non fermenting GN

gen characteristics of nonfermenters

gen characteristics of nonfermenters

• saccharolytic or asaccharolytic

• long thin GN rod or ccb

• mostly ox pos

• TSI is K/K

• moist environments (soil, water, plants, decaying vegetation)

• prefer aerobic environment

• resistant to multiple classes of antibiotics

what infections are these bacteria typically isolated in?

septicemia, meningitis, osteomyelitis, wound infections

pseudomonas spp

• ubiquitous; some ppl’s skin normal flora

• pools, hot tubs, catheters, humidifiers in hospitals

clinical infections - p. aeruginosa

• leading cause of nosocomial RTIs

• wound infections/burn pts

• pulm infections (CF)

• nosocomial UTIs, bacteremia

• endocarditis

• eye infections

• ear infections (swimmer’s ear)

• skin infections (hot tub folliculitis)

p. aeruginosa virulence factors

• endotoxins, motility, pili, capsule, phospholipases

• exotoxins: protease, hemolysin, lecithinase, elastase, DNase

• exotoxin A blocks protein synthesis

p. aeruginosa morphology

• GNR

• spreading colonies (mucoid in CF pts), beta hemolytic

• metallic sheen on BAP, NLF on MAC

• blue green pigment produced

• grape like/tortilla chip odor

cetrimide agar

• nutritive

• 0.1% cetrimide

• cetyl trimethyl ammonium bromide: inhibits bacteria other than p. aeruginosa

• enhances production of fluorescent pigments

p. aeruginosa biochemicals

• ox pos, cat pos

• nitrate pos

• oxidizes carbs

• ADH pos

• citrate pos

• growth 42C (differs from other in fluoro group)

p. aeruginosa AST

• kanamycin R, carbenicillin S

• opposite for fluorescens/putida

CLSI p. aeruginosa

• presumptive: ox pos, indole neg

• additional: fruity odor of grapes

• notes: strong beta hemolysis

p. fluorescens and putida

• other fluoros

• make pyoverdin (not pyocyanin)

• no growth at 42C

• neg nitrate

• low virulence

• infections: UTIs, post op abscesses, empyema, septic arthritis, wound infections

p. stutzeri

• rare isolate/pathogen

• dry, wrinkled, tough, adherent, yellow/brown with age

  • confused with b. pseudomallei

• BICH:

  • nitrate pos, ox pos

  • neg ADH, gelatinase

  • produce acid from glucose not lactose

acinetobacter spp

• second most common isolate of these organisms

• normal flora in 25% adults

• hospitals (vents, humidifiers, catheters)

• UTI, pneumonia, endocarditis, septicemia, meningitis, wounds, eye infections

acinetobacter morphology appearance

• GN ccb: large diplococci similar to neisseria, moraxella

  • difficult to decolorize

• varies on BAP: gray to white, yellow to tan, beta/gamma hemolytic

• NLF but can appear pink on MAC from oxidation of lactose with aging (not as pink as true LF)

acinetobacter biochemicals

• strict aerobes

• ox neg, cat pos

• non motile

a. baumanii

• saccharolytic

• resistant to a lot of antibiotics

• CRAB: carbapenemase resistant a. baumanii (isolate pt)

a. lwoffi

• asaccharolytic

• less virulent, more often contaminant or colonizer

stenotrophomonas maltophila

• third most common isolate of these organisms

• water, sewage, plant materials, hospital environment

• pneumonia, endocarditis (surgery/IV drug users), bacteremia, wound infections

• resistant to multiple antimicrobials (S to SXT)

s. maltophilia morphology

• slight odor of ammonia

• pale yellow on BAP (sometimes green with aging)

• NLF on MAC

s. maltophilia biochemicals

• ox neg, cat pos

• motile

• pos DNase, esculin, LDC, gelatin, ONPG

• strong oxidizer of maltose

b. cepacia

• nosocomial pathogen: hospital environment (fluids, anesthetics, nebulizers, detergents, disinfectants)

