lecture 21 vibrio cholerae
TRANSCRIPT
بسم الله الرحمن الرحيم
FAMILY: VIBRIONACEAE
Prof. Khalifa Sifaw Ghenghesh
3 Important Genera:
• Vibrio
• Aeromonas,
• Plesiomonas
• Oxidase +ve
Habitat:
بسم الله الرحمن الرحيمVibrio cholerae
I. V. cholera O1: •Agglutinate in Antisera Directed
Against O1 Antigen.•Produce Enterotoxin.
2. Non-Toxigenic V. cholera O1:
3. Non O1 V. cholera (NCV, NAV):
II. V. cholerae O139
Vibrio choleraeGram-negative, curved rods
Vibrio cholerae Leifson flagella stain
Vibrio choleraecurved rods with polar flagellum (EM)
V. cholerae O1---------------------------------------------------
Biotye
El-torClassic
Haemolysis (SRBC) + --
VP + --
Resistance to PB + -----------------------------------------------------
VIRULENCE FACTORS:• Enterotoxin: CT• Adherence: Ability to Attach to the
Microvilli at the Brush Borders of the Epithelial Cells.
EPIDEMIOLOGY:• Causes Widespread Disease.• Human Carriers: • Modern International Travel:
PATHOGENESIS & CLINICAL INFECTION:• Infectious Dose:• Incubation period:• Abrupt Onset of Diarrhoea & Vomiting• Stool > Watery (Rice Water), Odorless• Fatality Rate:
LAB. DIAGNOSIS:• Isolation & Identification of the
Organism.• Media: TCBS• Transport Media:
TREATMENT: • Prompt Replacement of Fluid &
Elecrolytes• Tetracycline and others
PREVENTION & CONTROL:• Adequate Sewage Treatment and
Water Purification Systems.• Vaccination: ??
Typical Vibrio cholera contaminated water supply
Vibrio parahaemolyticus
• Halophilic vibrio• Associated with seafood• Gastroenteritis:
– Outbreaks of Food Poisoning
• Extraintestinal infections > wounds• Virulence Factors:
– Haemolysin > – heat-stable cytotoxin– Heat-labile enterotoxin– Adherence to human intestinal cells
Aeromonas species
A. hydrophila, A. sobria & A. caviae• Enterotoxins, Cytotoxins, Haemolysins,
Etc…• Gastroenteritis, Septicaemia, and Skin
& Wound Infections TREATMENT
• TMP-SMX, Tetracycline, Gentamicin • Resistant to -Lactam Antibiotics.