gram-negative cause of severe diarrheal disease around 120,000 death per annum 200 known serogroups  cholera associated only with two serogroups (O1.

Slides:



Advertisements
Similar presentations
Slightly Curved Bacilli
Advertisements

Host-Pathogen Interactions. Symbiosis Commensual Mutualistic Parasitic.
Lecture 17: Microbial diseases of the digestive system Edith Porter, M.D. 1.
Pathogenesis. Fig KOCH’S POSTULATES Tools: Diseased animal Healthy animal Red blood cell Observe blood/tissue under the microscope Red blood cell.
The role of respiration in virulence gene expression of Vibrio cholerae HHMI 2011 Sara Fassio Dr. Claudia Häse Dr. Yusuke Minato.
Characteristics of Foodborne Toxicoinfections For sporeformers, ingestion of large numbers of live vegetative cells is usually necessary. Vegetative cells.
Flagella Slender rigid structures
Lecture Flagella and Motility 4.11 Gliding Motility 4.12 Bacterial Responses: Chemotaxis, Phototaxis, and other Taxes 4.13 Bacterial Cell Surface.
Vibrio cholerae.
Gram negative rods VibrionaceaeVibrio. General charcters of Vibrionaceae Gram negative, curved, comma shaped bacilli Motile by single polar flagella Non.
Bacterial Physiology (Micr430) Lecture 18 Bacterial Pathogenesis (Based on other textbooks such as Madigan’s)
Requisites for Successful Growth Attachment Nutrition Survival from host defence Transmission.
Vibrionaceae and Aeromonadaceae. Classification – contain three medically important genera Vibrio Aeromomas Pleisiomonas All members of these families.
Vibrio Cholera Michelle Ross, Kristin Roman, Risa Siegel.
Cholera Rose Lee and Ricardo Lé January 14, 2008 Rose Lee and Ricardo Lé January 14, 2008.
Warm-Up Why do you communicate? How do you communicate?
Bacterial Toxins Chapter 14 Add-on.
Food poisoning caused by microbial entry: Secretory (Watery ) diarrheal diseases: Causative agents: 1-Vibrionaceae. 2-Enterobacteriaceae. Cholera: is a.
Quorum Sensing This whole field has been created by Dr. Bonnie Bassler. She happened.
Katie Canul 1, Jeneva Foster 2, Christopher Wreden, PhD 2, and Karen Guillemin, PhD 2 1 California State University Monterey Bay, Seaside, CA 2, University.
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section B1: The Structure, Function, and Reproduction of Prokaryotes 1.Nearly.
Dr Sabrina Moyo Department of Microbiology and Immunology
Dr. Jyotsna Agarwal Dept. Microbiology
PowerPoint ® Lecture Slides for M ICROBIOLOGY Slightly Curved Bacilli.
Warm-Up  Why do you communicate?  How do you communicate?  How do you think cells communicate?  Do you think bacteria can communicate? Explain.
SHIGELLA By: Hunter Reynolds.
SHIGELLA Important Gram-negative, Lactose negative rods.
Analyzing the Increased and Decreased Expression of Microarray Data for Vibrio cholerae Merrell DS, Butler SM, Qadri F, Dolganov NA, Alam A, Cohen MB,
MECHANISM OF BACTERIAL PATHOGENICITY
Najran University College of Medicine Enterobacteriaecae 2 BY Dr. Ahmed Morad Asaad Professor of Microbiology.
According to the World Health Organization, “more than 2.6 billion people - over 40% of the world's population - do not have basic sanitation, and more.
MAIN IDEAS CHAPTER 11: 1. Cell communication processes share common features that reflect a shared evolutionary history. 2. Cells communicate with each.
VIBRIO CHOLERAE CHOLERA. CHARACTERISTICS GRAM-NEGATIVE, COMMA SHAPED BACILLI MOTILE – POLAR FLAGELLA OXIDASE – POSITIVE CATALASE – POSITIVE ALKALNE PH.
Cholera.
Chapter 16 Vibrio section 1 Vibrio cholera Biological characterization A. Morphology and identification  Comma shaped, curved rod  G-  Single polar.
Vibrio.
Other gram negative rods. Yersinia The genus yersinia is a member of the family enterobacteriaceae The genus yersinia includes three species of medical.
Vibrios, Campylobacters and Associated Bacteria
Methods by which pathogens cause disease: Adhesion: bacteria must bind to the cell surfaces Colonization: bacteria produce proteins and colonize parts.
How the cholera bacterium causes disease
Pathogenesis of Infectious Diseases CLS 212: Medical Microbiology.
Nature reviews Microbiology January Gram-negative Enterobacteria Diameter µm S. enterica serovar Typhimurium serovar Typhi Daniel Elmer.
General Microbiology (MICR300) Lecture 6 Microbial Physiology (Text Chapters: 3; 4.14; 4.16 and )
Non Invasive Enteritis II
Flagella. Cytoplasm Storage Granules Plasmids Ribosomes Genome Cytoplasmic Membrane Cell Wall Outer Membrane Peptidoglycan Pili Sex Pili Flagella Capsule.
Bacterial Interactions with Hosts. A. Terminology B. Hosts C. The Skin D. Oral cavity E. Intestinal Tract F. Respiratory Tract G. Genito-urinary Tract.
Medical Bacteriology MBIO 460 Lecture 9 Dr. Turki Dawoud 2 nd Semester 1436/1437 H.
 Coliform bacilli (enteric rods)  Nonmotile gram-negative facultative anaerobes  Four species  Shigella sonnei (most common in industrial world) 
Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae
Vibrio cholera Vibrio parahaemolyticus
Vibrio cholerae Vibrio is one of the most common bacteria in surface waters worldwide. They are curved aerobic rods and are motile, by polar flagellum.
PHARMACEUTICAL MICROBIOLOGY -1I PHT 313
Chapter 16 Host- Microbe Interaction
Bacteria and Disease Biotechnology.
Pathogenesis of Infectious Diseases
Gastrointestinal pathogens: Vibrio cholerae
Vibrio cholerae Gammaproteobacteria Gram-negative Comma-shaped
Vibrio cholerae Short, curved, rod-shaped with single polar flagellum
دانشگاه علوم پزشکی بوشهر برنامه ملی مبارزه با بیماریهای واگیر
SBM 2044 Lecture 9 Vibrio cholerae. SBM 2044 Lecture 9 Vibrio cholerae.
BIOL 398/S10: Bioinformatics Lab
MIC328: Lecture 19 AIMS: To provide
Salmonella Typhimurium Diarrhea Reveals Basic Principles of Enteropathogen Infection and Disease-Promoted DNA Exchange  Sandra Y. Wotzka, Bidong D. Nguyen,
Salmonella Typhimurium Diarrhea Reveals Basic Principles of Enteropathogen Infection and Disease-Promoted DNA Exchange  Sandra Y. Wotzka, Bidong D. Nguyen,
Chapter 4: Prokaryotic Profiles- the Bacteria and Archae
Virulence: Mechanisms of Gene Regulation II
Signal Transduction & Virulence
Sang Ho Lee, David L Hava, Matthew K Waldor, Andrew Camilli  Cell 
Presentation transcript:

