Exam 3 Gram Negative Cocci Flashcards
Neisseria is classified as a ___ ____ ____
gram negative diplococci
Are Neisseria aerobic or anaerobic?
Aerobic
Neisseria produces ______ which distinguishes it from oral Streptococci
cytochrome c oxidase (oxidase positive)
What medium is used to grow Neisseria
Thayer Martin
Positive oxidase test result
Indicator chemical turns blue when oxidized
Thayer Martin medium is best on ____ agar with _____
chocolate agar; increased CO2
True or false: many different species can survive on Thayer Martin medium
False - selective medium Neisseria only, other bacteria die from antibiotics that are present
Neisseria main virulence factors
- adhesion factors (pili)
- endotoxin (lipooligosaccharide)
The endotoxin of ____ is extremely potent
N. meningitidis
The endotoxin of _____ has low potency
N. gonorrhoeae
N. meningitidis has pili that are specific for:
epithelial cells of the oropharynx and meninges
Neisseria has ____ in its cell wall
LOS (lipooligosaccharide)
N. gonorrhoeae has pili specific for:
Mucosal cells
_____ is extracellular
N. meningitidis (spinal tap shows diplococci outside of cells)
_____ is intracellular
N. gonorrhoeae
N. meningitidis transmission
person to person by respiratory droplets
N. gonorrhoeae transmission
- sexual
- perinatal
True or false: N. meningitidis has a higher mortality than N. gonorrhoeae if untreated
True (85% if untreated)
IgG and IgM antibodies against ______ are protective
N. meningitidis capsular antigens
The pili of N. gonorrhoeae are _____ but highly _____, which leads to evasion of host immunity
immunogenic; polymorphic
Those with C5-C9 complement deficiencies are predisposed to:
Bacterial and Neisseria species infections
How does C5-C9 complement fight bacteria?
- form transmembrane channel in bacteria
- bacteria burst and die
N. meningitidis is part of ______. 5-15% are carriers in the ____
normal flora; nasopharynx
Where does N. meningitidis have high transmission rates?
- day care centers
- dorms
- barracks
What is the most common cause of acute meningitis?
N. meningitidis
N. meningitidis causes acute meningitis in:
- babies and children
- adolescents
- young adults
Most invasive disease of N. meningitidis is caused by what serogroups?
A, B, C, Y, W-135
Meningococcal disease incidence is highest in what age group?
Babies and children
N. meningitidis pathogenesis
Leading to meningitis
- adhere to and colonize the nasopharynx
- invade epithelium and then blood
- hematogenous spread causes endotoxemia
- toxins produces leads to meningitis
Meningococcal disease incidence has been decreasing recently due to:
Vaccine
True or false: N. meningitidis always results in meningitis
False - can also cause meningococcemia, pneumonia, arthritis, otitis media
Without treatment for N. meningitidis, fatality nears ___. With treatment, it nears _____ and up to ____ in meningococcemia
100%; 9-12%; 40%
Clinical findings of N. meningitidis
- acute bacterial meningitis
- CSF profile
What is the bacterial CSF profile?
WBC - 0-60,000
Cell type - neutrophils
Glucose - very low
Profile - high
What does the gram stain look like for N. meningitidis?
Gram negative diplococci in blood or CSF
____ is responsible for many severe systemic effects of N. meningitidis
Endotoxin (LPS)
N. meningitidis infection can lead to:
- hemorrhagic skin lesions (petechiae, may coalesce)
- septic shock
- disseminated intravascular coagulopathy (DIC)
- Waterhouse-Friderichsen syndrome
- multi-organ failure/death
What is Waterhouse-Friderichsen syndrome?
Hemorrhagic destruction of the adrenals, which regulate metabolism, immune system, blood pressure
Petechiae
Infection causes blood clots to develop in small blood vessels
Petechiae can coalesce into:
Hemorrhagic bullae (blood blister)
Septic shock can lead to _____
N. meningitidis
Hypotension/shock (systemic vasodilation)
toxins damage small blood vessels + leak fluid into surrounding tissues
N. meningitidis infection causes ____ to develop in small blood vessels, which leads to activation of ____ ultimately leading to ____
Blood clots; clotting system (systemic inflammation); disseminated intravascular coagulation (DIC)
No. 1 cause of death in intensive care units (ICU)
Septic shock
Disseminated Intravascular coagulation (DIC) - how does it lead to death?
- infection causes blood clots to develop in small blood vessels
- clots deplete platelets and clotting factors, leading to bleeding in blood vessels
- leaky blood vessels reduce blood to tissue (ischemic)
- damage to organs
Meningococcal disease timeline - symptoms such as confusion, delirium, loss of consciousness, or seizures can occur at:
24 hours after onset
N. meningitidis DOC
Penicillin (when organism is identified)
N. meningitidis treatment before organism is identified
Vancomycin and cephalosporin
True or false: those who have contacted someone with N. meningitidis infection does not need any treatment
False, they need antibiotic prophylaxis - rifampin and ciprofloxacin
There are ____ vaccines available for N. meningitidis, which are:
2; MenACWY and MenB
Which N. meningitidis vaccine provides better protection?
