Neisseria Flashcards
Neisseria
Aerobic, non-motile, non spore forming, gram negative diplococci with adjacent ends flattened that resemble tiny (2), except: (3) which are rod shaped.
“coffee beans” or “kidney beans”
N . weaveri
N .elongata
N. bacilliformis
All are catalase positive and cytochrome
oxidase positive, except:
N. elongata subspecies nitroreducens
N. bacilliformis
T or F
Neisseria
Capnophilic (3-10% CO2) and humidophiles
True
Neisseria
• Optimal temperature:
• Natural habitat:
between 35C and 37C (32C-36C)
Mucus membranes of the RT and urogenital tracts
Primary pathogens:
N.gonorrhoea & N.meningitidis
Neisseria gonorrheae (______)
and Neisseria meninigitidis
(_____) are highly fastidious:
Require_____ for growth
• Require_____ media for growth
gonococci
meningococci
iron
enriched
: grows on enriched CAP supplemented with
cysteine
X (hemin)
V (NAD or Coenzyme 1) factors
N.gonorrheae
- derived from: LYSED RBCS
- can derived from RBCs, but abundantly produced by some bacteria (Staphylococcus aureus) and can be obtained from yeast, yeast extracts and potato extracts
X factor
V factor
require SBA as the minimal growth
standard.
Neisseria meninigitidis (and Moraxella cattarhalis)
Neisseria
Note: Both organisms are highly sensitive to______ and must be protected from____!
They must be_____ immediately on their respective primary isolation media.
temperature changes
cold
inoculated
Remember!!
Enriched CAP for…
Remember!! Sheep Blood Agar (BAP) for…
Neisseria gonorrhea
Neisseria meningitidis
NEISSERIA
Virulence Factors
Receptors for human transferrin
Polysaccharide Capsule-
Pili
IgA protease
Cell membrane proteins
LOS (Lipooligosaccharide)
-competes human hosts for IRON
Receptors for human transferrin
- (N.meningitides only) -
resists phagocytosis
Polysaccharide Capsule
- for attachment to host’s mucus membranes;
also for conjugation and transfer of genetic materials such as genes that code for antimicrobial resistance.
Pili
-cleaves IgA antibodies in mucus membranes
IgA protease
Cell membrane proteins
Por (protein I)
Opa (Protein II)
Reduction modified protein (Protein III)
- channel for passage of nutrients and waste products
Coded by…
PorB expressed only by_______
- protective against host’s inflammatory response and complement mediated killing
Por (protein I)
PorA and PorB genes
N.gonorrheae
- facilitate adherence of organisms to phagocytic and epithelial cells
- blocks host IgG
Opa (protein II)
Reduction modified protein (protein III)
- contain the endotoxin portion of the organism
LOS (Lipooligosaccharide)
____ is anchored in the outer membrane.
The____ portion of the LOS contains the____.
During periods of rapid growth, Neisseria gonorrhea releases outer memorane fragments called “____”
which contain LOS.
LOS; Lipid; endotoxin
blebs
In large amounts,_____ can stimulate macrophages to produce increased amounts “pro-inflammatory” cytokines
endotoxins
• Tumor necrosis factor
• Interleukin 1
• Chemokines
• And other inflammatory mediator
Effects of endotoxin
• Prolonged inflammation and fever
• Prolonged vasodilation (vascular permeability)
• Capillary leakage (hemorrhage) - manifested by purpura and petechial rash.
• Hypotension
• Tachycardia - increased heartbeat
• Septic shock - abrupt cessation of the functions of vital organs due to decrease oxygen delivery
• Intravascular coagulation
is a “double-edged” sword. It is beneficial when it is able to achieve its primary purpose in the immune response.
But when it goes south, such as due to endotoxin stimulation, the heightened inflammatory response could be
damaging to the host.
Inflammation
Causative agent of____ - acute pyogenic infection of the non-ciliated columnar and transitional epithelium.
gonorrhoea
Gonorrheae aka
Flow of seed
Clap/ clapier
Also confused with syphilis
Also known
aร:
- urethral discharge mistaken for
semen.
Confused with syphilis - due to the lesions it produced that resemble the_____ in syphilis and both diseases
often come together in the same
individual.
