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40 Cards in this Set
- Front
- Back
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Haemophilus influenza
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blood loveing upper respiratory tract organism
causes invasive diseases preceede by URT infections w/ vague mild symptoms that progress to meningitis, pneumonia, septic arthritis, osteomyelitis, sepsis, pericarditis or epiglotitis |
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What are diseases caused by NON encapsulated Haemophilus influenza?
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The unencapsulated form causes Otitis media, sinusitis, bronchitis
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Which serotype of Haemophilus influenza causes the invasive diseases?
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Serotype b (Hib)
*capsule b is BAD! |
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What is the most common cause of bacterial otitis media?
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Streptococcus penuemoniae
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What contributes to the pathogenecity of Haemophilus influenza?
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pili
IgA protease Capsules are antiphagocytic- 6 antigenic types; type b makes up 95% of invasive diseases endotoxin- not prominent feature |
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What lab tequniques would you use to isolate/identify Haemophilus influenza?
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Gram stain of CSF
Slide agglutinations tests of CSF to detect polyribitol phosphate capsule (PRP) X-V factor tests Antibiotic susceptibility to determine best chemotherapy |
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What type of medium is needed to culture Haemophilus influenza?
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grows on Chocolate (or any similar) enriched with hemin (X factor) and NAD (V factor)
CO2 incubation is required from some strains |
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What two factors are required for growth of Haemophilus influenza on blood agar?
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NAD (V factor)
hemin (X factor) |
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Can you acquire immunity to Haemophilus influenza? if so, how?
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YES Infante get passive protection from their moms
acquired immunity includes opsonic Ab and bacteriocidal Ab adults have acquired immunity, but there is increased susceptibility in geriatric patients |
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Is there a vaccine for Haemophilus influenza?
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vaccine is primarily polyribosylribitol phosphate (PRP) capsule of Hib covalently linked to T cell independent protien
there are other protein carriers vaccines( see notes) side benefits of immunizations- it reduces passive carraige of Hib |
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How do you treat Haemophilus influenza?
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Immunize!
treated w/ cephalosporin or chloramphenicol (some strains have acquired ampicillin resistance by plasmids) rifampin is used for prophylactic treatment |
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Haemophilus parainfluenza?
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this org is commonc in upper respiratory tract and must be differentiated from H. influenza
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Haemophilus ducreyi: what disease does it cause?
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Causes chancroid or soft chancre that are PAINFUL*
supporative ulcers, buboes- secondary lesions assoc. w/ kissing *unlike syphilis lesions which are hard and painful |
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How is Haemophilus ducreyi diagnosed?
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diagnosis is made on clinical picture, elimination of other sexually transmitted diseases
Gram stain of lesion and aspirates of buboes culture growth is poor, may grow on chocolate |
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What STD may be confused with Haemophilus ducreyi?
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syphilis
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What bacteria causes whooping cough?
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Bordetella pertussis
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What are the clinical characteristics of whooping cough?
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this disease starts as a cold with inflammation of mucus membranes
it is followed by a persistant coughing state coughs are sudden and severe w/ an inspiratory whoop as child tries to get air from a narrowed glottis |
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What are the pathogenic mechanisms of Bordetella pertussis?
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non invasive infection of bronchial epithelium
filamentous hemagglutinin aids in attachtment tracheal cytotoxin causes epithelial injury pertussis toxin (lymphocyte promoting factor, promotes lymphocytosis and enhances attachment |
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How is Bordetella pertussis spread?
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spread by droplet nuclei, highly infectious
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Describe the Pertussis Toxin?
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an A + B (Bind and Action)
ADP ribosylates reg proteins for cytoplasmic adenylate cyclase * see notes about genetic variation of virulence genes |
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What type of media is used to grow Bordatella?
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Culture of nasopharynx is most successful
Bordet- Gengou media w/ 10-15% blood in a potatoe starch base 10% charcoal base media use a low conc of cephalosporin or other antiB to inhibit growth of normal throat flora |
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How is Bordetella diagnosed?
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direct flourescent Abs
PCR identification based on slide agglutination test or flourescent Ab test |
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Is there a vaccine for Whooping Cough?
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DTP vaccine - diptheria and tetanus toxoids with whole cell pertussis
DTaP - diptheria and tetanus toxoids with acellular pertussis components |
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How is whoping cough treated?
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Immunize!
AB treatment is of little vaule during thw whooping stage erythromycin is used for preventative prophylaxis |
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What diseases does Pseudomonas aeruginosa cause in healthy people?
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swimmers ear
skin infection from whirlpools eye infections from contaminated contact lens solution UTIs contribute to peritonitis |
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What diseases does P. aeruginosa cause in immunocomprimised?
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cystic fibrosis - pneumonia
burn patients - septicemia leukemic pts - septicemia diabetics - otitis externa and gangrene |
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How is P. aeruginosa tranmitted?
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only environment acquired, no person to person spread
org found in soil water, vegetation, and in humans |
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What makes P. aeruginosa virulent?
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pili and polysacchride slime (alginate) for adherence
Toxin A - identical mode to diptheria toxin Exotixin S - protease Phospholipase - destroys cell membranes |
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Is there a vaccine for P. aeruginosa?
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there is an experimental vaccine
immunity is poorly identified |
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How do you grow/ identify P. aeruginosa?
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isolated from blood, pus, fluids
grows aerobicallly on any routine media (blood or MacConkey) produces a greenwater souble pigment and a fruity odor pyocin and serotypin schemes not usually done * in CF pts isolates appear in mucoid colonies due to presence o polysacchride, alginate, capsule |
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How is P. aeruginosa treated?
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by not getting it in the first place
very resistant to the normal antibiotics due to outer membrane porins |
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Burkholderia cepacia
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formally cassified as a Psuedomonads
causes a lung infection in children with CF very resistant to antibiotics |
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Burkholderia pseudomallei
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formally cassified as a Psuedomonad
found in the tropics causes pnuemonia, septicemia in soldiers during Vietnam causes a disease called melioidosis |
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Stenotrophomonas maltophilia
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formally cassified as a Psuedomonad
cause of nosocomial infections of wounds, UTs, respiratory tract, cystic fibrosis patients and neurotropenic (low neutrophils) patients |
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Acinetobacter
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short gram negative bacilli
some strains may be confused with Neisseria in cases of urethritis ubiquitis in nature causes pneumonia, wound infections, septicemia, nosocomial infections |
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What are the leading causes of bacterial pneumonia in patients with AIDS?
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#1 Streptococcus pneumoniae
#2 Haemophilus influenzae #3 Pseudomonas aeruginosa #4 Staph aureus |
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What are two life threatening diseases caused by H. influenzae?
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epiglottitis
meningitis |
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What environmental bacterium is the cause of most oppurtunistic infections?
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P. aeruginosa
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Bacterial infections are the most frequent complication of hemodialysis patients. What are some of the bacteria that cause these infections?
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P. aeruginosa
Stenotrophomonas maltophilia Acinetobacter species |
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T/F most H. influenzae infections are caused by nonencapsulated thus nontypeable strains?
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TRUE - earaches
incidence of disease cause by the un encapsulated strain is decreased dramatically since the advent of the vaccine |
