This document discusses two gram-negative bacteria - Haemophilus influenzae and Bordetella pertussis. H. influenzae can cause localized infections like ear infections or more invasive diseases like meningitis. It exists in both encapsulated and unencapsulated forms. B. pertussis causes whooping cough and is highly contagious, especially in infants and young children. It presents with mild upper respiratory symptoms initially followed by severe paroxysmal coughing. Both organisms require special growth factors and are diagnosed through microscopy, culture, serology or PCR of clinical samples. H. influenzae is treated with antibiotics like ceftriaxone or amoxicillin for different infections. B. pert
2. Haemophilus influenzaeHaemophilus influenzae
Gram negative Rods.Gram negative Rods.
Range from coccobacillary to long filamentousRange from coccobacillary to long filamentous
forms.forms.
Non – motileNon – motile
AerobicAerobic
Fastidious organismsFastidious organisms
3. Haemophilus influenzaeHaemophilus influenzae
Humans are the only natural hostsHumans are the only natural hosts
Transmission:Transmission: respiratory droplet spreadrespiratory droplet spread
Peak Prevalence of Meningitis:Peak Prevalence of Meningitis: 6 – 126 – 12
monthsmonths
The incidence of Hib fell by 95% in populationsThe incidence of Hib fell by 95% in populations
with high rates of vaccinationwith high rates of vaccination
4. Haemophilus influenzaeHaemophilus influenzae
Two main typesTwo main types::
II The uncapsulated (untypable) strainsThe uncapsulated (untypable) strains
IIII The encapsulated strainsThe encapsulated strains
5. 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 form ofType b is associated with most severe form of
diseasedisease
Hib capsule is Polyribitol Phosphate (PRP)Hib capsule is Polyribitol Phosphate (PRP)
6. Haemophilus influenzaeHaemophilus influenzae
UnencapsulatedUnencapsulated
Responsible for localizedResponsible for localized
infections i.e.infections i.e.
Otitis mediaOtitis media
ConjuctivitisConjuctivitis
BronchitisBronchitis
SinusitisSinusitis
CapsulatedCapsulated
Responsible for InvasiveResponsible for Invasive
disease i.e.disease i.e.
MeningitisMeningitis
SepticaemiaSepticaemia
EpiglottitisEpiglottitis
PneumoniaPneumonia
Septic arthritisSeptic arthritis
CellulitisCellulitis
9. Growth requirements in VitroGrowth requirements in Vitro
FactorFactor VV HeminHemin
FactorFactor XX NADNAD
Chocolate agar provide both these factorsChocolate agar provide both these factors
Growth is enhanced in 5% CoGrowth is enhanced in 5% Co22
10.
11. 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
12. Haemophilus ducreyiHaemophilus ducreyi
Causes a sexually transmitted infection calledCauses a sexually transmitted infection called
ChancroidChancroid
Requires only Factor X for growthRequires only Factor X for growth
13. Bordetella pertussisBordetella pertussis
Small CoccobacillarySmall Coccobacillary
Gram negative rodGram negative rod
CapsulatedCapsulated
Causes Pertussis (Whooping Cough) – a highlyCauses Pertussis (Whooping Cough) – a highly
infectious disease in its early phaseinfectious disease in its early phase
14. 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
15. • Typical Organisms
The 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.
16. • 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.
17. CLINICAL FEATURESCLINICAL FEATURES
Acute tracheobronchitis in childrenAcute tracheobronchitis in children
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 cough)Paroxysmal cough lasting weeks (100 day cough)
Whoop is absentWhoop is absent
18. 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