Nonfermenting and miscellaneous gram-negative bacilli Flashcards by Dyanne YJH

The largest percentage of all non-fermenters isolated from clinical specimens.

Genus Pseudomonas

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Oxidase positive, except [2]

P. luteolus
P. oryzinahabitans

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Optimal temperature range for growth of most species.

[temp]

30°C to 37°C; that is, they are mesophilic.

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The most commonly isolated species of the genus in clinical specimens.

[pseudomonas]

Pseudomonas aeruginosa

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It is found in MOIST ENVIRONMENT, including tap water, pools, hot tubs, catheters, and humidifiers in hospitals, and in plants and soil.

[pseudomonas]

Pseudomonas aeruginosa

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The leading cause of healthcare-associated respiratory tract infections.

[pseudomonas]

Pseudomonas aeruginosa

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particularly in swimmers or divers;

[pseudomonas aeruginosa]

Otitis externa

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Referred to as Jacuzzi or hot tub syndrome.

[pseudomonas aeruginosa]

Necrotizing rash

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Forms MICROCOLONIES in tissue that are associated with QUORUM SENSING, biofilm producing strains, which indicates that quorum sensing is also linked to the formation of microcolonies below the surface in severe wounds.

[pseudomonas]

Pseudomonas aeruginosa

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Can survive harsh environmental conditions and displays intrinsic resistance to a wide variety of antimicrobial agent.

[pseudomonas]

Pseudomonas aeruginosa

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pyorubin

[color]

Pyorubin

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Pyomelanin

[color]

brown or black

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Produce flat, spreading colonies with a characteristic metallic sheen.

β-hemolytic on sheep blood agar (SBA)

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A selective and differential medium for the identification of P. aeruginosa.

Cetrimide agar

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Are of very low virulence, rarely causing clinical disease.

[pseudomonas]

Pseudomonas fluorescens and Pseudomonas putida

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It has been associated with catheter-related sepsis in patients with cancer.

[pseudomonas]

Pseudomonas putida

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From BLOOD CULTURE BOTTLES in asymptomatic patients has been responsible for clusters of pseudobacteremia, probably related to contaminated catheters and catheter-related devices.

[pseudomonas]

P. fluorescens

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P. fluorescens and P. putida can grow at what temp?

4° C (linked to transfusion-associated septicemia)

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Gelatin hydrolysis can be used to differentiate the two species from each other;

P. fluorescens (positive)
P. putida (negative)

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[2] They are usually susceptible to the aminoglycosides, polymyxin, and piperacillin, but are resistant to carbenicillin and SXT.

[pseudomonas]

P. fluorescens
P. putida

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a RARE ISOLATE and even rarer pathogen in the clinical laboratory.

[pseudomonas]

P. stutzeri

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Easily recognizable because of its characteristic macroscopic appearance of wrinkled, leathery, adherent colonies that may produce a light yellow or brown pigment.

[pseudomonas]

P. stutzeri

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Isolates are ADH negative and starch hydrolysis positive.

[pseudomonas]

P. stutzeri

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Found in SOIL and WATER but is rarely isolated from human specimens; when it is, it is often considered a contaminant.

[pseudomonas]

P. mendocina

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Produces nonwrinkled, flat colonies that may appear with a yellowish-brown pigment, smooth buttery appearance. [pseudomonas]

P. mendocina

It is oxidase and ADH positive. [pseudomonas]

P. mendocina

[2] Often considered contaminants when isolated from clinical specimens. [pseudomonas]

P. pseudo alcaligenes P. alcaligenes

They are oxidase positive and biochemically negative in many tests for which other Pseudomonas spp. test positive.

P. pseudo alcaligenes P. alcaligenes

[2] They grow on MAC agar and are variable in the reduction of nitrates to nitrites or nitrogen gas. [pseudomonas]

P. pseudo alcaligenes P. alcaligenes

These two pseudomonads are rarely isolated from humans but have been isolated from wounds, abscesses, blood cultures, peritoneal and chronic ambulatory peritoneal dialysis (CAPD) fluids, and other sources. [pseudomonas]

P. luteola P. oryzihabitans

[2] They have also been implicated in cases of peritonitis and possibly meningitis, although often in association with each other or with other bacteria. [pseudomonas]

P. luteola P. oryzihabitans

It can be differentiated from P. oryzihabitansby positive o-nitrophenyl-β d-galactopyranoside (ONPG) and esculin hydrolysis tests. [pseudomonas]

P. luteola

What color Acinetobacter spp. produces?

