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NEISSERIAE
MENINGITIDIS
Dr. Uzma Mussarat
LEARNING OBJECTIVES
 Enlist the bacterial causes of meningitis
 Describe the morphological features,virulence
factors an...
Meningitis
 Meningitis means inflammation but usually
implies serious infection of the meninges
 Microorganism reach the...
Meningococcal Meningitis
Is inflammation of the meninges-
meningitis, caused by the bacteria
Nesseria meningitidis.
Neis...
Meningococcal Meningitis
 Less common bacterial causes of Meningitis, such as
Staphylococci, enteric bacteria, group B st...
Pathology
 In acute bacterial meningitis, the pia arachnoid
is congested with polymorphs. A layer of pus
forms. This may ...
Neisseria
meningitides
General Characteristics of
Neisseria spp. Aerobic
 Gram-negative cocci often arranged in pairs
(diplococci) with adjacen...
Neisseria gonorrhoeae
Neisseria meningitidis
Important Human Pathogens
Other species normally colonize
mucosal surfaces of...
Neisseria Associated Diseases
(ophthalmia
neonatorum)
Encapsulated small, gram-negative
diplococci
Second most common cause (behind S.
pneumoniae) of community-acquired
menin...
Meningococcal meningitis
 Humans only natural hosts
 Person-to-person transmission by
aerosolization of respiratory tract
secretions in crowded c...
Highest incidence in children
younger than 5 years and
particularly those younger than 1
year of age as passive maternal
...
Occurrence
 Infections can occur through the year, but are more
common in late winter to early spring.
Mode of Transmissi...
Pathogenicity:
Pili-mediated, receptor-specific
colonization of nonciliated cells of
nasopharynx
Antiphagocytic polysacc...
Specific receptors (GD1 ganglioside) for bacterial
fimbriae on nonciliated columnar epithelial cells in
nasopharynx of ho...
Hyperproduction of endotoxin (lipid A of
LOS) and blebbing into surrounding
environment (e.g., subepithelial spaces,
bloo...
Following dissemination of virulent
organisms from the nasopharynx:
 Meningitis
 Septicemia (meningococcemia) with or
w...
Meningitis Clinical findings
 Clinically: rapid deterioration of flu like illness
 Headache, neck stiffness, +ve kerning...
Neisseria meningitidis in
Cerebrospinal Fluid
Skin Lesions of Meningococcemia
NOTE:
Petechiae
have
coalesced
into
hemorrhagi
c bullae.
Neck rigidity
Haemorrhagic
 Large numbers (e.g., >107cells/ml) of
encapsulated, small, gram-negative
diplococci (flattened along adjoining
side) and...
Contd…
Transparent, non-pigmented
nonhemolytic colonies on
chocolate blood agar with
enhanced growth in moist
atmosphere ...
Diagnosis
 Isolation of the organism
from CSF or blood.
2. Streptococcus pneumoniae
 (G+,Lancet shaped diplococci
Alpha- haemolytic colonies on
blood agar
Quelling Test +ive
...
Streptococcus pneumoniae
General characteristics
Inhabits the nasopharyngeal areas of healthy
individuals
Possess C sub...
The quellung reaction
(swelling reaction) forms the
basis of serotyping and relies
On the swelling of the
capsule upon bin...
Contd…
 Pneumoccus grow only in enriched media. (blood agar, glucose
broth)
 aerobes, facultative anaerobes
 optimal te...
Laboratory Diagnosis:
Streptococcus pneumoniae
Colony
morphology
Smooth,
glistening, wet-
looking, mucoid
a-Hemolytic
...
Laboratory Diagnosis:
Streptococcus pneumoniae
Identification
Catalase negative
Optochin-
susceptibility-test–
suscepti...
Alpha & Beta Haemolysis
S. pneumoniae
Pus cells and S. pneumoniae
in sputum gram stain
Neutrophil & Red Cells
3. Haemophilus influenzae
 Aerobic , Small, pleomorphic gram-negative coccobacilli
 Polysaccharide capsule
 Six differe...
Contd…
 95% of invasive disease caused
by type b
 The type b capsule is composed of polyribitol phosphates
 Unencapsula...