Flow of seed
lesions
Also known as the “____” - derived from the French word “___” which means “____”.
Other theories also suggest that the “clap” refers to the throbbing pain caused by the infection, or it may refer to the early treatment of gonorrhea that involves smashing or clapping the penis with both hands at the same time to get rid of the of the pus or discharge.
clap
clapier
brothel
Primarily acquired by ___and occur primarily in the (5)
sexual contact
urethra
endocervix
anal canal pharynx
conjunctiva.
• Primary reservoir -
• Incubation period of
asymptomatic carriers!
2-7 days
• In men: _____ and ____
•____% of cases are asymptomatic
• Due to:____
In women: common site is the____ - symptoms (4)
____% of women are asymptomatic
Purulent discharge and dysuria
3-5%
AHU strain
endocervix
cervical discharge, dysuria, & lower abdominal pain
50%
Note: The AHU strains of _____require additional amino acid requirements such as Arginine, Hypoxanthine, and Uracil.
They are also often isolated disseminated N.gonorrhea infections often from women but also from asymptomatic men.
N. gonorrhea
In women:
Complicates to:____
-an infection of one or more of the upper reproductive organs, including the uterus, fallopian tubes and ovaries
PIV (pelvic inflammatory disease)
Sterility
Ectopic pregnancy
Perihepatitis (Fitz-Hugh-Curtis syndrome)
a chronic manifestation of pelvic inflammatory disease (PID)
An inflammation of the serous or peritoneal coating of the liver, without the involvement of the liver parenchyma
Perihepatitis (Fitz-Hugh-Curtis syndrome)
dissemination of N.gonorrhea into the blood causing septicemia and from the blood to distant sites of the body.
Mostly caused by AHU strain.
Disseminated Gonococcal Infection (DI)
Disseminated Gonococcal Infection (DI)= Clinical manifestations include:
Septic arthritis
Polyarthralgias
Pyogenic Flexor Tenosynovitis
Petechial/pustular skin lesions
Endocarditis
Meningitis
- painful infection in the joint (though may be caused by a wide variety of bacteria, but in DGI, it is due to the disseminated infection caused by N.gonorrheae.
- joint pain
-inflammation of the protective sheath (the synovial membrane) that surrounds your tendons
Septic arthritis
Polyarthralgias
Pyogenic Flexor Tenosynovitis
- inflammation of the inner lining of the heart’s chambers and valves
inflammation of the fluid and membranes (meninges) surrounding your brain and spinal cord
Endocarditis
Meningitis
• Gonococcal eye infection in the
newborn
• Acquired during delivery through an
infected birth canal
• Can lead to blindness
Opthalmia neonatorum
Opthalmia neonatorum
• Treated with:
• Crede’s prophylaxis ~ 1% silver nitrate
• Erythromycin drops (antimicrobial eye drops)
Sources of Specimens:
genital sources (purulent discharge from the urethra in men & endocervix in women)
rectum
pharynx
joint fluid
Spx collection in men:
when no apparent discharge, swab is inserted up to____ in the anterior urethra and slowly rotated to collect the discharge
_____specimens must be collected. WHY?
2cm
Two swabbed
First - direct microscopy
Second - inoculation on primary culture media
• Swabs for rectal culture should be inserted_____ into the anal canal
4-5 cm
•(2) - Inhibits N. gonorrheae-____ swabs are preferred.
Calcium alginate & cotton swabs
DACRON
Neisseria
• Must be plated immediately to primary selective media due to extreme susceptibility to (2)
drying and temperature changes
• Blood Specimens - collected to
diagnose____
• N.gonorrheae - inhibited by ____
(anticoagulant in Blood Culture System)
•____ is added to neutralize SPS
DGI - Disseminated Gonococcal Infection
SPS - Sodium Polyanetolsulfonate
Gelatin
Commercial Transport Systems (3)
• Gono-Pak
• JEMBEC plates (James E. Martin
• Biological Environmental Chamber
Transgrow
Commercial Transport Systems
Note: These contain____ media and a___ atmosphere to provide optimal conditions until the specimen reaches the laboratory.
