Pasteurellaceae Human Pathogens v Haemophilus influenzae v Haemophilus

Pasteurellaceae

Human Pathogens v Haemophilus influenzae v Haemophilus ducreyi v Oppurtunists: Haemophilus parainfluenzae Haemophilus spp. v Pasteurella multocida v Actinobacillus actinomycetemcomitans

Pasteurellaceae General Overview Ø Taxonomic Confusion in Family Pasteurellaceae Ø Three Genera: • Haemophilus: Most Common in Human Disease • Actinobacillus • Pasteurella Ø Haemophilus Ø 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 Ø Gram-negative bacilli liking blood (as per genus name) Ø Obligate Parasites of Man and Animals Ø Major pathogens for which humans are natural hosts • Haemophilus influenzae üAcute pyogenic, normally invasive infections üChronic infections with H. influenzae as 2 o pathogen • Haemophilus ducreyi üTrue pathogen (i. e. , not found in healthy individuals) üSTD; Soft chancre (chancroid)

Haemophilus Diseases

Haemophilus Infections PRP = polyribitol phosphate (see others in text)

Haemophilus Infections (cont. ) NOTE: üPolysaccharide PRP is weakly immunogenic üPediatric immunity not mature for processing polysaccharide antigens until ~18 months üConjugated Vaccine: PRP conjugated to protein carrier induces protective immunity (carriers may include: diphtheria toxoid, tetanus toxoid or meningococcal OMP)

(per 100, 000) Haemophilus influenzae Incidence NOTE: Dramatic decrease in children <5 years; remains constant in older children

Haemophilus influenzae Diseases

Haemophilus ducreyi Incidence

Actinobacillus

Actinobacillus General Overview Ø Slow-growing; Small; Gram-negative Bacilli Ø Facultatively Anaerobic Ø Require CO 2 for growth on chocolate or blood agar Ø Three Species of Actinobacillus Associated with Human Disease Ø Actinobacillus actinomycetemcomitans is: ü Most serious pathogen of genus ü Hyperadherent in vitro and on damaged heart valves ü Commonly isolated with Actinomyces -comitans is Latin for “accompanying” ü Normal oropharyngeal flora in 20% of healthy people

Actinobacillus Diseases Juvenile & adult Subacute Human

Pasteurella

Pasteurella General Overview Ø Small; Gram-negative; Fermentative Pleomorphic Coccobacilli Ø Facultatively Anaerobic üTherefore infects sutured bites or scratches Ø Pasteurella multocida: üMost common human pathogen üDomestic pets serve as major reservoir üCommensals in upper respiratory tract of dogs, cats, etc. üHuman 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 Ø Localized cellulitis and lymphadenitis following animal bite or scratch Ø In patients with underlying lung dysfunction, worsening of chronic pulmonary disease from aspiration of organisms colonizing patient’s oropharynx Ø Systemic infection in immunocompromised üLiver disease patients at highest risk

Pasteurella Diseases (cont. ) Animal scratch or

REVIEW of Pasteurellaceae

Pasteurellaceae Differential Characteristics X factor = hemin (hematin) V factor = (NAD or NADP) nicotinamide adenine dinucleotide REVIEW

Review of Haemophilus

Haemophilus General Overview Ø Gram-negative bacilli liking blood (as per genus name) Ø Obligate Parasites of Man and Animals Ø Major pathogens for which humans are natural hosts • Haemophilus influenzae üAcute pyogenic, normally invasive infections üChronic infections with H. influenzae as 2 o pathogen • Haemophilus ducreyi üTrue pathogen (i. e. , not found in healthy individuals) üSTD; Soft chancre (chancroid) REVIEW

Haemophilus Diseases REVIEW

Haemophilus Infections (see others in text) PRP = polyribitol phosphate REVIEW

Haemophilus Infections (cont. ) NOTE: üPolysaccharide PRP is weakly immunogenic üPediatric immunity not mature for processing polysaccharide antigens until ~18 months üConjugated Vaccine: PRP conjugated to protein carrier induces protective immunity (carriers may include: diphtheria toxoid, tetanus toxoid or meningococcal OMP) REVIEW

(per 100, 000) Haemophilus influenzae Incidence 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 Ø Slow-growing; Small; Gram-negative Bacilli Ø Facultatively Anaerobic Ø Require CO 2 for growth on chocolate or blood agar Ø Three Species of Actinobacillus Associated with Human Disease Ø Actinobacillus actinomycetemcomitans is: ü Most serious pathogen of genus ü Hyperadherent in vitro and on damaged heart valves ü Commonly isolated with Actinomyces -comitans is Latin for “accompanying” ü Normal oropharyngeal flora in 20% of healthy people REVIEW

Actinobacillus Diseases Juvenile & adult Subacute Human REVIEW

Review of Pasteurella

Pasteurella General Overview Ø Small; Gram-negative; Fermentative Pleomorphic Coccobacilli Ø Facultatively Anaerobic üTherefore infects sutured bites or scratches Ø Pasteurella multocida: üMost common human pathogen üDomestic pets serve as major reservoir üCommensals in upper respiratory tract of dogs, cats, etc. üHuman 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 Ø Localized cellulitis and lymphadenitis following animal bite or scratch Ø In patients with underlying lung dysfunction, worsening of chronic pulmonary disease from aspiration of organisms colonizing patient’s oropharynx Ø Systemic infection in immunocompromised üLiver disease patients at highest risk REVIEW

Pasteurella Diseases (cont. ) Animal scratch or REVIEW