13. GNR's Non-Enterics

What are the 3 bioterrorism agents? (Group I)

Brucella, Francisella tularensis, Yersinia pestis

What does brucella cause and what is the infection referred to as (common name)?

brucellosis

Undulant fever, Mediterranean fever, Malta fever, Milk fever

What are the four groups of brucella & it’s mean of transmission?

melitensis (goat/sheep), abortus (cattle), canis, suis

transmission by contact through cuts, mucus membrane, contaminated food, or inhalation

How long do brucella blood cultures need to be kept? What 4 tests is it positive for?

4 weeks since they’re slow growers

oxidase, nitrate, urease, and catalase

What does fracisella tularensis cause and what are the 3 means of transmission?

tularemia (tick fever, deerfly fever, rabbit fever)

contaminated air, water, or soil

handling dead animals

bite from infected insects

Why is francisella tularensis considered a bioterrorism agent?

because it is a facultative intracellular pathogen

What does francisella need to grow? Why does it not grow on most media? What medias can it grow on?

cysteine

because it’s a strict aerobe & poor grower

Thayer-Martin and BCYE

What biochemical tests is francisella positive and negative for?

catalase positive

oxidase and urease negative

At what temperature does yersinia pestis grow best at?

25-30 C instead of 37

What are the 3 species that are glucose fermenters, MAC positive growers, and oxidase positive? (Group II)

aeromonas hydrophila, pleisiomonas shigelloides, vibrio spp.

What are the 2 clinical symptoms caused by Aeromonas?

gastroenteritis: include HUS & severe kidney disease associated w/ alt & ast genes

extraintestinal disease: wound infections, septicemia

What unique media can Aeromonas grow on? Is it salt tolerable?

CIN (cefsulodin-irgasan-novobiocin)

No

What are the clinical symptoms caused by Pleisiomonas?

same as Aeromonas (gastroenteritis & extraintestinal disease)

What are the 3 biochemical tests that pleisiomonas is positive for? Is it salt tolerable?

decarboxlyation of lysine, ornithine, and arginine

no

What are the four clinically important species of Vibrio?

cholerae (serogroups O1, O139, non-O1), fluvialis, parahaemolyticus, vulnificus

What are the clinical symptoms of each Vibrio species? What is the fatalies % of each if left untreated?

cholerae: cholera 50%

fluviales: gastroenteritis

parahaemolyticus: gastroenteritis (50-70% cases in japan) <1%

vulnificus: wound infections & primary septicemia ~50% in septicemia

What color on TCBS does each Vibrio species exhibit?

cholerae & fluviales: yellow

parahemolyticus: 99% green

vulnificus: 90% green 10% yellow

Which species of Vibrio are halophilic & which can grow without salt?

w/out salt: cholerae & mimicus

halophilic: fluviales, parahaemolyticus, vulnificus

What unique identification test is V. Cholerae positive for?

String test, like cheese pull on pizza

What are the 3 species that are non-fermenters that primarily are from the environment? (Group III)

pseudomonas, acinetobacter, burkholderia

What is the colony morphology, natural habitat, & epidemiology of P. aeruginosa?

weak beta hemolytic, serrated edge with a metallic sheen

moist environments

nosocomial, water-associated infections, & cystic fibrosis

What are the 2 common sites of infection related to p. aeruginosa?

otitis externa (“swimmer’s ear”) & eyes (from contact lens solution)

What are the oxidase, TSI, and diffusible pigments produced by P. aeruginosa non-mucoid isolates? What media can it grow on?

oxidase positive, TSI K/K

pyoverdin, pyocyanin, pyorubin, and/or pyomelanin

cetrimide agar

What are respiratory isolates of mucoid pseudomonas associated with?

cystic fibrosis

When must AST be performed for suspected P. aeruginosa, how often should testing be done, and what is used to perform AST?

must be performed when clinically indicated b/c susceptibility is NOT predictable

repeat testing done every 3-4 days

Kirby-Bauer method of disk diffusion on mucoid isolates

What fluorescent pigment does P. fluorescens & putida produce? And how are they distinguished from P. aeruginosa?

pyoverdin

inability to grow at 42 C

What is the colony morphology, natural habitat, & epidemiology of Acinetobacter?

non-hemolytic, smooth, opaque gray-white

dry & moist environments, indigenous flora of human skin, oral, upper resp, and lower GI tracts

opportunistic pathogen → nosocomial infections

What is the most common species of acinetobacter & what is unique about it?

baumannii

It is multi-drug resistant & has been associated w/ war wounds

What are the oxidase & catalase results for acinetobacter. Can it grow on MAC? What can it do/not do with glucose and lactose?

