Gram Negative Bacillus

8/18/2019 Gram Negative Bacillus

1/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال

یق ف و ت ل ا ب

GRAM NEGATIVE BACILLI

Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)

http://www.novapdf.com/http://www.novapdf.com/http://www.novapdf.com/http://www.novapdf.com/


2/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Salmonella spp

Gr –ve bacilli

Non sporing , motile bacilli

All exept S.typhi are non – capsulate bacilli

Facultative anaerobes

haracteristics

Animal gut

Human is the only natural host for S. typhi & S

paratyphi

Habitat

Foodborne roote

Faecal-oral route

Transmission

Endotoxin=cause fever , leukemia , hypotension

&shock

Capsule=antiphagocytosis

Can survive within macrophages

Pathogenesis

Typhoid fever (Enteric fever)

1. bacteria rich small intestine and then enter

lymphatics& blood streem

2. cause fever , malaria , headache ,

constipation etc

3.

spleen &liver become enlarged

Enterocolitis (gastroenteritis or

food poisoning )

septicemia

Diseases

Oxidase – ve , non –lactose fermentation

Produce acid &gas from glucose

Grow well on macConnkey agar , DCA , .S.S

agar

Commercial kits available for full identification

Laboratory

Identification




3/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Shigella

Gram –Ve bacillus

Faculitatie anaerobic

Most shigella pathogen is S.sonnei

Non lactose fermentive .

Non motile .

haracteristics

Endotoxin

Capsule

Antigenic phase variation .

Pathogenesis

Gastroenteritis (( shigellosis ))

S.dysenteriae cause bacterial dysenteria

Diseases

Oxidase – Ve

Isolation from specimens requires use of

selective media .

Laboratory

Identification




4/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Vibrio

-the second major group of gram-negative ,facultative anaerobic, fermentative rods.

- Were separated from Enterobacteriaceae on the basis of positive oxidase reaction

and the presence of polar flagella.

-the most important members of Vibrio spp are:1)Vibrio cholera.

2)Vibrio parahaemolyticus.

3)Vibrio vulnificus.

-Vibrio species can grow on a variety of simple media within temp rate (14-40C).

V.cholerae can grow in the absence of salts(most other species of vibrio that are

pathogenic in human require salt [halophilic species]).

-Vibrio tolerate a wide range of PH (e.g.PH of 6.5-9.0) but are susceptible to stomachacids. If gastric acid production is reduced or neutralized , patients are more

susceptible to Vibrio infection.

-most vibrio have asingle polar flagella (in contrast with peritrichous flagella in the

family Enterobacteriaceae.

-vibrio have also various pili that are important for virulence.

-epidemic strains of V.cholerae the etiologic agent of cholera




5/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Vibrio cholerae

Small , curved (comma – shapped )

Gr –ve bacilli

Non sporing , motile bacilli , non capsulate

bacilli


Were separated from Enterobacteriaceae on the

basis of positive oxidase reaction and the

presence of polar flagella.

haracteristics

Contaminated water (usually) or food

(sometimes )

Habitat

Foodborne route

Faecal – oral routeTransmission

Choleragen enterotoxin = hypersecretion of

electrolytes andwater.Pathogenesis

Cholera

1. bacteria colonize the intestinal tract in

very high numbers

2. bacteria attach to but do not invade the

intestinal mucosa

3. intese vomiting & diarrhea

4.

severe loss of water &electrolytes*gastroenteritis

Diseases

Oxidase +ve


Special selective media for vibrio thiusulfate

citrate bile salts sucrose(TCBS).

Do not require salts for growth. But can tolerate

it.

Laboratory

Identification




6/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Vibrio cholerae are rarely seen in Gram-stained

stool or wound specimens.

By using darkfield microscope may able to detect

the motile bacteria in stool specimen.




7/31


8/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


-members of the Enterobacteriaceae family are

moderately in size, gram-negative rods .

-they share a co

mmon antigen (enterobacterial common antigen)

-are either nonmotile or motile with peritrichous

flagella

-do not form spore.

-all members can grow rabidly, facultative

anaerobic) on variety of nonselctive

media(e.g.blood agar) and selective

(e.g.macConkey agar).

