““ParvobacteriaParvobacteria””(Small, Gram negative cocco bacilli)Need blood or blood products for growth.

Include the genera:HaemophilusBordetellaBrucellaPateurellaFrancisellaActinobacillusGardnerella

Haemophilus speciesHaemophilus species Gram negative coccobacilliGram negative coccobacilli With pleomorphism- different shapes in Clinical With pleomorphism- different shapes in Clinical

specimens e. g. C.S.Fspecimens e. g. C.S.F

Habitat:Habitat: Usually found in upper respiratory tract of man.Usually found in upper respiratory tract of man. CultureCulture All species need blood or blood products for growthAll species need blood or blood products for growth Haemophilus influenzae can grow on:Haemophilus influenzae can grow on:

e.g. (A) Chocolate agar it contains both x and v factors e.g. (A) Chocolate agar it contains both x and v factors

Haemophilus InfluenzaeHaemophilus Influenzae (Cont.) (Cont.)(B)(B) Blood agarBlood agar with growth of with growth of

Staphylococcus aureusStaphylococcus aureus – a phenomenon called – a phenomenon called satellitismsatellitism

Large colonies of H. influenzae near Staphylococcuscolonies

Colonies of Staphylo-coccus aureus producingV factor

Small colonies of H. influenzae away from colonies of Staph. aureus

Blood Agar Plate

Providing X Factor

44BAP culture showing Haemophilus influenzae satelliting

around Staphylococcus aureus, Picture from CDC.

This is responsible for the phenomenon of “Satellitism” in which Hemophilus influenzae forms colonies in the vicinity of Staphylococcal colonies.

c)c) On nutrient agar with:On nutrient agar with:

X Factor = Haematinand / or

V Factor = DI or TRI Nucleotide According to need for X, V OR XV Factors

Haemophilus species can be divided into:

Factor Required SpeciesX and V H. influenzae, H. aegyptius

H. haemolyticus

X H. ducreyiV H. parainfluenzae,

parahaemolyticus

Pathogenecity of Pathogenecity of Haemophilus speciesHaemophilus species (Diseases (Diseases))

SpeciesSpecies DiseaseDisease

H. influenzae capsulated Meningitis, arthritis, osteomyelitis, (mainly type a, b) cellulitis, epiglottitis, bacteremia

H. influenzae non- Exacerbations of chronic bronchitis,capsulated sinusitis, otitis media, others.

H. aegyptius ConjunctivitisH. ducreyi Chancroid (Sexually Transmitted)

H. parainfluenzae Commensals of the upperH. Haemolytic Respiratory tract; rarelyH. Parahaemolyticus Cause disease in

immunocompromised patients

Haemophilus influenzaeHaemophilus influenzae

The most important pathogenic species:

1. Gram – negative coccobacilli

2. Growth on chocolate agar

3. Shows smooth drop like colonies on chocolate agar

4. Needs X and V factors for growth on nutrient agar

5. Shows satellalism near Staphyloccocus aureus colonies

6. Shows pleomorphism from clinical specimens eg csf7. Divided into Capsulated and Non-capsulated strains.

Capsulated StrainsCapsulated Strains

a) Capsule is made of Polysaccharides

b) It is antigenic

c) It increases the pathogenecity of strains

d) Prevents phagocytosis

e) Capsulated strains are divided into 6Serotypes a b c d e f

f) Most pathogenic is type b.

H.influenzaeH.influenzae invasive Infections (mainly by type invasive Infections (mainly by type BB))

Include:Include:a) Meningitisa) Meningitisb) Epilottitisb) Epilottitisc) Cellulitisc) Cellulitisd) Arthritisd) Arthritise) Osteomyelitise) Osteomyelitis

Usually accompanied with bacteriaemia Usually caused by type b The major virulence factor is the polysaccharide capsule Affects children between 3 months to 3 years. Infection under two(2) months is rare because of presence of

maternal IgG antibodies.

Laboratory DiagnosisLaboratory Diagnosis

Specimens depends on the type of diseases

a. CSF – in meningitis

b. Blood –meningitis and bacteriaemia and all types of invasive disease.

c. Sputum – in pneumonia

d. Swab – in cellulitis

e. Synovial fluid – in arthritis Direct smear shows pus cell + pleomorphic gram –ve

coccobacilli CSF Culture, on chocolate agar CSF detection for presence of antigens by agglutination

Epidemiology of Invasive Epidemiology of Invasive H. influenzaeH. influenzae InfectionInfection

More common in winter after viral infection. More common in crowded families with poor status. Family members can infect each other. Mortality is 5% In meningitis neurological lesions - 10-15 % Production of conjugate vaccine (Hib) reduced the

morbidity and mortality.

ImmunizationImmunization Early preparations consists of purified type b

polysaccharide vaccines. But found not to be effective in children ↓ 18 months old.

Now conjugated vaccine which consist of polysaccharide combined with a carrier molecule, (which could be tetanus toxoid, non toxic diphtheria toxin or N. meningitidis components). This vaccine is protctive for children younger than 2 years.

