BACTERIAL INFECTION ON UPPER RESPIRATION TRACT

eri dianMikrobiologi FK Yarsi

Haemophilus

Characteristics of Haemophilus

• Small, pleomorphic gram-negative coccobacilli, non motile• Growth in culture on chocolate agar & requires exogenous hemin

(oxidized ferroprotoporphyrin) (X factor) and/or nicotinamide adenine dinucleotide (NAD) (V factor)

Haemophilus: Natural Habitats

• Normal inhabitant of the upper respiratory, gastrointestinal, and genital tracts of humans except Haemophilus ducreyi (not normal microbial flora)

Haemophilus species of clinical importance

1. H. influenzae

-type b is an important human pathogen2. H. ducreyi

-sexually transmitted pathogen (chancroid)3. Other Haemophilus are normal flora

- H. parainfluenzae

- H. aphrophilus

- H. aegyptius

Haemophilus: Modes of Infection

• Encapsulated strains of Haemophilus influenzae associated with invasive infection caused by person-to-person spread of H. influenzae due to inhalation of infectious respiratory droplets• Type b H. influenzae was most commonly

associated with disease prior to conjugate vaccine but prevalence has declined with advent of vaccination

Haemophilus: Types of Infectious Disease

• Encapsulated (types a-f) strains of H. influenzae produce invasive infection (pneumonia, meningitis, epiglottitis, and bacteremia)• Unencapsulated (non-typeable) strains of H.

influenzae cause otitis media in children, and lower respiratory tract infections (acute tracheobronchitis, pneumonia) in children and adults

Haemophilus influenzae

Differentiation of Species

HemolysisHemolysisX X VV

GrowthGrowthFactorFactor

Haemophilus influenzae

• Aerobic/facultativ anaerob gram-negative bacteria• Polysaccharide capsule • Six different serotypes (a-f) of polysaccharide capsule• 95% of invasive disease caused

by type b

Cellulitis6%

Arthritis8% Bacteremia

2%

Meningitis50%

Epiglottitis17%

Pneumonia15%

Osteomyelitis2%

Haemophilus influenzae type bClinical Features*

*prevaccination era

Haemophilus influenzae type b Epidemiology

• Reservoir Human Asymptomatic

carriers

• Transmission Respiratory droplets

Haemophilus influenzae type bPathogenesis

• Organism colonizes nasopharynx• In some persons organism invades bloodstream and cause infection

at distant site• Antecedent upper respiratory tract infection may be a contributing

factor

Pathogenic MechanismsPathogenic Mechanisms

• H. influenzae

• Antiphagocytic polysaccharide capsule is the major pathogenesis factor

• Lipopolysaccharide lipid A component from the cell wall (major role in non capsule strains)

• All virulent strains produce neuraminidase and an IgA protease

• No exotoxins

• Hib conjugate vaccine (Poliribitol phosphate ( PRP) capsule)

• The Hib conjugate vaccine does not protect against nontypeable strains

• Persons at risk for invasive H influenzae disease

• Asplenia

• Immunocompromised

Pathogenesis – Host Factors

Basis for the H.influenzae type B vaccine• The polysaccharide capsule of H.influenzae type B is and

represent its major virulence antiphagocitic Factor. The capsule contain ribose,ribitol,and phosphate,known collectively as polyribitol phosphate (PRP). Phagocytosis and complement-mediated activity are stimulated in the presence of antibodies directed at the H.influenzae type B capsule. • H.influenzae type B vaccine contain PRP antigens

conjugated to specific protein carriers.

Haemophilus influenzae requires X and V factors for growth. In this culture haemophilus has only grown around the paper disc that has been impregnated with X and V factors. There is no bacterial growth around the discs that only contain either X or V factor.

Public Health Aspects-H. influenzae

• Typing based on capsule polysaccharide a → f

• Polyribose-ribitol phosphate (PRP) capsule (type b)

• Nonencapsulated (nontypeable) organisms are part of normal flora of the respiratory tract

• 95% of invasive disease caused by type b

Moraxella spp

Moraxella spp• M. atlantae, M. bovis, M. canis, M. caprae. M. catarrhalis, M.

equi, M. lacunata, M. lincolnii, M. nonliquefaciens, M. oblonga, M. osloensis, M. pluranimalium. Moraxella phenylpyruvica

Characteristics of Moraxella

• CHARACTERISTICS: • The genus Moraxella is a member of the family

Moraxellaceae; • coccobacillary gram negative rods that are usually in short

chains or pairs . • Species that are rod shaped range from 1.0-1.5 x 1.5-2.5 μm in

size and species that are cocci shaped are 0.6-1.0 μm in diameter(2). Most species are aerobic, and oxidase and catalase positive

PATHOGENICITY/ TOXICITY

• Moraxella species are normally present in the oropharynx, mucous membranes, skin, and genital tract,.

• The organisms are commensals of mucosal surfaces and sometimes give rise to opportunistic infection

• Moraxella catarrhalis usually resides in respiratory tract, but can gain access to the lower respiratory tract in patients with chronic chest disease or compromised host defenses, thus causing tracheobronchitis and pneumonia.

• Moraxella lacunata is one of the causes of blepharoconjunctivitis in human

• Moraxella bovis is the cause of Infectious bovine keratoconjunctivitis

• Other Moraxella species can cause conjunctivitis and keratitis (Moraxella lacunata), meningitis, and arthritis (Moraxella oloensis), endocarditis (Moraxella lacunata), osteomyelitis (Moraxella oloensis), upper and lower respiratory tract infections (Moraxella nonliquefaciens) and otolaryngologic infections (Moraxella lacunata). Several species are found in the natural human flora; however, their pathogenicity, if any, has not been established

Selected Biochemical Reactions for Identification of Neisseria and Moraxella catarrhalis1

Glu Mal Lac Suc DNa BE N. gon + – – – – –

N. men + + – – – –N. lac + + + – – –M. cat – – – – + +1Glu=glucose, Mal=maltose, Lac=lactose, Suc=sucrose,

DNa=DNase, BE=butyrate esterase (indoxyl butyrate substrate), N. gon=N. gonorrhoeae, N. men=N. meningitidis, N. lac=N. lactamica, M. cat=Moraxella catarrhalis

Fusobacterium species • Fusobacterium is a genus of anaerobic, Gram-negative

bacteria,rod-shaped bacilli with pointed ends.• Strains of Fusobacterium cause several human diseases,

including periodontal diseases, Lemierre's syndrome, and topical skin ulcers.

• Although older sources state that Fusobacterium is part of the normal flora of the human oropharynx, the current consensus is that Fusobacterium should always be treated as a pathogen. [2] In 2011, researchers discovered that this bacterium flourishes in colon cancer cells, and is often also associated with ulcerative colitis, although researchers have not determined if the organism actually causes these diseases or if it simply flourishes in the environment these diseases create