2. Gram negative cocci

Gram negative cocci

Neisseria
moraxella

General neisseria morphology

diplococci

Oxygen requirements of neisseria

aerobes

How is neisseria distinguished from other oral streptococci

Oxidase positive

Neisseria oxidase test

Indicator chemical turns blue for OXIDASE POSITIVE

Which medium do you use for neisseria ISOLATION

Thayer Martin medium for contaminated samples

Thayer-Martin

Selective medium containing antibiotics (incl. vancomycin) that inhibit growth of other bacteria to isolate & culture Neisseria.

N. meningitidis pili

specific for epithelial cells of oropharynx and meninges

N. gonorrhoeae pili

specific for mucosal cells

N. meningitis endotoxin

extremely potent

N. gonorrhoeae endotoxin

much lower potency

Neisseria meningitidis lifestyle

extracellular

Neisseria gonorrhoeae lifestyle

intracellular

Neisseria meningitidis transmission

person to person via respiratory droplets

Neisseria gonorrhoeae transmission

sexual, perinatal

fatality of N. meningitidis

85% without treatment so very lethal

Fatality of N gonorrhoeae

pretty low

N. meningitidis protection

vaccine because IgM and IgG protect against capsular antigens

C5-C9 complement deficiencies

increased risk of Neisseria infection

Pili of N. gonorrhoeae functions

Immunogenic but highly polymorphic for immune evasion

Where is N. meningitidis normally found

normal flora of nasal passage (respiratory droplet transmission!)

High transmission of N. meningitidis rates in

daycares, dorms, barracks

Most common cause of acute meningitis in babies, children, and young adults

N. meningitidis

Most invasive serogroups of N. meningitidis

A, B, C, Y, and W-135

Who is at highest risk of meningococcal disease

babies and children

Critical step for pathogenesis of N. meningitidis

Adhere to & colonize nasopharynx

Trends in meningococcal disease in the last 4 years

serogroup Y has dramatically increased

Serogroup Y of N. meningitis often presents as

bacteremia and sepsis

Why has meningococcal disease inreased so much in the last 5 years

post pandemic rebound bc of lifted social restrictions

Demographic shifting of meningococcal disease

adults age 30-60, black/AA people, and HIV people getting more

2 most common clinical manifestations of N. meningitidis infection

meningococcemia (in blood)
meningitis

UNtreated meningitis

near 100% fatality

CSF profile for bacterial meningitis- WBC count

very high (0-60,000)

CSF profile for bacterial meningitis- cell type

neutrophils

CSF profile for bacterial meningitis- glucose

very low

CSF profile for bacterial meningitis- protein

high

gram stain of N. meningitidis

gram negative diplococci in blood or CSF

Many of the severe systemic effects of meningococcemia are attributed to

release of highly potent endotoxin

N meningitidis skin manifestations

hemorrhagic skin lesions (petechiae)

Meningococcemia hemorrhagic skin lesion

infection causes blood clots to develop in small blood vessels (petechiae)

what syndrome is associated with N. meningitidis

Waterhouse-Friderichsen syndrome

Rapid release of highly potent N. meningitidis endotoxin causes

septic shock from vascular collapse (hypotension)

Waterhouse-Friderichsen syndrome

Hemorrhagic destruction of the adrenals (regulate metabolism, immune system, blood pressure)

#1 cause of death in intensive care units (ICU)

septic shock

Septic shock is aka

disseminated intravascular coagulation (DIC)

disseminated intravascular coagulation (DIC)

increase in small blood clots depletes platelets,leaky vessels reduce blood to tissue —> ischemia and organ death

Adult respiratory distress syndrome

fluids leak into lungs

24 hours from onset of meningococcal disease

confusion, delirium, loss of consciousness, seizures

any meningitis infection is intiially treated with

Vancomycin + cephalosporin until organism identified

Once N. meningitidis has been identified as cause of meningitis, then what is treatment

DOC is penicillin

Preventing spread of meningococcal disease

prophylaxis for close contacts

2 meningitis vaccines

are MenACWY and MenB vaccines.

In infants less than 1 year old, which N. meningitidis serogroups are most prevalent

Serogroup B

MenACWY

quadrivalent conjugate vaccine that protects against A, C, Y, and W-135

With which age groups do most MenACWY vaccines happen

routine childhood vaccine starting at 2 mo
adolescents
College freshmen

MenB vaccine

age 16-23 for short term protection!

N. meningitidis OPA proteins

helps invade epithelial cells

N gonorrhoeae is often visualized as

(small dots) in a Gram stain of gonococcal urethral discharge INSIDE PNMs

most common bacterial STD in the US

chlamydia

2nd most common bacterial STD in US

is gonorrhea

Although a certain number of gonorrhea cases are REPORTED each year it is though that

twice as many new infections actually occur each year

Which is the demographic with the highest reported cases of gonorrhea

black/AA people

Gonorrhea is most common in which group

men who have sex with men

Sexual transmission of gonorrhea

genital, rectal, and oral

Perinatal transmission of gonorrhea

from mother to infant

Those with gonorrhea have an increased transmission and susceptibility to

HIV

Most female cases of gonorrhea

are asymptomatic

Gonorrhea male urethritis

very painful purulent discharge

Male patients with gonorrhea are much more likely to immediately

seek treatment due to painful purulent discharge

Most common local complication of gonorrhea in males

epididymitis

Gonorrhea cervicitis

HIGHLY INFECTIOUS discharge

Issue with gonorrhea in women

cervicitis is very infectious BUT NOT PAINFUL and normally asymptomatic

Most common cause of infertility

pelvic inflammatory disease

Ascending infection of gonorrhea in women

can cause pelvic inflammatory disease which commonly cause infertility

Gonococcal arthritis

dissemination causing inflammation and PAIN in joints

Perinatal transmission of gonococcal infection often causes

Ophthalmia neonatorum

Ophthalmia neonatorum

severe eye infection in newborns caused by gonorrhea and chlamydia

Ophthalmia neonatorum specific to gonorrhea

gonococcal ophthalmitis which can cause BLINDNESS

Gonococcal infection in older children can indicate

sexual abuse

Diagnosis of gonorrhea- microscopy

gram stain of discharge and cells for rapid same-day diagnosis

Gram stain of discharge is recommended to

males with discharge and ALL FEMALES

Microscopy for pharyngeal gonococcal infection

not useful because we have neisseria in normal flora

Modern diagnostic standard for gonorrhea diagnosis

PCR to amplify genetic material

Issue with treatment of gonorrhea

increasing RESISTANCE (plasmid and chromosomal mediated)

DOC for N. gonorrhea

IM Ceftriaxone AND tetracycline

Why are patients with gonorrhea also given tetracycline with the IM ceftriaxone

Effective for assumed coexisting Chlamydia infection

Prophylactic newborn treatment

tetracycline ophthalmic ointment