Fe A. Bartolome, MD, DPASMAP Department of Microbiology & Parasitology Our Lady of Fatima University

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Miscellaneous Bacteria
Fe A. Bartolome, MD, DPASMAP Department of
Microbiology Parasitology Our Lady of Fatima
University
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HAEMOPHILUS

• Family Pasteurellaceae
• Small, gram negative, pleomorphic
• Require enriched media containing blood or its
  derivatives
• Facultative anaerobes
• Obligate parasites

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Haemophilus influenzae

• Found on mucus membrane of URT in humans
  (noncapsular form) ? encapsulated species
  uncommon members of normal flora
• Short, coccoid bacilli in pairs or chains

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Haemophilus influenzae

• Classification
• Serotype based on capsular antigen
• Biotype based on biochemical properties
• a. indole production
• b. urease activity
• c. ornithine decarboxylase activity
• Biogroup useful for clinical purposes

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Haemophilus influenzae
Culture

• Chocolate agar flat, grayish brown colonies
  after 24 hrs incubation
• Does not grow on sheep blood agar except around
  colonies of Staphylococci ? satellite phenomenon

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Haemophilus influenzae
Growth Characteristics

• Requires X factor (hemin) and V factor (NAD)
• Ferments carbohydrates poorly and irregularly

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Haemophilus influenzae
Characteristics Growth Requirements
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Haemophilus influenzae
Virulence Factors

• Capsule
• Antiphagocytic impair ciliary function
• Main virulence factor
• With capsular polysaccharides (a to f)
• Type b polyribose-ribitol phosphate (PRP)

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Haemophilus influenzae
Virulence Factors

• Somatic antigen
• Outer membrane proteins ? lipooligo-saccharides
  (endotoxin)
• IgA1 proteases

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Haemophilus influenzae
Clinical Features

• H. influenzae type b
• Most common serotype causing systemic disease
• Meningitis
• Pneumonia empyemia
• Epiglottitis
• Cellulitis
• Septic arthritis

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Haemophilus influenzae
Clinical Features

• Non-typeable (non-encapsulated) H. influenzae
• opportunistic
• Chronic bronchitis
• Otitis media
• Sinusitis
• Conjunctivitis

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Haemophilus influenzae
Clinical Features

• Meningitis
• 20 to bacteremic spread from nasopharynx
• Peak incidence 3 18 mos. Old
• Epiglottitis
• Cellulitis swelling of supraglottic tissues
• Pharyngitis, fever dyspnea ? complete airway
  obstruction ? death

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Haemophilus influenzae
Clinical Features

• Cellulitis
• Reddish blue patches on cheeks or periorbital
  areas

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Haemophilus influenzae
Clinical Features

• Arthritis
• Infection of a single large joint
• Children lt 2 y/o or immunocompromised patients or
  those with previously damaged joints
• Conjunctivitis
• Epidemic and endemic
• H. influenzae biogroup aegypticus

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Haemophilus influenzae
Clinical Features
Sepsis with gangrene
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Haemophilus influenzae
Prevention

• Chemoprophylaxis with Rifampin for non-immune
  children lt 4 y/o who are close contacts
• Hib conjugate vaccine
• gt 2 mos. Old ? Hib conjugated with C.
  diphtheriae toxin protein or N. meningitidis
  outer membrane complex
• gt 15 mos. Old ? Hib conjugated with diphtheria
  toxoid

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Haemophilus aegypticus

• H. influenzae biotype III
• Koch-Weeks bacillus
• Resembles H. influenzae closely
• Diseases
• Conjunctivitis highly communicable
• Brazilian purpuric fever fever, purpura, shock
  and death

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Haemophilus ducreyi

• Causes chancroid (soft chancre)
• Ragged ulcer on genitalia with marked swelling
  and tenderness
• Lymph nodes enlarged and painful
• Organism grows best on chocolate agar incubated
  in 10 CO2
• No permanent immunity

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Haemophilus ducreyi
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Bordetella pertussis

