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21 Cards in this Set
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- Back
Pathogenic Neisseria: common metaboilic Characteristics?
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- N. meningitidis, N.gonorrhoeae
- Gram Negative diplococci - oxidase (+), glucose (+) - optimal growth on inc. CO2 and chocalate agar - differentiation by sugar test and slide agglutination *Martin Lewis: chocalate agar containing antibiotics active against gram(+)bacteria |
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Pathogenic Neisseria: common pathogenic characteristics?
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both species contain pili and outer membrane proteins(OMP), may change antigenically from gen to gen
Contain lipoOligosacchride(LOS) lipid A and core oligosacchride function as endotoxin |
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N. Meningitidis: disease states?
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upper respiratory meningococcal disease ranging from mild febrile to severe pharyngitis
may progress to systemic meningococcemia presenting w/ fever, weakness, petechial rash 20-40 % progress to meningitis, then arthritis, endocarditis and Waterhouse- Friderichsen syndrome (adrenal coritcal necrosis) |
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N. Meningitidis: describe the epidemiology?
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2-3000 cases of meningococcal disease in US/year with fatality rate 10%
4-10% nasopharyngeal carriers carrier state is 30-90% as a result of and during epidemics |
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What makes N. Meningitidis pathogenic?
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pili - for ATTACHMENT
IgA protease - colonization, deactivation of IgA LOS(polysacchride capsule) with sialic acid - interferes with complement Endotoxin; sheds blebs of toxin Outer Membrane Protein OMP binds IgG |
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What are methods used to id/diagnose N. meningitidis?
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Gram stain spinal fluid, even buffy coat of blood
Ag detection in spinal fluid culture spinal fluid, blood and petechiae (*remember CSF, glucose down, protein up) nasopharyngeal swabs and throat * there are 12 polysacchride serogroups |
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N. Meningitidis: Immunity?
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most adults have immunity to cidal Abs
newborns have passive immunity *children 6 mos to 2 yrs are most susceptible asplenic persons and those with C5, C6, C7 deficiencies are esp susceptible |
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N. Meningitidis: Rx and Vaccines?
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Penicillin in massive doses (is of very little risk to hospital personnel)
vaccine recommended for pts w/ asplenia or complement deficiencies for families, soldiers use rifampin, ciproflaxin or ceftriazone for prophylaxis vaccine contains polysacchride capsular antigens, used extensively by military and international travelers |
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N. gonorrhoeae: What are the disease manifestations common to men and women?
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Short incubation 2-7 days
infection of the columnar and transitional epithelia of the urogenital tract infection makes patients more susceptible to other STDs and HIV pharyngitis occurs from oral genital sex |
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N. gonorrhoeae: What are the clinical manisfestations in MALES?
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urethral infections subside in several weeks
repeated infections can lead to sequelae most males present with pain on urination and a purulent pus |
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N. gonorrhoeae: What are the disease manifestations in FEMALES?
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asymptomatic in about 30% of cases but may present with pain on urination , abdominal pain, and vaginal discharge
sequelae inc. fallopian tube inflammation w/ scarring pelvic pain, ectopic pregnacy and recurring PID Disseminated Gonococcal (DGI) infections can result in septic arthritis and tenosynovitis Gonococcal perihepatitis (Fitz Hugh Curtis Syndrome) and meningitis are rare complications |
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N. gonorrhoeae: What are disease manisfestations in children?
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opthalmia neonatorum (eye infection) during passage thru birth canal as a reuslt of mom being infected with this bacterium
infection from sexual abuse leads to vulvovaginitis |
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N. gonorrhoeae: Epidemiologic characteristics?
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The risk of getting this infection from an infected partner is 30% for females and 10% for males
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N. gonorrhoeae: Describe its pathogenicity?
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this bacteria has a pili and OMPs for attachment
Parasite directed endocytosis allows this org to enter cells which are not phagocytic it forms a LOS/sailic complex it upregulates catalase inside phagocytes to defend agst killing Genetic variation in pili and surface Opa proteins help delay Ab reponse |
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N. gonorrhoeae: Rx and immunity?
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30% are resistant to penicillin and tetracycline
Fluoroquinolones are used w/ other antibiotics to cover possibility of multiple infection repeated infections can occur lack of immunity is due to genetic variation of gonococci there is NO vaccine |
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N. gonorrhoeae: What is the criteria for diagnosis?
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this org requires an enriched choclate agar for growth (if taken fron anorectal area)
for women take and endocervix specimen and anal canal culture Men urine may be used as a specimen but it must be cultured immediately; for men gram negative intra cellular diplococci on direct smear from urethral exudate is diagnostic throat cultures |
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What is the difference btwn Presumptive and Definitive diagnoses of N. gonorrheae?
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garam(-) diplococci colonies on chocolate agar w/ antibiotics(thayer-Martin) that are oxidase positive, are adequate in uncomplicated cases
vs. complicated cases where suspect colonies must be subjected to sugar utilization tests or slide agglutination; recommended for sites other than anal or genital region |
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N. gonorrheae: What are tequniques used for daignosis?
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non culture tests which allow gc to be transported or stored over a pd of days
ELISA detect gc antigens genetic transformation test to detect gc DNA Nucleic Acid amplification tests, expensive |
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N. Sicca
N. flvescens |
these are other sp. of Neisseria that are normal in the pharynx and can occasionally cause infection
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Branhamella (Moraxell) catarrhalis
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common commensal in the throat
it causes Otitis media in children |
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T/F Slide agglutination is the major way to detect cases of pirulent meningitis in the Cerebral Spinal Fluid.
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False. Gram stain of CSF can detect bacteria in about 50 % of cases and can be used to distinguish between Hemophilus influenza, Strep pneumoniae, and N. meningitis.
Slide agglutination may also be used as an adjunct but not a substitute for Gram stain. |