Neis & Mor

• STREP-LIKE ORGANISMS: NUTRITIONALLY VARIANT STREP

  Also known as Pyridoxal Requiring Streptococci, Satelliting Streptococci, Thiol Requiring Streptococci, Cell wall deficient Streptococci
• Abiotrophia & Granulicatella

  These are S. adjacens and S. defectives
• Abiotrophia & Granulicatella

  • Viridans Strep needing vitamin B6 for growth
  • When mixed with S. aureus they satellite around colonies of S. aureus
  • BAP and CAP negative
• Other gram positive, catalase negative organisms isolated from clinical specimens

  • Pediococcus
  • Lactococcus
  • Aerococcus
  • Leuconostoc
  • Rothia
• Pediococcus, Lactococcus, Aerococcus, Leuconostoc & Rothia

  • Have low virulence potential and are pathogenic only in immunocompromised host
• Organisms that are vancomycin resistant

  • Pediococcus
  • Leuconostoc
  • Enterococcus
• VANCOMYCIN RESISTANCE

  1. For ID of Pediococcus & Leuconostoc

  2. Differentiates Pediococcus = R from S. viridans = S
• LAP TEST (LEUCINE AMINO PEPTIDASE)

  1. Presumptive test for catalase negative, gram positive cocci

  2. Involves detection of the enzyme: L

  3. Substrate: Leucine-beta-naphthylamide

  4. Reagent: cinnamaldehyde

  5. (+) result: red; E. faecalis and Pediococcus

  6. (-) no color or slight yellow; Leuconostoc
• BIOCHEMICAL TEST

  • (+) CONTROL
  • (-) CONTROL
  • Catalase test
  • Coagulase test
  • Bacitracin disk test
  • CAMP test
  • Bile Esculin Test
  • Bile Solubility Test
  • Butyrate disk test
• Bacitracin disk test (Taxo A)

  • To presumptively identify S. pyogenes
  • To differentiate Staphylococci (R) from Micrococci (S)
• Butyrate disk test

  (+) result = blue, blue-violet, or indigo
• GRAM NEGATIVE COCCI

  • Neisseria
  • Moraxella
• NEISSERIA

  • Significant: N. gonorrhoeae, N. meningitidis, Pigmented Neisseria
  • Non-motile, aerobic, capnophilic (need 5-10% CO2)
  • Cold Sensitive
  • Non-hemolytic
  • Most species are CHO fermenters
  • Develops non-pigmented colonies except: N. flava, N. flavescens, N. subflava
  • All are catalase (+) except: N. elongata
  • All are Cytochrome Oxidase Test (+) except: N. elongata
• CYTOCHROME OXIDASE TEST

  1. Reagent: 1% oxidase reagent

  2. Reagent chemical name: tetramethyl-p-phenylenediamine dihydrochoride

  3. Procedure: A loopful of organism is placed on a filter paper, and the reagent is added, wait for a change in color

  4. (+) Result: purple

  5. Modified oxidase = 6% reagent, no DMSO, positive is blue color (for Micrococci detection)
• OXIDASE POSITIVE

  • Pseudomonas
  • Plesiomonas
  • Aeromonas
  • Moraxella
  • Vibrio
  • Campylobacter
  • Helicobacter
  • Neisseria
• CHO UTILIZATION TEST

  1. Media: Cystine Trypticase agar (CTA) + CHO

  2. Indicator: phenol red

  3. In an acid pH (+) media will turn YELLOW
• CANDLE JAR

  May be used for Neisseria isolation because the use of this jar may provide the organism with increased CO2
• TRANSPORT MEDIA

  • Amies with charcoal
  • Transgrow (traditionally used)
  • Flat bottles coated with MTM and a bottle under increased CO2 rarely used nowadays
  • JEMBEC (commercial transport system)
  • John E. Martin Biological Environment System uses a tablet to generate CO2
• Neisseria gonorrhoeae