H.INFLUENZAE IS THE LEADING
CAUSE OF MENINGITIS IN YOUNG
CHILDREN
Important cause of URTI(otitis
media,sinusitis and epi...
LABORATORY DIAGNOSIS
Specimens:
 Oral swab: avoid contamination with oral secretions
 Sputum from LRT
 Direct needle a...
LABORATORY DIAGNOSIS
 Heated blood (chocolate) agar for isolation(to inactivate nonspecific inhibitors of
H.influenzae gr...
Contd..
Definitive identification can be
made by biochemical tests or the
capsular swelling “QUELLUNG
“reaction
Fluoresc...
Streptococcus agalactiae
Streptococcus agalactiae
 Gram +ive cocci in small chains
 Beta haemolytic colonies on blood agar
 Lance-field gouping ...
FIG. 6. CAMP-
positive Streptococcus
agalactiae (group B) inoculated
at right angles to the test
organism Staphylococcus a...
Listeria Monocytogenes
 Gram +ive , motile rod. Coccobacillus , Non –
capsulated
 Motile at 18 – 20 C°, non motile at 37...
Listeria Monocytogenes
Laboratory Diagnosis
Gram staining----G+ive rods
Small grey coloured colonies
with narrow zone of beta
hemolysis on bloo...
THANKS
Bacterial meningitis
Bacterial meningitis
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Bacterial meningitis

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Meningitis
Bacterial Meningitis

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Bacterial meningitis

  1. 1. NEISSERIAE MENINGITIDIS Dr. Uzma Mussarat
  2. 2. LEARNING OBJECTIVES  Enlist the bacterial causes of meningitis  Describe the morphological features,virulence factors and diagnosis of following bacteria  Neisseria meningitides  Listeria monocytogenes  Haemophilus influenzae  Streptococcus agalactae  streptococcus pneumonia
  3. 3. Meningitis  Meningitis means inflammation but usually implies serious infection of the meninges  Microorganism reach the meninges either by direct extension from the ears, nasopharynx, cranial injury or congenital meningeal defect, or by bloodstream spread.  Non infectious causes of inflammation include malignant cells, drugs and blood following subarachnoid hemorrhage
  4. 4. Meningococcal Meningitis Is inflammation of the meninges- meningitis, caused by the bacteria Nesseria meningitidis. Neisseria meningitidis,Streptococcus pneumoniae and Haemophilus influenzae are the most common agents of bacterial meningitis.
  5. 5. Meningococcal Meningitis  Less common bacterial causes of Meningitis, such as Staphylococci, enteric bacteria, group B streptococci and Listeria, occur in sub-populations like the immunocompromised, neonates, or head trauma patients.  Patients with Meningococcal Meningitis present with sudden onset of fever, intense headache, nausea, vomiting, stiff neck and, frequently, a petechial rash with pink macules or, very rarely, vesicles. Delirium and coma often appear.  Case fatality rate is between 5% and 15%.
  6. 6. Pathology  In acute bacterial meningitis, the pia arachnoid is congested with polymorphs. A layer of pus forms. This may organize to form adhesions, causing cranial nerve palsies and hydrocephalus.  In chronic infection (e.g. TB), the brain is covered in a viscous grey green exudates with numerous meningeal tubercles. Adhesions are invariable. Cerebral edema occurs in any bacterial meningitis.  In viral meningitis there is a predominantly lymphocytic inflammatory CSF reaction without pus formation, polymorphs or adhesions, there is little or no cerebral edema unless encephalitis develops.
