Neisseriaceae and Moraxella catarrhalis Flashcards
A sexually transmitted infection (STI) in both men and women
Gonorrhea
invasion of the mucous membranes of the genital tract, rectum and the throat causing inflammation
Gonorrhea
Genital gonorrhea In males:
- Primary site of infection is the
urethra
Genital gonorrhea In males:
Incubation period ranges from [?] days or longer, with an average of 2 to 7 days.
1 to 14
Symptoms of [?] occur in 90-95% of infected males
urethritis
(burning sensation during urination)
dysuria
(yellow, creamy pus)
purulent urethral discharge
Genital gonorrhea In females:
- Primary site of infection is the
endocervix, with concomitant urethral infection
Genital gonorrhea In females:
Incubation period ranges from [?] days
8 to 10
Symptoms of [?] occur in 10-20% of infected females
endocervicitis
Symptoms of endocervicitis
‣ purulent cervicovaginal discharge
‣ dysuria
‣ menorrhagia (intermenstrual bleeding)
‣ dyspareunia (painful vaginal intercourse)
In untreated cases, ascending infection may occur and can result in [?] that is manifested as salpingitis (infection of the Fallopian tubes), endometritis, and tubo-ovarian abscess.
pelvic inflammatory disease (PID)
is a risk factor for ectopic pregnancy, infertility, chronic pelvic pain, and Fitz–Hugh–Curtis syndrome
Salpingitis
an infection and inflammation of liver capsule and “violin string” adhesions of peritoneum to liver.
perihepatitis
When gonorrhea is present in a child after the newborn period and before puberty, this infection may be a sign of
sexual abuse.
In prepubertal girls, gonorrhea manifests as a [?] with a vaginal discharge, rather than a cervicitis.
vaginitis
The epithelium of the prepubertal vagina is composed of [?], which are the cell types that N. gonorrhoeae preferentially infects.
With the onset of puberty, these cells are replaced by a[?] that is not susceptible to gonococcal infection.
columnar epithelial cells
stratified squamous epithelium
Seen in MSM (men having sex with men)
Oropharyngeal gonococcal infection
women who acquire the infection by engaging in orogenital sexual contact with an infected partner
Oropharyngeal gonococcal infection
Over 90% are asymptomatic
Oropharyngeal gonococcal infection
Patients with oropharyngeal gonococcal infection often have gonococcal infection at
genital and/or rectal sites
Seen primarily in MSM who practice unprotected [?] anal intercourse; among MSM, gonococcal infection of the rectum may be the only infected anatomic site.
receptive
Women may also acquire rectal infections by [?] anal intercourse, but most rectal infections in women are due to [?] contamination with infected cervicovaginal secretions.
receptive
perianal
Are often asymptomatic, but some individuals may experience symptoms ranging from [?] to with anorectal pain and itching, a mucopurulent discharge, bleeding, tenesmus, and constipation 5 to 7 days following infection.
mild pruritis
acute proctitis
Painful, purulent conjunctivitis
Ocular gonococcal infection
Occurs in adults who become infected by self-inoculation of the eyes from genital secretions
Ocular gonococcal infection
An infection of the eye in newborns
Gonococcal ophthalmia neonatorum
Acquired during passage through the birth canal of an infected mother
Gonococcal ophthalmia neonatorum
Initial purulent conjunctivitis occurs 2-5 days after birth, rapidly progresses and, if untreated, results in blindness
Gonococcal ophthalmia neonatorum
Results from the spread of gonococci into the bloodstream
Disseminated Gonococcal Infection (DGI)
Characterized by low-grade fever, painful, hemorrhagic skin lesions (initially appear as papules that evolve into
necrotic pustules) on the hands, forearms, feet, and legs; tenosynovitis and suppurative arthritis, usually of the knees, ankles, and wrists.
Disseminated Gonococcal Infection (DGI)
Complications include permanent joint damage, endocarditis, and rarely, meningitis.