• Small, coccobacillary, encapsulated, gram (-)
• With bipolar metachromatic granules (toluidine
  blue stain)
• Non-motile strict aerobe
• Forms acid from glucose and lactose
• Requires enriched media
• Bordet-Gengou medium (potato-blood-glycerol agar)
• Contains Pen G 0.5 ug/mL
• Virulence genes bvgA and bvgS

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Bordetella pertussis
Gram stain
Culture on chocolate agar
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Bordetella pertussis

• Virulence Factors
• Filamentous hemagglutinin
• Protein on pili adhesion to ciliated epithelial
  cells
• Pertussis toxin
• a. promote lymphocytosis via inhibition of
  signal transduction by chemokine receptors ?
  lymphocytes do not enter lymphoid tissues
• b. promote sensitization to histamine
• c. enhance insulin secretion
• d. stimulate adenylate cyclase via
  ADP-ribosylation

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Bordetella pertussis

• Virulence Factors
• Adenylyl cyclase toxin inhibit phagocytosis
• Tracheal cytotoxin
• Fragment of bacterial peptidoglycan
• Induce nitric oxide ? destroy ciliated epithelium
• Dermonecrotic toxin
• Hemolysin

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Bordetella pertussis

• Pathogenesis
• Adheres to and multiplies rapidly on epithelial
  surface of trachea and bronchi ? interfere with
  ciliary action
• No invasion of blood

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Bordetella pertussis

• Clinical
• MOT airborne droplets
• Source of infection patients in early catarrhal
  stage
• Disease Pertussis or Whooping Cough ? acute
  tracheobronchitis
• Incubation period approx. 2 weeks

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Bordetella pertussis

• Clinical Stages of Disease
• Catarrhal
• Mild coughing and sneezing
• Highly infectious but not very ill
• Paroxysmal (1-4 weeks)
• Series of hacking coughs, accompanied by copious
  amts. of mucus, ending with inspiratory whoop ?
  exhaustion, vomiting, cyanosis and convulsions
• High wbc count (16,000-30,000/uL) with absolute
  lymphocytosis
• Convalescence - slow

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Bordetella pertussis

• Laboratory Diagnosis
• Specimen saline nasal wash (preferred) or
  nasopharyngeal swab
• Direct fluorescence antibody test 50
  sensitivity
• Culture of saline nasal wash fluid
• PCR most sensitive
• Serology () only on third week of illness ? of
  little diagnostic value

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Bordetella pertussis

• First defense is antibody that prevents
  attachment
• Recovery from disease or immunization is followed
  by immunity
• Second infection may occur but is mild
• Re-infection occurring years later in adults may
  be severe
• Vaccine-induced immunity not completely protective

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Bordetella pertussis

• Prevention
• Chemoprophylaxis Erythromycin ? for exposed,
  unimmunized individuals OR exposed, immunized
  children lt 4 years old
• Vaccine two vaccines available
• a. acellular vaccine contains 5 purified
  antigens ? main immunogen is inactivated
  pertussis toxin first vaccine to contain a
  genetically inactivated toxoid ?
  ADP-ribosylating activity removed
• b. DPT x 3 doses

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BRUCELLA

• Zoonotic ? obligate parasite of animals humans
• Intracellular organism
• Gram negative coccobacilli
• Aerobic non-motile nonspore-forming
• Catalase () oxidase ()
• Produces H2S
• Culture trypticase soy agar OR blood culture
  media B. abortus requires 5-10 CO2 for growth

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BRUCELLA

• Route of infection in humans
• Intestinal tract ingestion of infected milk
  contaminated dairy products (cheese from
  unpasteurized goats milk)
• Mucous membranes droplets
• Skin contact with infected tissues of animals
• Pathogenesis endotoxin O antigen polysaccharide

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BRUCELLA
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BRUCELLA

• Clinical Brucellosis (Undulant or Malta Fever)
• Acute
• Malaise, fever, weakness, aches sweats
• Fever rises in the afternoon ? fall during the
  night with drenching sweats
• () lymphadenopathy w/ palpable spleen
  hepatitis with jaundice
• Chronic
• With psychoneurotic symptoms
• Weakness, aches pains, low grade fever