  7. 7. Neisseria meningitides
  8. 8. General Characteristics of Neisseria spp. Aerobic  Gram-negative cocci often arranged in pairs (diplococci) with adjacent sides flattened (like coffe beans)  Oxidase positive  Most catalase positive  Nonmotile  Acid from oxidation of carbohydrates, not from fermentation
  9. 9. Neisseria gonorrhoeae Neisseria meningitidis Important Human Pathogens Other species normally colonize mucosal surfaces of oropharynx and nasopharynx and occasionally anogenital mucosal membranes
  10. 10. Neisseria Associated Diseases (ophthalmia neonatorum)
  11. 11. Encapsulated small, gram-negative diplococci Second most common cause (behind S. pneumoniae) of community-acquired meningitis in previously healthy adults; swift progression from good health to life-threatening disease Introductionof Neisseria meningitidis
  12. 12. Meningococcal meningitis
  13. 13.  Humans only natural hosts  Person-to-person transmission by aerosolization of respiratory tract secretions in crowded conditions  Close contact with infectious person (e.g., family members, day care centers, military barracks, prisons, and other institutional settings) Epidemiology of Meningococcal Disease
  14. 14. Highest incidence in children younger than 5 years and particularly those younger than 1 year of age as passive maternal antibody declines and as infants immune system matures Commonly colonize nasopharynx of healthy individuals; highest oral and nasopharyngeal carriage rates in school-age children, young adults and lower socioeconomic groups
  15. 15. Occurrence  Infections can occur through the year, but are more common in late winter to early spring. Mode of Transmission  By direct contact- respiratory droplets from nose and throat of infected people.  Infection usually causes subclinical infection, severe systemic infection is rare.  Carrier prevalence can be as high as 25%.
  16. 16. Pathogenicity: Pili-mediated, receptor-specific colonization of nonciliated cells of nasopharynx Antiphagocytic polysaccharide capsule allows systemic spread in absence of specific immunity Toxic effects mediated by hyperproduction of lipooligosaccharide  Serogroups A, B, C, Y, W135 account for about 90% of all infections
  17. 17. Specific receptors (GD1 ganglioside) for bacterial fimbriae on nonciliated columnar epithelial cells in nasopharynx of host Organisms are internalized into phagocytic vacuoles, avoid intracellular killing in absence of humoral immunity and complement system (patients with late complement deficiencies are particularly at risk) Replicate intracellularly and migrate to subepithelial space where excess membrane fragments are released athogenesis of Meningococcal Disease
  18. 18. Hyperproduction of endotoxin (lipid A of LOS) and blebbing into surrounding environment (e.g., subepithelial spaces, bloodstream) mediates most clinical manifestations including diffuse vascular damage (e.g., endothelial damage, vasculitis (inflammation of vessel walls), thrombosis (clotting), disseminated intravascular coagulation (DIC)
  19. 19. Following dissemination of virulent organisms from the nasopharynx:  Meningitis  Septicemia (meningococcemia) with or without meningitis  Meningoencephalitis  Pneumonia  Arthritis  Urethritis Diseases Associated with Neisseria meningitidis
  20. 20. Meningitis Clinical findings  Clinically: rapid deterioration of flu like illness  Headache, neck stiffness, +ve kerning’s sign, fever,  Diagnosis: CSF + blood culture  CSF: WBC , RBCs  Gram stain: bacteria & cells
  21. 21. Neisseria meningitidis in Cerebrospinal Fluid
  22. 22. Skin Lesions of Meningococcemia NOTE: Petechiae have coalesced into hemorrhagi c bullae.
  23. 23. Neck rigidity
  24. 24. Haemorrhagic
  25. 25.  Large numbers (e.g., >107cells/ml) of encapsulated, small, gram-negative diplococci (flattened along adjoining side) and polymorphonuclear leukocytes (PMN’s) can be seen microscopically in cerebrospinal fluid (CSF) Laboratory Characterization of Neisseria meningitidis
  26. 26. Contd… Transparent, non-pigmented nonhemolytic colonies on chocolate blood agar with enhanced growth in moist atmosphere with 5% CO2 Oxidase-positive Acid production from glucose and maltose but not from other sugars
  27. 27. Diagnosis  Isolation of the organism from CSF or blood.