  • Never a normal flora, always a pathogen
  • #1 cause of Sexually Transmitted Disease
  • Kidney, coffee bean shaped diplococci intracellular within PMN
  • Major virulence factor: Pili (Common Pili; used for adherence or attachment)
  • Superoxol test (+) — rapid test for N. gonorrhoeae
  • Ferments glucose only
• Can cause

  • Gonorrhea – STD
  • Opthalmia neonatorum
  • PID (Pelvic Inflammatory Disease)
• Opthalmia neonatorum

  • A gonococcal eye infection (gonorrheal form of conjunctivitis) acquired by newborns when discharge from infected mother accumulates in their conjunctiva
  • Prevented by placing silver nitrate on the baby's eyes
• PID (Pelvic Inflammatory Disease)

  • May cause sterility, Perihepatitis or Fitz Hugh Curtis syndrome
  • Agents of PID: C. trachomatis, M. hominis, and N. gonorrhoeae
• Specimen collection for N. gonorrhoeae

  • Use Dacron/Rayon fibers (swabbing)
  • Never use: Calcium alginate and cotton swab; they are toxic or inhibitory to N. gonorrhoeae
  • Sensitive to cold temperature
  • Specimen: pus secretions from the urethra, cervix, prostate, throat, and rectal mucosa
• Media used for Cultivating Neisseria gonorrhoeae

  • Thayer Martin media
  • Modified Thayer Martin media
  • Martin Lewis Media
  • New York City Media
  • GC-LECT Medium
• N. gonorrhoeae is BAP negative and CAP positive, while N. meningitidis is BAP positive and CAP positive
• Neisseria meningitidis

  • Bean shaped diplococcic; sensitive to SPS
  • Can be a normal flora; Natural habitat is oropharynx and nasopharynx
  • Virulence factor: Capsule
  • Ferments maltose and glucose; Negative for lactose, sucrose, and fructose
• Neufeld Quellung Test

  Positive for Neisseria meningitidis capsule
• Specimen to detect carrier state

  Nasopharyngeal swab
• Can cause

  • Bacterial meningitis (5-29 years old)
  • Meningococcemia (presence of N. meningitidis in the blood)
  • Waterhouse-Friderichsen syndrome
• Waterhouse-Friderichsen syndrome

  • Severe form of meningococcemia
  • Can lead to the bleeding of adrenal glands due to severe bacterial infection
  • Positive for Disseminated Intravascular Coagulation (DIC)
• Other Neisseria species

  • N. lactamica: Glucose, Maltose, Lactose (+) & ONPG (+)
  • N. sicca: Glucose, maltose, Sucrose (+)
• N. lactamica

  • The only Neisseria which is lactose positive
  • ONPG = yellow (positive)
• Broth (CTA: Cystine Trypticase Agar) + Serum + Sugar + Indicator (phenol red)

  Used for acid production testing
• Neisseria meningitidis

  Bean shaped diplococcic; sensitive to SPS
• Neisseria meningitidis

  • Can be a normal flora; Natural habitat is oropharynx and nasopharynx
  • Virulence factor: Capsule
  • Neufeld Quellung Test (+)
  • Ferments maltose and glucose; Negative for lactose, sucrose, and fructose
• Diseases caused by Neisseria meningitidis

  • Bacterial meningitis (5-29 years old)
  • Meningococcemia (presence of N. meningitidis in the blood)
  • Waterhouse-Friderichsen syndrome
• Waterhouse-Friderichsen syndrome

  • Severe form of meningococcemia
  • Can lead to the bleeding of adrenal glands due to severe bacterial infection
  • Positive for Disseminated Intravascular Coagulation (DIC)
• Other Neisseria species

  • N. lactamica: Glucose, Maltose, Lactose (+) & ONPG (+)
  • N. sicca: Glucose, maltose, Sucrose (+)
• N. lactamica

  The only Neisseria which is lactose positive
• ONPG

  Yellow (positive)