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Roseomonas: How Classical Tests Play a Major Role in Bacterial Identification
Robin Barteluk, ART, CMPT Editor and Web Manager
I
ntroduction In the recent Clinical Bacteriology survey
M083-4 (dialysate with pure culture of Roseomonas) only
63% (43/68) of category A laboratories reported Roseomonas.
Participants noted using both classical (or conventional) methods and a variety of commercial systems (API 20NE, MicroScan, Vitek2, and RapID NH). No commercial system was superior over the others in reporting the correct identification.
What did the 43 laboratories reporting Roseomonas observe that
the others did not? The Manual of Clinical Microbiology (9th
ed.) provides an algorithm for gram-negative bacteria that grow
on blood agar (p. 372)1. If the isolate is a gram-negative rod,
glucose not fermented, pink pigment present this leads directly
to the group with Roseomonas. Apparently, the identification
was much more difficult than following these three simple
steps. Classical methods (morphology and biochemical results)
and commercial systems require skill in interpretive judgment.
Commercial systems must be used as instructed by their manufacturers and technologists must be aware of the status of the
database being used. In addition, the clinical microbiology laboratory must also keep up with changes in taxonomy and the
evolution of pathogens.
A Ve r y B r i e f H i s t o r y o f Ta x o n o m y
(Classification, Nomenclature, Identification) It is important to recognize that taxonomy was created by man and it comes
with a history full of diverse opinions and clashing doctrines.
Throughout history there have been healers, herbalists, village
elders, and others who “classified” which plants were edible or
poisonous and which animals were dangerous. Aristotle is credited with creating the first written system of classification. He
divided animals based on their means of transportation (air,
land, or water), those that have red blood and live births and
those that do not and he divided plants into trees, shrubs, and
herbs. Botanists were the first to study bacteria and classified them
in the same way as plants, that is, mainly by shape 2. The first formal bacterial classification scheme originated with the Gram stain,
which separated bacteria based on the structural characteristics of
their cell walls. In the 1950s and 1960s were the pheneticists
and cladists. The pheneticists prioritized quantitative or numerical analysis and the recognition of similar characteristics among
organisms (“classical tests”). Cladism groups organisms by
evolutionary relationships, and arranges taxa in an evolutionary
tree. Most modern systems of biological classification are based
on cladistic analysis. In 1970, Colwell used the term
“polyphasic taxonomy” to describe using genotypic, phenotypic, and phylogenetic information into a consensus type of
general purpose classification 3.
Based on the sequencing of 16S rRNA, in 1990 Woese4 introduced
the three-domain system: Eukaryota, Bacteria and Archaea. The
prokaryotes were separated into two groups, the Bacteria
(originally labelled Eubacteria) and the Archaea (originally labeled Archaebacteria). Woese concluded, “The system we propose here will repair the damage that has been the unavoidable
consequence of constructing taxonomic systems in ignorance of
the likely course of microbial evolution, and on the basis
of flawed premises (that life is dichotomously organized;
that negative characteristics can define meaningful taxonomies).” The majority of biologists accept the domain
system, but a large minority uses the five-kingdom
method and a few scientists add Archaea or Archaebacteria
as a sixth kingdom but do not accept the domain method.
Due to lateral gene transfer, some closely related bacteria
can have very different morphologies and metabolisms.
To overcome this uncertainty, modern bacterial classification emphasizes molecular systematics, using genetic
techniques such as guanine cytosine ratio determination,
genome-genome hybridization, as well as sequencing
genes that have not undergone extensive lateral gene
transfer, such as the rRNA gene 3,5. The rapid increase in
the number of genome sequences that are available and
will be available means bacterial classification will remain
a changing and expanding field. To assist with changes,
January 1, 1980 was chosen as the new starting date for
bacterial nomenclature 3. Classification of bacteria is determined by publication in the International Journal of
Systematic Bacteriology and Bergey's Manual of Systematic Bacteriology 6. The International Committee on Systematic Bacteriology (ICSB) maintains international rules
for the naming of bacteria and taxonomic categories and
for the ranking of them in the International Code of Nomenclature of Bacteria 3.
