Chapter 18- Haemophilus, Bordetella, Brucella, Francisella Flashcards by Maryzen Sagrado

haemophilus sp that is the major human pathogen

Haemophilus influenzae

How well did you know this?

Not at all

Perfectly

H. influenza is normally found on

Mucous membranes of the upper respiratory tract

How well did you know this?

Not at all

Perfectly

typical morphology of H. influenzae

short, 1.5 um coccoid bacilli occurring in pairs or short chains

How well did you know this?

Not at all

Perfectly

at what hours that small coccobacillary forms of H.influenza predominate

6-8 hours

How well did you know this?

Not at all

Perfectly

At what hours that H.influenzae express a definite capsule?

6-18 hours

How well did you know this?

Not at all

Perfectly

How many hours of incubation does H.influenzae must have?

24 hours on chocolate agar

How well did you know this?

Not at all

Perfectly

Factor that physiologically acts as hemin

Factor X

How well did you know this?

Not at all

Perfectly

Factor that is replaced by NAD

Factor V

How well did you know this?

Not at all

Perfectly

Useful in species identification of Haemophilus as is the presence or absence of hemolysis

Carbohydrate fermentation

How well did you know this?

Not at all

Perfectly

H.influenza and H.parainfluenzae can be biotyped on the basis of?

Production of indole, ornithine decarboxylase and urease

How well did you know this?

Not at all

Perfectly

Capsular antigen of type b (H.influenzae)

PRP (polyribitol ribose phosphate)

How well did you know this?

Not at all

Perfectly

H. influenzae can be typed by

Slide agglutination
Coagglutination with Staphylococci
Agglutination of latex particles
Immunoflorescence

How well did you know this?

Not at all

Perfectly

Somatic antigens of H.influenza consists of

outer membrane proteins

How well did you know this?

Not at all

Perfectly

The major virulence factor of H.influenzae

Polyribose phosphate capsule of type B of H.influenza

How well did you know this?

Not at all

Perfectly

Common cause of bacterial meningitis in children aged 5 months to 5 years

H. influenzae type b

How well did you know this?

Not at all

Perfectly

Specimens used for diagnostic lab tests for H. influenzae

Sputum
Pus
Blood
Spinal Fluid

How well did you know this?

Not at all

Perfectly

Direct identification of H. Influenzae is through

NAATs using CSF

How well did you know this?

Not at all

Perfectly

Media that enhances the growth of H. influenzae

IsoVitalex-enriched chocolate agar

How well did you know this?

Not at all

Perfectly

A better test for X factor requirement is based on the?

Inability of H. influenzae to synthesize heme from g-aminolevulinic acid

How well did you know this?

Not at all

Perfectly

Haemophilus organisms that do not require C factor synthesizes

porphobilinogen
porphyrins
protoporphyrin IX
heme

How well did you know this?

Not at all

Perfectly

under ultraviolet light (-360 nm), it indicates the presence of porphyrins and a positive test result

presence of red fluorescence

How well did you know this?

Not at all

Perfectly

H. influenzae are susceptible to?

Ampicillin
3rd-generation cephalosporins
Carbapenems

How well did you know this?

Not at all

Perfectly

Give excellent results against H.influenzae

Cefotaxime

How well did you know this?

Not at all

Perfectly

Formerly called as Koch-Weeks bacillus and causes pinkeye in children

H. aegyptius

How well did you know this?

Not at all

Perfectly

Causative agent of brazilian purpuric fever

H.influenza biotype III

small gram-negative rods occurs in strands in the lesions

H.ducreyi

Haemophilus that requires X factor but not V factor

H.ducreyi

Best culture media for H.ducreyi

Chocolate agar with 1% IsoVitalex and 3 ug/mL vancomycin incubated in 10% CO2 at 33 C

Best identification test for H.ducreyi

NAATs

Recommended treatment for H.ducreyi

1 g of oral azithromycin

Other treatments for H.ducreyi

IM Ceftriaxone Oral ciprofloxacin Oral erythromycin

Haemophilus species that is the most markedly hemolytic organism of the group in vitro

H. haemolyticus

Causes whopping cough in humans

Bordertella pertussis

Bordetella species that causes bacteremia among immunosuppressed patients

Bordetella holmesii

Bordetella species that causes wound infections and otitis media

Bordetella trematum

Gram-negative encapsulated coccobacilli that resembles H.influenzae

Bordetella pertussis

Preferred culture for B.pertussis

Charcoal-containing medium with sheep’s blood cephalexin and amphotericin B (Regan-Lowe)

Primary isolation media for B.pertussis

Bordet-Gengou medium (potato-blood-glycerol agar) with 0.5 ug/mL Pen G

Required degrees and days of incubation for B.pertussis

35-37 C for 3-7 days

B.pertussis are identified using

Immunofluorescence staining

Positive enzymes for B.pertussis

Oxidase, Catalase Positive | Nitrate, Citrate and Urea Negative

Central regulator of virulence genes of B.pertussis

Bordetella operons (bvgA) (bvgS)

Bordetella operon that is a transcriptional activator of the virulence genes

bvgA

Mediates adhesion to ciliated epithelial cells and are essential for tracheal colonization

Filamentous hemagglutinin + Fimbrae

Bordetella toxin that promotes lymphocytosis

Pertussis toxin

B.pertussis toxin that inhibits phagocyte function

Adenylate cyclase toxin

Among all B.pertussis toxin, what toxin is not regulated by bvg?

