WEEK 15: HAEMOPHILUS AND OTHER FASTIDIOUS Flashcards by ZACHARIE JAEDIEL GONZAGA

i. Nonmotile and facultative anaerobic
ii. Ferment Carbohydrates (Except for H. ducreyi)
iii. Oxidase and Catalase Positive
iv. Reduce Nitrates to nitrite
vi. Obligate parasites
vii. Requires growth factors
▪ Hemin/hematin (X Factor)
▪ Nicotinamide adenine dinucleotide (NAD or V Factor)

Haemophilus

How well did you know this?

Not at all

Perfectly

What are the required growth factors for Haemophilus?

▪ Hemin/hematin (X Factor)
▪ Nicotinamide adenine dinucleotide (NAD or V Factor)

How well did you know this?

Not at all

Perfectly

It is also called Pfeiffer’s bacillus.

Haemophilus influenzae

How well did you know this?

Not at all

Perfectly

Lacks adherent capability; associated with systemic and invasive infections

Encapsulated

How well did you know this?

Not at all

Perfectly

Associated with localized infections or may be carried asymptomatically (nasopharynx).

Non encapsulated

How well did you know this?

Not at all

Perfectly

“Koch-Weeks bacillus”
Purulent conjunctivitis “pink eye”

Haemophilus aegyptius

How well did you know this?

Not at all

Perfectly

What is the organism that causes chancroid (genital diseases)?

Haemophilus ducreyi

How well did you know this?

Not at all

Perfectly

▪ Small, flat, smooth, transparent to opaque
▪ Colonies can be pushed intact
▪ Clumpy in saline

H. ducreyi

How well did you know this?

Not at all

Perfectly

BPF (Brazilian Purpuric fever)- skin lesion, sepsis, fever

H. influenzae Biogroup aegyptius

How well did you know this?

Not at all

Perfectly

▪ 5% to 10% CO2 at 35°C to 37°C
▪ 24 to 72 hours

Most Haemophilus spp.

How well did you know this?

Not at all

Perfectly

▪ 5% to 10% CO2 at 33°C with high humidity
▪ Up to 7 days

Haemophilus ducreyi

How well did you know this?

Not at all

Perfectly

coccobacilli that appear as “school of fish”, “railroad tracks” or “finger prints” from genital lesions.

H. ducreyi

How well did you know this?

Not at all

Perfectly

Small. Gram (-) coccobacilli
to long filaments. May be
encapsulated

Haemophilus

How well did you know this?

Not at all

Perfectly

▪ Translucent, smooth and convex
▪ “Mousy” or bleach like odor in CHOC agar
▪ Encapsulated strains are larger and mucoid

H. influenzae

How well did you know this?

Not at all

Perfectly

Satellite phenomenon

Staphylococcus Streak

How well did you know this?

Not at all

Perfectly

Antisera is reacted with the antigens in the capsule making the capsule more prominent

Neufeld Reaction

How well did you know this?

Not at all

Perfectly

Quadrant I

Hemin (X)

How well did you know this?

Not at all

Perfectly

Quadrant II

Isovitale (V)

How well did you know this?

Not at all

Perfectly

Quadrant III

Hemin(X) and Isovitale (V)

Quadrant IV

Horse blood (X) / NAD (V

Porphobilinogen is detected using?

Kovac’s rgt

i. Dysgonic (slower or poorer
growing)
ii. Associated to subacute bacterial endocarditis
iii. Normal biota of the oral cavity
iv. Fail to grow in MacConkey
v. Glucose fermenter
(Require serum to the
fermentative media)
vi. Opportunistic bacteria

Fastidious Gram Negative Bacilli

i. “foam loving” or needing high conc.of CO2
ii. Found in dental and gingival scrapings
iii. With V factor dependent and independent strains
iv. Gram Stain: Small Gram (-) coccobacilli
v. Colony Characteristics: Convex, granular and yellow with an opaque zone near the center

Aggregatibacter aphrophilus

Infections
▪ Periodontitis; Local infection to fulminant infection (septicemia) esp. in neutropenic patients
Laboratory Diagnosis
i. Microscopy
▪ Thin and fusiform, spindle-shaped, coccoid and curved filaments

ii. Culture Characteristics
▪ Haze (gliding motility) on solid surface
▪ opaque, shiny; pale beige or yellowish
▪ Resemble HACEK in CO2 requirement
▪ May produce yellow pigment; can resemble colonies of E.corrodens

Capnocytophaga

1. Infections ▪ Systemic, pneumonic and cutaneous infection from animal (often cats) bites (zoonosis) 2. Laboratory Diagnosis i. Microscopy ▪ Coccobacilli (ovoid, filamentous or bacilli); Bipolar staining ii. Culture Characteristics ▪ Grayish, non hemolytic, mucoid with narrow green to brown halo around the colony

