Term
| General characteristics of Haemophilus spp |
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Definition
Gram negative pleomorphic bacillus.
Normal flora of respiratory tract in humans and animals.
Non-motile
Require Co2
Must be kept moist |
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Term
| Colonies of Haemophilus spp |
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Definition
Very small and very clear (look like dew)
Often satellite around STA |
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Term
| How are Haemophilus spp identified? |
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Definition
| Based on requirements for X and V factor. Indole urease and ornithine can be used to subdivide H. influenzae and H. parainfluenzae into biotypes |
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Term
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Definition
Heme
Heat stable
Used in biosynthesis of respiratory cytochromes. Present in BAP and CHOC |
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Term
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Definition
NAD (satelliting factor)
Heat labile
Involved in oxidation-reduction process
Available in CHOC |
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Term
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Definition
| Used for the identification of Haemophilus spp. Contains 4 quadrants. Each with a different combination of X and V factors. |
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Term
| Satellite growth around the feeder organism inicates the need for what factor? |
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Definition
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Term
| How to perform X and V factor studies |
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Definition
| Prepare a McFarland suspension of the organism and make a lawn of the organism on a Mueller-Hinton plate (no Heme, no NAD) Supply the factors via discs X, V and X&V. |
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Term
| X and V factor studies interpretation |
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Definition
Growth around both X and X&V the organism needs X factor
Growth around V and X&V the organism needs V factor
Growth around only X&V the organism needs both factors. |
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Term
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Definition
| If an organism is satelliting on the BAP STAX, we know it needs V (NAD) and we then need to determine if it needs X (heme) in order to ID it. Test for the ability of the organism to synthesize heme from precursors (which means it wouldn't require heme in the media) |
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Term
| How do you perform the ALA test |
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Definition
ALA substrate in solution
Add organism and incubate at 35 degrees Celsius for 4 hours
Expose the tube to UV light. Red fluorescence indicates a positive test which means the organism has made porphyrins and therefore is INDEPENDENT of the X factor. Alternatively, add Kovac's reagent, shake and look for color in the lower phase. |
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Term
| Most Haemophilus infections including osteomyelitis, cellulitis, pericarditis and pneumonia are caused by what? Also most pediatric diseases are caused by this organism. |
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Definition
| Haemophilus influenzae type B (HIB) |
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Term
| Infections by non-influenzae Hemophilus species include |
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Definition
Bacteremia/septicemia/endocarditis
Brain abscess, sinutis, empyema
Brazilian purpuric fever (BPF) |
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Term
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Definition
| Sexually transmitted disease (chancroid) |
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Term
| Haemophilus influenzae biogroup aegypticus |
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Definition
| Causes a severe conjunctivitis in tropical countries |
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Term
| Haemophilus haemoglobinophilus |
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Definition
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Term
| Haemophilus parahemolyticus |
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Definition
| Found in human dental plaque |
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Term
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Definition
| Doesn't require X or V factor. It can be upper respiratory flora |
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Term
| Haemophilus parainfluenzae |
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Definition
| Can be URF, can cause endocarditis, bacteremia |
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Term
| Haemophilus parapphrophilus |
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Definition
| Can be URF, can cause endocarditis, bactermia. |
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Term
| Most strains of Haemophilus are susceptible to what? |
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Definition
| Penicillin, chloro, sulfonamides and tetracyclines |
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Term
| Haemophilus ampicillin resistance |
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Definition
| Resistance is conveyed by a plasmid mediated Beta-lactamase. Testing for resistance is demonstrated by tests including the acidometic method or the chromogenic test |
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Term
| Haemophilus ducreyi specimen collection |
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Definition
Clean ulcer with sterile gauze and saline
Collect exudate on a pre-moistened swab or in sterile syringe
Swab is then placed in transport media
Transport to laboratory within 1 hour of collection
Specimen should be processed ASAP |
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Term
| Gram stain of Haemophilus ducreyi will show |
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Definition
| School of fish clumping of organisms occurs when organism is grown in broth culture. |
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Term
| Media for Haemophilus ducreyi must contain what? |
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Definition
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Term
| Characteristics of Haemophilus ducreyi |
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Definition
Adherent colonies
Gram neg bacilli
Oxidase Pos
Catalse Neg
SPS (sodium polyanephol sulfate) disc susceptible |
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