TreatmentTreatment

a) Ampicillin (amoxycillin) if not β lactamase Producer if β lactamase producer it destroy ampicillin and amoxycillin so use.

b) Chloramphenicol

c) Ceftriaxone,Cefuroxime

d) Chemoprophylaxis: Contacts of patient with H. influenzae type b infection can be given Rifampicin for 4 days as prophylaxis.

H = Haemophilus

I = Influenzae

B = Pittman type b

Composition Polysaccharide + Carrier protein to increase antigenecity

Carrier Protein 1) Toxoid of diphtheria2) Toxoid non-toxogenic diphtheria3) Toxoid of Tetanus4) Outer Membrane protein of N. Meningitidis.

Hib VaccineHib Vaccine

HibHib (Contact)(Contact)

Total doses = 3 - 4 dosesStarting at = 2/12 ageRoute = IntramuscularEffective after = 2/52Not effective in = 1. HIV, antibodies deficiency

2. Asplenia, anatomical3. Functional asplenia4. Sickle cell disease5. Bone marrow transplant6. Therapy for malignancy

Non capsulatedNon capsulated strains morphology is similar strains morphology is similar to capsulated strains.to capsulated strains.

They cause:They cause:a)a) Otitis media:Otitis media: presenting with pain and presenting with pain and

discharge of pus from the ear.discharge of pus from the ear.

b)b) Sinusitis:Sinusitis: presenting with headache and presenting with headache and postnasal discharge with low grade fever.postnasal discharge with low grade fever.

c)c) ExacerbationExacerbation of chronic bronchitis in elderly, of chronic bronchitis in elderly, smoking people presenting with cough and smoking people presenting with cough and large amount of sputum.large amount of sputum.

( Cont. Non capsulated strains)

a) Pneumonia: mainly affecting both lungs called Bronchopneumonia.

b) Bronchiectasis: collection of pus in dilated bronchi presenting with cough, chest pain, fever, and production of large amount of sputum

Bordetella pertussis Bordetella pertussis And And Bordetella parapertussisBordetella parapertussis

B. pB. pertussis – causes WHOOPING COUGH

B. parapertussis – causes a MILDER FORM OF WHOOPING COUGH.

Live mainly in the human respiratory tract. Morphology: short, gram – negative coccobacilli.

MEDIAa. Bordet Gengue medium

b. Charcoal blood agar

BORDET – GENGUE CONTAINS:

a. 30 % blood

b. Penicillin

c. Glycerol

d. Penicillin WHY? To supress normal flora

COLONIES look like mercury drops

ANTIGENIC STRUCTURE: Sharing 3 antigens 1, 2, 3 organism can carry

TYPETYPE 1, 2 antigens1, 2 antigens

TYPETYPE 1, 2, 3 antigens1, 2, 3 antigens

TYPETYPE 1, 3 antigens1, 3 antigens

PATHOGENECITYPATHOGENECITY – – Strict human pathogenStrict human pathogen

Causes Causes WHOOPING COUGHWHOOPING COUGH Due to Due to PRODUCTION OF ENDOTOXINPRODUCTION OF ENDOTOXIN which affect the respiratory mucosa.which affect the respiratory mucosa.

PathogenesisPathogenesis Non invasive disease Does not cause bacteremia Human are the only natural host Incubation period 1-2 weeks Initial stage colonization of ciliated epithelium of the

bronchi and trachea. Production of cytotoxin which paralysis the cilia - so

cough as the only protective mechanism Production of pertussis toxin (PT)

Lymphocytosis Can also predispose to secondary bronchopneumonia.

Clinical FeaturesClinical Features

a) Affect preschool children

b) Severe in under 1 year of age

c) An acute Tracheobronchitis

Divided into 3 stages

a) Catarrhal stage 2 / 52

- Fever

- Rhinorrhoea, sneezing

- Anorexia

- Malaise

(Cont. 3 STAGES)(Cont. 3 STAGES)

b) Paroxysmal cough 2 / 52

-Violent cough followed by inspiratory (whoop)

- Vomiting

- Convulsions

c) Convalences stage 4 / 52

-Leucocytosis (Lymphocytosis) can mimic lymphocytic leukemia.

DiagnosisDiagnosis

a) Clinical

b) Pernasal swab

c) Cough plate

d) Swab by Immunofluorescence (Rapid Method)

TreatmentTreatment

a) Erythromycin

b) Effective on early stage

c) Not effective in later stage WHY??

VaccinationVaccination

1. Whole killed bacterium vaccine2. Give Intramuscularly as part of the Triple

Vaccine DPTD = DIPTHERIAP = PERTUSSIST = TETANUS

3. Safe but there are some cases of CNS involvement.

4. A cellular vaccine formed of

a) PT = Pertussis toxin

b) FHA = Filamentous haemagglutinin

is supposed to be more save.

Complications Of Whooping (Cough)Complications Of Whooping (Cough)

A) Bronchopneumonia - due to pyogenic cocci

B) Bronchiatiasis

C) Sub conjunctival haemorrgae