Tracheal cytotoxin | Pertussis toxin, ACT, Dermonecrotic toxin (DCT) and hemolysis are regulated by bvg system

IP of B.pertussis

2 weeks

Stage of B.pertussis that is highly infected

Catarrhal stage

Stage where pertussis cough is explosive and there “whoop” inhalation

Paroxysmal stage

Stage of pertussis in 2-3 weeks where patients is susceptible to other respi diseases

Covalescent stage

Common cause prolonged 4-6 week cough in adults

B.pertussis

Specimens for diagnostic lab test for B.pertussis

Nasopharyngeal swab NP aspirates Cough droplets

reagent used for direct examination of B.pertussis in NP swabs

Direct fluorescent antibody test

0-2 weeks culture examination of B. Pertussisis through

Immunofluorescent staining | Slide agglutination w/ specific antiserum

0-4 weeks examination and is the most sensitive methods to diagnose pertussis

PCR and NAATs

Used for 2-8 weeks identification of IgA, IgG and IgM antibodies against B.pertussis is through

Enzyme immunoassays

Primary treatment for B.pertussis

Macrolide | Alternative: TMP

Administration of this drug during catarrhal stage eliminates B.pertussis

Erythromycin

Disease in humans cause Brucella that is characterized by acute bacteremic phase followed by a chronic stage

Brucellosis/Undulant fever/Malta fever

Gram-negative, aerobic, nonmotile,non-spore-forming,cocci to rods, 1-2 um in lengtj

Brucella

Culture of Brucella in media appears in how many days?

2-5 days

Fresh specimen from animal or human is best inoculated at

Trypticase-soy agar or blood culture media

Positive enzymes of Brucella

Catalase | Oxidase

Produced by many strains of Brucella that enables them to reduced nitrates to nitrites

Hydrogen sulfide

Antigenic structure of Brucella

A and M antigens

The main histological reaction in brucellosis

1. Proliferation of mononuclear cells 2. Exudation of fibrin 3. Coagulation necrosis 4. Fibrosis

Placenta and fetal membranes of cattle,sheep,swine and goats contain this agent which is a growth factor for brucellae

Erythritol

IP of Brucella

1-4 weeks

Specimens for diagnostic lab test for Brucella

Blood Serum Biopsy culture from lymph nodes, bone

Media used for Brucella culture

trypticase-soy medium with or without 5% sheep blood, brain heart infusion medium and chocolate agar

Specimens where from which brucellae are most often isolated

Bone marrow and blood

Enzymes that positive in Brucella

Catalase and oxidase positive

A positive ______ test result is a characteristic of Brucella species

Positive urease test result

Predominant antibody in acute phase of Brucellosis (peak @ 3 mos)

IgM

Predominant antibody in subacute phase of Brucellosis

IgA

Predominant antibody about 3 weeks after the onset acute Brucellosis

IgG

Tests for diagnosing Brucellosis

1. Agglutination test 2. Blocking antibody 3. Brucellacapt 4. ELISA

IgG agglutinin titers for active infection of Brucella

1:80 above

these are IgA antibodies that interfere with agglutination by IgG and IgM that appears during subacute stage of infection

Blocking antibodies

Rapid immunocapture agglutination method based on the Coombs test that detects NONAGGLUTINATING IgG and IgA antibodies.

Brucellacapt (Vircell, Granada and Spain)

Test that used cytoplasmic proteins as antigens

ELISA assays

Amino acid that predominates in Brucella cell wall

Lysine

Treatment for brucellosis

Tetracycline + streptomycin or gentamicin for 2 weeks or rifampin for 6-8 weeks

Brucellosis patients who has endocarditis or neurological disease, the treatment will be

Doxycylcine Rifampin Aminoglycoside

The most virulent type of Francisella Tularensis

Type A (Terrestrial)

Specimens for identification of F.tularensis

``` Blood Lymph node aspirates Bone marrow Peripheral blood Deep tissue Ulcer biopsies ```

Growth of F.tularensis in media must contain

Cysteine

Media for F.tularensis

Chocolate agar Modified Thayer-Martin agar Buffered charcoal yeast extract

Required incubation for F. tularensis

35-37 C for 2-5 days

Strain of F.tularensis that produce severe lethal illness in humans, ferments glycerol and contains citrulline ureidase

Jellison Type A

The usual antibody response consists of agglutinins developing _____ days after the onset of illness.

7- 10 days

Infection of F.tularensis is through

Penetration of the skin or mucous membranes | Inhalation of 50 organisms

In _____ days, an inflammatory infection from F.tularensis develops ulcerating papule

2-6 days

Potential agent of bioterrorism and is a Tier Agent 1 because it is very highly infectious

F. Tularensis

Titer for single-tubed agglutination for F. tularensis

> 1:60

Titer for microagglutination for F. tularensis

> 1:128

Treatment against Tularensis

Streptomycin or gentamicin for 10 days

Other potential agents for F. Tularensis

Tetracycline | Fluoroquinolones

F. Tularensis is resistant to all?

B-lactam antibiotics