• pneumonia in CF pts

• endocarditis, UTIs, osteomyelitis, dermatitis, wound infections

b. cepacia morphology

• opaque, glistening

• NLF on MAC: may appear pink from strong lactose oxidation after aging

• earthy odor

OFPBL agar

• ox-ferm, polymixin B, bactracin, lactose

• bromthymol blue

• b. cepacia looks yellow from acidic end products (lactose metabolism)

BC agar

• CV, bile salts, ticarcillin, polymixin B, pyruvate

• phenol red

• b. cepacia looks pink/red from alkaline end products (pyruvate metabolism)

b. cepacia biochemicals

• slow ox pos

• motile

• LDC pos

• ODC neg

• oxidizes glu, mal, lac, mannitol

b. mallei

• glanders: disease in horses, transmitted via contact with infected animals (zoonotic)

  • severe suppurative or acute pulm infections

  • 1 case of human disease (lab accident)

• potential bioterrorism agent

b. mallei biochemicals

• V MAC, slow grower on BAP, non pigmented

• non motile

• slow oxidizer (not xylose/sucrose)

• ADH pos

• nitrate pos

• ox V

b. pseudomallei

• SE asia, north aus, mexico

• melioidosis: aggressive pulm disease with septicemia, pneumonia; latent infections can relapse

• ingestion, inhalation, inoculation

• tier 1 select agent, agent of bioterrorism

b. pseudomallei morphology

wrinkled colonies (differentiate from p. stutzeri)

b. pseudomallei biochemicals

• putrid (later earthy odor)

• motile

• nitrate, gelatinase, ADH pos

• 42C growth

• oxidizes carbs

where is moraxella found?

• normal flora of mucous membranes

• isolated from resp tract, urinary tract, eye but rarely cause disease

moraxella ID

• ox pos

• asaccharolytic

• strict aerobes, slow growers

• non motile GN ccb (only catarrhalis is cc)

m. nonliquefaciens

• neg gelatin, urease, PAD, no MAC growth

• bacteremia, keratitis, endophthalmitis

m. osloensis

like nonliquefaciens but can acidify etoh and produce alk rxn in acetate medium

m. atlantae

• MAC growth, will pit any agar

• neg gelatin, PAD, nitrate

m. lacunata

• unable to grow on MAC

• gelatin pos

• urease neg

• PAD V

• conjunctivitis

alcaligenes and achromobacter

• divided into asaccharolytic and saccharolytic

• found in water (pools, tap)

• hospital pts (urine, stool, sputum, wound, blood)

alcaligenes and achromobacter ID

• ox pos

• OF media: no oxidation with blue at top

• motile

• nitrate pos

• neg indole, esculin, gelatin

• some a. faecalis have fruity green apple odor

flavobacteriaceae

• ubiquitous (soil/water)

• contams of hospital equipment = nosocomial

flavobacteriaceae ID

• nonmotile

• yellow pigment, can turn BAP lav/green color

• fruity odor (juicy fruit)

• no/poor growth on MAC

• pos: ox, DNase, gelatin, indole (w)

chryseobacterium indologenes

• most frequently isolated species

• nosocomial: bacteremia, ocular infections

elizabethkingia meningosepticum

• cause of most flavo-related diseases

• NB meningitis, septicemia (preemies)

• pneumonia, endocarditis, bacteremia, meningitis

chromobacterium violaceum

• violet colored pigment (violacein)

• opportunistic; tropical and subtropical climates in soil, water

• skin lesion is portal of entry

methylobacterium

• bacteremia, perionitis, synovitis, skin ulcers

• slow grower 4-5days; grow on fungal media, no MAC growth, prefer 25-35C

• large vacuolated pleomorphic rods

• use methanol as sole source of carbon/energy

roseomonas

• pink pigment

• mucoid

• catheter related blood infections