Glucose Non-Fermenting Gram-Negative Bacilli (Exam 2)

What are some general characteristics of glucose non-fermenting GN bacilli?

- Non spore-forming

- Ubiquitous

- Rarely normal flora

- Opportunistic

What are some common conditions that put a patient at risk for colonization by a glucose non-fermenting GN bacillus?

- Immunosuppression

- Foreign body (ex. implants)

- Trauma

What diseases are caused by Burkholderia pseudomallei?

- Melioidosis

- Pneumonia

- Bacteremia

What diseases are caused by Burkholderia cepacia?

- Bacteremia

- Pneumonia

- Septic arthritis

- Peritonitis

What diseases are caused by Stenotrophomonas maltophilia?

- Skin and skin structure infections

- Bacteremia

- Pneumonia

- UTIs

- CNS infection

- Endocarditis

- Mastoiditis

- Epididymitis

- Cholangitis

- Bursitis

- Peritonitis

What diseases are caused by Pseudomonas aeruginosa?

- UTIs

- Bacteremia

- Pneumonia (especially in CF patients)

- CNS infections

- Ocular infections

- Skin infections

Pseudomonas are ______ with one or several polar flagella.

motile

Pseudomonas can be _______ or _______.

fluorescent, non-fluorescent

Pseudomonas aeruginosa gram stain

Pseudomonas aeruginosa colonies are ______ in color, large, and most are ______ hemolytic.

green, beta

Pseudomonas aeruginosa is acetamide, oxidase, and arginine ______.

positive

Pseudomonas aeruginosa has a ______-like odor.

grape

Pseudomonas aeruginosa grows at ______C.

42C

Pseudomonas aeruginosa has ______, which is unique and gives a blue color.

pyocyanin

Pseudomonas aeruginosa have what other pigments?

- Pyoverdine (green)

- Pyorubin/pyorubrin (red)

- Fluorescein (yello/green)

Pseudomonas aeruginosa can cause ______ or ______ infections.

endogenous, exogenous

What are the intrinsic methods of resistance possessed by Pseudomonas aeruginosa?

- Inducible AmpC beta-lactamase

- Multi Drug Resistant efflux pumps

What are some acquired methods of resistance that Pseudomonas aeruginosa can develop?

- MDR efflux pumps

- Impermeability mutations (OprD)

- Beta-lactamases

- Aminoglycoside modifying enzymes (rmtA)

- Transmissible quinolone resistance (qnr)

Acinetobacter baumannii gram stain

Acinetobacter baumannii gives ______ hemolytic colonies.

non

Acinetobacter baumannii colonies will have a ______ hue on MacConkey agar.

purple

______ resistant Acinetobacter baumannii is becoming a real problem.

Carbapenem (CRAb)

CRAb possesses resistance to ______ major classes of antibiotics.

all (beta-lactams, fluoroquinolones, aminoglycosides)

What methods of resistance do CRAb have?

- AmpC cephalosporinases

- Acquired ESBL

- Porin mutations

- Efflux pump overexpression

______ enzymes are commonly reported in CRAb.

Oxacillinase (OXA-like)

Acinetobacter are ______ (motile/non-motile), gram negative coccobacilli.

non-motile

Acinetobacter are catalase ______ and oxidase ______.

positive, negative

Acinetobacter are found in ______ and _____.

soil, water

Acinetobacter grows well on ______ agar.

MacConkey

On MAC, Acinetobacter may look pink/purple but do not ferment ______.

lactose

Burkholderia are ______ (aerobic/anaerobic).

aerobic

Burkholderia are ______ forming (spore/non-spore) GN bacilli.

non-spore

Burkholderia are resistant to ______ and ______.

polymyxin B, colistin

Burkholderia cepacia gram stain

Burkholderia cepacia colonies

Patients with ______ or ______ are at increased risk for infection with Burkholderia cepacia

CGD, CF

Burkholderia cepacia can be a ______ pathogen.

nosocomial

______ antimicrobial resistance is common with Burkholderia cepacia.

Broad-spectrum

80% of Burkholderia infections in the U.S. are caused by what strains?

B. multivorans and B. cenocepacia

15% of Burkholderia infections in the U.S. are caused by what strains?

B. vietnamiensis, B. cepacia, B. dolosa

What selective medias can be used to enhance the recovery of Burkholderia cepacia complex?

- Psuedomonas cepacia selective agar (PCSA; hot pink)

- Burkholderia cepacia selective agar (BCSA; purple with yellow or pink zone)

- Oxidative-fermentative polymyxin bacitracin lysine (uncommon; yellow)

Burkholderia pseudomallei is acquired through environmental exposure to ______ and ______.

soil, water

Most people who contract Burkholderia pseudomallei don't develop ______.

clinical infection

50% of Burkholderia pseudomallei cases cause ______, 50% cause ______.

pneumonia, bacteremia

Positive Burkholderia pseudomallei blood culture within 24 hours indicates an increased risk of ______.

mortality

Burkholderia pseudomallei can become a ______ infection.

latent (can reactivate)

Burkholderia pseudomallei and mallei are category ______ select agents for HHS and USDA.

A (etiologic agents - dangerous)

Stenotrophomonas are ______ due to polar flagella.

motile

Stenotrophomonas maltophilia gram stain

Stenotrophomonas maltophilia colonies

Stenotrophomonas maltophilia has substantial ______ rates.

morbidity/mortality

Stenotrophomonas maltophilia is multidrug ______.

resistant

Stenotrophomonas maltophilia is oxidase ______.

negative (20% of strains are positive)

Stenotrophomonas maltophilia can grow on MacConkey agar but is ______ fermenting.

non-lactose

Stenotrophomonas maltophilia can oxidize ______ and ______.

glucose, maltose

Stenotrophomonas maltophilia is DNase and lysine decarboxylase ______.

positive

Stenotrophomonas maltophilia possesses ______ hydrolysis.

gelatin

What intrinsic methods of antimicrobial resistance does Stenotrophomonas maltophilia possess?

- MDR efflux pumps

- L1 and L2 beta-lactamasese

- Aminoglycoside-modifying enzymes

- Qnr gene family

Stenotrophomonas maltophilia has ______ virulence.

low

The first line of treatment against Stenotrophomonas maltophilia is ______.

trimethoprim-sulfamethoxazole

Second line agents against Stenotrophomonas maltophilia are ...

Fluoroquinolones, minocycline, cefiderocol

Shewanella putrefaciens

Shewanella putrefaciens is oxidase and H2S _______.

positive

Shewanella putrefaciens is indole ______ and ______ (motile/non-motile).

negative, motile

50% of Shewanella putrefaciens strains produce acids from ______.

glucose

Shewanella putrefaciens is ______ resistant.

colistin

OF test - fermentation result

Yellow for both aerobic and anaerobic tubes

OF test - oxidation result

Yellow at the top of the aerobic tube, green in the anaerobic tube

______ is overlayed at the top of one of the OF tubes to create an anerobic environment.

Mineral oil

What are the fluorescent Pseudomonas species?

- P. aeruginosa

- P. fluorescens

- P. stutzeri

What are the nonfluorescent Pseudomonas species?

- P. pseudoalcaligenes

- P. alcaligenes

- P. luteola

- P. oryzihabitans

Patients with CF have abnormal transport of ______ and ______ across respiratory epithelium.

sodium, chloride