《病原生物学（医学微生物学）》课程教学课件（英文）19A_Haemophilus_Bordetella

Section III BacteriologyHaemophilus & BordetellaSHIHEZI UNIVERSITY

Section III Bacteriology Haemophilus & Bordetella SHIHEZI UNIVERSITY

KEY TERMS Haemophilus influenzae satellite phenomenon Bordetlla pertussis Respiratory infectionSHIHEZI UNIVERSITY

KEY TERMS  Haemophilus influenzae  satellite phenomenon  Bordetella pertussis  Respiratory infection SHIHEZI UNIVERSITY

HaemophilusSmall, gram-negative, pleomorphic bacteriarequires enriched media. usually containing blood or itsderivatives, for cultureHaemophilus influenzae type b is an importanthuman pathogenHaemophilus ducreyi, a sexually transmittedpathogen, causes chancroidOther species are among the normal flora of mucousmembranes and only occasionally cause diseaseSHIHEZI UNIVERSITY

Haemophilus  Small, gram-negative, pleomorphic bacteria  requires enriched media, usually containing blood or its derivatives, for culture  Haemophilus influenzae type b is an important human pathogen  Haemophilus ducreyi, a sexually transmitted pathogen, causes chancroid  Other species are among the normal flora of mucous membranes and only occasionally cause disease SHIHEZI UNIVERSITY

Haemophilus influenzae Pleomorphic shapeshort(1.5 μ m) coccoid bacilli, sometimesoccurring in pairs or short chainsCapsuleType-specific- 6 serotypes Type B pathogenicSHIHEZIUNIVERSITY

Haemophilus influenzae  Pleomorphic shape short (1.5 μm) coccoid bacilli, sometimes occurring in pairs or short chains  Capsule Type-specific  6 serotypes  Type B pathogenic SHIHEZI UNIVERSITY

satellite phenomenonChocolate agar plategrow on a blood agar plate around the coloniesof beta-hemolytic Staphylococcus aureusStaphHaemophilusSHIHEZI UNIVERSITY

 Chocolate agar plate grow on a blood agar plate around the colonies of beta-hemolytic Staphylococcus aureus “satellite phenomenon” Staph Haemophilus SHIHEZI UNIVERSITY

X- and V-FactorsGrow on a plate (Mueller-Hinton agarthat has been fortified with both X.factor (found to be hemin) and V-factor (found to be NAD)+ but not either one aloneThe above plate has been streakedWith enough Haemophilus influenza toform a lawn on the plate. but there isonly growth around the XV filterwhich has been fortified with both Xand V factor (Hemin and NAD)* NAD: Nicotinamide adenine nucleotide, acoenzymeHaemophilus infuenzae fnutritionalfactorsX-hemin Y=WADSHIHEZI UNIVERSITY

X- and V-Factors  Grow on a plate (Mueller-Hinton agar) that has been fortified with both X- factor (found to be hemin) and V- factor (found to be NAD)  but not either one alone  The above plate has been streaked with enough Haemophilus influenza to form a lawn on the plate, but there is only growth around the XV filter, which has been fortified with both X and V factor (Hemin and NAD) * NAD: Nicotinamide adenine nucleotide, a coenzyme SHIHEZI UNIVERSITY

Pathogenesis: Virulent Factor Capsuleantiphagocytic in the absence of specific anticapsularantibodies The polyribose phosphate capsule of type b Hinfluenzae is the major virulence factor The nonencapsulated H influenzae is a regularmember of the normal respiratory flora ofhumansSHIHEZI UNIVERSITY

Pathogenesis: Virulent Factor  Capsule  antiphagocytic in the absence of specific anticapsular antibodies  The polyribose phosphate capsule of type b H influenzae is the major virulence factor  The nonencapsulated H influenzae is a regular member of the normal respiratory flora of humans SHIHEZI UNIVERSITY

DiseasesH.AegyptiusH influenzae type bH.Infuenzae2enters by way ofCorjunctitisMeningitis(typeb)Purpuriefeverthe respiratoryOtitis (non-typable)Sinustis (non-typable)tractEpigltitistype bTrachaoranchtis npabeBaterermia (typeb)There may be localPneumonia(non-typable)extension with1involvement of theH. Ducreyisinuses or theChanchroidmiddle ear(genitals andlymph nodes)Then reach thebloodstreamSHIHEZI UNIVERSITY

Diseases  H influenzae type b enters by way of the respiratory tract  There may be local extension with involvement of the sinuses or the middle ear  Then reach the bloodstream SHIHEZI UNIVERSITY

Pathogenesis H influenzae type b+One of the 2 most common etiologic agents ofbacterial otitis media and acute sinusitis Anther is pneumococciThe most common cause of bacterial meningitis inchildren age 5 months to5 yearsBacteremiaSHIHEZI UNIVERSITY

Pathogenesis  H influenzae type b  One of the 2 most common etiologic agents of bacterial otitis media and acute sinusitis  Anther is pneumococci  The most common cause of bacterial meningitis in children age 5 months to 5 years  Bacteremia SHIHEZI UNIVERSITY

Diagnostic Laboratory TestsSpecimens+ nasopharyngeal swabs, pus, blood, and spinal fluidDirect IdentificationCommercial kits are available for immunologicdetection of H influenzae antigens in spinal fluidA positive test indicates that the fluid contains highconcentrations of specific polysaccharide from H influenzaetype b Culture IsoVitaleX-enriched chocolate agarSHIHEZI UNIVERSITY

Diagnostic Laboratory Tests  Specimens  nasopharyngeal swabs, pus, blood, and spinal fluid  Direct Identification  Commercial kits are available for immunologic detection of H influenzae antigens in spinal fluid  A positive test indicates that the fluid contains high concentrations of specific polysaccharide from H influenzae type b  Culture  IsoVitaleX-enriched chocolate agar SHIHEZI UNIVERSITY