(F) Lesson 13: Non-fermenters and Miscellaneous Gram-Negative Bacilli (Part 3) Flashcards
- Family: Alcaligenacea
- Found in water
- Isolated in specimens from hospitalized patients: urine, feces, sputum, and wound specimens
- Resistant to disinfectants: chlorhexidine and quaternary ammonium compounds
- Motile using peritrichous flagella and are obligate anaerobes, G(-) bacilli
- (+) MAC, nitrate reducers
- (+) SBA = non-pigmented colonies
- (+) OF = non-oxidative isolates w/ deep blue coolor at the top
- Alcaligenes spp.
- Achromobacter spp.
T or F: Asacchaorlytic members are isolated more frequently than saccharolytic ones.
T
The only exception in Alcaligenes spp. and Achromobacter spp. wherein they are glucose-positive and xylose-positive.
A. xylosoxidans
- Usually seen in clinical specimens
- Usually in patient blood with or without septicemia
- Linked to eye infections, pancreatic abscesses and other infections
- Nitrite reducer to nitrogen gas
Alcaligenes faecalis
Asaccharolytic species of Achromobacter?
- Achromobacter piechaudii
- Achromobacter denitrificans
This asaccharolytic organism from the Achromobacter spp. is retrieved from the ear of a diabetic patient.
Achromobacter piechaudii
Asaccharolytic Achromobacter spp.
Resistant/Susceptible?
- Aztreonam
- Aminoglycosides
Resistant
Asaccharolytic Achromobacter spp.
Resistant/Susceptible?
- SXT
- Piperacillin
- Ticarcillin
- Ceftazidime
- Quinolones
Susceptible
The only saccharolytic Achromobacter spp.
Achromobacter xylosoxidans
- Most commonly isolated
- Causes nosocomial infection associated with intravenous catheters, patients of advanced age experiencing neutropenia
- Linked to otitis media, meningitis, pneumonia, surgical wound infections, UTIs, peritonitis, bacteremia
- Colonizer of patients with CF
- Nitrite reducer to nitrogen gas
- Treatment: there is increasing resistance
Achromobacter xylosoxidans
Achromobacter xylosoxidans
Resistant/Susceptible?
* Aminoglycosides
* Ampicillin
* First- and second-gen cephalosporins
* Chloramphenicol
* Fluoroquinolones
Resistant
Achromobacter xylosoxidans
Resistant/Susceptible?
* Piperacillin
* 3rd-gen cephalosporins
* Carbapenems
* SXT
Susceptible
- Recovered from sputum, wounds, and blood
I’m sorry, eto lang talaga description niya. </3
Advenella incenata
- Infrequent isolates
- Can be a significant pathogen
- B. diminuta and B. vesicularis are differentiated by esculin hydrolysis
Brevudimonas spp.
Brevudimonas spp.
Positive for esculin hydrolysis?
Brevudimonas vesicularis
Brevudimonas spp.
Negative for esculin hydrolysis?
Brevudimonas diminuta
- In blood, CSF, urine, and wounds as a contaminant
- Pathogenic in those immunocompromised
- (+) VIM-2-metallo-β-lactamase causing multidrug resistance
- Motile with a single polar flagellum
- (+) oxidase, glucose
- (+) MAC
- (-) esculin hydrolysis
Brevudimonas diminuta
Brevudimonas diminuta
Resistant/Susceptible?
* Ampicillin
* Cefoxitin
* Nalidixic acid
* Fluoroquinolones
Resistant
- Causes meningitis, infective endocarditis, and infections in CAPD patients
- Isolated in urine and eye specimens
- Motile with a single polar flagellum
- (+) oxidase, glucose, maltose
- (+) esculin hydrolysis
Brevudimonas vesicularis
Brevudimonas vesicularis
Resistant/Susceptible?
* Carbapenems
* Aztreonam
* Cephalosporins
Resistant
Brevudimonas vesicularis
Resistant/Susceptible?
* Fluoroquinolones
* Piperacillin-tazobactam
Susceptible
- Unclear taxonomy
- EO means eugonic oxidizer
- (+) oxidase, glucose, xylose wherein they differ in oxidation of lactose and mannitol
- Weak grower, if at all, on MAC
- Non-motile, saccharolytic coccobacilli
- Unknown susceptibility to antimicrobial agents
CDC Groups EO-3, EO-4, and Paracoccus
- Now named Paracoccus yeeii
- From blood cultures and wound infections and cutaneous bullae
- Found in at least one case of uveitis as a potential pathogen
- In infections following keratoplasty, myocarditis in heart transplant patient, infections associated with CAPD
- Produces characteristic coccoid or O-shaped cells on G/S (from vacuolated or peripherally stained cells)
EO-2
- In CAPD infection
- Isolated from urine, eye discharge, blood, pleural fluid, CSF, lung and genitourinary tract specimens (same with EO-4)
- Produce a yellow non-diffusible pigment as well as some EO-4
EO-3
- Only clinically relevant from this genus
- Reservoirs: soil and water
- Commonly found in tropical and subtropical climates
- Opportunist
- In cases of osteomyelitis, abscesses, septicemia, urine and gastrointestinal infections
- Skin lesions are typical portal of entry
- G(-) bacilli, fermentative
- (+) oxidase, motile (polar flagella), glucose fermentation, sucrose (variably), MAC, enteric media, 42 deg C
- Produces violacein
- Causes fever, sepsis, skin lesions, abdominal pain, localized abscesses in the liver
- Risk Factors: young age, (+) localized abscess, short clinical course, inappropriate antimicrobial treatment
- Possible relapse and reinfections
Chromobacterium violaceum
Chromobacterium violaceum
Resistant/Susceptible?
