Download P. Aruginosa Virulence Factors I

P. aeruginosa
•
•
•
•
Gram negative bacilli
Aerobic non-fermenting
Chromatid size 5.7 Mb
Found in soil, vegetation, water
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
P. Aruginosa Virulence Factors I
• Adhesins
• Alginate Production
• Endotoxin
• Neuraminidase
• Exotoxin A
• Exoenzyme S
P. Aruginosa Virulence Factors II
• Elastolytic Activity - LasA, LasB
• Phospholipase C
• Pyocyanin, Pyochelin
• Antibiotic Resistance
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
Mycobacteria
Bacteria reproduce
in macrophages
ls
ce l
Phag
, T cells
tes
,
y
c
B
Bacteria reach lungs;
enter macrophages
o
Granuloma
Dead
Phagocytes
Lesion begins to form
(caseous necrosis)
Bacteria cease to
grow; lesion calcifies
Lesion
liquifies
Spread to
blood, organs
Reactivation
Death
Bacteria
coughed
up in
sputum
M. Tuberculosis Diagnosis
• Mantoux test – PPD
• Positive test – Redness and swelling
(erythema)
Hardening (induration)
• Disadvantages – BCG Vaccination
Slow development
Anergy
M. Leprae
• Disease – Leprosy (Hansen’s disease):
tuberculoid and lepromatous form.
• Virulence factors – unknown
• Transmission –
Lepromatous leprosy:
Highly infectious
Tuberculoid leprosy:
Low
N. gonorrhoea
Aerobic, gram negative cocci.
Horizontal and vertical transmission
Health Problem:
 High rate of asymptomatics
 Antigenically variable
N. gonorrhoeae
Oropharyngeal
infection
Pharyngitis
Anal or genital
Infection
Local irritation,
discharge
Systemic
spread 1%
(arthritis,
endocarditis
meningitis)
Asymptomatic
(especially women)
N. gonorrhoeae Cervical infection
(symptomatic or
asymptomatic)
Ascending infection of
uterine cavity, fallopian
tubes (pelvic inflammatory
disease, infertility, ectopic
pregnancy)
Blindness
N. gonorrhoeae
Surface
colonization
of infant at birth
Eye infection
Conjunctivitis
N. gonorrhoea Virulence Factors
•
•
•
•
•
•
Capsule
Pilus (PilE, PileS antigenic variation)
Opa (Slipped strand mispairing)
LOS
Iron binding proteins: Tbp1,2,Lbp
Protease
Stages in
interaction of N.
gonorrhoeae with
cultured
mammalian cells
Stages in
interaction of N.
gonorrhoeae with
cultured
mammalian cells
Phase Variation II: Slipped
Strand Mispairing