Gram negative cocci

• Neisseria


  • Gram negative diplococci
  • Non motile
  • Non-spore forming
• Most pathogenic Neisseria


  • N. Gonorrhoeae
  • N. Meningitidis
• Neisseria species


  • NEISSERIA GONORRHOEAE
  • MORAXELLA CATARRHALIS
  • OTHER NEISSERIA SPP
  • NEISSERIA ANIMALORIS
• Neisseria gonorrhoeae


  • Aka gonococci
  • Causative agent of "Gonorrhea"
  • Gram-negative intracellular diplococci
• Virulence factors of N.gonorrhoeae

  • Pili
  • Protein II (OPA)
  • Protein II (RMP)
  • Lipo-oligosaccharide (Endotoxin)
  • Outer-membrane porin (PorB)
  • Immunoglobulin A (IgA) protease
  • Plasmids
• Pili


  • T1-T2: Virulent
  • T3-T4: Avirulent
  • Mediate the exchange of genetic material
  • Attachment
  • Survival through the inhibitions of phagocytosis in the presence neutrophils
• Protein II (OPA)


  • Short for Opacity
  • Facilitates adherence to phagocytic and epithelial cells
• Protein II (RMP)


  • Reduction Modified Protein
  • Blocks the bactericidal affect of host
• Lipo-oligosaccharide (Endotoxin)


  Mediates damage to body tissue and have an effect on inflammatory response
• Outer-membrane porin (PorB)


  Provides protection from the host's immune response, including serum complement-mediated cell death
• Immunoglobulin A (IgA) protease


  Cleaves human immunoglobulin A (IgA)
• Plasmids


  Encodes for beta-lactamase responsible for resistance to certain antibiotics
• Diseases caused by N.gonorrhoeae

  • Gonorrhea
  • Prostatitis
  • Epididymitis
  • Ophthalmia neonatorum
  • Anorectal Infection
  • Pharyngitis
  • Disseminated Gonoccal Infection (DGI)
• Gonorrhea


  • Acute pyogenic infection of non ciliated columnar and transitional epithelium
  • Short incubation period of approximately 2 to 7 days
• Gonorrhea (men)


  Usually manifested as an Acute Urethritis with purulent discharge and dysuria
• Gonorrhea (women)


  • Endocervix
  • Acute urethritis
  • Cervivilis
  • Dysuria
  • Lower abdominal pain
• Pelvic Inflammation Disease (PID)

  • May cause ectopic pregnancy
  • Sterility
  • Perihepatitis (Fitz-Hugh-Curtis syndrome (FHCS))
• Ophthalmia neonatorum


  • Gonoccal eye infection during vaginal delivery through an infected birth canal
  • 1% silver nitrate (Crede's Prophylaxis): used to prevent newborns from having Ophthalmia neonatorum
• Anorectal Infection


  • Rectal discharge
  • Pain in the anal area
  • Blood stool
• Pharyngitis


  Common in men who have sex with men
• Disseminated Gonoccal Infection (DGI)

  • Fever, chills, joint pain
  • Skin lesions (red/purple spots)
  • Gonococcal Arthritis
  • Septicemia
  • Meningitis
  • Endocarditis
• Laboratory diagnosis for N. gonorrhoeae

  • N. gonorrhoeae is inhibited by SPS
  • Calcium alginate and cotton swab are inhibitory to N. gonorrhoeae
  • Cotton swab: Toxic to N. gonorrhoeae
  • Thayer-Martin medium or New York City medium
  • Glucose fermenter
  • Female: Endocervical specimen
  • Male: Urethral specimens
  • Prolyl-hydroxylprolyl amino peptidase - positive (+)
  • NA at 35C
  • Blood Agar at 25C
  • Chocolate agar at 25C
  • Sensitive to temperature
  • Direct plating too gonococcal-selective media
  • Use of transport media (JEMBEC, Gono Pak, Transgrow, Amies Medium)
• Neisseria meningitidis


  • Medium, smooth, gray-white
  • Mucoid colonies
  • Polysaccharide capsule
  • Gram negative "coffee bean shape"
  • Leading cause of fatal bacterial meningitis in children and adults
• Virulence factors of N. meningitidis

  • Surface structure (pili)
  • Polysaccharide capsule
  • Endotoxins
  • Por and Opa
  • IgA protease
• Fulminant Meningcoccemia


  • Appearance of Petechiae (rash)
  • Spread to the bloodstream
• Waterhouse-Friedrichsen syndrome


  • Hemorrhage in adrenal glands
  • DIC
• Pneumonia


  • Elderly
  • Caused by the serotypes Y or W - 135 infection
• Diseases caused by N.meningitidis

  • Purulent arthritis
  • Pericarditis
  • Otitis media
  • Conjunctivitis
  • Urethritis
• Laboratory diagnosis for N. meningitidis

  • CSF- diagnose meningitis
  • Blood- Meningococcemia
  • Skin lesion- Petecibial skin rashes
  • Nasopharungeal swabs - asymptomatic carrier
  • Glucose fermenter
  • Maltose fermenter
  • Nitrate fermenter- negative (-)
  • 0.1% Nitrite Reduction Variable
  • ONPG - negative
• Moraxella catarrhalis


  • Large, pinkish-brown
  • Opaque, smooth: Friable "hockey punk" consistency
  • Brannamella catarrhalis
  • Normal flora of URT
  • DNAse - positive (+)
  • Hydrolyze tributyrin
  • Blood agar at 22C
  • Nutrient Agar at 35C
  • Nitrate reduction - positive(+)
  • Inability to utilize carbohydrate
  • Oxidase positive
• Diseases caused by M. catarrhalis

  • Pneumonia
  • Acute exacerbation of chronic bronchitis
  • Otitismedia (up to 20% in children)
  • Sinusitis