-the Enterobacteriaceae have simple nutritional

requirements, ferment glucose.

-catalase +ve, oxidase –ve.

-the absence of cytochrome oxidase activity is

important characteristic , because it can bemeasured rabidly with simple test and is used to

distinguish the Enterobacteriaceae from many other

fermentative and nonfermentative gram-negative

rods.

-a few exceptions to these rules exits (e.g.

plesiomonas shigelloides is oxidase +ve, klebsiella




9/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


granulomatis can not be cultured on traditional

media.

-the ability to ferment lactose has been used todifferentiate lactose-fermenting strains(e.g.

Echerichia, klebsiella, enterobacter, citrobacter ,

serratia spp) from strains that do not ferment

lactose or do so slowly(e.g. proteus, salmonella,

shiglla, yersinia spp).

-resistance to bile salts in some selective media has

been used to separate enteric pathogen(e.g.

shigella, salmonella) from commensal organisms

that are inhibited by bile salts(e.g. gram+ve and

some gram-ve bacteria present in the

gastrointestinal tract)

-some Enterobacteriaaceae have prominent

capsules (e.g. most klebsiella, some Enterobacter,

Escherichia strains),

-the heat-stable lipopolysaccharide(LPS) is the

major cell wall antigen.

-most the Enterobaceriaceae are motile with the

exception of the common isolates Klebsiella,

shigella, yersinia.

-the motile strains posses peritrichous flagella.




10/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


-there are other species of Enterobacteriaceae :

1)Enterobacter

2)Citrobacter

3)Serratia4)Morganella

-These species subdivide as lactose fermenter

Enterobacteriaceae.

-these species caused infections rarely in

immunocompetent patients.

-they are more common causes of

immunocompromised patients.

-e.g. citrobacter koseri cause meningitis and brain

abscesses in neonates.




11/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Escherichia coli

Gr –ve bacilli

Non sporing , motile , non capsulated bacilli but

some strains are capsulate


haracteristics

Common normal flora of human intestinal tractabitat

Foodborne route

Faecal – oral route

Endogenous spread

Transmission

Endotoxin = cause fever , leucopenia

Capsule (in some strains ) = antiphagocytosis

Enterotoxin = cause diarrhea

Pathogenesis

Urinary tract infection (UTI)

Diarrhoeal disease

Neonatal meningitis

Septicemia

Gastroenteritis.

Diseases

Oxidase –ve , lactose fermentive

Grow well on macConkey agar , DCA , XLD

agar


Laboratory

Identification




12/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٢بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Proteus spp

Gr –ve bacilli

Non sporing highly motile , non capsulate bacilli


P.mirabilis is the most common species.

Produce large quantitiesof urease.(this process

raises the urine PH and facilitates the formation

of renal stones , the increased alkalinity of the

urine is also toxic.

haracteristics

Common normal flora of the human intestinal tractabitat

Foodborne route


Endogenous spread

Transmission


Pathogenesis

UTI

SepticemiaDiseases

Oxidase –ve , non lactose fermentive


agar

Swarming colonies on solid media


Laboratory

Identification




13/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٣بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Yersinia pestis

Gr –ve bacilli (cocobacilli ) (facultative

anaerobes)

Have a tendency for bipolar staining (in

which the endof the bacilli stain darker

than the central part)

Nonsporing , non motile bacilli . capsulate

bacilli

Some species (e.g.Y.enterocolitica) can

grow at cold temp.

haracteristics

Animal reservoirs are rodents such as ratsHabitat

Bacteria spreads between anmals by fleas

Major outbreaks in humans result from

exposure to infected rats

The rat flea carries infection from rat to rat

& from rat to human

Bubonic plague is not transmitted from

person to person

Pneumonic plague spread from person

to person by droplets (airborne route )

Transmission

Intracellular murine toxin = causing

irreversible shock and death

Capsule (f1) = antiphagocytosis

The V/M antigen = specific protein act as

antiphagocytosis & promote intracellular

growth of the bacteria

Pathogenesis




14/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٤بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


PLAGUE :

1. is normally azoonotic disease of rodents

that exists in 2 kinds of epidemic centers

2.

permanent but relatively resistant rat

population (wild rat)

3. temporary but susceptible rat population

(domestic rats )

4. epidemics of plague usually occur in

crowded areas poor sanitation

bubonic plague :

1. bacteria multiply at the entery

site in the skin

2. bacteria spread via the

lymphatics to lymph nodes

3.

