Pasteurellaceae
Haemophilus influenzaeHaemophilus ducreyi
Oppurtunists:Haemophilus parainfluenzaeHaemophilus spp.
Pasteurella multocidaActinobacillus
actinomycetemcomitans
Human Pathogens
Pasteurellaceae General Overview Taxonomic Confusion in Family Pasteurellaceae Three Genera:
• Haemophilus: Most Common in Human Disease
• Actinobacillus• Pasteurella
Haemophilus Common Characteristics of Family
• Small (0.2 x 0.3-2.0 mm) Gram-negative Nonmotile bacilli• Aerobic or facultatively anaerobic• Fastidious growth requirements
Pasteurellaceae Differential Characteristics
X factor = hemin (hematin)
V factor = (NAD or NADP) nicotinamide adenine dinucleotide
Haemophilus
Haemophilus General Overview Gram-negative bacilli liking blood (as per genus name)
Obligate Parasites of Man and Animals Major pathogens for which humans are natural hosts
• Haemophilus influenzae Acute pyogenic, normally invasive infectionsChronic infections with H. influenzae as 2o pathogen
• Haemophilus ducreyi True pathogen (i.e., not found in healthy individuals)
STD; Soft chancre (chancroid)
Haemophilus Diseases
Haemophilus Infections
PRP = polyribitol phosphate
(see others in text)
Haemophilus Infections
(cont.)
NOTE: Polysaccharide PRP is
weakly immunogenicPediatric immunity not
mature for processing polysaccharide antigens until ~18 months
Conjugated Vaccine: PRP conjugated to protein carrier induces protective immunity (carriers may include: diphtheria toxoid, tetanus toxoid or meningococcal OMP)
Haemophilus influenzae Incidence
NOTE: Dramatic decrease in children <5 years; remains constant in older children
(per
100
,000
)
Haemophilus influenzae Diseases
Haemophilus ducreyi Incidence
Actinobacillus
Actinobacillus General Overview Slow-growing; Small; Gram-negative Bacilli
Facultatively Anaerobic
Require CO2 for growth on chocolate or blood agar
Three Species of Actinobacillus Associated with Human Disease
Actinobacillus actinomycetemcomitans is: Most serious pathogen of genusHyperadherent in vitro and on damaged heart valvesCommonly isolated with Actinomyces
-comitans is Latin for “accompanying”Normal oropharyngeal flora in 20% of healthy people
Actinobacillus Diseases
HumanJuvenile & adult Subacute
Pasteurella
Pasteurella General Overview Small; Gram-negative; Fermentative Pleomorphic
Coccobacilli
Facultatively Anaerobic
Therefore infects sutured bites or scratches
Pasteurella multocida:Most common human pathogen Domestic pets serve as major reservoirCommensals in upper respiratory tract of dogs,cats,etc.Human infection often related to animal bites or scratches
or shared food (and you wondered why that lady was buying so
much cat food --- it’s cheaper!)
Pasteurella DIseases
Three Forms of Disease Localized cellulitis and lymphadenitis following
animal bite or scratch
In patients with underlying lung dysfunction, worsening of chronic pulmonary disease from aspiration of organisms colonizing patient’s oropharynx
Systemic infection in immunocompromisedLiver disease patients at highest risk
Pasteurella Diseases (cont.)
Animal scratch or
REVIEWof
Pasteurellaceae
Pasteurellaceae Differential Characteristics
X factor = hemin (hematin)
V factor = (NAD or NADP) nicotinamide adenine dinucleotide
REVIEW
Review of Haemophilus
Haemophilus General Overview Gram-negative bacilli liking blood (as per genus name)
Obligate Parasites of Man and Animals Major pathogens for which humans are natural hosts
• Haemophilus influenzae Acute pyogenic, normally invasive infectionsChronic infections with H. influenzae as 2o pathogen
• Haemophilus ducreyi True pathogen (i.e., not found in healthy individuals)
STD; Soft chancre (chancroid)
REVIEW
Haemophilus Diseases
REVIEW
Haemophilus Infections
PRP = polyribitol phosphate
(see others in text)
REVIEW
Haemophilus Infections
(cont.)
NOTE: Polysaccharide PRP is
weakly immunogenicPediatric immunity not
mature for processing polysaccharide antigens until ~18 months
Conjugated Vaccine: PRP conjugated to protein carrier induces protective immunity (carriers may include: diphtheria toxoid, tetanus toxoid or meningococcal OMP) REVIEW
Haemophilus influenzae Incidence(p
er 1
00,0
00)
NOTE: Dramatic decrease in children <5 years following use of PRP conjugated vaccine; Disease rate remains constant in older children
REVIEW
Haemophilus ducreyi Incidence
REVIEW
Review of Actinobacillus
Actinobacillus General Overview Slow-growing; Small; Gram-negative Bacilli
Facultatively Anaerobic
Require CO2 for growth on chocolate or blood agar
Three Species of Actinobacillus Associated with Human Disease
Actinobacillus actinomycetemcomitans is: Most serious pathogen of genusHyperadherent in vitro and on damaged heart valvesCommonly isolated with Actinomyces
-comitans is Latin for “accompanying”Normal oropharyngeal flora in 20% of healthy people
REVIEW
Actinobacillus Diseases
HumanJuvenile & adult Subacute
REVIEW
Review of Pasteurella
Pasteurella General Overview Small; Gram-negative; Fermentative Pleomorphic
Coccobacilli
Facultatively Anaerobic
Therefore infects sutured bites or scratches
Pasteurella multocida:Most common human pathogen Domestic pets serve as major reservoirCommensals in upper respiratory tract of dogs,cats,etc.Human infection often related to animal bites or scratches
or shared food (and you wondered why that lady was buying so
much cat food --- it’s cheaper!)REVIEW
Pasteurella DIseases
Three Forms of Disease Localized cellulitis and lymphadenitis following
animal bite or scratch
In patients with underlying lung dysfunction, worsening of chronic pulmonary disease from aspiration of organisms colonizing patient’s oropharynx
Systemic infection in immunocompromisedLiver disease patients at highest risk
REVIEW
Pasteurella Diseases (cont.)
Animal scratch or
REVIEW
