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71 Cards in this Set
- Front
- Back
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Name the morphology of the Neisseria genus |
Gram neg. Diplococci Aerobic or facultative anaerobic |
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Name the Pathogenic species of Neisseria |
Neisseria meningitidis Neisseria gonorrhoeae |
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Name the unique enzyme produced by Neisseria organisms |
Cytochrome oxidase |
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What percentage of the population caries Neisseria meningitidis in their nasopharynx |
10% |
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Describe the three pathologies caused by Neisseria meningitidis |
Nasopharyngitis-short, symptomless
Septicemia-(organism in blood) high fever, rash, fatal
Meningitis-(organism in CSF) high fever, extreme headache, neck and back pain
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Neisseria meningitidis has a capsule.
True or False |
True |
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Name the skin disease and type of lesion caused by Neisseria meningitidis |
Meningococcemia and coalescing hemorrhagic bullae |
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Neisseria meningitidis is normally found in the CSF
True or false |
False. The CSF is normally sterile. Neisseria meningitidis is often found as part of the normal flora in the nasopharynx. |
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Name the five virulence factors of Neisseria organisms |
1. pili -attachment to mucous cells 2. transport - host cell vesicles to submucosa 3. polysaccharide capsule 4. protease - cleaves IgA (mucous antibody) 5. endotoxin - (gram negative) causes disseminated intravascular coagulation |
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What is the effect of bacterial endotoxin on the body? |
DIC (disseminated intravascular coagulation) - acts a cloak for hiding the organism in the blood stream. |
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Describe the 4 laboratory methods of diagnosing a Neisseria meningitidis infection |
1. culture - colonial morphology, gram negative, cytochrome oxidase 2. differentiate - carbohydrate utilization tests 3. DNA probe tests 4. serology test - CSF latex agglutination test (fluorescent antibody staining) |
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Name the methods of treating and preventing Neisseria meningitidis infections |
1. Antibiotics within 30-60 mins! 2. Meningococcal polysaccharide vaccine (Menomune) -not good for children 3. Meningococcal conjugate vaccine -polysaccharide + protein -better for children
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What do vaccines against Neisseria meningitidis act upon? |
Polysaccharide capsule |
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What ages have the highest rates of Neisseria meningitidis infection |
Ages 11-21 |
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What locales have the highest rates of Neisseria meningitidis infection? |
Crowded places -schools -jails -nursing homes -mental institutions |
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Name the pathologies caused by Neisseria gonorrhoeae in males |
1. Urinary tract infection Male: acute urethritis, polyurea, or asymptomatic; rectal pain in homosexuals
2. conjunctivitis, pharyngitis, disseminated septicemia and meningitis, arthritis
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Name the pathologies caused by Neisseria gonorrhoeae in females |
1. Urinary tract infection endocervical infection, rectal pain, pelvic pain, vaginal discharge, pelvic inflammatory disease
2. Salpingitis - scarring of the fallopian tube leading to sterility
3. conjunctivitis, pharyngitis, disseminated septicemia and meningitis, arthritis |
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Neisseria gonorrhoeae has a capsule.
True or false |
False, but it has a polysaccharide coating (look up the difference) |
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How can Neisseria species in the normal flora be distinguished from pathogenic organisms? |
Normal flora Neisseria will never be found engulfed in a Neutrophil. |
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Describe the laboratory procedures for diagnosing Neisseria gonorrhoeae |
1. Culture: intracellular G- diplococci in smears of urethral pus
2. Fluorescent antibody test |
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Describe the treatments for Neisseria gonorrhoeae infections |
-Run antimicrobial susceptibility assay -Give antibiotics (Look up more information) |
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Neisseria gonorrhoeae infections are more common in men
True or False |
False (according to chart on slide 29) |
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Describe the events that lead to induction of disease by Neisseria |
I don't know |
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Name the 4 pathogenic spirochetes of interest and the diseases they cause |
1. Treponema pallidum - syphilis 2. Borrelia hermsii - relapsing fever 3. Borrelia burgdorferi - Lyme disease 4. Leptospira interrogans - infectious jaundice |
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Describe the general spirochete morphology |
-Gram negative -Motile -Viewed with Dark-field microscopy
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What morphological characteristic is unique to Leptospira (spirochete) |
Hooked ends |
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What are the axial filaments of a spirochete called? |
Periplasmic flagella |
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Name the three modes of contraction for Treponema pallidum |
1. 90% by sexual contact 2. contact with lesions 3. congenital |
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What results in a newborn from congenital contraction of Treponema pallidum? |
Still birth or serious birth defects |
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Describe the primary phase of Syphilis (Treponema pallidum) |
Single lesion on any cutaneous or mucous membrane -hard but painless chancre -appears 3 wks -disappears 4-12 wks -dark field microscopy |
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Describe the lesion that occurs in primary Syphilis |
-hard but painless chancre -appears 3 wks -disappears 4-12 wks |
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What is the only reliable test for a Treponema pallidum infection? |
Dark field microscopy (looking for fluorescent treponemal antibody) |
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Describe secondary Syphilis |
-6 weeks to months -more cutaneous and mucous membrane lesions -macular skin rash -infectious, live treponemes in lesions |
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Treponema Pallidum can be grown in enriched mediums, such as chocolate agar.
