Gram Negative Cocci Flashcards
It is the leading cause of sexually transmitted disease
Neisseria gonorrhoeae
It is found in urogenital tract, anorectal area, oropharynx, or conjunctiva
Neisseria gonorrhoeae
Virulence factors of Neisseria gonorrhoeae
Pili
principal virulence factor, promotes attachment of organism to the mucous membrane, initiating infection
Pili
affects antibody formation, leukocyte response
and cell mediated immunity
Outer membrane proteins
source of endotoxin
Lipopolysaccharide
allows the organism to insert itself into the host cells
Protein I
allows organism to attach to neutrophils and epithelial cells and to resist the effects of antibodies
Protein II
bind to the columnar epithelial cells lining the urethra and cervix.
Pili and LOS
also bind to the columnar epithelial cells and then cause the cytoskeleton of the cell to engulf the bacteria bound to the surface of the host cell.
opacity associated proteins (Opa)
N. gonorrhoeae produces extracellular secretory________ that clip the Fc portion of the IgA molecules off but allows the Fab portions to remain bound to the bacterial cell surface. Thus, decorating the bacteria with host protein and preventing opsonization by phagocytes.
IgA proteases
Those bacteria that are phagocytized by the PMN’s are protected from intracellular killing by the bacterial ________. It prevents the fusion of the lysosome with the phagosome and allows the bacteria to, for a time, survive in the PMN.
PorB protein
It means a “flow of seed” and “brothel”
Gonorrhea
Acute pyogenic infection mainly of the mucous membranes of endocervix (females) and urethra (males)
Gonorrhea
Incubation period of Gonorrhea
2 to 7 days
Symptoms: purulent discharge, lower abdominal pain and dysuria (men); dysuria and vaginal bleeding (women)
Gonorrhea
Long term effects on female of gonorrhea
scarred fallopian tubes and uterus, ectopic pregnancy and sterility
Conjunctivitis acquired by newborns from gonococcus-infected mother during delivery
Ophthalmia neonatorum
All newborns with Ophthalmia neonatorum are prophylactically treated with________ –(or previously_______) or cream to prevent the infection from occurring
antibiotic drops
silver nitrate
Gonococcal infection that spreads to the blood
Disseminated gonococcal infection (DGI)
Septicemia characterized by hemorrhagic skin infections
Disseminated gonococcal infection (DGI)
Can cause endocarditis and gonococcal arthritis
Disseminated gonococcal infection (DGI)
This is discouraged because fatty acids are toxic to the bacterium
Cotton swab
Can be used for SPECIMEN COLLECTION AND HANDLING in Disseminated gonococcal infection (DGI)
Dacron rayon,
calcium alginate or
cotton swabs treated with charcoal
For Blood-borne dissemination of gonorrhea – the organism will not be recovered from routine blood cultures because it is inhibited by
SPS
Collect blood in evacuated tubes and must be transferred to the broth culture system within
1 hour of collection
should be kept at room temperature or placed at 37°C before plating
Body fluids
Use ________ before inoculation on culture media
transport medium
The direct gram stain of body fluids is best accomplished using a
cytocentrifuge
Intracellular gram-negative diplococci, kidney or coffee bean shaped is
Diagnostic for Neisseria
Diagnostic microscopy of Neisseria
Intracellular gram-negative diplococci,
kidney or coffee bean shaped
Specimens on swab should be inoculated or rolled onto media in a _______ and cross-streaked with a loop
Z pattern
Neisseria spp is incubated at _____ with ______ which can be achieved using candle jar, CO2 Bio-Bag System or Pouch System or CO2 incubators
35°C with 3-5% CO2
consists of a flat bottle with modified Thayer-Martin and a bottle under increased carbon dioxide
Transgrow bottles
consists of a flat plastic dish containing a medium selective for gonococci and a tablet that acts as a carbon dioxide generator
JEMBEC (John E. Martin Biological Environmental Chamber)
Colonies of Neisseria are typically ______ in color and_______
clear gray to medium gray
opaque
Is a chocolate agar with enrichment supplement and antibiotics
Thayer Martin Agar (TMA)
Antimicrobial agents of Thayer Martin Agar (TMA)
vancomycin, colistin, and nystatin (VCN)
Antimicrobial agents of Modified Thayer Martin Agar (MTM)
vancomycin, colistin, nystatin, and trimethoprim lactate (VCNT)
Antimicrobial agents of Martin Lewis Medium (ML)
vancomycin, colistin, anisomycin, trimethoprim lactate (VCAT)
Antimicrobial agents of New York City Medium (NYC)
vancomycin, colistin, trimethoprim and amphotericin (VCTA)
A transparent medium with lysed horse blood, horse plasma and yeast dialysate
New York City Medium (NYC)
genital mycoplasma (Mycoplasma hominis and Ureaplasma
urealyticum) will also grow on this agar
New York City Medium (NYC)
Antimicrobial agents of GC-LECT Medium
vancomycin, colistin, trimethoprim, amphotericin, and lincomycin
It is the standard method of identifying N. gonorrhoeae
CHO Utilization Test
CHO Utilization Test detects acid production from
glucose, maltose, lactose, fructose, and sucrose
Medium for CHO Utilization Test
Cystine Trypticase Agar (CTA) – 1% carbohydrate + phenol red
Positive result for CHO Utilization Test
yellow color within 24 to 72 hours at 35°C
N. gonorrhea ferments________ only
glucose
Reagent: 1% tetramethyl-p-phenylenediamine dihydrochloride
Oxidase Test
Positive result of Oxidase Test
purple color within 10 seconds
Reagent: 20-30% H2O2
Superoxol Test
Positive result of Superoxol Test
vigorous bubbling
Most strains of N. gonorrhoeae are resistant to Penicillin therefore injectable_________ are commonly used
cephalosporins
Treatment:
Single intramuscular of _______ and single dose of ________ for uncomplicated cases.
