vibriosios, helicobacter &...

VibriosVibrios, Helicobacter & , Helicobacter & CampylobactersCampylobacters

Junqi Zhang (张俊琪), PhD

MOH&MOE Key Lab of Medical Molecular VirologyShanghai Medical College, Fudan UniversityShanghai Medical College, Fudan University

(复旦大学上海医学院分子病毒学教育部/卫生部重点实验室)

Vibrios, Helicobacter & Campylobacters

Dr. Junqi Zhang [email protected]

Department of Medical Microbiology & Parasitology,Shanghai Medical College,FudanUniversity

mailto:[email protected]

General Introduction

uVibrio cholerae produces an enterotoxin that causes cholera, a profuse watery diarrhea that can rapidly lead to dehydration and death

2014/10/19 Vibrios, Helicobacter & Campylobacters/ Junqi Zhang

3

can rapidly lead to dehydration and death

uHelicobacter pylori has been associated with gastritis and duodenal ulcer disease

uCampylobacter jejuni is a common cause of enteritis in humans

üVibrio choleraefree-living inhabitant of fresh water, but causes infection only in humans


4

Electronic microscope Gram’s stain

The Medically Important Vibrios Organism Human Disease

V.cholerae serogroups O1 and O139 Epidemic and pandemic cholera

V.cholerae serogroups non-O1/non-O139

Cholera-like diarrhea; mild diarrhea; rarely, extraintestinal infection


5

V.parahaemolyticus Gastroenteritis, perhaps extraintestinal infection

Others

V.mimicus, V.vulnificus, V.hollisae, V.fluvialis, V.damsela, V.anginolyticus, V.metschnikovii

Ear, wound, soft tissue, and other extraintestinal infections, all uncommon

Genus Vibrio

V.cholerae

Serotype O1

Non-O1 -other serovars

biotypes

Serosubgroups

Phage types

E1 Tor

classical

OgawaInabaHikojima


6

Genus Vibrio

Other species

Non-O1 -other serovars

V. parahaemolyticus: food-associated diarrheal diseaseV. vulnificus: wound infection; septicemiaV.alginolyticus: otitis externa; wound infection

Non-agglutinating vibriosNon-cholerae vibrios

üGram-negative

üComma shape or curved rod

üactively motile by means of a

Morphology & Identification


7

üactively motile by means of a polar flagellum

Growth Characteristics v ferments sucrose and mannose but not arabinose

vHalophilic( requiring the presence of NaCl to grow )

Culture


8

Culturevconvex, smooth, round colonies that are opaque and granular in transmitted light

vV.cholerae grows well one (TCBS) agar

vvibrios grow at a very high pH (8.5–9.5) and are rapidly killed by acid

Negative control


9

(TCBS) agar pH (8.5–9.5)

Antigenic Structure & Biologic Classification

ua single heat-labile flagellar H antigen

uO lipopolysaccharides (confer serologic specificity )

pAntigenic Structure

pBiologic Classification(O1)


10

uclassic biotypes

uEl Tor biotypes

produces a hemolysin resistant to polymyxin B

pBiologic Classification(O1)

üVibrio cholerae EnterotoxinV.cholerae produce a heat-labile enterotoxin

consisting of 5 subunits B and 1 subunit A

Adenyl cyclase activated cyclic AMP secretion water/ions

subunit A


11

Mechanism similar to Heat labile toxin of ETEC

Diarrhea occurs—as much as 20–30 L/d—with resulting dehydration, shock, acidosis, and death

secretion water/ions

Vibrio choleraeEnterotoxin

1 2

hypersecretion of electrolytes and water

3 4

Dehydrationshockacidosisdeath

2014/10/19 12Vibrios, Helicobacter & Campylobacters/ Junqi Zhang

n Do not reach the bloodstream but remain within the intestinal tractn Virulent V.cholerae organisms attach to the microvilli of the brush

Pathogenesis & Pathology


13

Pathogenisis of Cholera toxin

attach to the microvilli of the brush border of epithelial cells nMultiply and liberate cholera toxin and perhaps mucinases and endotoxin n Infective dose vary dependent on host gastric acidity

Clinical Findingsüincubation period : 1–4 days

üsudden onset of nausea and vomiting and profuse diarrhea with abdominal cramps

ürice water stool: contain mucus, ürice water stool: contain mucus, epithelial cells, and large numbers of vibrios

“rice water” stool2014/10/19 14Vibrios, Helicobacter & Campylobacters/ Junqi Zhang

Diagnostic Laboratory TestsSpecimens

stools contains mucus flecks for culture

Smearsmotile vibrios

Culture


15

Culture

Enrichment culture: peptone agar, on blood agar with a pH near 9.0Selection: on TCBS agar

Specific Testsidentified by slide agglutination tests using anti-O group 1 or group 139 antisera

Treatment

u water and electrolyte replacement

u antimicrobial agents


16

ØMany antimicrobial agents are effective against V cholerae (Oral tetracycline )

Prevention & Control

Øspread by water, food, and flies

ØVibrio cholerae lives attached to algae, copepods, and crustacean shells

Prevention


17

ØRest on education and on improvement of sanitation, particularly of food and water

ØPatients should be isolated, their excreta disinfected, and contacts followed up

Control

Epidemiology

Seventh pandemics (worldwide epidemics) of cholera occurred between 1817 to date

Six pandemics (worldwide epidemics) of cholera occurred between 1817 and 1923, caused most likely by V cholerae O1 of the classic biotype and largely


18

V cholerae O1 of the classic biotype and largely originating in Asia, usually the Indian subcontinent.