Comparison of Isolates Reported in M083-4
(Dialysate) to Roseomonas Table 1 includes “Classic
tests” information for all bacterial identifications submitted
for M083-4; bacteria are listed alphabetically. Compare the
Gram morphology, pigment production, urease, and oxidase
results of Roseomonas to the other isolates listed. Additional
characteristics for each organism are briefly described below
as well as information, if available, about other organisms
that may present similar characteristics leading to identification errors. The critique number of those organisms sent in
CMPT challenges is noted. It must be stressed that
there are many additional gram-negative bacilli that
are not included in this article and Table 1.
7
are strictly aerobic gram-negative short
rods that are rod-shaped during the active growth phase in
fluid and on plates containing cell wall-active antimicrobial agents, and appear coccobacillary or coccoid during
the stationary phase and on nonselective agars. Bacterial
cells are frequently arranged in pairs and their cellular
morphology may be confused as diplococci in direct Gram
smears from clinical samples; Acinetobacter are infrequently misidentified as Moraxella sp. or Neisseria sp.
These organisms are also noted for their tendency to resist
decolourization, and may also be mistaken as grampositive organisms. This is especially seen in smears pre-
Acinetobacter
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pared from positive blood culture bottles. It is important to recognize the Gram smear morphology of Acinetobacter species in
direct samples, and to correlate culture isolates with direct smear
reports. Some glucose-oxidizing strains produce a unique
brown colour on media with glucose, e.g. BAP, MacConkey,
Mueller-Hinton. Acinetobacter species are negative for oxidase,
motility, indole, and nitrate, but are catalase positive and utilize
carbohydrates oxidatively. Automated systems (Vitek2, Vitek,
MicroScan, BD Phoenix, API 20E, API 20NE) and API can usually identify this organism correctly to the species level with and
without classical tests. In most conventional manual identification systems such as API, this organism is relatively inert and this
is another clue to its identity. A. baumannii: glucose-oxidizing
nonhemolytic; A. lwoffii: glucose-negative nonhemolytic; and
A. haemolyticus: hemolytic. The most common nosocomial
infections with A. baumannii involve the respiratory tract, urinary
tract, wounds, and catheter sites, which may progress to bacteremia. The greatest impact of Acinetobacter has been as a causative
agent of ventilator-associated pneumonia, with mortality rates of
70% reported in ICU’s in France. M081-3 Foot ulcer: Acinetobacter baumannii May 2008
staining. B. bronchiseptica produce small circular glistening or rough colonies 0.5 to 1.0 mm in diameter after 48
hours of incubation. Extended incubation, often required
for the other species is not necessary. It is oxidase, catalase
and urease +, indole (-), utilizes citrate, and reduces tetrazolium. Motility is best demonstrated in semi-solid agar at
30oC. Most commercially available identification systems
give reliable results. Biochemically Bordetella resemble
either Acinetobacter spp. or Alcaligenes/Achromobacter spp.
B. avium, which closely resembles Alcaligenes faecalis has
been reported only to affect birds, but a B. avium-like organism has been isolated from a human with chronic otitis media.
B. bronchiseptica is commonly found both as a commensal
and as a causative agent of respiratory disease in domestic and
wild animals. However, it is capable of causing infections in
humans, and there is often a history of exposure to animals. In
addition, it has been shown to cause infections in patients with
serious underlying diseases including haematologic disorders, hepatic or splenic diseases, alcoholism, trauma and
peritoneal dialysis. M81-5 Sputum (young child): Bordetella bronchiseptica May 1998
Actinobacillus sp.8 resembles Pasteurella. Fermenter. Fac- Cupriavidus pauculus
ultatively anaerobic coccoid to small gram-negative bacilli on
solid media, in liquid media or with glucose or maltose tend
to show bipolar staining; single, pairs, rarely short chains.
Growth requires enriched media, improved with 5-10% CO2.
