Pasteurellaceae D

 Haemophilus influenzae  Haemophilus ducreyi  Oppurtunists: Haemophilus parainfluenzae Haemophilus spp.  Pasteurella multocida  Actinobacillus 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 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 infections  Chronic infections with H. influenzae as 2 o 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 immunogenic  Pediatric 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 CO 2 for growth on chocolate or blood agar  Three Species of Actinobacillus Associated with Human Disease  Actinobacillus actinomycetemcomitans is:  Most serious pathogen of genus  Hyperadherent in vitro and on damaged heart valves  Commonly isolated with Actinomyces -comitans is Latin for “accompanying”  Normal oropharyngeal flora in 20% of healthy people

Actinobacillus Diseases HumanJuvenile & adultSubacute

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 reservoir  Commensals 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 immunocompromised  Liver 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  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 infections  Chronic infections with H. influenzae as 2 o 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 immunogenic  Pediatric 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 (per 100,000) 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 CO 2 for growth on chocolate or blood agar  Three Species of Actinobacillus Associated with Human Disease  Actinobacillus actinomycetemcomitans is:  Most serious pathogen of genus  Hyperadherent in vitro and on damaged heart valves  Commonly isolated with Actinomyces -comitans is Latin for “accompanying”  Normal oropharyngeal flora in 20% of healthy people REVIEW

Actinobacillus Diseases HumanJuvenile & adultSubacute 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 reservoir  Commensals 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 immunocompromised  Liver disease patients at highest risk REVIEW

Pasteurella Diseases (cont.) Animal scratch or REVIEW