2 to 6 days after the flea bite

occurs , lymph nodes become

very tender , and enlarge to form

buboes with haemorrhagic

inflammation

4. death rate is about 75% in

untread bubonic plague pneumonic plague (black

death) :

1. bacteria

disseminates from

lymph nodes by

way of the

Diseases




15/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٥بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


bloodstream to

the spleen , liver ,l

lungs

2.

pneumonic plague

can be transmitted

by respri atory

route but Iis

3. death tate is nearly

100%in untreaed

pneumonic plague

stained smears should show bipolar

staining

organism can be grow from aspirtes of

enlarged buboes , or from sputum in case

of pneumonic plague

colonies are grayish , mucoid & rough

colonies may be noted

the organism are not fastidious ; it can be

rrown on routine media

oxidase –ve .

Laboratory

Identification




16/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٦بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Pasteurella

Garm –Ve bacillus

Non spore forming

Non motile

Faculitative anaerobic

Fermentative coccobacilli .

Most common P.multocida and P.canis

haracteristics

abitat

Transmission

Pathogenesis

Bite wound infection .

Chronic pulmonary disesase

Bacteremia

Meningitis

Diseases

Grow well in blood and choclate agar . and

poorly in macConkey agar .

After over night incubation in blood agar

large buttery colonies with musty odor cuase

by product indole

Laboratory

Identification




17/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٧بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Klebsiella pneum oniae

Gr –ve bacilli

Non sporing , non motile , prominent capsulate

that responsible for the mucoid.


Formerly called (Donovaina granulomatis)

haracteristics

Common normal flora of the human intestinal

tract & oropharynxHabitat

Foodborne route


Endogenous spread

Transmission


Capsule = antiphagocytosisPathogenesis

UTI

Neonatal meningitis

Septicemia

Pneumonia (Rare )

Diseases

Oxidase –ve , lactose fermentive


agar

Large mucoid colonies


Laboratory

Identification




18/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٨بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Brucella spp

Gr –ve small coccibacilli

Non sporing ,non motile , non capsulated bacilli

Intracellular pathogen

Slow growth requirements

Fastidious.

Is member of the alpha –proteobacteria group

Strictly aerobic

Does not ferment carbohydrates.

Four species:

1)Brucella abortus 2)Brucella melitensis.

3)Brucella suis 4)Brucella canis

haracteristics

Chronic infection in domestic animalsHabitat

Contaminated milk or other unpasteurized dairy

products

Direct contact

Transmission

Invasion of the body by brucella results in

lymphatic dissemination of the bacteria

As regional lymph nodes become infected , the

brucella are phagocytized , but they are capable

of survive & intracellular multiplication inside

phagocytic cells

As phagocytic cells die , brucella , are released

into the blood stream and intracellularly ,

establish localized infection in bone marrow ,

liver &spleen , and thus hide from host defence

Pathogenesis

Undulant fever (malta fever or brucellosis )

1.

patients frequently present with PUO

2. chronic , debilitating febrile illness usually

without any localizing signs

3.

intracellularly , bacteria localize and cause

Diseases




19/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٩بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


granulomas lesions in the spleen , liver

bone marrow & lymph nodes

4. patients presents with intermittent fever &

profound weakness , chills , sweats ,

headache , backache

5. two types of infection occur ; (acute

infection ) or (chronic infection – lasting

12 months )

requiring complex growth media like :glucose

serum or liver infusion broth or agar

usuakky require 3-5 days incubation

blood provides the best material for culture

grow occasionally on MacConkey agar.

Oxidase +ve

Urease+ve

Laboratory

Identification




20/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Francisella tularensis

Gr – Ve small bacilli (coccobacilli)

Often showing bipolar staining

Non motile , non sporing , capsulate , coccobacilli

Strick aerobic

Fastidious.