Colonies about 2mm in diameter after 24 h at 37oC, smooth,
or rough, viscous, bluish hue with transmitted light, often
adhere to the agar surface, variable growth on MacConkey
agar. Actinobacillus spp.: urease +, oxidase +; ONPG +; A.
ureae (formerly Pasteurella ureae) ONPG (–), no growth on
MacConkey. NOTE: Actinobacillus actinomycetemcomitans
recently transferred to a new genus Aggregatibacter (see M0822) in the family Pasteurellaceae. The species of the genus Aggregatibacter are independent of X factor and variably dependent
on V factor for growth in vitro. Aggregatibacter. actinomycetemcomitans: urease (-); variable oxidase; MacConkey, no
growth; ONPG (-); colonies central dot, develops into a starlike or crossed cigars, pits agar.
(formerly CDC Group
Ivc-2 and Ralstonia paucula) Short to medium-sized
gram-negative bacilli, may stain irregularly, straight or
slightly curved gram-negative bacilli, 1-5 um x 0.5-1.0 µm.
May grow slowly > 72 h before colonies are visible. C.
pauculus is asaccharolytic and rapidly urease + (often
within minutes), which is similar to Bordetella bronchiseptica and Oligella ureolytica. Cupriavidus spp. and Ralstonia spp. are phenotypically similar; both have been isolated
from patients with cystic fibrosis. NOTE: C. gilardii formerly called Ralstonia gilardii is the new name for an Alcaligenes faecalis-like organism isolated from human
clinical sources and the environment. Vandamme9 proposed
the name Wautersia be replaced by Cupriavidus and that all
species of the genus Wautersia be considered species of the
genus Cupriavidus. Species occur in soil and human clinical
specimens, particularly in samples from debilitated patients.
The type species is Cupriavidus necator.
7,9,10
Alcaligenes faecalis 7 is currently the only Alcaligenes species of Methylobacterium sp.7 Gram-negative bacilli, may apclinical importance. Rods – 0.5-1 x 0.5-2.6 µm, nonpigmented colonies with a thin, spreading irregular edge; some strains (previously
named “Alcaligenes odorans” produce a fruity ‘green apples’ odor,
and greenish discoloration of BAP. Reduce nitrite but not nitrate;
oxidase +, indole (-), and asaccharolytic. Phylogenetically and biochemically, A. faecalis are closely related to members of the genus
Bordetella. It is often found in diabetic ulcers of the feet, but its clinical significance is difficult to determine. NOTE: Alcaligenes denitrificans was reclassified as Achromobacter denitrificans.
7
is rapidly urease +, must be differentiated from Cupriavidus pauculus and Oligella ureolytica
two species that are also rapidly urease positive. There are eight
Bordetella spp. that will grow on ordinary culture media ( i.e.,
BAP and MacConkey). The Bordetellae are small gram-negative
coccobacilli that occur singly or in pairs, and often show bipolar
Bordetella bronchiseptica
pear as large, vacuolated, pleomorphic rods that stain
poorly and may resist decolorization (photograph p. 785 7)
Usually no growth on MacConkey agar, grow slowly, 1mm colonies after 4-5 days, best growth on Sabouraud’s
agar, optimal temperature for growth is between 25-30oC;
colonies are dry, pink or coral in incandescent light; under
UV light appear dark due to absorption of UV light; urease
+; oxidization of sugars is weak (xylose, sometimes glucose). Members of the genus Methylobacterium are ubiquitous in nature and can be isolated from almost any freshwater environment where dissolved oxygen exists. This
genus is composed of a variety of pink-pigmented, facultatively methylotrophic (PPFM) bacteria that have been reported to cause CAPD related peritonitis, septicemia, skin
ulcers, synovitis, as well as pseudoinfections (tap water).
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NOTE Methylobacterium mesophilicum (formerly Pseudomo- M061-4 Dialysate: Myroides species May 2006 97% (69/71)
nas mesophilica, Pseudomonas extorquens, and Vibrio ex- of category A laboratories received an acceptable grade.
torquens) and M. zatmannii are the two species most commonly
Oligella ureolytica 7 ,11 colonies are slow growing, pinpoint
reported from clinical samples.
at 24 h, but after 3 days on BAP are large, white, opaque,
Myroides spp.7 are gram-negative rods (0.5 x 1-2 μm) that grow nonhemolytic, motile. Phenylalanine deaminase +; rapid
on most media and most form yellow pigmented colonies. There urease + (often within minutes), which is similar to Bordetella
are two species within the genus Myroides, M. odoratus and M. bronchiseptica and Cupriavidus pauculus. O. ureolytica is
odoratimimus, however, there are no routine phenotypic tests for found primarily in the urine, usually from patients with longdifferentiating the species. Most strains have a fruity odor simi- term urinary catheters or other urinary drainage systems.