Purple

Most glucose-oxidizing nonhemolytic strains were previously identified a? [acinetobacter]

A. baumannii

Most non-glucose utilizing, nonhemolytic strains were designated as? [acinetobacter]

A. Iwoffi

Most beta-hemolytic strains are identified as? [acinetobacter]

A. haemolyticus

Infections primarily affect patients with weakened immune systems and coexisting diseases.

Acinetobacter

There are reports of eye infections caused by this Acinetobacter including endophthalmitis, conjunctivitis, and corneal ulcerations. [acinetobacter]

A. baumannii

Much less virulent, and when isolated, it usually indicates contamination or colonizatio rather than infection. [acinetobacter]

A. Iwoffii

An oxidase-negative, non-fermentative, gram negative bacillus that produces BIOCHEMICAL PROFILES similar to those of Burkholderia cepacia. [stenotrophomonas]

S. maltophilia

Also oxidizes maltose faster than glucose (hence the species name, maltophilia, or “maltose loving”), and can produce a BROWN PIGMENT ON BRAIN HEART infusion agar that contains tyrosine. [stenotrophomonas]

S. maltophilia

Lavender to lavender green pigment of Blood Agar: [stenotrophomonas]

S. maltophilia

When isolated from clinical specimens, it is initially regarded as a SAPROPHYTE or colonizer. [stenotophomonas]

S. maltophilia

Can quickly colonize the respiratory tract of hospitalized patients. [stenotrophomonas]

S. maltophilia

endocarditis, especially in a setting of prior intravenous drug abuse or heart surgery; wound infections, including cellulitis and ecthyma gangrenosum; bacteremia; and, rarely, meningitis and UTIs. [stenotrophomonas]

S. maltophilia

Is rarely associated with lower respiratory tract infections, although it has been isolated from 6.4% to 10.2% of patients with CF. [stenotrophomonas]

S. maltophilia

The World Health Organization has designated carbapenem-resistant A. ______ (CRAB) as one of the critical priority pathogens for new antimicrobial drug development.

A. baumannii

Are classified as MDR or extremely drug resistant (XDR) if they have chromosomally encoded AmpCbeta-lactamases, mutations in porin channels, and overexpression of BACTERIAL EFFLUX PUMPS.

Acinetobacter spp.

Are PLUMP COCCOBACILLI that tend to resist alcohol decolorization, thus sometimes appearing gram positive.

Acinetobacter spp.

are coccobacilli or short rods.

Bordetella spp.

[3] short to medium-sized straight rods

1. S. maltophilia 2. P. oryzihabitans 3. P. luteola

It should be incubated only in ambient air. [agar]

MacConkey agar

Associated with pneumonia in patients with CF or chronic granulomatous disease (CGD).

Burkholderia cepacia complex

Cause endocarditis, pneumonitis, UTIs, osteomyelitis, dermatitis, and other wound infections resulting from the use of contaminated water.

Burkholderia cepacia complex

Complex often produces a weak, slow, positive oxidase reaction.

Burkholderia cepacia complex

Causes glanders, a respiratory tract zoonosis primarily affecting livestock such as horses, mules, and donkeys. [burkholderia]

Burkholderia mallei

Severe local suppurative or acute pulmonary infections. [burkholderia]

Burkholderia mallei

a potential bioterrorism agent. [burkholderia]

Burkholderia mallei

Isolates are resistant to polymyxins. [burkholderia]

Burkholderia mallei

Causes melioidosis, an aggressive, granulomatous, pulmonary disease caused by ingestion, inhalation, or inoculation of the organisms, with metastatic abscess formation in lungs and other viscera. [burkholderia]

Burkholderia pseudomallei

Considered a potential BIOTERRORISM AGENT. [burkholderia]

B. pseudomallei

[2] Isolates of both are found in WATER (e.g., swimming pools, tap water, dialysis fluids) and are resistant to disinfectants, such as chlorhexidine and quaternary ammonium compounds.