Disseminated Gonococcal Infection (DGI)
Neisseria gonorrhoeae
Enhance attachment of gonococci to host cells and resistance to phagocytosis
Pili
Neisseria gonorrhoeae
Undergo antigenic variation; a single strain can make many antigenically distinct forms
Pili
Neisseria gonorrhoeae
Associated with porins; Undergo antigenic variation
Protein I (Por proteins)
Neisseria gonorrhoeae
Prevents intracellular killing of gonococci within neutrophils by preventing phagosome–lysosome fusion
Protein I (Por proteins)
Neisseria gonorrhoeae
Responsible for variable resistance of gonococci to killing by normal human serum
Protein I (Por proteins)
Neisseria gonorrhoeae
A portion is in the gonococcal outer membrane, and the rest is exposed on the cell surface
Protein II (Opa proteins)
Neisseria gonorrhoeae
adhesion of gonococci within colonies and attachment of gonococci to host cell receptors
Protein II (Opa proteins)
Neisseria gonorrhoeae
Undergo antigenic variation
Pili Protein I (Por proteins) Protein II (Opa proteins) Endotoxin
Neisseria gonorrhoeae
Structurally associates with Por in the outer membrane
Protein III (Reduction-modifiable Protein or Rmp)
Neisseria gonorrhoeae
antigenically conserved in all gonococci
does not display antigenic variability
Protein III (Reduction-modifiable Protein or Rmp)
Neisseria gonorrhoeae
Diminishes the bactericidal effects of normal human serum
Protein III (Reduction-modifiable Protein or Rmp)
Neisseria gonorrhoeae
gonococcal lipopolysaccharide (LPS) does not have an O polysaccharide side chain
lipooligosaccharide or LOS
Neisseria gonorrhoeae
Associated with toxicity in gonococcal infections; causes ciliary loss and
mucosal cell death
Endotoxin
Allows attachment to host mucosal surfaces by splitting and inactivating IgA1
IgA1 protease
a major mucosal immunoglobulin of humans
IgA1
Plasmid-mediated production responsible for penicillin resistance (PPNG = penicillin-producing N. gonorrhoeae)
β-lactamase
• Results from the entry of meningococci from the nasopharynx into the blood stream probably by way of the cervical lymph node
Meningococcemia
Abrupt onset with fever, chills, malaise,
prostration, and petechiae
Meningococcemia
occurs in about 10% of patients with
meningococcemia
Purpura fulminans
characterized by:
- ecchymoses (larger form of petechiae)
- disseminated intravascular coagulation (DIC)
- shock
- coma
- Waterhouse-Friderichsen Syndrome - acute hemorrhage into the adrenal glands, resulting in death in 6-8 hours
Purpura fulminans
Usually associated with epidemic meningitis; and the second most common cause of bacterial meningitis in adults
Meningococcal meningitis
May occur simultaneously with meningococcemia
Meningococcal meningitis
Symptoms usually begin with sudden onset of fever, with an intense headache, stiff neck, convulsion, vomiting and progresses to coma within a few hours
Meningococcal meningitis
• The primary virulence factor of meningococci associated with blood stream invasion
Capsule
Capsule consists of polysaccharide, which classifies meningococci into 13 serogroups :
A, B, C, D, H, I, K, L, W135, X, Y, Z, and 29E
The most important serogroups associated with disease in humans are
A, B, C, X, Y, and W-135
• Enables meningococci to resist the bactericidal activity of the complement and prevents destruction of the organism by phagocytes.
Capsule
Protrudes through the organism’s capsule.
Pili
Mediates initial attachment to surface proteins on non-ciliated cells in the nasopharyngeal epithelium of the host
Pili
aggregates the meningococcal cells into microcolonies allowing attachment to epithelial microvilli and entry in to the bloodstream
Pili
Endotoxin specifically referred as
meningococcal lipooligosaccharide (LOS).
Responsible for many of the toxic effects found in meningococcal disease.
Endotoxin
Neutralizes the protective action of the mucosal immunoglobulin
IgA1 Protease
which in each dose consists of four purified bacterial capsular polysaccharides is said to be poorly immunogenic in children younger than age 18 months
Polysaccharide tetravalent vaccine
contains capsular polysaccharide conjugated to diphtheria toxoid, and is licensed for use in persons 9 months to 55 years of age
Tetravalent conjugate vaccine
With the availability of effective vaccines for meningococcal serogroups [?]. N. meningitidis has become the major cause of bacterial meningitis worldwide
A, C, Y, and W135, serogroup B
Polysaccharide vaccines do NOT contain [?] because they are poorly immunogenic in both children and adults. It is attributed to resemblance of group B capsular material, comprised of a linear polymer of [?] to the polysialated form of the neural cell adhesion molecules found in fetal brain tissue.
group B polysaccharides
⍶2-8 N acetylneuraminic acid (sialic acid)
Current efforts to develop group B vaccine have centered around the [?]. It is fairly new and not yet recommended as a routine vaccination for healthy people. CDC recommends routine serogroup B meningococcal vaccination for people 10 years or older at increased risk for
meningococcal disease.
OMP (outer membrane proteins)
is administered to individuals who had close contacts with primary case of meningitis or meningococcemia, ideally, within less than 24 hours after identification of the index case
Chemoprophylactic antimicrobial therapy
PREVENTION AND CONTROL
• avoiding multiple sexual partners
• rapid eradication gonococci from infected individuals
o instillation of silver nitrate solution to the conjunctiva of newborns
Neisseria gonorrhoeae
o early diagnosis and treatment o case finding o education and screening of populations at high risk o use of mechanical prophylaxis condoms o chemoprophylaxis antibiotic resistance
• avoiding multiple sexual partners
o instillation of silver nitrate solution to the conjunctiva of newborns
Crede’s Method
Crede’s Method is replaced by
0.5% erythromycin or 1% tetracycline ointment at the site of infection
HABITAT
• NOT considered normal flora
• mucous membranes of the genitourinary tract, rectum, throat, and the eye at time of infection
• polymorphonuclear cells
Neisseria gonorrhoeae
• human nasopharynx
o pharyngitis – 10% of healthy individuals
o carrier state may last for a few days to months
Neisseria meningitidis
• direct contact through inhalation of respiratory secretions or droplets
Neisseria meningitidis
• direct contact (sexually or perinatally)
Neisseria gonorrhoeae