lar to Alcaligenes faecalis. They are asaccharolytic, catalase, These patients have a propensity to develop urinary stones,
oxidase, urease and gelatinase +; indole (-), nitrite reduced, ni- possibly because the organism hydrolyzes urea and alkalintrate not reduced. Myroides and Bacillus both produce effuse, izes the urine, leading to precipitation of phosphates. Bacspreading colonies, but a Gram stain of the colonies can differ- teremia has occurred in a patient with obstructive uropathy.
entiate these organisms. Testing of 74 strains by the CDC O. ureolytica exhibits a variable susceptibility pattern.
showed that the type strain of M. odoratus did not grow on
Oligella urethralis7,11 (formerly Moraxella urethralis)
MacConkey, whereas that of M. odoratimimus grew luxuriantly.
coccobacillary, oxidase +, nonmotile; colonies are
Myroides is identified by conventional and commercially availopaque
to
whitish,
urease
negative.
able methods. Myroides sp. are environmental organisms (found
O. urethralis is a commensal of the GU tract, and most
in soil and water) and behave as opportunistic pathogens in
clinical isolates are from the urine, predominantly from
man, causing infections in immunocompromised hosts1. A varimen. Although symptomatic infections are rare, bacteremia,
ety of infections has been reported including urinary tract, celluseptic arthritis that mimics gonococcal arthritis, and peritolitis, necrotizing fasciitis, bacteraemias, endocarditis, and vennitis have been reported.
triculitis. Most strains are resistant to penicillins, cephalosporins, aminoglycosides, aztreonam and carbapenems 7. The Oligella genus is distinct from the genera MoraxNOTE In 1996, on the basis of phenotypic characteristics and ella and Neisseria, whereas it shares close genetic and
hybridization studies, Flavobacterium odoratum strains were phenotypic relationships with the genera Alcaligenes,
Bordetella, and Taylorella 11 .
reclassified as a new genus called Myroides.
Table 1. Comparison of classic tests for some infrequently isolated gram-negative bacilli that grow on blood agar.
Observations
Acinetobacter
Actinobacillus
Alcaligenes
Bordetella
Cupriavidus
bronchiseptica
pauculus
faecalis
Gram stain
morphology
Growth, Colony
morphology on
blood agar
1-1.5 x 1.5-2.5 µm, sometimes difficult to decolorize, frequently arranged
in pairs; may initially
appear as gram-positive
cocci in direct smears
prepared from + blood
culture bottles
punctate colonies,
smooth, opaque, slightly
smaller than those of
Enterobacteriaceae
Growth on
MacConkey
many strains grow as
colourless or slightly pink
colonies
Oxidase
-
Urease
Unique feature
-
(some + prolonged
incubation)
some glucose-oxidizing
strains produce a unique
brown colour on media;
some fail to grow in nutrient broth; relatively inert;
may mimic Neisseria or
Moraxella on Gram stain
coccoid to small gramnegative rods on solid
media, in liquid media or
with glucose or maltose
tend to show bipolar
staining, arranged single,
pairs, rarely short chains
0.5-1 x 0.5-2.6 µm
bacilli
small gram-negative
coccobacilli that occur
singly or in pairs, and
often show
bipolar staining
1-5 x 0.5-1.0 µm, may
stain irregularly straight
or slightly curved bacilli
requires enriched me- non pigmented colonies glistening or rough colo- may grow slowly > 72 h
with a thin, spreading nies 0.5-1.0 mm in diame- before colonies are visible
dia, best with 5-10%
irregular edge; some ter after 48 hours of incuCO2; colonies about
2mm (24 h at 37 o C),
strains produce a fruity
bation; strict aerobes,
smooth, or rough, vis‘green apples’ odor,
with optimal growth at
cous, bluish hue with greenish discoloration
35oC
transmitted light, often
adhere to the agar
+/- varies with species
+
+
+ (may grow slowly)
+
+
+
+
+ (most, rapid; some weak)
-
rapid +
( often within minutes)
rapid +
(often within minutes)
Actinobacillus spp.