Alcaligenes Achromobacter

The species usually seen in clinical specimens, and it has been isolated from the BLOOD OF PATIENTS WITH AND WITHOUT SEPTICEMIA. It has also been linked to eye infections, pancreatic abscesses, and other infections. [alcaligenes]

Alcaligenes faecalis

Isolated from the EAR of DIABETIC PATIENT . [achromobacter]

Achromobacter piechaudii

The most commonly isolated member of the genus Achromobacter that it is a cause of NOSOCOMIAL INFECTION associated with the use of intravenous catheters; [achromobacter]

Achromobacter xylosoxidans

Has been found in blood, CSF, urine, and wounds; it is often considered a contaminant. [brevundiomonas]

Brevundimonas diminuta

Are motile and possess a single polar flagellum, oxidize glucose, and are oxidase positive. Most strains grow on MAC agar. [brevundimonas]

B. diminuta

Has been reported as a cause of meningitis, infective endocarditis, and infections in a CAPD patient; it was also isolated, with unknown significance, from URINE and EYE SPECIMENS. [brevundimonas]

B. vesicularis

Most strains of B. ______ produce an orange intracellular pigment. B. ______ is also oxidase positive and oxidizes glucose and maltose. [brevundimonas]

B. vesicularis

Best test to differentiate the two species; approximately 88% of B. vesicularis isolates are positive, whereas B. diminuta isolates are rarely positive.

Esculin hydrolysis

Refers to eugonic oxidizer.

Has been named Paracoccus yeei.

EO-2

Isolates of P. ____ have been recovered from blood cultures and wound infections. It has been seen in infections following KERATOPLASTY, MYOCARDITIS in a heart transplant patient. [paracoccus]

P. yeei

Further characterized by the production of characteristic coccoid or O-shaped cells on Gram stain. [paracoccus]

P. yeei

The only clinically relevant species in the genus. [chromobacterium]

Chromobacterium violaceum

The reservoirs are soil and water; isolates are more commonly found in tropical and subtropical climates, particularly in Southeast Asia and India. [chromobacterium]

Chromobacterium violaceum

An opportunist, ATTACKING IMMUNOCOMPROMISED PATIENTS with neutrophil deficits, including CGD, usually as a result of contamination of wounds with water or soil. [chromobacterium]

Chromobacterium violaceum

[2] Straight to slightly curved rods, produce alkalinity in OF media, are catalase and oxidase positive, are usually motile by multitrichous polar flagella, and reduce nitrate to nitrite.

Comamonas spp. Delftia spp.

Has been associated with keratitis in soft CONTACT KENS WEARERS and nosocomial infections including bacteremia and endocarditis. [Delftia]

Delftia acidovorans

Are not considered part of the normal human microbiota.

Weeksellaceae

Most diseases produced by members of the Weeksellaceae are caused by?

Elizabethkingia meningoseptica

The most frequently isolated species in this genus found in human specimen. [chryseobacterium]

Chryseobacterium indologenes

Has been isolated from cases of CELLULITIS, TENOSYNOVITIS, septicemia, pneumonia, and meningitis, particularly in association with dog and cat bite wounds, because it is part of their normal oral biota. [bergeyella]

Bergeyella zoohelicum

Isolates produce a characteristic PINK TO CORAL PIGMENT and can use METHANOL as a sole source of carbon and energy. [methylobacterium & roseomonas]

Methylobacterium

Isolated from soil, vegetation, sewage, water, and hospital nebulizers. [methylobacterium & roseomonas]

Methylobacterium

They prefer a lower temperature ( __° to __° C), produce distinctive large vacuolated pleomorphic rods, and are oxidase variable and motile with a polar flagellum. [methylobacterium]

25° to 35° C

Catheter-related bloodstream infection was the most common infection seen. [methylobacterium & roseomonas]

Roseomonas spp.

Will usually grow on MAC agar. [methylobacterium & roseomonas]

Roseomonas spp.

It requires NaCl (halophilic) and is asaccharolytic. [shewanella]

Shewanella algae

Nonhalophilic and saccharolytic. [shewanella]

Shewanella putrefaciens

Can be isolated from many water sources, including swimming pools, as well as from hospital equipment and laboratory supplies. [sphingomonas]

Sphingomonas paucimobilis

The yellow-pigmented S. ______ does not grow on MAC agar and requires more than __ hours for culture on SBA. [sphingomonas]

1. Sphingomonas paucimobilis 2. 48 hours

dry, coral, or pink colonies in 4 to 5 days. [methylobacterium, roseomonas spp.]

Methylobacterium

Although uncommon isolates, they are the MOST COMMON PINK PIGMENTED, gram-negative, nonfermentative bacillus recovered in clinical laboratories. [methylobacterium, roseomonas spp.]

Roseomonas spp.