* Fluoroquinolones
* Tetracyclines
* Carbapenems
* Gentamicin
* SXT
Resistant
Chromobacterium violaceum
Resistant/Susceptible?
* B-lactam antibiotics
Susceptible
- Straight to slight curved rods
- Alkaline in OF media
- (+) oxidase, catalase, nitrate reducer
- Motile w/ multitrichous polar flagella
- In soil and water
- Rarely from specimens, but in hospital equipment and fluids
Comamonas and Delftia
- Difficult to distinguish phenotypically, reported as ____ spp.
Comamonas spp.
These Comamonas spp. cause nosocomial bacteremia.
Two (2)
Comamonas testeroni and Comamonas terrigena
- Associated with keratitis in soft contact lens wearers and nosocomial infections (bacteremia, endocarditis)
- (+) oxidize fructose and mannitol
- Resistant: aminoglycoside
Delftia acidovorans
- Associated with catheter-related bacteremia
- Incorrectly ID-ed by VITEK 2 as D. acidovorans
Delftia tsuruhatensis
Delftia spp.
Resistant/Susceptible?
* Ampicillin
* Aminoglycosides
* Colistin
Resistant
Delftia spp.
Resistant/Susceptible?
* Fluoroquinolones
* Carbapenems
* 3rd-gen cephalosporins
* Piperacillin-tazobactam
Susceptible
- Family: Weeksellaceae
- In soil and water
- Not part of the normal human microbiota
- Causes nosocomial infections as they often contaminate hospital equipment
- Are weak fermenters, hence, their reactions are usually delayed
Weeksellaceae spp.
Weeksellaceae spp.
Resistant/Susceptibility?
* Aminoglycosides
Resistant
Weeksellaceae spp.
Resistant/Susceptible?
* Vancomycin
Susceptible
- In newborns as meningitis or septicemia in conjunction with immaturity
- In adults as pneumonia, endocarditis, bacteremia, and meningitis, especially in those critically ill
- Infections follow the use of materials contaminated with the organism
- (+) fermentation of glucose, maltose, mannitol, esculin hydrolysis, indole, MAC (variable)
- Long, thin bacilli, often with bulbous ends
- Susceptible to clindamycin and vancomycin
Elizabethkingia meningoseptica or Meningosepticum
- Reduced activity to vancomycin
- Good activity to SXT, fluoroquinolones, and piperacillin-tazobactam
Chryseobacterium
- Most frequently isolated but are insignificant in rare numbers or from only one medium or specimen.
- Linked to nosocomial infections: bacteremia in immunosuppressed or those who have been receiving long-term antimicrobial therapy, and to ocular infections
- Long, thin bacilli, often with bulbous ends
Chryseobacterium indologens
- Causes endophthalmitis following cataract surgery due to poor sterilization procedures
Empedobacter brevis
- From blood and surgical wounds
- Resemble E. brevis
Wautersiella
- Asaccharolytic, nonmotile
- Has intracellular pigment: salmon-pink or pale yellow
- Some have distinct fruity odor
- (+) indole (weak), oxidase, DNase, gelatin hydrolysis
- (-) MAC
Weeksella
T or F: In Indole Test, Kovac’s Reagent is more recommended over Erlich.
F (other way around)
- In genitourinary specimens
- (+) on Modified Thayer-Martin and other media selective for Neisseria gonorrhoeae
Weeksella virosa
- Susceptible to penicillin and other antimicrobial agents
Bergeylla
- From cellulitis, tenosynovitis, septicemia, pneumonia, and meningitis
- Associated with dog and cat bite wound (it is part of their normal oral biota)
Bergeylla zoohelicum
- Family: Methylobacteriaceae
- Characteristic pink to coral pigment
- Uses methanol as sole source of carbon and energy
- From soil, vegetation, sewage, water, hospital nebulizers
- In throat swabs bronchial washes, blood
- Presence in blood cultures can be attributed to contaminated tap water from irrigations during bone marrow transplant
- Causes bacteremia, peritonitis, synovitis, skin ulcers in the immunocompromised
Methylobacterium spp.