The swab containing the specimen should be rolled in a “___” pattern on the medium.
On receipt in the laboratory, the media can be cross-streaked with a loop to facilitate growth of isolated colonies.
selective; CO2
Z
Smears are prepared from UROGENITAL SPECIMENS
Direct Microscopy Examination
Direct Microscopy Examination
- not recommended for gram stain due to the presence of commensal Neisseria
Significant finding: PRESENCE OF…
Nasopharyngeal specimens
GRAM NEGATIVE, INTRACELLULAR DIPLOCOCCI
Virulent form
Avirulent form
Virulent form - INTRACELLULAR
Avirulent form - EXTRACELLULAR (lose their pili)
N. gonorrheae
Culture and Incubation
• Does not grow well on_____ agar.
Medium of choice:_____
Incubation:_____
SHEEP BLOOD AGAR
ENRICHED CAP
35°C in a 3-5% CO2
N. gonorrheae
Provision of sufficient humidity
•______evaporating from the media in a closed jar
• CO2 incubator with____
• Pan of water place at the bottom of the incubator
Moisture
humidifier
N. gonorrheae
Culture and incubation
• Examined for growth for
7 days
Inhibitor
Vancomycin - inhibits gram +
Colistin - Inhibits gram -
Nystatin - inhibits fungi
Thayer Martin
- inhibits gram positiVe
- Inhibits gram negative
- inhibits fungi
Vancomycin
Colistin
Nystatin
Inhibits swarming if proteus
Trimethoprim lactate
Nutrients of Thayer Martin/ Modified
Hemoglobin as source of
X-ractor; enriched with V factor, vitamins, amino acids, coenzymes, and dextrose
Organisms that Grow in Thayer Martin
Neisseria gonorrhoea
Neisseria meningitidis
Martin Lewis inhibitor
Vancomycin
Colistin
Trimetophrim Lactate
Anisomcyin - inhibits fungi
Nutrients Present that Support Fastidious Neisseria gonorrheae
MARTIN LEWIS
______that provides X-factor,
nitrogenous nutrients in the form of_____,_____ to maintain pH,_____ that neutralize toxic fatty acids present in the mediu,______,_____,____,____,____,____, and other growth factors necessary for improvement and optimal growth of pathogenic Neisseria species.
Bovine hemoglobin
casein and meat peptone
phosphate buffer
cornstarch
V factor
vitamins, amino acids, coenzymes, dextrose, ferric ions
New York City Agar INHIBITORS
Vancomycin
Colistin
Trimetophrim Lactate
Amphotericin B inhibits fungi
Nystatin
Anisomycin
Amphotericin B
Thayer Martin
Martin Lewis
NYC Agar
NYC Agar Nutrients
Peptone,_____ that neutralize toxic
metabolites producea by Nersseria,
Horse plasma, horse hemoglobin, dextrose, and yeast autolysate.
______provides essential electrolytes maintaining osmotic equilibrium thereby maintaining the integrity of cells.
cornstarch
Sodium chloride
N. gonorrheae
Medium
Thayer Martin
Modified Thayer Martin
Martin Lewis
NYC Agar
N. gonorrheae
Culture and Incubation
• Colonies are(3), and raised after ____hours of incubation
small, gray to tan, translucent
24-48 hrs
N. gonorrheae
5 colony types
T1
T2
T3
T4
AHU colonies
N. gonorrheae
: piliated, virulent colonies
• Smaller and raised, appear bright in
reflected light
T1 andT2
N. gonorrheae
: non piliated, avirulent
• Larger, flatter colonies
T3-T5
N. gonorrheae
: smaller colonies and grow slowly
• AHU colonies
N. gonorrheae
•______ culture is recommended for workup since the organism can produce their own____ enzyme
Fresh culture
autolytic
N. gonorrheae
Indirect Microscopy
• Gram stain of colonies obtained from
________
• Observe for:….