MenACWY
MenACWY vaccine is also called:
Meningococcal C & Y vaccine
MenACWY is a ____ ____ vaccine
quadrivalent conjugate vaccine
MenACWY prevents meningococcal disease caused by serogroups:
A, C, Y, W-135
When is the MenACWY vaccine given?
- routine childhood vaccination starting at 2 months
- adolescents age 11-12
- booster age 16
Who is at increased risk of invasive meningococcal disease?
- college freshmen living in a dormitory
- complement component deficiency
- HIV
- asplenia
- taking eculizumab (Soliris)
- military recruits
- meningococcal outbreaks
- microbiologists if routinely exposed
- travelers
When was MenB approved in the US?
2014
MenB is recommended for age ____
age 16-23 (prefer age 16-18)
True or false: MenB provides long term protection against most serogroup B strains
False - short term protection
Currently, MenB is being administered to:
Increased-risk groups for now
Broader age recommendations being discussed
Unlike N. meningitidis, N. gonorrhoeae does not contain:
Capsule or hemolysin
____ help N. gonorrhoeae invade epithelial cells
OPA proteins
Second most commonly reported STD in the US
Gonorrhea
Most common reported STD in the US
Chlamydia
____ as many new infections of gonorrhea are estimated to occur each year as are reported
Twice
What race/ethnicity has the most reported cases of gonorrhea?
Black/African American (similar pattern in other STDs)
Which group of sex/sex partners have the highest reports of gonorrhea cases?
Men who have sex with men (MSM)
What is the difference between STI and STD?
- STI = sexually transmitted infection
- infection doesn’t necessarily mean you are experiencing symptoms (disease = symptoms)
There has been a _____ increase/decrease in cases of gonorrhea since 2017
28% increase
Gonorrhea transmission routes
- sexual (genital, oral, rectal)
- perinatal (mother to infant)
Gonorrhea is associated with increased transmission of and susceptibility to
HIV infection
Men with gonorrhea can experience:
- urethritis
- epididymitis
Women with gonorrhea can experience:
- urethritis
- cervicitis
- pelvic inflamatory disease
True or false: most females with gonorrhea are asymptomatic
True
Male urethritis symptoms
- purulent discharge
- very painful
Males with urethritis usually seek immediate ____
Medical attention (very painful/pus)
Epididymitis symptoms
Unilateral testicular pain and swelling
Epididymitis is usually associated with
Urethritis
Most common local complication of gonorrhea in males
Epididymitis
____ of women with cervicitis are asymptomatic
50%
Cervicitis symptoms
- purulent discharge
- usually painless
Cervicitis is highly _____
Infectious
If a woman with cervicitis is feeling pain, the pain can often be confused with:
Period pain
Most common cause of infertility
Pelvic inflammatory disease (PID)
Pelvic inflammatory disease entails infection of:
- uterus
- fallopian tubes
Pelvic inflammatory disease can lead to:
- infertility
- ectopic pregnancy
- abscess formation
- chronic pelvic pain
Oral gonorrhea can lead to:
- pharyngeal gonorrhea
- gingival gonorrhea
True or false: you can contract conjunctivitis from gonorrhea
True (fluids are very infectious)
N. gonorrhoeae can disseminate and cause ____ _____
Gonococcemia lesions
Gonococcemia can manifest as _____ if they reach the joints
Gonoccal arthritis
Types of gonoccal arthritis
- monoarthritis (one joint at a time)
- oligoarthritis (a few joints at a time)
How do gonoccocal infections occur in babies?
perinatal infection via conjunctiva, pharynx, respiratory tract
Ophthalmia neonatorum
Eye infection in a newborn caused by chlamydia, gonorrhea, or other genital/rectal bacteria
Ophthalmia neonatorum can lead to:
Blindness
Gonococcal infection in older children is a sign of:
Possible evidence of sexual abuse
If you notice gonococcal infection in older children, what do you have to do?
- collect evidence and laboratory documentation
- required to report to social services/law enforcement (all 50 states)
How is N. gonorrhoeae diagnosed?
- Gram stain of discharge and cells
- immunofluorescence
- culture (Thayer Martin medium)
Microscopy is sufficient to diagnose gonorrhea in ___. Sensitivity test also needs to be used to diagnose _____
males with purulent discharge; all females
True or false: microscopy/gram stain can be used to diagnose pharyngeal gonorrhea
False - other Neisseria species can colonize pharynx so can lead to false positive
True or false: Neisseria gonorrhea shows antibiotic resistance
True - half of infections resistant to at least one antibiotic
DOC for N. gonorrhoeae
Ceftriaxone IM and a tetracycline
also effective for assumed coexisting Chlamydia infection
N. gonorrhea confers antibiotic resistance via:
- plasmid
- chromosome
N. gonorrhea is becoming increasingly resistant to:
Cephalosporins
Why is a tetracycline also used in treatment of gonorrhea?
Reduces ceftriaxone resistance risks
Opthalmia neonatorum prophylaxis
- erythromycin (Ilotycin)
- tetracycline ophthalmic ointment