HaemophilHaemophilus & us &

BordetellaBordetella

A. L. Samer FaisalA. L. Samer Faisal

Haemophilus influenzaeHaemophilus influenzae Gram negative Rods.Gram negative Rods. Range from coccobacillary to long Range from coccobacillary to long

filamentous forms.filamentous forms. Non – motileNon – motile Aerobic Aerobic Fastidious organismsFastidious organisms

Haemophilus influenzaeHaemophilus influenzae Humans are the only natural hostsHumans are the only natural hosts

Transmission:Transmission: respiratory droplet spread respiratory droplet spread

Peak Prevalence of Meningitis: Peak Prevalence of Meningitis: 6 – 12 6 – 12 monthsmonths

The incidence of Hib fell by 95% in The incidence of Hib fell by 95% in populations with high rates of vaccinationpopulations with high rates of vaccination

Haemophilus influenzaeHaemophilus influenzaeTwo main typesTwo main types::

II The uncapsulated (untypable) The uncapsulated (untypable) strainsstrains

IIII The encapsulated strainsThe encapsulated strains

CapsuleCapsule Polysaccharide in naturePolysaccharide in nature

Six types : a, b, c, d, e and fSix types : a, b, c, d, e and f

Type b is associated with most severe Type b is associated with most severe form of disease form of disease

Hib capsule is Polyribitol Phosphate (PRP)Hib capsule is Polyribitol Phosphate (PRP)

Haemophilus influenzaeHaemophilus influenzaeUnencapsulatedUnencapsulated

Responsible for Responsible for localized infections localized infections i.e.i.e.

Otitis mediaOtitis media ConjuctivitisConjuctivitis BronchitisBronchitis SinusitisSinusitis

CapsulatedCapsulated Responsible for Responsible for Invasive disease Invasive disease i.e.i.e.

MeningitisMeningitis SepticaemiaSepticaemia EpiglottitisEpiglottitis PneumoniaPneumonia Septic arthritisSeptic arthritis CellulitisCellulitis

LABORATORY LABORATORY DIAGNOSISDIAGNOSIS

Clinical SpecimensClinical Specimens Blood, sputum, CSF, Joint fluidBlood, sputum, CSF, Joint fluid

MicroscopyMicroscopy Gram StainGram Stain Flourescent antibody stainFlourescent antibody stain

CultureCulture Chocolate Agar (Factor V & X)Chocolate Agar (Factor V & X)

SerologySerology Latex agglutination, Counter Latex agglutination, Counter

immunoelectrophoresisimmunoelectrophoresis PCRPCR

Growth requirements in Growth requirements in VitroVitro

Factor Factor VV HeminHemin

FactorFactor XX NADNAD

Chocolate agar provide both these Chocolate agar provide both these factorsfactors

Growth is enhanced in 5% CoGrowth is enhanced in 5% Co2 2

TREATMENTTREATMENT Meningitis – CeftriaxoneMeningitis – Ceftriaxone Otitis media & Sinusistis – Amoxycillin-Otitis media & Sinusistis – Amoxycillin-

clavulanate & Co-trimoxazoleclavulanate & Co-trimoxazole

PREVENTIONPREVENTION Vaccine against hemophilus type-b (Hib)Vaccine against hemophilus type-b (Hib)

Age 2-15 monthsAge 2-15 months Conjugate vaccineConjugate vaccine

RifampicinRifampicin

Haemophilus ducreyiHaemophilus ducreyi

Causes a sexually transmitted Causes a sexually transmitted infection called Chancroidinfection called Chancroid

Requires only Factor X for growthRequires only Factor X for growth

Bordetella pertussisBordetella pertussis Small Coccobacillary Small Coccobacillary Gram negative rodGram negative rod CapsulatedCapsulated Causes Pertussis (Whooping Cough) Causes Pertussis (Whooping Cough)

– a highly infectious disease in its – a highly infectious disease in its early phaseearly phase

Bordetella pertussisBordetella pertussis Pathogen only for humansPathogen only for humans Transmitted by airborne dropletsTransmitted by airborne droplets Highly contagiousHighly contagious Worldwide distributionWorldwide distribution Primarily infants & young childrenPrimarily infants & young children

• Typical OrganismsThe organisms are minute, gram-negative

coccobacilli resembling H influenzae. A capsule is present.

• Culture Primary isolation of B pertussis requires

enriched media. Bordet-Gengou medium (potato-blood-glycerol

agar) that contains penicillin G, 0.5 μg/mL, can be used.

A charcoal-containing medium supplemented with horse blood, cephalexin, and amphotericin B (Regan-Lowe) is preferable because of the longer shelf life.

The plates are incubated at 35–37°C for 3–7 days aerobically in a moist environment.

The small, faintly staining gram negative rods are identified by immunofluorescence staining.

B pertussis is non-motile.

• Growth Characteristics

The organism is a strict aerobe. it is oxidase and catalase positive. but nitrate, citrate, and urea

negative, the results of which are useful for differentiating among the other species of bordetellae.

It does not require X and V factors on subculture.

CLINICAL FEATURESCLINICAL FEATURES Acute tracheobronchitis in Acute tracheobronchitis in

childrenchildren Mild upper respiratory tract symptomsMild upper respiratory tract symptoms Severe paroxysmal cough (1 to 4 weeks)Severe paroxysmal cough (1 to 4 weeks) Death due to pneumoniaDeath due to pneumonia

In AdultsIn Adults Paroxysmal cough lasting weeks (100 day Paroxysmal cough lasting weeks (100 day

cough)cough) Whoop is absentWhoop is absent

Laboratory DiagnosisLaboratory Diagnosis Clinical SpecimensClinical Specimens

Nasopharyngeal swabNasopharyngeal swab MicroscopyMicroscopy

Gram negative rodsGram negative rods Flourescent antibody stainingFlourescent antibody staining

CultureCulture Bordet gengou medium (20-30% blood)Bordet gengou medium (20-30% blood)

SerologySerology Agglutination with specific antiseraAgglutination with specific antisera

PCRPCR

TREATMENTTREATMENT AntibioticAntibiotic

ErythromycinErythromycin Supportive CareSupportive Care

Oxygen TherapyOxygen Therapy Suction of mucusSuction of mucus

PREVENTIONPREVENTION VaccinesVaccines

Acellular pertussis vaccineAcellular pertussis vaccine BoostrixBoostrix AdacelAdacel

Killed Vaccine Killed Vaccine Higher side effects (encephalopathy)Higher side effects (encephalopathy)

AntibioticsAntibiotics ErythromycinErythromycin

Un-immunized & exposedUn-immunized & exposed Immunized & < 4 yrs.Immunized & < 4 yrs.

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