• (2) may occasionally grow - RODS
selective media
gram negative diplococci, “bean or kidney” shaped
Kingella and Acinetobacter
Presumptive Biochemical Test for N. gonorrheae
Cytochrome Oxidase Test
Oxidase Reagent/s:
• 1% dimethyl p-phenylenediamine dihydrochloride
• 1% tetramethyl dihydrochloride
Cytochrome oxidase test
• Positive Result:
• Interpretation:
Purple color within 10-30 seconds
Presence of Neisseria species
Cytochrome oxidase test
Alternative procedure:
• Oxidase reagent may be drop directly on the colony
• Positive result:
Colony turns deep purple to black
Definitive Test
Carbohydrate Utilization Test using CTA Medium
Carbohydrate Utilization Test using CTA Medium
Medium:
pH Indicator:
1% of individual CHO ( what is the sugar used for N. gonorrheae?)
Cystine Trypticase Agar
Phenol Red
Glucose
Carbohydrate Utilization Test using CTA Medium
• Result:
• N. gonorrheae: Ferments GLUCOSE
Yellow color in the medium as a result of fermentation
Other Tests for N. Gonorrheae
Chromogenic Substrates Methods of CHO utilization
Multitest Method
Beta lactamase test for Neisseria gonorrhea
• Based on colour changes after bacterial enzymes hydrolyse the CHO
substrates
• Useful for identification of N.gonorrheae with aberrant CHO utilization
Chromogenic Substrates Methods of CHO utilization
Multitest Method
• Multitest conventional chromogenic enzyme method
• Combine substrates of other biochemical tests
• Can also identify other genera such as…(2)
Haemophilus spp & Moraxella spp
Beta-lactam drugs - contain beta lactam rings in their structure
Examples
penicillins
cephalosporins
penems
cephemscarbapenems
monobacatams
binds to the penicillin-binding proteins (PBPs) of the peptidoglycan layer of both gram positive bacteria that result in the inhibition of cell wall synthesis.
This leads to bacterial lysis and death.
Beta-lactam ring
Norma function of ____ (transpeptidase) - catalyze the polymerization of the peptidoglycan strands and cross linking between glycan chains.
____of beta-lactam drugs- bind to these enzymes (PBPs) inhibiting the polymerization and cross-linking of peptidoglycan layer.
This leads to loss of cell wall integrity, cell lysis, and death.
PBPs
Beta-lactam rings
______produced by both gram + and gram - bacteria and it hydrolyses the beta lactam ring, making beta-lactam drugs ineffective.
______producing bacteria are resistant to penicillin and other beta-lactam drugs
Beta-lactamase (a.k.a penicillinase) enzyme-
Beta-lactamase
Examples of bacteria that produce beta-lactamase (penicillinase) - NES
Neisseria, Escherichia coli, Staphylococci
The_______ binds to the beta-lactam ring, preventing it from binding to the PBPs.
The beta-lactam ring is hydrolyzed by it, making them ineffective in inhibiting peptidoglycan synthesis.
Beta-lactamase enzyme
- determines the ability of the bacterial isolate to produce the Beta-lactamase enzyme chat hydrolyzes Beta-lactam rings, makine them resistant to penicillin and other beta lactam drugs.
The beta-lactamase test
- Detects beta-lactamase production from colonies…. Isolates containing these organisms should be routinely tested for B-lactamase activity
Cefinase test
Staphylococcus species,
Haemophilus influenzae,
Neisseria gonorrhoeae,
of and anaerobic bacteria
Beta lactamase test
Reagent: - impregnated with chromogenic cephalosporin which is a beta-lactam ring-containing drug.
Cefinase disk
Cefinase test
Procedure:
1. Moisten the cefinase disk with___
2. Using a sterile loop or needle, obtain a colony from the culture medium
3. Smear the colony on the moistened disk
4. Observed for color change:
1 drop of purified water
Cefinase test
Result:
Colonies positive for beta-lactamase: color change of Cefinase disk from ___ to ____
• Colonies negative for beta-lactamase: color change does not occur on the disk.
yellow to red
Previously susceptible to Penicillin
•- resistant to penicillin
• - N.gonorrhea acquire plasmids that code for beta-lactamase production.
Penicillinase-Producing Neisseria gonorrhoea (PPNG)
Plasmid mediated penicillin resistance
• Plasmid mediated and chromosomally mediated resistance to:
tetracycline
spectinomycin
fluoroquinolones