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BRUCELLA

• Diagnosis
• Culture
• BM blood commonly used specimen
• Brucella agar, trypticase soy medium, brain heart
  infusion medium, chocolate agar
• Serology inc. IgM during 1st week of illness
  peak at 3 months

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Francisella tularensis

• Small, gram (-) pleomorphic rod
• Widely found in animal reservoirs (rabbits, deer,
  rodents)
• Humans are accidental dead-end hosts
• Two biotypes
• Jellison type A more virulent US
• Jellison type B less virulent Europe
• Culture glucose cysteine blood agar OR glucose
  blood agar

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Francisella tularensis
Gram stain
F. tularensis colonies on agar plate
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Francisella tularensis

• Mode of transmission
• Contact with animal tissue
• Bite of vector (Dermacentor tick)
• Ingestion of infected meat
• Inhalation
• Symptoms caused by endotoxin

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Francisella tularensis

• Clinical
• Ulceroglandular 75 ulceration at site of
  entry with swollen painful LN
• Glandular
• Oculoglandular
• Typhoidal
• GI pulmonary
• Disease confers lifelong immunity

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Francisella tularensis
Cutaneous tularemia
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Francisella tularensis

• Diagnosis culture not done due to high risk to
  lab workers
• Agglutination test most frequently used
• Fluorescent antibody staining of infected tissue
• Treatment Streptomycin (DOC)
• Prevention live, attenuated vaccine partial
  immunity not available commercially

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YERSINIA

• Short, pleiomorphic gram (-) rods with bipolar
  staining
• Catalase and oxidase ()
• Microaerophilic or facultative anaerobe
• All with LPS that have endotoxic activity

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Yersinia pestis

• Non-motile, facultative anaerobe
• Growth more rapid in media containing blood or
  tissue fluids at 300C ? gray and viscous colonies

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Yersinia pestis

• Virulence Factors
• LPS endotoxin
• Envelope with protein (fraction I) ?
  antiphagocytic
• Coagulase
• V-W antigens (virulent, wild type) essential
  for virulence
• Pesticin - bacteriocin

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Yersinia pestis

• Pathogenesis
• Bite of vector (Xenopsylla cheopis) ? organism
  phagocytosed by PMNs monocytes ? multiply in
  monocytes ? lymphatics ? () intense hemorrhagic
  inflammation in enlarged LN ? bloodstream ?
  hemorrhagic necrotic lesions in all organs
• Inhalation of infective droplets from coughing
  patients ? primary pneumonic plague with
  hemorrhagic consolidation, sepsis and death

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Yersinia pestis

• Clinical Plague
• I.P. 2 7 days
• High fever painful lymphadenopathy (buboes)
• Vomiting diarrhea may develop with early sepsis
• Later ? DIC ? hypotension, altered mental status,
  renal and cardiac failure
• Terminal signs of pneumonia meningitis

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Yersinia pestis
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Yersinia pestis

• Diagnosis
• Smear Giemsa stain or Waysons stain ( bipolar
  appearance)
• Culture blood agar or MacConkeys agar plates
  infusion broth all cultures highly infectious
• Serology - examination of acute and convalescent
  sera for antibody levels
• Treatment Streptomycin (DOC)

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Pasteurella multocida

• Primarily animal pathogens
• Non-motile gram (-) coccobacilli with bipolar
  appearance on stained smears
• Occurs worldwide in respiratory tract and GIT of
  many domestic and wild animals
• Most common organism in human wounds inflicted by
  bites from cats and dogs
• Virulence factors include capsule and endotoxin

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Pasteurella multocida

• Clinical
• Rapidly spreading cellulitis at site of animal
  bite
• Incubation period lt 24 hours
• May present as bacteremia or chronic respiratory
  infection
• Complication osteomyelitis (cat bites)
• Treatment Penicillin G (DOC)

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Pasteurella multocida