B3.3 OTHER NEISSERIA SPP. Flashcards
What infections are caused by N. meningitidis?
Endemic and epidemic meningitis, meningococcemia, and rarely pneumonia, purulent arthritis, or endophthalmitis
What is the leading cause of fatal bacterial meningitis
N. meningitidis
Where is N. meningitidis commonly found in the human body?
Nasopharynx and oropharynx (asymptomatic human carriage in the upper respiratory tract).
What carbohydrates does N. meningitidis ferment?
Glucose and maltose
What growth requirement is specific to N. meningitidis?
Requires iron for growth
What does a positive beta-lactamase test indicate for N. meningitidis?
It produces beta-lactamase
What is the mode of transmission for N. meningitidis?
Close contact with respiratory droplet secretions.
What is observed in microscopy of encapsulated strains of N. meningitidis?
A halo around the organism.
List the virulence factors of N. meningitidis.
Pili, polysaccharide capsule, LOS endotoxin, IgA protease, and cellular proteins
What are the key porin proteins in N. meningitidis
PorA and PorB.
Which encapsulated serogroups of N. meningitidis are the most common causes of infection?
Serogroups A, B, C, Y, and W-135.
List the infections and diseases caused by N. meningitidis
Meningococcemia, meningitis, meningococcal pneumonia, conjunctivitis, and urethritis.
The presence of N. meningitidis in the blood, occurring with or without meningitis
meningococcemia
What are the hallmark symptoms of meningococcemia?
Purpura, petechial skin rash, tachycardia, hypotension, and thrombosis
What syndrome is associated with hemorrhage in the adrenal glands during meningococcemia
Waterhouse-Friderichsen Syndrome
What complications can result from meningococcemia?
Arthritis, pericarditis, pneumonia, disseminated intravascular coagulation (DIC), and septic shock.
What are the sequelae of meningococcemia?
Eighth nerve deafness, CNS damage, and skin or tissue necrosis due to vascular thrombosis
What serogroup of N. meningitidis is associated with meningococcal pneumonia?
Serogroup Y.
What age group and condition are associated with meningococcal pneumonia?
Older individuals with underlying pulmonary problems.
What are the symptoms of meningitis caused by N. meningitidis?
Abrupt onset of frontal headache, stiff neck (nuchal rigidity), confusion, and photophobia
What sequelae can result from meningitis caused by N. meningitidis?
Neurologic complications or seizures
List the specimens used for the laboratory diagnosis of N. meningitidis.
CSF, blood, nasopharyngeal swabs, synovial fluids, aspirates of petechiae, sputum, and urogenital sites.
What is the appearance of N. meningitidis in a Gram stain?
Intracellular and extracellular Gram-negative diplococci
What culture media are used to grow N. meningitidis?
BAP, CAP, and TMA.
Why must the SPS content of culture media for N. meningitidis not exceed 0.025%?
Because N. meningitidis is sensitive to higher concentrations of SPS.
Describe the colony morphology of N. meningitidis.
Medium-sized, gray, convex colonies; encapsulated strains appear mucoid.
What are the key biochemical test results for N. meningitidis?
Oxidase test (+), ferments glucose and maltose, γ-glutamyl aminopeptidase (+).
What serologic tests are used for N. meningitidis?
Countercurrent immunoelectrophoresis (CIE) and particle agglutination techniques (latex and coagglutination).
What is the treatment of choice for N. meningitidis infections?
Penicillin G.
Which Neisseria species is the only one that uses lactose?
Neisseria lactamica
What disease does Neisseria cinerea cause?
Bacteremia, conjunctivitis, nosocomial pneumonia, and prostatitis.
Which Neisseria species is associated with a yellow pigment and asaccharolytic growth at 22°C?
Neisseria flavescens
Which Neisseria species is rod-shaped and catalase-negative?
Neisseria elongata
What disease is caused by Neisseria subflava?
Bacteremia, meningitis, septicemia, endocarditis, and bacteriuria.
What is the colony morphology of Neisseria sicca?
Dry, wrinkled, adherent, breadcrumb-like colonies.
What is the role of Neisseria weaver in animals?
It is part of the normal oral microbiota in dogs
