neisseria/moraxella

• Neisseria


  • Kingella
  • Eikenella
  • Simonsiella
  • Alysiella and others
• Neisseria species


  • Neisseria gonorrhoeae
  • Neisseria meningitidis
  • Moraxella catarrhalis
  • Neisseria cinerea
  • Neisseria lactamica
  • Neisseria polysacchraea
  • Neisseria subflava
  • Neisseria sicca
  • Neisseria mucosa
  • Neisseria flavescens
• Neisseria


  • Small, grey-white opaque, convex and glistening colonies – best observed in enriched medium
  • Diplococci with kidney bean shape except N. elongate, N. weaver and N. bacilliformis
  • Facultative aerobe, non-motile, non-hemolytic
• Biochemical tests for Neisseria

  • Gram (-)
  • Catalase (+) except N. elongata subsp. nitroreducens and N. bacilliformis
  • Oxidase (+)
  • Carbohydrate fermenter, requires moisty/humid environment
  • Microaerophilic, capnophilic
• Neisseria can grow anaerobically as long as there is alternative electron receptor such as nitrite
• Neisseria are sensitive to drying and extreme temperature
• Neisseria are found on mucus membrane of the respiratory tract and urogenital tract
• Neisseria gonorrhoeae


  Often called gonococci
• Neisseria gonorrhoeae


  • Pathogenic, found on mucus membranes of genitalia, anorectal area, oropharynx, or conjunctiva with purulent response
  • Not a normal flora; only in humans
• Virulence factors of Neisseria gonorrhoeae

  • Pili – for attachment, invasion of host cells and survival in the presence of inflammatory cells
• Transmission of Neisseria gonorrhoeae

  • Horizontal through sexual contact (rectal and orogenital)
  • Vertical through mother to baby
• Clinical manifestations of Neisseria gonorrhoeae

  • Purulent urethritis in males
  • Cervicitis in females
  • Pharyngitis
  • Anorectal infections
  • Conjunctivitis (ophthalmia neonatorum)
  • Septicemia
• Laboratory diagnosis of Neisseria gonorrhoeae

  1. Collection: Do not use cotton swabs, use Dacron or rayon fiber, do not store in cold temperatures, plate ASAP

  2. Staining: Gram negative, intracellular diplococci

  3. Culture: Culture for 72 hours, may require increased CO2 and iron, fastidious organism, may use JEMBEC, CAP or others
• Biochemical tests for Neisseria gonorrhoeae

  • Oxidase (+) – purple color
  • CHO utilization test (+) – yellow color with 24 hours of incubation
  • Superoxol test (+) – vigorous bubbling
  • DNase test (-) – differentiation of Moraxella catarrhalis
• Neisseria gonorrhoeae infections are common in sex workers, patients 18 years old and below, and rape victims
• For patients 18 years old and below, the results cannot be disclosed
• Dual therapy of Azithromycin and Ceftriaxone is used to treat Neisseria gonorrhoeae
• Neisseria meningitidis


  Often called meningococci
• Neisseria meningitidis


  • Pathogenic, found on oropharyngeal and nasopharyngeal mucus membranes
  • Carrier patient is common; found as commensal inhabitant
• Virulence factors of Neisseria meningitidis

  • Pili – for attachment, invasion of host cells
  • Polysaccharide Capsule – for survival
  • Lipooligosaccharide
  • Endotoxin – mediates septic shock
  • With serogroups: A,B,C,Y,W-135
• Transmission of Neisseria meningitidis

  Respiratory droplets, close contact
• Clinical manifestations of Neisseria meningitidis

  • Life-threatening, acute and purulent meningitis with petechiae
  • Bacteremia with thrombocytopenia, DIC and shock
  • Sometimes, conjunctivitis, pneumonia and sinusitis
• Waterhouse-Friderchsen Syndrome (WFS)


  A group of symptoms caused when the adrenal glands fail to function normally due to bleeding into the glands
• Laboratory diagnosis of Neisseria meningitidis

  1. Collection: Do not use cotton swabs, use Dacron or rayon fiber, do not store in cold temperatures, plate ASAP

  2. Staining: Gram negative, intracellular and extracellular diplococci with halo if capsulated

  3. Culture: May require increased CO2, may use JEMBEC, BAP, CAP, TMA
• Biochemical tests for Neisseria meningitidis

  • Oxidase (+) – purple color
  • CHO utilization test (+) – yellow color with 24 hours of incubation
  • Superoxol test (+) – vigorous bubbling
  • DNase test (-) – differentiation of Moraxella catarrhalis
• Non-pathogenic Neisseria species

  • Neisseria cinerea
  • Neisseria flavescens
  • Neisseria lactamica
  • Neisseria mucosa
  • Neisseria sicca
  • Neisseria elongata
• Neisseria cinerea


  The colony is similar to T3 colonies of N. gonorrhoeae on CAP
• Neisseria flavescens


  Yellow pigment, asaccharolytic, can grow at 22 degree Celsius
• Neisseria lactamica


  Commonly isolated from children 2 years of age and rare from adults; ONPG +
• Neisseria mucosa


  Large, adherent to agar, very mucoid colonies
• Neisseria sicca


  Dry, wrinkled, adherent to agar, and breadcrumbs like colony
• Neisseria elongata


  Has a weakly positive or negative catalase test
• Differentiating Neisseria species


  • Glucose: N. gonorrhoeae (+), N. meningitidis (+), N. lactamica (-), N. subflava (-)
  • Maltose: N. gonorrhoeae (+), N. meningitidis (+), N. lactamica (-), N. subflava (-)
  • Lactose: N. gonorrhoeae (+), N. meningitidis (+), N. lactamica (+), N. subflava (-)
  • Sucrose: N. gonorrhoeae (+), N. meningitidis (+), N. lactamica (-), N. subflava (+)
• Moraxellaceae


  • Moraxella atlantae
  • Moraxella boevrei
  • Moraxella bovis
  • Moraxella bovoculi
  • Moraxella caprae
  • Moraxella catarrhalis
  • Moraxella caviae
  • Moraxella cuniculi
  • Moraxella equi
  • Moraxella lacunata
  • Moraxella lincolnii
  • Moraxella nonliquefaciens
  • Moraxella oblonga
  • Moraxella osloensis
  • Moraxella pluranimalium
  • Moraxella porci
  • Moraxella saccharolytica
• Moraxella catarrhalis


  Normal flora of URT, only isolated in humans and is an opportunistic pathogen, sometimes colonizes female genital tract
• Moraxella catarrhalis is the most commonly isolated member of the genus Moraxella, previously known as Branhamella catarrhalis / N. catarrhalis
• Moraxella catarrhalis is the 3rd most common cause of sinusitis and otitis media in children
• Breakdown of mucosal defensive barrier leads to Moraxella catarrhalis infections
• Laboratory diagnosis of Moraxella catarrhalis

  1. Collection: No special consideration

  2. Staining: Gram negative, intracellular coccobacilli

  3. Culture: BAP if 22 degree Celsius; CAP if 35 degree Celsius, inhibited by colistin
• Biochemical tests for Moraxella catarrhalis

  • Catalase (+)
  • Oxidase (+) – purple color
  • CHO utilization test (-)
  • DNase test (+) – differentiation of Neisseriaceae