ONPG +;
A. ureae ONPG (–),
no growth on
MacConkey
A. faecalis only species
of clinical importance;
reduce nitrite but not
nitrate;
phylogenteically and
biochemically very
similar to Bordetella
Resemble either
Acinetobacter spp. or
Alcaligenes/
Achromobacter spp.
indole negative, utilize
citrate, and
reduce tetrazolium
Cupriavidus &
R. insidiosa glucose (-),
R. pickettii is glucose +;
citrate +
Isolated from patients
with CF
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Paracoccus yeei 7 (formerly CDC group EO-2) The genus
Ralstonia pickettii 10 Ralstonia and Cupriavidus are pheno-
Paracoccus comprises 17 species of aerobic, gram-negative
coccobacilli. The coccobacilli have been described as donutshaped “O-shaped” cells due to vacuolated or peripherally
stained cells by some, but not all investigators 12. Optimal
growth detected at 35°C rather than at 20 to 25°C. P. yeei
form whitish-greyish, convex colonies 0.5 to 1 mm in diameter on Columbia sheep blood agar and chocolate agar plates
but growth on MacConkey is delayed (>72 h) or negative.
After 72 h on Columbia sheep blood agar the whitishgreyish colonies develop into very mucoid beige colonies. P.
yeei is catalase + and strongly oxidase +, reduce nitrate, nonmotile (hanging drop), indole (-), and saccharolytic (acid
from glucose). Discrepancy in urease activity testing in both
the API NH and API NE systems has been described and
might be explained by the stronger buffering capacity in the
API NE well 12.
typically similar and differentiating them may be difficult. R.
pickettii will grow on BAP, MacConkey, and Burkholderia
cepacia selective agar. Most Ralstonia species show a fast,
strong oxidase reaction, although some may have a weak oxidase reaction. R. pickettii are catalase +, lysine decarboxylase
(-), glucose +, and urease +. Cupriavidus and Ralstonia insidiosa do not produce acid from glucose. Based on phenotypic characterization, Burkholderia pickettii, B. solanacearum, and Alcaligenes eutropha were transferred to the new
genus Ralstonia. When both biochemical tests and automated
identification systems are used, Ralstonia spp. can be misidentified as Burkholderia spp. or, less often, as nonaeruginosa Pseudomonas spp. R. pickettii is easily confused
with Pseudomonas fluorescens. Of note, most B. cepacia are
non-pigmented, but on TSI (iron-containing media) many
produce a bright yellow pigment and a dirt-like odor.
Paracoccus have their natural habitat in soil and brines and
are known for their physiological versatility. Only two blood
culture isolates have been described in the literature 12. This
is perhaps due to its macroscopic appearance with colonies
initially resembling those of a coagulase-negative staphylococcus (CNS). If a Gram stain or an oxidase reaction test is
not performed, then misidentification of P. yeei as a CNS
may occur, in particular because of the delayed growth of P.
yeei on MacConkey agar plates. In addition, a suspected
CNS with susceptibility to nearly all of the antimicrobial
agents tested may not trigger any further biochemical investigations for species identification 12.
R. pickettii belongs to a group of gram-negative bacilli found
in the environment, primarily in water, soil, and on plants (as
plant crop pathogens); occasionally from clinical samples.
Ralstonia spp. have traditionally exhibited low virulence in
humans but have been found in respiratory secretions of cystic fibrosis patients13 and several nosocomial outbreaks involving contaminated solutions14. Several newly recognized
R. pickettii-like species are now known to be involved in human infection, especially in CF patients 10. Ralstonia mannitolilytica accounts for more infections in CF patients than
does R. pickettii 10.
NOTE: (see M081-5 BAL: B. cepacia complex).
Table 1. Comparison of classic tests for some infrequently isolated gram-negative bacilli that grow on blood agar.
