P. aeruginosa

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P. aeruginosa

• Gram negative bacilli
• Aerobic non-fermenting
• Chromatid size 5.7 Mb
• Found in soil, vegetation, water

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P. aeruginosa and Nosocomial Infections

• Found in hospital environment in moist
  reservoirs food, cut flowers, sinks, toilets,
  floor mops, medical equipment, disinfectant
  solutions.
• Common problem in immunocompromised patients,
  burn victims, resident catheters, cystic fibrosis
• Resistant to antibiotics

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P. Aruginosa Virulence Factors I

• Adhesins
• Alginate Production
• Endotoxin
• Neuraminidase
• Exotoxin A
• Exoenzyme S

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P. Aruginosa Virulence Factors II

• Elastolytic Activity - LasA, LasB
• Phospholipase C
• Pyocyanin, Pyochelin
• Antibiotic Resistance

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Mycobacteria

• Non-motile, aerobic gram positive bacilli
• Acid-fast
• Slow growth
• Resistant to detergents
• Immunostimulatory
• 74 different species, a third associated with
  human disease e.g M. tuberculosis, M. leprae

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Mycobacteria
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M. Tuberculosis Diagnosis

• Mantoux test PPD
• Positive test Redness and swelling
  (erythema) Hardening (induration)
• Disadvantages BCG Vaccination Slow
  development Anergy

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M. Leprae

• Disease Leprosy (Hansens disease) tuberculoid
  and lepromatous form.
• Virulence factors unknown
• Transmission Lepromatous leprosy Highly
  infectious Tuberculoid leprosy Low

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N. gonorrhoea

• Aerobic, gram negative cocci.
• Horizontal and vertical transmission
• Health Problem
• High rate of asymptomatics
• Antigenically variable

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N. gonorrhoea Virulence Factors

• Capsule
• Pilus (PilE, PileS antigenic variation)
• Opa (Slipped strand mispairing)
• LOS
• Iron binding proteins Tbp1,2,Lbp
• Protease

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Stages in interaction of N. gonorrhoeae with
cultured mammalian cells
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Stages in interaction of N. gonorrhoeae with
cultured mammalian cells
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Phase Variation II Slipped Strand Mispairing