Glossary of Micro: Haemohphilus, Bordatella, Pseudomonads
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- Haemophilus influenza
- 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
- What are diseases caused by NON encapsulated Haemophilus influenza?
- The unencapsulated form causes Otitis media, sinusitis, bronchitis
- Which serotype of Haemophilus influenza causes the invasive diseases?
- Serotype b (Hib)
*capsule b is BAD!
- What is the most common cause of bacterial otitis media?
- Streptococcus penuemoniae
- What contributes to the pathogenecity of Haemophilus influenza?
Capsules are antiphagocytic- 6 antigenic types; type b makes up 95% of invasive diseases
endotoxin- not prominent feature
- What lab tequniques would you use to isolate/identify Haemophilus influenza?
- 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
- What type of medium is needed to culture Haemophilus influenza?
- grows on Chocolate (or any similar) enriched with hemin (X factor) and NAD (V factor)
CO2 incubation is required from some strains
- What two factors are required for growth of Haemophilus influenza on blood agar?
- NAD (V factor)
hemin (X factor)
- Can you acquire immunity to Haemophilus influenza? if so, how?
- 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
- Is there a vaccine for Haemophilus influenza?
- 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
- How do you treat Haemophilus influenza?
treated w/ cephalosporin or chloramphenicol (some strains have acquired ampicillin resistance by plasmids)
rifampin is used for prophylactic treatment
- Haemophilus parainfluenza?
- this org is commonc in upper respiratory tract and must be differentiated from H. influenza
- Haemophilus ducreyi: what disease does it cause?
- Causes chancroid or soft chancre that are PAINFUL*
supporative ulcers, buboes- secondary lesions assoc. w/ kissing
*unlike syphilis lesions which are hard and painful
- How is Haemophilus ducreyi diagnosed?
- 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
- What STD may be confused with Haemophilus ducreyi?
- What bacteria causes whooping cough?
- Bordetella pertussis
- What are the clinical characteristics of whooping cough?
- 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
- What are the pathogenic mechanisms of Bordetella pertussis?
- 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
- How is Bordetella pertussis spread?
- spread by droplet nuclei, highly infectious
- Describe the Pertussis Toxin?
- an A + B (Bind and Action)
ADP ribosylates reg proteins for cytoplasmic adenylate cyclase
* see notes about genetic variation of virulence genes
- What type of media is used to grow Bordatella?
- 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
- How is Bordetella diagnosed?
- direct flourescent Abs
identification based on slide agglutination test or flourescent Ab test
- Is there a vaccine for Whooping Cough?
- DTP vaccine - diptheria and tetanus toxoids with whole cell pertussis
DTaP - diptheria and tetanus toxoids with acellular pertussis components
- How is whoping cough treated?
AB treatment is of little vaule during thw whooping stage
erythromycin is used for preventative prophylaxis
- What diseases does Pseudomonas aeruginosa cause in healthy people?
- swimmers ear
skin infection from whirlpools
eye infections from contaminated contact lens solution
contribute to peritonitis
- What diseases does P. aeruginosa cause in immunocomprimised?
- cystic fibrosis - pneumonia
burn patients - septicemia
leukemic pts - septicemia
diabetics - otitis externa and gangrene
- How is P. aeruginosa tranmitted?
- only environment acquired, no person to person spread
org found in soil water, vegetation, and in humans
- What makes P. aeruginosa virulent?
- pili and polysacchride slime (alginate) for adherence
Toxin A - identical mode to diptheria toxin
Exotixin S - protease
Phospholipase - destroys cell membranes
- Is there a vaccine for P. aeruginosa?
- there is an experimental vaccine
immunity is poorly identified
- How do you grow/ identify P. aeruginosa?
- 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
- How is P. aeruginosa treated?
- by not getting it in the first place
very resistant to the normal antibiotics due to outer membrane porins
- Burkholderia cepacia
- formally cassified as a Psuedomonads
causes a lung infection in children with CF
very resistant to antibiotics
- Burkholderia pseudomallei
- formally cassified as a Psuedomonad
found in the tropics
causes pnuemonia, septicemia in soldiers during Vietnam
causes a disease called melioidosis
- Stenotrophomonas maltophilia
- formally cassified as a Psuedomonad
cause of nosocomial infections of wounds, UTs, respiratory tract, cystic fibrosis patients and neurotropenic (low neutrophils) patients
- 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
- What are the leading causes of bacterial pneumonia in patients with AIDS?
- #1 Streptococcus pneumoniae
#2 Haemophilus influenzae
#3 Pseudomonas aeruginosa
#4 Staph aureus
- What are two life threatening diseases caused by H. influenzae?
- What environmental bacterium is the cause of most oppurtunistic infections?
- P. aeruginosa
- Bacterial infections are the most frequent complication of hemodialysis patients. What are some of the bacteria that cause these infections?
- P. aeruginosa
- T/F most H. influenzae infections are caused by nonencapsulated thus nontypeable strains?
- TRUE - earaches
incidence of disease cause by the un encapsulated strain is decreased dramatically since the advent of the vaccine
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