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Neisseria
By:
Maria Rosario L. Lacandula,MD,MPH
Department of Microbiology and Parasitology
College Of Medicine
Our Lady of Fatima University
Neisseria
• German Physician- A.L.S. Neisser
• 2 specie- N. gonorrhea
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N. meningitidis
Strict human pathogen
Fastidious organism
Aerobic,gram negative cocci, pairs, coffee bean
shaped
Non motile, non sporing
Neisseria
• Oxidase positive
• Acid production by oxidation
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N. meningitidis- maltose, glucose
N. gonnorhea- glucose
Growth-non specific- blood agar
specific- Thayer Martin media
VCN antibiotics
enhance-exposure to 5% CO2
Organism
Neisseria gonorrhea
• Optimum growth-tempt. is 35 C to 37 C
with poor survival –cool temperature
• Structure is typical of Gram negative
• Outer surface is not covered with a true
CHON capsule
Neisseria gonorrhea
• Virulence factors
1. PILI- fresh clinical isolates
– Control by Pil gene
– Expression of pili is associated with virulence
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T1 T2 T3 T4 T5
Antigenic variation of pili proteins and phase
variation of pilin expression
Neisseria gonorrhea
• 2.Por proteins
– Form pores or channels in the outer
membrane
– inhibits phagosome lysosomal fusion
– Por A- express resistant to serum killingdisseminated disease
– Por B
– Antigenic variation –serotype classification
Neisseria gonorrhea
3.OPA-opacity protein
– Mediates binding to epithelial cells
– Opaque colonies
– Adherence of bacteria to each other and to
eukaryotic cell
Neisseria gonorrhea
4 RMP- reduction modifiable proteins
-Stimulate antibodies that block serum
bactericidal activity
5. Transferrin binding protein
Lactoferrin binding protein
Hemoglobin binding protein
6. LOS-endotoxin activity
7. IgA proteases- degrades secretory IgA
8. Beta lactamase- hydrolyzes Beta lactam ring
Neisseria gonorrhea
• Epidemiology
Transmitted by sexual contact
Women
50% risk developing disease after single
exposure
Men
20% risk developing disease after single
exposure
The risk of infection increases with more sexual
partners
Neisseria gonorrhea
Major resorvoir-asymptomatic infected
person
Asymptomatic carriage-common in women
Half of infected women- have mild
asymptomatic infection
Men-symptomatic
Asymptomatic infection- rectal and
pharyngeal
Neisseria gonorrhea
Clinical Diseases
Men-urethritis-urethral d/c and dysuria
Complication is rare- epididymitis,prostatitis &
periurethral abscesses
Women- Cervicitis- infect endocervical columnar
epithelial cells.
-d/c,dysuria, and abdominal pain
10-20%- ascending infection can occur
Neisseria gonorrhea
• 1-3% of infected women-Disseminated
infection, infection of skin and joints
• Clinical Manifestation of disseminated
disease include fever, migratory
arthralgias,suppurative arthritis in
wrist,knees, ankles and a pustular rash on
an erythematous base over the extremities
Neisseria gonorrhea
• Other diseases:
– Fitz-hugh-Curtis Syndrome
– Opthalmia neonatorum
– Anorectal gonorrhea
– Pharyngitis
– conjuctivitis
Neisseria gonorrhea
• Laboratory Diagnosis
1.Gram stain- 90% sensitive and 98% specificsymptomatic cases
60% or less- asymptomatic cases
-confirmed by culture
useful in purulent arthritis
2.Genetic probes- sensitive, specific and rapid
3.Serology- not recommended
Neisseria gonorrhea
• Treatment, Prevention & Control
Ceftriaxone, cefexime, ciprofloxacin or
ofloxacine
doxycline or azithromycin
1% tetracycline, 0.5% erythromycin eye
oitment
Neisseria Meningitidis
• Gram negative diplococci, coffee bean
shaped
• Encapsulated
• Common colonizer of nasopharynx of
healthy people
• Blood agar- transparent,non pigmented
colonies
• With large capsule- mucoid
Neisseria Meningitidis
• 13 serogroups- antigenic differences on
their capsule
serogroups- A,B,C,X,Y and W135
• Serotype classification- differences in the
outer membrane proteins and
oligosaccharide component of LOS
– Epidemiologic classification
Neisseria Meningitidis
• 4 factors that determine outcome of
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infection
bacteria colonize the nasopharynx
Specific group and serotype-specific
antibodies are present
Systemic spreads occurs w/o Ab
mediated phagocytosis
Toxic effects are expressed
Neisseria Meningitidis
• Incidence of disease- greatest in children
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younger than 2 y/o
Def in C5,C6,C7 or C8- increase risk
Toxic effects- LOS endotoxin
• Epidemiology
-occurs worldwide
-epidemics-common in developing countries
Neisseria Meningitidis
• Develop countries-serogroup B,C, or Y
• Underdevelop countries- serogroup A
• Meningococcal pneumonia-serogroup Y and
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W135
MOT: respiratory droplets
Humans- natural carriers
– School aged children and young adults with high
incidence in low socioeconomic group
– Common during dry cold months of the year
Neisseria Meningitidis
• Clinical Disease
• Meningitis
-start abruptly with HA,meningeal signs, and fever
-neurologic sequelae is low-hearing defects and arthritis
• Meningococcemia
- septicemia with or w/o meningitis
-thrombosis of small bld vessel and multiorgan
involvement
• DIC with bilateral hge of the adrenals- WaterhouseFriderichsen syndrome
Neisseria Meningitidis
Neisseria Meningitidis
– Pneumonia
– Arthritis
– Urethritis
• Laboratory Diagnosis
– Specimens-blood and CSF
– Gram stain
– Latex agglutination
Neisseria Meningitidis
• Treatment
-Penicillin
- rifampicin or Minocycline- prophylaxis
- Vaccine- polyvalent vaccine A,C,Y,W135