- Usually isolate
- Prefers low temperatures at 25-350C
- Distinctive large vacuolated pleomorpihc rods
- Oxidase variable, motile with polar flagellum
- Slow grower, producing 1mm dry, coral/pink colonies in 4-5 days
- Grows on fungal media: Sabouraud dextrose agar
- Not as well on SBA, chocolate, modified Thayer-Martin, Buffered Charcoal-Yeast Extract (BCYE)
- (-) MAC
Methylobacterium mesophilicum and Methylobacterium zatmanii
- Family: Acetobacteraceae
- Most common: Pink-pigmented, non-fermentative, G(-) bacilli recovered
- From the environment and clinical specimens: blood, CSF, sputum, abscess, wound specimens
- In immunocompromised, mainly producing catheter-related bloodstream infection
- SDA growth: pink, mucoid, almost runny colonies that do not appear black under long wavelength UV light
- Nonvacuolated, coccoid bacteria, forming pairs or short chains
- (+) oxidase (weak), urease, MAC
Roseomonas spp.
Most common isolate of Roseomonas spp.
Roseomonas mucosa
- Family: Burkholerdiaceae which includes Ralstonia, Cupriavidus, Burkholderia
Ralstonia spp. and Cupriavidus spp.
- Most common species out of the 7 genus
- In sterile hospital fluids, urine, nasopharynx, abscess, wound, blood specimen as colonizers or contaminants
- Colonization increased in patients mechanically ventilated
- Linked to meningitis, endocarditis, ostomyelitis
- Along with R. mannitolytica are isolated from respiratory specimens from CF and non-CF patients
- Slow growers, requiring >72 hours in primary cultures
- (+) oxidase, catalase
- Opportunistic, causing septicemia, peritonitis, abscesses, tenosynovitis, in immunocompromised
Ralstonia pickettii
Ralstonia spp.
- Most common cause of infections in CF patients
Ralstonia mannitolytica
- Outbreak rooting from the unusual practice of moistening culturette swabs with tap water before collecting microbiology samples
- Motile with pertitrichous flagella
- Asaccharolytic G(-)
- (+) oxidase, catalase, MAC
Cupriavidus pauculus
Cupriavidus spp.
Resistant/Susceptible?
- Aminoglycosides
- Ampicillin
- 1st- and 2nd-gen cephalosporins
Resistant
Cupriavidus spp.
Resistant/Susceptible?
* Quinolones
* 3rd-gen cephalosporins
* Piperacillin
* Doxycycline
Susceptible
Cupriavidus spp.
- Found in CF patients
Cupriavidus gilardi
- Family: Shewanellaeae
- Colonies: mucoid, with tan to brown pigment with greenish discoloration on SBA
Shewanella spp.
- Infrequent isolates from various human specimens: abscesses, traumatic ulcers, otitis media, ocular infections, osteomyelitis, peritonitis, septicemia, and mixed culture
- In the environment: stagnant water, natural gas (petroleum), brine, spoiled dairy products, meat, fish
- Rarely pathogenic
- Motile
- (+) ornithine decarboxylase, nitrate reductase,
- H2S producers in TSIA
Shewanella algae and Shewanella putrefaciens
Shewanella spp.
- Like Enterobacterales (except Plesiomonas) which are differentiated ____
Oxidase Test
Shewanella spp.
Positive for Oxidase Test?
Shewanella spp.
Shewanella spp.
Negative for Oxidase Test?
Enterobacteriaceae
Shewanella spp.
Resistant/Susceptible?
* Penicillin
* Cefazolin
Resistant
Shewanella spp.
Resistant/Susceptible?
* Ampicillin
* Tetracycline
* Chloramphenicol
* Erythromycin
Susceptible
Shewanella spp.
- Halophilic → requires NaCl
- Asaccharolytic
Shewanella algae
Shewanella spp.
- Nonhalophilic
- Saccharolytic
Shewanella putrefaciens
Two significant species of Sphingomonas?
- Sphingomas paucinobilis
- Sphingomonas parapaucinobilis
- From many water sources (swimming pools), hospital equipment, laboratory supplies
- Causes peritonitis associated with CAPD, septicemia, meningitis, leg ulcers, empyema, splenic and brain abscesses
- Yellow-pigmented
- (+) oxidase
- (-) MAC, indole
- Requires >48hrs incubation on SBA
- Motile at 18-22 deg C, not at 37 deg C
- Variable resistance to antimicrobial agents
- Its susceptibility to polymyxin B differentiates it from other Sphingobacterium
- Its vancomycin susceptibility is unusual for a G(-) bacteria
Sphingomonas paucinobilis
Sphingomonas paucinobilis
Resistant/Susceptible?
* Colistin
Resistant
Sphingo paucinobilis
Resistant/Susceptibility?
- Aminoglycosides
- Tetracyclines
- Chloramphenicol
- SXT
- 3rd-gen cephalosporins (ceftazidime, ceftriaxone, ceftizoxime) (variable)
- Fluoroquinolones (variable)
Susceptible
- From sputum, urine, vaginal specimens
- Produce esterases, endotoxin, lipases, and phosphatases, inherent virulence is limited
- Considered colonizers or contaminants, unless repeatedly isolated from samples
- Resemble S. paucinobilis
- (+) H2S by lead acetate method, Simmon citrate
- (-) DNase
Sphingomonas parapaucinobilis