Methylobacterium
Myroides
Oligella
ureolytica
Oligella
urethralis
Paracoccus
yeei
Gram: large, vacuolated, pleomorphic
rods that may resist
decolourization
0.5 x 1-2 µm
rod-shaped
coccobacilli
coccobacilli
BAP: dry colonies;
opt temp 25-30oC
most are yellow and form
effuse, spreading colonies
slow, pinpoint at 24 h, but
large white, opaque,
nonhemolytic colonies
after 3 days
opaque to whitish
MAC - (usually no
growth)
+ Myroides
odoratimimus;
- M. odoratus
Oxidase, rapid +
+
coccobacilli; may
have donut- “O”
shaped cells due to
vacuolated or peripherally stained cells
whitish-greyish,
convex colonies 0.5
to 1 mm developing
into very mucoid
beige colonies; optimal growth 35°C
delayed, poor,
growth after
72 h or NG
+ strong
Urease - /variable
coral or pink
Positive UV
absorption
of colonies
+
(may be delayed
> 48 h)
+
rapid + (often within
minutes)
phenylalanine deaminase
yellow
pigment, fruity +; both Oligella have been
odour similar
isolated from the human
to A. faecalis;
urinary tract, cause
spread like a
urosepsis;
Bacillus
motile
+
+
+
reduce nitrate;
(morphology can be
confused with
Moraxella osloensis
[nitrate negative]);
nonmotile
Ralstonia
pickettii
Roseomonas
straight or slightly plump, coccoid rods
curved rod-shaped, in pairs & short
1-5 x 0.5-1.0 µm
chains
may grow slowly 2 to 3 days, pinpoint,
> 72 h before
grow better at
colonies are visible < 30oC; become
mucoid and runny;
will grow at 42oC
+
+ (usually), delayed
4-5 days at RT
weakly oxidase
positive
(30 seconds) or
negative
- /variable
+
+
variable
very mucoid beige indole-negative; pink (best on SAB)
Might be confused easily confused with may be better at
with a CNS;
Cupriavidus,
25 o C, and may be
delayed; also easreduce nitrate, nonPseudomonas
motile; indole fluorescens and ier to see pigment
Burkholderia ce- on a white swab
pacia complex;
ONPG (-)
+
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Roseomonas species15 are gram-negative, ranging from
plump coccoid rods, in pairs or short chains, to mainly cocci
with occasional rod forms. They are not fastidious and will
grow on most laboratory media, including MacConkey agar (up
to 91% of strains), however, growth on MacConkey may be
delayed. Growth occurs across a wide range of temperatures,
and after 2 to 3 days, pinpoint, pale-pink, shiny, often
mucoid, runny colonies will appear. The pink pigment may
be best viewed on a white swab of the colony. Occasional
strains may grow more slowly, taking 4 to 5 days. The best
growth and pigmentation is observed on Sabouraud’s agar 7.
Although initial incubation of media should be at 35-37oC, it
is important to note that many of the pink-pigmented strains
grow better at < 30oC and may be detected on plates left at
room temperature after the initial readings.
Members of this group include Roseomonas, Methylobacterium,
Asaia, and Azospirillum. Of those isolates that grow better at <
30oC carry out all identification tests at < 30oC (including
some of the commercial ID kits, e.g., API 20NE 7). The oxidase reaction is variable, as most strains will be either oxidase negative or only weakly positive. Young cultures grown
on blood agar may be oxidase positive, whereas older cultures (>72 hours) or cultures grown on chocolate agar may
give negative oxidase results. Roseomonas sp. are catalase
and urease positive and most strains are motile. Roseomonas
sp. are negative for a number of other common laboratory
tests: indole production, ONPG, hydrogen sulfide production, gelatin liquefaction, phenylalanine deaminase, esculin
hydrolysis, lysine and ornithine decarboxylases, and arginine
dihydrolase; variable reactions are obtained for citrate utilization and nitrate reduction. CMPT M083-4 (dialysate):
Roseomonas, Nov 2008.
Conclusions Bacteriology has deviated from traditional
taxonomy because it has migrated to a system that is not binomial. Increasingly new genera and species are being created faster than manufacturers can incorporate into their systems. Several of these isolates are environmental organisms
and many automated systems do not include environmental
organisms in their databases. This makes clinical laboratorians vulnerable to computerized database systems and automated identification systems. In cases of misidentification,
communication between the laboratory and manufacturer of
commercial systems may help to update databases.