Ceftriaxone and Azithromycin
Treatment:
for disseminated infections.
Ceftriaxone and Cefixim
Treatment:
for Ophthalmia neonatorum
Ceftriaxone
Treatment:
applied directly to the eye for Ophthalmia neonatorum
Routine prophylaxis of silver nitrate and erythromycin or tetracycline
It is the causative agent of epidemic meningococcal meningitis/meningococcemia/cerebrospinal fever/spotted fever
Neisseria meningitidis
It is the leading cause of fatal bacterial meningitis
Neisseria meningitidis
Serogroups are based in the type of
capsular polysaccharide
Serogroup of Neisseria meningitidis include
A, B, C, D, X, Y, Z, 29E, W135
Incubation period of Neisseria meningitidis
1 to 14 days
Virulence factors of Neisseria meningitidis:
promotes attachment
Pili
Virulence factors of Neisseria meningitidis:
cases petechial formation and DIC
Endotoxin
Virulence factors of Neisseria meningitidis:
enables organism to resist phagocytosis and enables them to cross the blood brain barrier, leading to meningitis
Capsule
It refers to the presence of N. meningitidis in the blood and can occur as an acute or chronic form
Meningococcemia
is characterized by recurrent episodes of meningococcemia, petechiae formation and eventual development of arthritis
Chronic meningococcemia
causes the formation of petechial rash which are tiny hemorrhages into the skin which leads to disseminated intravascular coagulation (DIC, uncontrollable clotting of blood within the bloodstream)
Endotoxin
Presence of Neisseria meningitidis in the central nervous system
Meningitis
Signs and symptoms: frontal headache, stiff neck, fever (epidemic
meningitis in adults)
Meningitis
remains the drug of choice for treatment of meningococcal
meningitis
Penicillin G
Fulminant meningococcemia associated with bleeding in the adrenal glands
Waterhouse Friderichsen Syndrome
to detect carriers, should be plated immediately to the JEMBEC system, or submitted on swabs placed in charcoal transport media
Nasopharyngeal swab
Specimen for meningitis
CSF
Specimen for meningococcemia
Blood
Specimen for petechial rashes
Skin lesions
Specimen for septic arthritis
Synovial fluid
Intracellular or extracellular gram-negative diplococci with adjacent sides flattened
Neisseria meningitidis
Nasopharyngeal swab may contain contaminants therefore a _____ must be used
selective plate (Modified Thayer Martin or Martin Lewis)
Colonies are round, smooth, glistening and gray in color; encapsulated strains are mucoid
Neisseria meningitidis
In CHO Utilization Test, Neisseria meningitidis ferments
glucose and maltose
Oxidase Test: N. meningitidis is oxidase
positive
Reagent: cephalosporin disk or cefinase nitrocefin disk
Beta Lactamase test/Cephalosporinase Test
Positive result of Beta Lactamase test/Cephalosporinase Test
deep pink/red color
Gamma-glutamyl aminopeptidase Test:
N. meningitidis
Positive
the drug of choice for the treatment of meningococcal meningitis and septicemia.
Penicillin
A single dose (500 mg) of_____ may be effective for the eradication of meningococcal carriage in adults
ciprofloxacin
Patients in whom meningococcal disease is suspected should receive a high dose of this drug, which interferes with synthesis of cell wall mucopeptide during active multiplication, resulting in bactericidal activity against susceptible microorganisms
Penicillin G
Can be mistaken as Neisseria gonorrhoeae
Moraxella catarrhalis
The most commonly isolated member of the genus Moraxella
Moraxella catarrhalis
It is only isolated from humans; an opportunistic pathogen
Moraxella catarrhalis
It causes upper respiratory tract infection
Moraxella catarrhalis
It is the 3rd most common cause of otitis media and sinusitis in
children
Moraxella catarrhalis
Is fastidious, encapsulated organism with pili (adhesins) and
nonmotile
Moraxella catarrhalis
Microscopy:
Small intracellular gram-negative diplococci that tend to grow in pair end-to-end; with adjacent sides flattened
Moraxella catarrhalis
Moraxella catarrhalis grows on
BAP at 22°C – nonhemolytic
nutrient agar at 35°C –nonpigmented, opaque, gray and smooth
Moraxella catarrhalis is inhibited on gonococcal media by
colistin
Colonies are smooth, opaque, gray to white with “hockey puck”
appearance
Moraxella catarrhalis
48-hour colony maybe have elevated center, thinner wavelike periphery
“wagon wheels” appearance
Moraxella catarrhalis
It does not utilize any sugar in CTA medium
Moraxella catarrhalis
Asaccharolytic in CHO degradation test – lack oxidative metabolism
Moraxella catarrhalis
Positive result of Butyrate Esterase Test
Blue color
Specimen for Butyrate Esterase Test
eye or ear culture