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ماهي وتعريفيها Bordetella


الاجابة هي 


Bordetella

هي كلمة لاتينية معناها intense cough

Bordetella pertussis contains seven  species bordetalla is by far most important species

it the causative agent of whooping cough that effect respiratory tract

morphology

It is gram negative small ovoid coccobacilli

culture

Bordetella pertussis  is stric aerobic with optiumum temperature for growth is 35C°

it grow in charcoal agar ,strarch and athers agar buy it do not grow in blood and nutrient agar

bordet gengou agar with 15_20% blood is common media used for primary isolation of bordetella

biochemical reaction

oxidase and catalase positive

becteria do not ferment carbohydrates

do not produce indole

killed by heating  to 55C° for 

30 minute

humans are only know resvoir of B pertussis

cell wall component and antigenic properties

 B .pertussis Possesses lipopolysaccharide

With two distinic types  lipid A and lipid B which activate alternative pathway of complement system and realase cytokines

pathogenesis

B. Pertussis colonizes the cilia of respiratory epithelium

ودي نقطه مهمة  

ال pertussis غالباً ما بيصيب  ال tissue 

whooping cough is highly contagious ➡️infection is primary transmitted by inhalation of air borne droplet

ودي اكتر حاجة في ال catarrhal stage  

virulence factors 

1) filamentous hemagglutinin

Most important virulence factor,mediate attachment of B.pertussis to ciliated cell 

 2) pertussis toxin

Involved in adhesion of B.pertussis to tracheal epithelium .pertussis toxin consist of two subunit  A  is enzymaticlly active subunit  B is binding subunit

3) invasive adenylate cyclase or hemolysin➡️cause lysis of RBCs

4) tracheal toxin 

Killed cilited respiratory cell, stimulate relase of cytokines  e.g IL-1 and inhibit ciliary movement

5) lethal toxin 

Causes inflammation and lethal necrosis around the site of adherence of bacteria

clinical syndrome

whooping cough( pertussis)

Incubation varies (7_10)days the disease typically has three stages 

1)catarrhal stage is the first stage of the whooping cough ➡️the symptom like the symptom of upper respiratory tract ( rhinorrhea , nasal congestion...etc.).

2) paroxymal stage➡️is the second stage classic whooping cough or paroxsmys more common in night

3) convslescen stage  is gradul fading stage 

lab diagnosis

Specimens

Nasopharyngeal aspirate are specimen of choice 

The specimen for culure are collecting by following method

1 pernasl swab

2cough plate method 

3 west's postnasl swab 

microscopy 

By direct fluorscent 

culture 

Specimen culured on freshly prepared bordet gangau method , or charcoal blood agar

   serology 

Indirect hemogglutination and ELISA

molecular diagnosis 

Polymerase chain reaction

treatment

Erythromycin is the drugs of choice

Also ampicillin is effective

vaccine

There are two types of vaccine

1  whole cell inactivated vaccine

2 acellular vaccine

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أفضل إجابة
ال bordetella contains seven species

And  bordetella pertussis  is most  important species
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