Two species of Francisella spp:

1)F.tularensis

2)F.philomiragia

*require cystein for growth.

haracteristics

Widely found in animal reservoirsHabitat

biting arthropods

direct contact with infected animal tissue

ingestion of contamination food or water

inhalation of aerosols

Transmission

F.tularensis is highly infection ; penrtration of the

skin or mucous membranes or inhalation of 50

organism can result in infection

F.tularensis is an intracellular pathogen of

phagocytosis cells

Capsule= phagocytosis

Pathogenesis




21/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


tularemia (sometimes called rabbit fever or

glandular fever or tick fever or deer fly fever ):

1-clinical presentation dependes on the route of

infection2- a plague – like disease of rodents

Diseases

blood is taken for serological tests

growth dose not occur in most ordinary

bacteriological media but small colonies appear in

1-3 day on glucose , blood agar incubated at 37 C

under aerobic conditions

culture on cystein-supplemented

media(e.g.choclate agar, BCYE agar ) is specific.

Culture on cystin blood agar.

Culture on cystin glucose agar

BCYT= buffered charcoal yeast extract.

Laboratory

Identification




22/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٢بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


emophilus

-the family pasteurllaceae spp are1)Haemophilus

2)Actinobacillus3)Pasteurella

-the members of this family are:

Small gram-negative* Non-spore* Nonmotile*

Aerobic or facultative anerobic rods*

-most members of this family have fastidious growthneeds, requiring enriched media for growth.

the mostare Haemophilusmembers of the genus-

commonly and significant human pathogen.




23/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٣بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Haemophilus influenzae

Gr –ve bacilli (coccobacilli)

Non sporing , non moitile ,

The surface of many(but not all) strains of

H.influenzae is covered with polysaccharide

capsule.


Haemophillic bacteria

Pyogenic (pus –producing ) bacteria

Plemorphic.

Is the most species of Haemophilus that cause

disease.

The cell wall structure is typical of other gran-

negative rods(lipopolysaccharide with endotoxin

activity is present in thecell wall.

Is fermentive.

haracteristics

Human upper respiratory tract as anormal flora

but many also cause respiratory disease , usually

as secondary invader

Habitat

Airborne routeTransmission

Endotoxin = causing damage to the epithelial cell

of the upper respiratory tract

Capsule = antiphagocytosis

IgAase = degrades IgA antibodies that is key host

defense mechanism in mucous membrane

H.influenzae type b is most virulent withRPR(polyribitol phosphate) in capsule

Pili=adhere to host cells.

Pathogenesis

Cause severe infection in children ( acute

meningitis )

H.influenzae serotype was responsible for more

than 95% of all Haemophilus infection.

Serotypes C and F and noncapsulated

Diseases




24/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٤بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


H.influenzae diseases.

Cause chronic , less severe infection beyond age 6

(,pneumonia,Otitis media , sinusitis , bronchitis )

in older children and adult This bacteria is the most common cause of

bacterial meningitis in children from 5 months to

5 years of age

Mortality rate of untreated H. influenzaw

meningitis may be up to 90%

Act synergistically with viral infection ,

predisposing to severe haemophilus infection , the

incidwnce increase during influenza outbreaks

Require enriched media such as blood or

chocolate agar or(Levinthals agar)

Need both od tow growth factor (factor V-X)

1. heat stable X factor = hemin or some

other iron – containing prophrin

2. heat stable V factor = nicotinamide

adenine nucleotide (NAD)

grow poorly in the absence of oxygen & growth

is enhancedin an atmosphere with add CO2

on chocolate or blood agar : a streak of staph .

aureus across the plate produce V factor and

enlarges the size of adjacent colonies of H .

inflluenzae = satellitism phenomena

colonies are small , translucent , non hemolytic

microscopy is sensitive test for detecting

H.influenzae in(cerebrospinal fluidCSF .synovial

fluid, and lower respirtory specimens.

Laboratory

Identification




25/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٥بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Pseudomonas aeruginosa

Gr –ve bacilli arranged in pairs.

Non sporing , motile , capsulate (polysaccharide)

Obligae aerobes

Nonfermentative.