  28. 28. 2. Streptococcus pneumoniae  (G+,Lancet shaped diplococci Alpha- haemolytic colonies on blood agar Quelling Test +ive Optochin –sensitive Bile solubility test +ive (bile soluble) Capsular polysaccharide Antigen detection from CSF by Latex
  29. 29. Streptococcus pneumoniae General characteristics Inhabits the nasopharyngeal areas of healthy individuals Possess C substance Virulence factors Polysaccharide capsule Clinical infections pneumonia meningitis bacteremia
  30. 30. The quellung reaction (swelling reaction) forms the basis of serotyping and relies On the swelling of the capsule upon binding of homologous antibody. The test consists of mixing a loopful of colony with equal quantity of specific antiserum and then examining microscopically for capsular swelling
  31. 31. Contd…  Pneumoccus grow only in enriched media. (blood agar, glucose broth)  aerobes, facultative anaerobes  optimal temperature – 37C (25-42C)  optimal pH – 7.8 (6.5-8.3)  increased growth in 5-10% CO2
  32. 32. Laboratory Diagnosis: Streptococcus pneumoniae Colony morphology Smooth, glistening, wet- looking, mucoid a-Hemolytic CO2enhances growth
  33. 33. Laboratory Diagnosis: Streptococcus pneumoniae Identification Catalase negative Optochin- susceptibility-test– susceptible Bile-solubility-test– positive
  34. 34. Alpha & Beta Haemolysis
  35. 35. S. pneumoniae
  36. 36. Pus cells and S. pneumoniae in sputum gram stain
  37. 37. Neutrophil & Red Cells
  38. 38. 3. Haemophilus influenzae  Aerobic , Small, pleomorphic gram-negative coccobacilli  Polysaccharide capsule  Six different serotypes (a-f) of polysaccharide capsule(based on the antigenicity of capsular polysacchrides)
  39. 39. Contd…  95% of invasive disease caused by type b  The type b capsule is composed of polyribitol phosphates  Unencapsulated and untypeable strains can cause sinusitis and otitis media but are usually noninvasive  Growth in culture requires heme (X factor) and/or nicotinamide adenine dinucleotide (NAD) (V factor) for adequate energy production
  40. 40. H.INFLUENZAE IS THE LEADING CAUSE OF MENINGITIS IN YOUNG CHILDREN Important cause of URTI(otitis media,sinusitis and epiglottitis) and sepsis in children It causes pneumonia in adults particularly in those having COPD (chronic obstructive pulmonary disease)
  41. 41. LABORATORY DIAGNOSIS Specimens:  Oral swab: avoid contamination with oral secretions  Sputum from LRT  Direct needle aspiration  Cerebrospinal fluid (CSF) and blood (>107 bacteria/ml) Microscopy: both sensitive & specific; G(-) bacilli in CSF in >80% cases before antibiotics treatment
  42. 42. LABORATORY DIAGNOSIS  Heated blood (chocolate) agar for isolation(to inactivate nonspecific inhibitors of H.influenzae growth)  Growth require heme (x factor) and nicotinamide adenine dinucleotide, NAD (v factor)
  43. 43. Contd.. Definitive identification can be made by biochemical tests or the capsular swelling “QUELLUNG “reaction Fluorescent-antibody staining of the organism and counterimmunoelectrophoresis or latex agglutination tests detect the capsular polysacchride.
  44. 44. Streptococcus agalactiae
  45. 45. Streptococcus agalactiae  Gram +ive cocci in small chains  Beta haemolytic colonies on blood agar  Lance-field gouping ---group B (specific antiserum)  Hippurate Hydrolysis test +ive  CAMP – TEST +ive (Chtist,Atkin,Mouch,Peterson)  Bacitracin Disk ----Negative
  46. 46. FIG. 6. CAMP- positive Streptococcus agalactiae (group B) inoculated at right angles to the test organism Staphylococcus aureus. Note the arrow-shaped zones of enhanced hemolysis. FIG. 7. CAMP-negative Streptococcus pyogenes (group A) inoculated at right angles to the test organism Staphylococcus aureus. Note the absence of arrow-shaped zones of enhanced hemolysis.)
  47. 47. Listeria Monocytogenes  Gram +ive , motile rod. Coccobacillus , Non – capsulated  Motile at 18 – 20 C°, non motile at 37 C°  Tumbling/ Rotating motility  Grows at Refrigerating temp 2-8 C°also  Can cross placenta  Causes meningitis in new born and pregnant women
  48. 48. Listeria Monocytogenes
  49. 49. Laboratory Diagnosis Gram staining----G+ive rods Small grey coloured colonies with narrow zone of beta hemolysis on blood agar Motile nature differentiate it from corynaebacteria
  50. 50. THANKS

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