The seventh pandemic began in 1961 in the Celebes Islands, Indonesia, with spread to Asia, the Middle East, and Africa. This pandemic has been caused by V cholerae biotype El Tor

18

The Ganges River in India is considered sacred, and people wash in the river and drink from it.


However, cholera bacilli frequently inhabit the river and pass easily among unsuspecting bathers.2014/10/19 20Vibrios, Helicobacter &

Campylobacters/ Junqi Zhang

Questions

What are the virulent determinants of V.cholera, clarify its pathogenesis


21

21

üVibrio parahaemolyticusV.parahaemolyticus is a halophilic bacterium that causes acute gastroenteritis following ingestion of contaminated seafood such as raw fish or shellfish

üThe enteritis induced by V.parahaemolyticus


22

by V.parahaemolyticus occurs worldwide, with highest incidence in areas where people eat raw seafood

ürestoration of water and electrolyte balance

üHelicobacter pylori

vHelicobacter pylori is a spiral-shaped gram-negative rod

vH.pylori is associated with antral gastritis, duodenal (peptic) ulcer disease,

gastric ulcers, and gastric carcinoma


24

In 2005, the Karolinska Institute in Stockholm awarded the Nobel Prize in Physiology or Medicine to Marshall and Robin Warren, his long-time collaborator, "for their discovery of the bacterium Helicobacter pylori and its role in gastritis and peptic ulcer disease"

Culture H pylori grows in 3–6 days when incubated at 37 °C in a microaerophilic environment

Growth Characteristics


25

Øoxidase-positive Øcatalase-positiveØmobileØstrong producer of urease

PathogenesisvThe bacteria invade the epithelial cell surface to a limited degree vToxins and lipopolysaccharide may damage the mucosal cells vammonia produced by the urease activity may directly damage the cells also


26

Pathologyvchronic and active inflammation vPolymorphonuclear and mononuclear cell infiltrates

Clinical Findings

vupper gastrointestinal illness with nausea and pain; vomiting and fever

vthe H.pylori infection persists for years and perhaps decades or even a lifetime


28

decades or even a lifetime

vAbout 90% of patients with duodenal ulcers and 50–80% of those with gastric ulcers have H.pylori infection

vhave a role in gastric carcinoma and lymphoma

Diagnostic Laboratory Tests

Specimens

Smears

Gastric biopsy specimens

gastroscopy procedure with biopsy is required


29

Special TestsRapid tests to detect urease activity are widely used for presumptive identification of H pylori in specimens

gastroscopy procedure with biopsy is required

Treatment

Triple therapyvwith metronidazole veither bismuth subsalicylate or bismuth subcitrateveither amoxicillin or tetracycline for 14 days


30

veither amoxicillin or tetracycline for 14 days

Proton pump inhibitors directly inhibit H.pyloriand appear to be potent urease inhibitors

Epidemiology & Control

H pylori is present on the gastric mucosa of less than 20%of persons under age 30 but increases in prevalence to 40–60% of persons age 60, including persons who are asymptomatic


31

In developing countries, the prevalence of infection may be 80% or higher in adults

Person-to-person transmission of H pylori is likely because intrafamilial clustering of infection occurs

31

Questions

ó Which diseases can be caused by Hp？


32

ó What are the culture condition for Hp？

ó What are therapy for eradication of Hp in

patient?

Key words

Cholerae

Vibrio cholerae enterotoxin

Vibrio cholerae O1,O139 & El Tor biotypes (Serotype)

TCBS agar , Halophilic


33

TCBS agar , Halophilic

Helicobacter pylori, duodenal (peptic) ulcer , gatric ulcer,

gastric carcinomaVibrio parahaemolyticus

üCampylobactercause both diarrheal and systemic diseases

Campylobacter jejuni & Campylobacter colicausing mainly enteritis and occasionally systemic infection


35

causing mainly enteritis and occasionally systemic infection

Morphology & Identification

p gram-negative rods with comma shapep motile, with a single polar flagellump do not form spores


36

Culture

ü Incubation of primary plates for isolation of C jejuni should be at 42 °C to prevent growth of most of the other bacteria

Antigenic Structure & Toxins

Ø lipopolysaccharides with endotoxic activity

Ø Cytopathic extracellular toxins and enterotoxins

Pathogenesis & PathologyØ acquired by the oral route from food, drink, or contact


37

acquired by the oral route from food, drink, or contact with infected animals or animal products

Ø multiply in the small intestine, invade the epithelium, and produce inflammation that results in the appearance of red and white blood cells in the stools

Ø Localized tissue invasion coupled with the toxic activity appears to be responsible for the enteritis

Clinical Findingsacute onset of cramp abdominal pain, profuse diarrhea that may be grossly bloody, headache, malaise, and fever

Diagnostic Laboratory Tests


38

Diagnostic Laboratory TestsSpecimens Diarrheal stool

Smears Gram-stained smears of stool may show the typical "gull wing"-shaped rods

Culture Culture on the selective media

vibriosios, helicobacter &...

Documents