Polymyxin B, cephaothin, Trimethoprim and Amphotericin B )
Campylobacter
Campylobacter blood agar
SELECTIVE
due to the presence of (5)
Vancomycin
Polymyxin B
cephaothin
Trimethoprim
Amohotericin B
Campylobacter
(Vancomycin, polymyxin B, trimethoprim)
Skirrow’s medium
Skirrow’s medium
Vancomycin
polymyxin B
trimethoprim
Incubated at reduced atmospheric oxygen (___% O2) with____% CO2,___% N Fastidious
5
10
85
Campylobacter
Optimal Temperature for growth:
42 to 43 degrees Celsius
Gray to pink; yellow to gray colonies, nonhemolytic and slightly mucoid
Campylobacter
Helicobacter
Previously:
Campylobacter pylori
Characteristics:
Small, curved Gram negative bacilli, sometimes U form
Helicobacter
Microaerophilic
Requirement: Oxygen (5% 02), with 10% CO2, 85% N -> incubated at 35-37 C
• Can’t grow at 42 C
Helicobacter
Helicobacter
UREASE
OXIDASE
CATALASE
NITRATE
STRONG PRODUCER
POSITIVE
POSITIVE
NEGATIVE
It is known to be the agent of
• ANTRAL GASTRITIS
• DUODENAL ULCERS
• PEPTIC ULCERS
• GASTRIC ULCERS
• Implicated in GASTRIC CARCINOMA
H. pylori
• Grows best at pH 6- 7 (cannot survive acidic pH of the gastric lumen, so it burrows itself into the folds of the stomach wall)
• Invades mucosa, and releases the toxins and lipopolysaccharides;
damages the mucosal cells
Produces protease and ureases
and causes damage to the mucus secreting cells
When these cells are damaged, they can no longer produce mucus—it is very important covering of the epithelium to protect it from the effects of acids found inside the lumen
H. pylori
CLINICAL SYNDROME
• Chronic gastritis
• Duodenal ulcer
Helicobacter pylori
Helicobacter pylori LABORATORY DIAGNOSIS
MICROSCOPY
• stain???
• GOLD STANDARD:???
Special silver stain or Modified Giemsa
Histological staining and culture of biopsy from stomach or duodenum
• Tissue (mashed) → plated on SBAP = incubate at 37 C in microaerophilic and increased humidity environment
• Colonies: Small, gray, translucent, slightly beta hemolytic*
BIOCHEM: strong and very rapid urea production—
STRONGLY POSITVE
H. pylori
DIAGNOSIS
• Serum = determination of serum IgG antibodies
Stool antigen tests = ELISA
Carbon urea breath test = detects urease
• Endoscopy → to provide sample for testing for
• Biopsy
• Microbial culture
H. pylori
CHEMOTHERAPY
• Triple therapy
Metronidazole + bismuth subsalicylate or bismuth subtrate + amoxycillin or tetracycline 14 days
• Acid suppressing agent given 4-6 week
Helicobacter pylori