The presence of cytochrome oxidase(detected in

rabid,5minute test) in pseudomonas species is

used to differentiate them from the

Enterobacteriaceae

Some pseudomonas produce diffusible pigments

(e.g.pyocyanin

[blue],fluorescein[yellow],pyorubin[raddish-

brown]

P.aeruginosa is the most common type.

haracteristics

Widley distributed in water , soil & moist areas

Carriage as a part of normal gut flora in higher

proporation of hospital inpatients

Habitat

Direct contact

Endogenous spreadTransmission

Exdotoxin = cause fever , leucopenia

Exdotoxin A = inhibit protein synthesis

Exdotoxin S = inhibit protein synthesis

Protease & Elastase = destruction of tissue

Capsule=inhibits antibiotics+suppresses

neutrophil and lymphocyte activity.

Pili=adhesin

Pathogenesis

UTI

Septicemia

Pneumonia

Burn wounds & wound infection

Ear and eye infection

Diseases




26/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٦بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Oxidase +ve , lactose fermentive

Identified by colonial characteristics(e.g.

hemolytic, green pigment, grape like odor)

Grow well on macConkey agar , DCA , XLDagar


Laboratory

Identification




27/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٧بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


cinetobacter spp

Gr –ve bacilli (plump coccobacilli)

Non sporing , non moitile , capsulated

coccobacilli

Strictly aerobic

The genus can be subdivided into two groups:

1)glucose oxidizing species(A.baumannii)

2)glucose nonoxidizing species(A.lwoffii)

haracteristics

Survive in moist surfaces. Including respiratory therapy

equipment .And survive on dry surface including human skin(the

latter feature is unusual for gram-negative rods)

Habitat

Direct contact

Indirect contact via invasive devicesTransmission

It has ability to colonize on internal surfaces of

the invasive devicesPathogenesis

*pulmonary infection.

*opportunistic pathogens that cause:

Respiratory tract unfection and urinary tract infection and

wound and septicemia.

Diseases

Oxidase –ve

Grow well on simple mediaLaboratory

Identification




28/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٨بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Bacteriodes

Gram –Ve bacillus .

Obligate anaerobic .

Most common species is b.fragilis .

Polymorphic in size and shape .

haracteristics

Intraabdominal infection .

Gynecologic .

Skin and soft tissues infection .

Bacteremia .

Diseases

Grow rapidly (( detected in 2 days )) .

Stimulated growth in 20% bile .Laboratory

Identification




29/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م

خص ل م ٩بی غ ل ا

ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Bordetella pertussis

Gr –Ve extremely smaal bacilli

Non sporing , non motile bacilli

Capsulate bacilli

Obligate aerobes

haracteristics

Human respairatory tract

Habitat

airborne route

direct contactTransmission

tracheal cytotoxin = inhibits DNA synthesis in

ciliated cells

fimbrial antigen (pili ) = permit the adherence of

bacteria to the ciliated epithelium of the

respiratory tract

endoxin = causing damage to the epithelial cells

of the upper respiratory tract

pertussis toxin

Pathogenesis

whooping cough (pertussis ) by Bordetella

pertussis.

Mild pertussis by Bordetella para pertissis.

Respirtory disease in dogs by Bordetella

bronchiseptica.

Diseases

slow growing & fastidious in its growth

requirement

bordet – gengous agar or blood – charcoal agar

requires media supplemented with charcoal,

starch, blood, or albumin.

Laboratory

Identification




30/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

كرو ی ا م


ھر ظ

في

كم ئ ا ع د

لح ا ص

من

ا ن و س ن ت

ال


Differential characteristics of Bordetell species

B.bronchisepticaB.parapertussisB.pertussischaracteristics

+ - + oxidase

+ + - urease

+ - - motility

+ + - On sheep agar

+ /+- - On macConkeyagar

requires 3-5 day incubation in moist atmosphere

it dose not require X and V factors on culure

oxidase amino acids.

Not ferment carbohydrates.




31/31

بي ر حل ا

دي ا ش

كرو ی ا م

خص ل م

بي ر حل ا

مي ا س

Gram Negative Bacillus

Documents

Transcript of Gram Negative Bacillus