gram-negative cause of severe diarrheal disease around 120,000 death per annum 200 known serogroups  cholera associated only with two serogroups (O1 and O139)  O1 divided in two serotypes (Inaba and Ogawa) and further in two biotypes (classical and El Tor) humans are the only known vertebrate host, infection by ingestion V. cholerae is not particular ph-resistant, so infection seems to require high dose (about a million bacteria) small intestine is the main site of infection idea that chemotaxis needed to find colonization niche and virulence factor expression Vibrio cholerae:

Virulence factors cholera toxin:  ribosylating enterotoxin  secreted AB 5 subunit toxin, B unit binds to epithelia cells, A units enter cells via endocytosis  permanent ribosylation of G proteins resulting in constitutive cAMP production.  leads to secretion of H2O, Na+, K+, Cl-, and HCO3- into the lumen  responsible for watery diarrhea (rice-water stool) toxin co-regulated pilus (TCP)  required for colonization in human and animal models  pili are believed to mediate microcolony formation gene expression is tightly regulated, no expression in extra-intestinal growth

Lifecycle of pathogenic Vibrio cholerae:

can shed ten trillion bacteria per day these bacteria are highly motile Shed bacteria can be ingested by other humans or settle into enviromental-reservoir stage Cholera is natural inhabitant of freshwater, brackish and coastal-water habitats It can exist in a free-living form or associated with hosts like zooplankton or form biofilms

Flagellar-based motility:

Different kinds of flagellation in bacteria Peritrichous flagella are found for example in E.coli, monotrichous flagellum in V. Cholerae covered by extension of the outer membrane can achieve around 100,000 revolution per minute (sodium-motive force) other forms of motility: twitching motility and gliding motility

Chemotactic in V. cholerae and other bacteria: in flagellar motility chemotaxis is achieved by modulating direction, speed… best understood in E.coli

Chemotactic in V. cholerae and other bacteria: in flagellar motility chemotaxis is achieved by modulating direction, speed… best understood in E.coli signal reception by methyl-acccepting chemotaxis proteins MCP cluster at cell pole ligand occupancy is communicated to flagella can respond to change of a few molecules

Chemotactic in V. cholerae and other bacteria: in flagellar motility chemotaxis is achieved by modulating direction, speed… best understood in E.coli V. cholerae has many chemotaxis paralogues organized in three operons but only operon 2 important in vitro strains with single or combined mutations in the paralogues retain full virulence in mouse model speculated that operon 1 and 3 regulate flagellum-independent motility

The role of chemotaxis in virulence: motility and chemotaxis ranges from being crucial to being dispensable Shigella species that are non-motile but highly infectious invasive enteric bacteria might nor require motility for infection (translocation through M cells) non-invasive pathogens (H. pylori) require chemotaxis to stay within the mucus layer chemotaxis inhibits V. cholera colonization non-chemotactic mutants showed 10-fold increased infectivity advantage is specific to host small intestine

Intestine colonization by V. cholerae: wild-type mainly colonize in the lower half of the small intestine  bile is a possible attractant non-chemotactic mutants are found in the whole small intestine  less specific – greater surface area to colonize only CCW-biased flagellar mutants show out-competition phenotype these mutants swim in straight runs direction is random but the covered distance is enough in regard to diameter of small intestine lumen

Intestine colonization by V. cholerae: wild-type colonize at the base of villi proposed that there are antimicrobial substances present that kill bacteria  like definsins released from Paneth cells non-chemotactic mutants are mainly found in the mucus layer and the luminal side of the villi reasons for wild-type to be attracted to the base of the villi: signal of max. expression of cholera toxin better protection from peristalsis might be crucial in humans

Motility and V. cholerae virulence: to determine the role of motility it must be separated from adherence effects of the flagella  comparison of fla - and fla + mot - mutants no differences in V. cholerae but motility itself seems to be important in some organism motility is inhibited by virulence gene expression - not in V. cholerae bacteria in rice-water stool are highly motile  switched back on before exit the host speculated that rice-water V. cholerae might be in a transiently non- chemotactic CCW-biased state  improved infection of new human hosts

Thank you for your attention