True or False |
False |
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Describe Latent Syphilis |
-up to two years infectious lesions still appear -after two years lesions diminish (noninfectious stage) |
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Describe Tertiary or Late Syphilis |
-Noninfectious -Gummas form (granulomas) -Saber shin -Neurosyphilis |
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Syphilis is more prominent in men than in women in the united states.
True or False |
True |
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In what stages of Syphilis can dark field microscopy be employed for diagnoses? |
Primary, secondary, latent.
(Late phase no longer produces antibodies) |
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Name the antibody that is tagged to diagnose Syphilis. |
Flourescent treponemal antibody (Treponema pallidum hemagglutination) |
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Describe the treatment regimen for primary and secondary syphilis |
-Benzathine penicillin -2.4 million units intramuscular single dose |
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Describe the treatment for late latent and tertiary syphilis |
-Benzathine penicillin -intramuscular doses of 2.4 million units totaling 7.2 million units -weekly intervals |
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What is the treatment for Neurosyphilis |
-Aqueous crystalline penicillin G 18-24 million units daily for 10-14 days |
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Describe the disease caused by Borrelia hermsii |
Cyclic fever -North America -tick vector -chills, fever, -3 to 4 days |
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Describe the disease caused by Borrelia Bugdorferi |
Lyme's Disease -Lyme, Connecticut -Deer Tick Stage 1 - Bull's eye rash, headache, fever, muscle aches Stage 2 -weeks to months later, arthritis, neurological complications (paraplegia)
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What is the technique for diagnosing Lyme Disease |
-stained blood smear -Enzyme-linked immunosorbent assay (ELISA) test -PCR |
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What two antibiotics are used for treating infections of Borrelia Bugdorferi |
tetracycline
chloramphenicol
(or Amoxicillin and Penicillin G according to different slide) |
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Name the bluish-red skin lesions of late untreated Lyme Disease |
Acrodermatitis chronica atrophicans |
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The immune system will usually eliminate Borriella bugdorferi from the system after many years
True or False |
False, needs antibiotics |
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What is the Leptospira organism that causes infectious jaundice? |
Leptospira interrogans |
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Describe host, transmission, and pathogenic effects of a Leptospira infection |
Host - animals, livestock
Transmission - urine/water contact with mucosal surface
Effect - jaundice, chills, headache, severe muscle pain
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How is a Leptospira infection diagnosed? |
microscopic agglutination test |
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What antibiotics may be prescribed for a Leptospira infection? |
penicillin
tetracyclin |
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Describe the morphology of the Streptococci |
-Gram + -chains of cocci -catalase negative (distinguish from staph) |
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Describe the three hemolytic classifications of Strep |
alpha - incomplete hemolysis beta - complete hemolysis gamma - no hemolysis |
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What is the basis of Lancefield Streptococcus grouping?
Give an example. |
Based on cell wall oligosaccharide antigens
Group A - Streptococcus pyogenes Group B - Streptococcus agalactiae |
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Describe the shape and distinguishing characteristics of Streptococcus pneumoniae |
-Gram + -Diplococcus -bile soluble -optochin sensitive -capsulated (virulence factor) -C polysaccharide |
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What is the virulence factor of Streptococcus pneumoniae? |
polysaccharide capsule |
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What is the significance of the C polysaccharide on Streptococcus pneumoniae? |
Increases C-reactive protein in the blood produced by the liver
Can be useful for diagnosis |
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What are the minor virulence factors of Streptococcus pneumoniae? |
-protein adhesins -pneumolysin -IgA protease -cell wall fragments -teichoic acid -phosphorylcholine
Major factor - capsule |
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What is the mechanism of harm to the body in a Pneumococcal disease? |
vigorous inflammation in response to virulence factors, especially the capsular polysaccharide |
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What potentially harmful organism resides in the normal flora of the URT of 5-60% of people? |
Streptococcus pneumoniae |
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What are the diseases and mode of transmission of Streptococcus pneumoniae? |
-pneumonia -meningitis -sepsis -otitis media -sinusitis
Transmission- close human to human contact |
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Name 6 predisposing factors for Streptococcus pneumoniae pathologies |
1. alcoholism 2. asplenia 3. sickle cell anemia 4. antecedent viral URI (influenza) 5. HIV |
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What is the preferred treatment for a Streptococcus pneumoniae infection? |
Penicillin, if susceptible |
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By what mechanism are Streptococcus pneumoniae becoming increasingly penicillin resistant? |
Altered penicillin-binding proteins
NOT increased prevalence of Beta-lactamase |
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What therapies are indicated for Meningitis from Penicillin Resistant Strep Pneumoniae (PRSP)? |
Vancomycin -100% susceptible 3rd gen cephalosporins -50 to 65% susceptible |
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What therapies are available to prevent Streptococcus pneumoniae infections? |
23-valent polysaccharide vaccine (Pneumovax) -targets capsule
Protein conjugate vaccines -better in children -covers less serotypes |
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Describe the laboratory diagnosis of Streptococcus pneumoniae infections |
-Gram stain -culture blood, CSF, sputum, sinus aspirate, tympanocentesis fluid -Urine antigen test |
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What is the hemolytic classification of Streptococcus pneumoniae? |
Alpha-hemolysis |
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What is the Quellung Reaction? |
Addition of a specific antibody to Strep pneumoniae culture
Illuminates the capsule |
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Streptococcus viridans includes what 4 subgroups? |
1. Strep mutans 2. Strep mitis 3. Strep salivarus 4. Strep anginosus |