oxidase negative catalase positive

It can grow on MAC → colorless or slightly pink colonies

cannot ferment, but can oxidize glucose & lactose

What are the 2 common pathogen species of Burkholderia?

cepacia & pseudomallei

What is the natural habitat, mode of transmission, & epidemiology of Burkholderia?

water, soil, vegetation

through aerosols or cuts in contact w/ contaminated soil, water, or vegetaton

nosocomial UTI &/or septicemia. fatal pneumonia in CF patients

What is the colony morphology & oxidase test result for B. cepacia?

smooth & raised on selective BCSA. Dark pink to red on MAC after 4-7 days due to lactose oxidation

weak oxidase positive

What is the unique symptom associated with Burkholderia pseudomallei?

meliodosis (most prevalent in SE Asia & N. Australia)

What is the oxidase result & microscopic morphology of B. pseudomallei? What can it potentially be?

positive

GNR with bipolar staining

potentially a bioterror agent

What are the 2 species of bartonella & the disease associated with them?

quintana: trench fever & bacillary angiomatosis

henselae: cat scratch disease & bacillary angiomatosis

What are the symptoms & diagnosis of cat scratch disease?

symptoms: lesion @ inoculation site & lymphadenitis

diagnosis: depends on history of animal contact & positive skin test

How is bartonella isolated? What 3 biochem tests is it negative for?

5-10% CO₂ on chocolate agar

oxidase, urease, and catalase

What is the most common isolate of pasteurella, how is it spread, and what symptoms are exhibited?

multocida

cat or dog bites/scratches, and licking of skin lesions

wound infections, abcesses, septicemia, arthritis, peritonitis

What are the microscopic & colony morphology of pasteurella?

microscopic: pleomorphic, bipolar staining under Wright or Giemsa stains

colony: non-hemolytic, convex shiny on BAP

How is pasteurella isolated? What 4 biochem tests is it positive for? What selective media is used to test AST?

5-7% CO₂ on BAP. Does not grow on MAC

oxidase, catalase, indole, and nitrate

vancomycin, clindamycin, and amikacin

What disease is campylobacter known to cause?

gastroenteritis (most common bacterial cause of diarrhea in US)

What are the 3 species of campylobacter, and are there intestinal or extraintestinal?

intestinal: c. jejuni, c. coli

extraintestinal: C. fetus

How is campylobacter transmitted to humans? (3)

contaminated poultry, milk, and water

What are the 3 medias used to isolate campylobacter? What environment are they cultured at?

Skirrow’s agar (lysed horse blood, antibiotics, enriched media)

Campy blood agar (brucella agar base w/ blood + 5 antibiotics)

CVA agar (cefoperazone, vancomycin, amphotericin)

42 C microaerophilic environment 3 days

What is unique about the microscopic morphology of campylobacter? What is used to counterstain instead of safarin?

GNR (curved, spiral, gull-wings, s shaped) with darting motility

Kinyoun’s carbol fuchsin

Is campylobacter oxidase positive? What is used to treat it?

yes

fluoroquinolones

What are the 3 diseases observed with helicobacter pylori?

chronic active gastritis, peptic ulcer disease, gastric cancer

Describe the urease production in helicobacter pylori and how it affects the body.

Urea → ammonia + CO2 + water

Increase in pH in gastric mucosa

resists stomach acidity → one of the 3 diseases

What are the steps to culturing bordatella pertussis? (4)

1. culture most sensitive during first 2 weeks of paroxysmal coughing

2. collect specimen w/ nasopharyngeal swab

3. inoculate media at bedside

4. use selective media Bordet Gengou & Regan-Lowe

How long does B. pertussis need to grow on culture? What do the colonies look like on charcoal medium (Regan-Lowe)?

3-4 days

white-gray resembling mercury droplets

What is the difference between B. pertussis & B. bronchiseptica?

Bronchiseptica is rapidly urease positive & grows on MAC

What is the drug of choice for treating Bordatella?

Erythromycin

What are the 2 diseases caused by legionella pneumophila?

Legionnaire’s disease: pneumoniae, potentially severe & disseminate to other organs

Pontiac fever: flu-like syndrome, milder than legionnaire’s

What culture is used to grow legionella?

buffered charcoal yeast extract agar (BCYE)

Which Haemophilus requires X,V, or both X & V?

influenzae: X & V

parainfluenzae: V minimum

ducreyi: X minimum

What are the 5 species under HACEK group and what does it cause?

Haemophilus Aggregatibacter

Actinobacillus Aggregatibacter

Cardiobacterium hominis

Eikenella corrodens

Kingella

endocarditis

Where is the HACEK group normally found? What do they need for growth? When may they become opportunistic pathogens?

normal flora of oral cavity

5-10% CO₂

during dental procedures