As previously mentioned, classical methods (morphology
and biochemical results) and commercial systems require
skill in interpretive judgment. The laboratory standard operating procedures manual must list actions to confirm identification results when confronted with an identification that is
questionable, rare, or very unusual for the sample source.
The expected outcomes of the ‘classic tests’ should match
the organism in question. If not, then actions may include
setting up additional biochemical tests, prolonging incubation, incubating at varying temperatures and atmospheres,
looking at Gram morphology from growth on several media,
5
researching the latest text books, and so on. Sometimes it may
be necessary to forward an organism to a reference laboratory
for definitive identification.
REFERENCES
1. Schreckenberger PC, Lindquist D. 2007. Ch. 24. p. 372375. Algorithms for identification of aerobic gram-negative
bacteria. In PR Murray et al. (eds.) Manual of Clinical Microbiology, 9th ed. American Society for Microbiology,
Washington, D.C.
2. URL: http://www.newworldencyclopedia.org/entry/Bacteria
3. Vandamme PAR. 2007. Taxonomy and classification of
bacteria. Ch. 19. p. 275-290. In PR Murray et al. (eds.)
Manual of Clinical Microbiology, 9th ed. American Society
for Microbiology, Washington, D.C.
4. Woese C, Kandler O, Wheelis M. 1990. Towards a natural
system of organisms: proposal for the domains Archaea,
Bacteria, and Eucarya". Proc Natl Acad Sci. 87:12. p.
4576–9. doi:10.1073/pnas.87.12.4576
5. URL: http://en.wikipedia.org/wiki/Molecular_systematics
6. Garrity GM. (ed.) 2005. Bergey's Manual of Systematic
Bacteriology. 2nd ed. Volume 2 : The Proteobacteria Bergey's Manual of Systematic Bacteriology
7. Schreckenberger PC, Daeshvar MI, Hollis DG. 2007. Ch.
50. p. 770-802. Acinetobacter, Achromobacter,Chryseobacterium, Moraxella, and other nonfermentative gram-negative rods. In PR Murray et al. (eds.) Manual
of Clinical Microbiology, 9th ed. American Society for Microbiology, Washington, D.C.
8. Von Graevenitz A, Zbinden R, Mutters R. 2007. Ch. 40.
p. 621-635. Actinobacillus, Capnocytophaga, Eikenella,
Kingella, Pasteurella, and other fastidious or rarely encountered gram-negative rods. ibid. 9th ed.
9. Vandamme P, Coenye T. 2004. Taxonomy of the genus
Cupriavidus: a tale of lost and found. Int J Syst Evol Microbiol 54. p. 2285-2289; DOI 10.1099/ijs.0.63247-0
10.LiPuma JL, Currie BJ, Lum GD, Vandamme PAR. 2007.
Ch. 49. Burkholderia, Stenotrophomonas, Ralstonia, Cupriavidus, Pandoraea, Brevundimonas, Comamonas, Delftia, and Acidovorax. In PR Murray et al. (eds.) Manual of
Clinical Microbiology, 9th ed. American Society for Microbiology, Washington, D.C.
11. Rossau R, Kersters K, Falsen E, et al. 1987. Oligella, a
new genus including Oligella urethralis comb. nov.
(formerly Moraxella urethralis) and Oligella ureolytica sp.
nov. (formerly CDC group IVe): relationship to Taylorella
equigenitalis and related taxa. Int. J. Syst. Bacteriol.
37:198-210.[Abstract/Free Full Text]
12.Funke G, Reinhard Frodl R, Sommer H. 2004. First comprehensively documented case of Paracoccus yeei infection in a human. J Clin Microbiol. 42:7. p. 3366–3368.
13.Coenye T, Vandamme P, LiPuma JL. 2002. Infection by
Ralstonia species in Cystic Fibrosis patients: Identification
of R. pickettii and R. mannitolilytica by polymerase chain
reaction. CDC Emerging Infectious Dis. 8:7.
14.CDC. 2005. Ralstonia associated with Vapotherm oxygen
delivery device---United States. MMWR 54:1052--3.
15.M083-4 Dialysate: Roseomonas. November, 2008.
CMPT Connections “on-line” Volume 12 Number 4—Winter 2008