Pasteurella multocida

HACEK Group

1. Aggregatibacter (formerly Haemophilus) aphrophilus 2. Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans 3. Cardiobacterium hominis 4. Eikenella corrodens 5. Kingella spp.

i. Virulence Factor ▪ Collagenase and Leukotoxin ii. Disease ▪ Destructive periodontitis ▪ Subacute bacterial endocarditis iii. Other Characteristics ▪ Glucose fermenter (dysgonic); lactose & sucrose non-fermenter ▪ Catalase (+); Urease (-) w/c differentiates it from genus Actinobacillus

Aggregatibacter actinomycetemcomitans

i. Disease ▪ Oral Infections ▪ Subacute bacterial endocarditis ii. Characteristics ▪ Fermenter (dysgonic); pits agar ▪ Pleomorphic gram (-) rod that tend to form rosettes or long filaments Teardrop or arrowhead appearance

Cardiobacterium hominisv

a. Microscopic characteristics ▪ Short bacilli in pairs /chains ▪ Bipolar staining “Morse Code” appearance. b. Colonial appearance ▪ Pinpoint (24 hr ). With star shape with 4 to 6 point” in the center of the colony (48 hrs).

Aggregatibacter actinomycetemcomitans

i. Disease ▪ Infections from human bites or fights (clenched fist wounds) ▪ Cellulitis-needle use by drug addicts ▪ Oral Infections and Subacute bacterial endocarditis ii. Characteristics ▪ Non Fermenter; Pit agar; Chlorine bleachlike odor ▪ Non-motile, oxidase positive, asaccharolytic, catalase negative; yellow pigment

Eikenella corrodens

1. Infections- zoonosis (ingestion, inhalation, arthropod bite), highly infectious ▪ Tularemia (ulceroglandular, pneumonic, etc)- rabbit fever, water rat trappers disease 2. Laboratory Diagnosis i. Microscopy ▪ Small, non-motile, coccobacili or bacilli ii. Culture and Other Characteristics ▪ Strictly aerobic; require cysteine, cystine or thiosulfate (SBA, BCYE agar, CHOC) ▪ Gray-white, smooth, raised colonies ▪ Biosafety Practice Level 3

Francisella tularensis

i. Disease-major gram(-) bacteria in bone infections in children below 3y.o ▪ Oral, blood, bone Infections ▪ Subacute bacterial endocarditis ii. Characteristics ▪ Short bacilli to coccobacilli with squared ends in pairs/in chains ▪ Fermenter (dysgonic); pits agar ▪ Nonhemolytic (K. denitrificans) or β-hemolytic (K.kingae)

Kingella spp

interferes to signal transduction

Pertussis toxin

▪ Aquatic sources (lakes, rivers, hot springs and mud) ▪ Man made distribution systems ▪ Humidifiers and respiratory therapy equipment

Legionella pneumophila

a. Enter, survive and multiply within macrophages b. Survive and multiply within free-living protozoa c. Multiply at 20°C to 43°C and survive at 40°C to 60°C d. Capacity to adhere and persist in piped water systems

Legionella pneumophila

fever w/ pneumonia

Legionnaire’s disease

▪ Tiny gram-negative coccobacilli ▪ Smooth, glistening and silver, resembling mercury droplets

Bordetella pertussis and B. parapertussis

fever w/o pneumonia

Pontiac Fever

a. Isolation Methods ▪ Requires Iron and L-cysteine ▪ Chocolate agar and BCYE ▪ Ground-glass appearance b. Colony Morphology ▪ Grayish-white or blue green, convex, and glistening measuring 2-4 mm in diameter ▪ Characteristic "ground-glass" colony

Legionella pneumophila

facilitate attachment to ciliated epithelial cells

FHA and Pertactin

inhibits host epithelial and immune effector cells

Adenylate cyclase toxin

▪ Bordet-Gengou potato infusion agar, Regan-Lowe, and Charcoal-horse blood ▪ Incubate at moist chamber at 35°C for ≥7 days

Bordetella pertussis and B. parapertussis

causes ciliostasis and DNA synthesis

Tracheal cytotoxin

- a-hemolytic with fruity odor similar to apples and strawberries on BAP - grows well on Mac and motile - grow on 6.5% NaCl broth - oxidase and catalase positive

Alcaligenes faecalis

- colonize distal urethra and may cause serious and active infection - cannot grow on Mac

Oligella

- water, dairy, and other environmental sources - motile, saccharolytic and strong H2S producer - isolated from humans with ocular infections, otitis media and septicemia - colonies appear mucoid and greenish - oxidase and ornithine decarboxylase positive

Shewanella putrefaciens

- angular catarrhalis - small colonies and pits the agar - no growth on Mac - catalase, oxidase and nitrate reduction positive

Moraxella lacunata