Am. J. Respir. Crit. Care Med.,
Volume 160, Number 1, July 1999, 374-375
NOSOCOMIAL ACQUISITION OF BURKHOLDERIA
GLADIOLI IN PATIENTS WITH CYSTIC FIBROSIS
To the Editor:
The article "Nosocomial Acquisition of Burkholderia gladioli
in Patients with Cystic Fibrosis" by Wilsher and colleagues (1) described a cross-infection problem due to B. gladioli among
six cystic fibrosis patients in an Auckland hospital. We received these isolates independently and identified them all as
B. cepacia by PCR using species-specific 16S (2) and 23S rRNA
(3) primers. In addition, all six isolates were negative with
primers specific for the internal transcribed spacer region of
B. gladioli (3). Partial 16S rRNA gene sequencing of the isolates demonstrated genetic homology to B. cepacia sequences
(less than four mismatched nucleotides) rather than to those
of B. gladioli (greater than 12 mismatched nucleotides).
Pulsed-field gel electrophoresis of XbaI DNA digests
showed that the isolates were indistinguishable from each
other and from the UK "epidemic" strain (4). These findings
were supported by the demonstration of the cbIA gene (5, 6)
and the B. cepacia epidemic strain marker (BCESM) (7) in all
six isolates. Four of the six were also positive for an insertion
sequence hybrid gene (8).
All isolates were asaccharolytic in ammonium salt sugars and
were classified as B. cepacia genomovar III biovar c (9) in contrast to Wilsher and colleagues (1) who reported them to be glucose-, xylose-, and mannitol-positive in a commercial kit system.
Simpson and coworkers (10) found that some members of
the B. cepacia "epidemic" clone ET12 described by Johnson
and colleagues (11) have phenotypic characteristics of both B. cepacia and B. gladioli. API 20 NE cannot distinguish between them; by fatty acid analysis the isolates were B. gladioli. Maltose and lactose assimilation tests which usually distinguish between the two species can give weak results for the
E 12 isolates. This is further compounded by the frequency of
asaccharolytic variants of B. cepacia as found here.
We conclude that phenotypic methods for the identification of B. cepacia and its differentiation from B. gladioli are
unreliable and that confirmation by PCR using species specific
primers is required.
FIONA E.
CLODE,
LOUISE A.
METHERELL,
and
TYRONE L.
PITT
Epidemiological Typing Unit, Laboratory of Hospital Infection, Molecular Biology Unit, Hepatitis and Retrovirus Laboratory, Central Public Health Laboratory, London, United Kingdom,
1.
Wilsher, M.,
J. Kolbe,
A. Morris, and
D. Welch.
1997.
Nosocomial acquisition of Burkholderia gladioli in patients with cystic fibrosis.
Am. J. Respir. Crit. Care Med.
155:
1436-1440
[Abstract].
2.
Campbell, P. W.,
J. A. Phillips,
G. J. Heidecker,
M. Krishnamani,
R. Zahorchak, and
T. L. Stull.
1995.
Detection of Pseudomonas (Burkholderia) cepacia using PCR.
Pediatr. Pulmonol.
20:
44-49
[Medline].
3.
Tyler, S.,
C. Strathdee,
K. Rozee, and
W. Johnson.
1995.
Oligonucleotide primers designed to differentiate pathogenic pseudomonads on
the basis of the sequencing of genes coding for 16S-23S rRNA internal
transcribed spacers.
Clin. Diag. Lab. Immunol.
2:
448-453
[Abstract].
4.
Pitt, T. L.,
M. E. Kaufmann,
P. S. Patel,
L. C. A. Benge,
S. Gaskin, and
D. M. Livermore.
1996.
Type characterisation and antibiotic susceptibility of Burkholderia (Pseudomonas) cepacia isolates from patients
with cystic fibrosis in the United Kingdom and the Republic of Ireland.
J. Med. Microbiol.
44:
203-210
[Abstract/Free Full Text].
5.
Sajjan, U. S.,
L. Sun,
R. Goldstein, and
J. F. Forstner.
1995.
Cable (Cb1)
type II pili of cystic fibrosis-associated Burkholderia (Pseudomonas)
cepacia: nucleotide sequence of the cbIA major subunit pilin gene and
novel morphology of the assembled appendage fibers.
J. Bacteriol.
177:
1030-1038
[Abstract/Free Full Text].
6.
Sun, L.,
R.-Z. Jiang,
S. Steinbach,
A. Holmes,
C. Campanelli,
J. Forstner,
U. Sajjan,
Y. Tan,
M. Riley, and
R. Goldstein.
1995.
The emergence of a highly transmissible lineage of cbl+ Pseudomonas (Burkholderia) cepacia causing CF centre epidemics in North America and
Britain.
Nature Medicine
1:
661-666
[Medline].
7.
Mahenthiralingam, E.,
D. A. Simpson, and
D. P. Speert.
1997.
Identification and characterisation of a novel DNA marker associated with epidemic Burkholderia cepacia strains recovered from patients with cystic fibrosis.
J. Clin. Microbiol.
35:
808-816
[Abstract].
8.
Tyler, S. D.,
K. R. Rozee, and
W. M. Johnson.
1996.
Identification of
IS1356 a new insertion sequence and its association with IS402 in epidemic strains of Burkholderia cepacia infecting cystic fibrosis patients.
J. Clin. Microbiol.
34:
1610-1616
[Abstract].
9.
VanDamme, P.,
B. Holmes,
M. VanCanneyt,
T. Coenye,
B. Hoste,
R. Coopman,
H. Revets,
S. Lauwers,
M. Gillis,
K. Kersters, and
J. Govan.
1997.
Occurrence of multiple genomovars of Burkholderia cepacia in cystic fibrosis patients: proposal of Burkholderia multivorans sp.
nov.
Int. J. Syst. Bacteriol.
47:
1188-1200
[Abstract/Free Full Text].
10.
Simpson, I.,
J. Finlay,
D. Winstanley,
N. Dewhurst,
J. Nelson,
S. Butler, and
J. Govan.
1994.
Multi-resistance isolates possessing characteristics
of both Burkholderia (Pseudomonas) cepacia and Burkholderia gladioli
from patients with cystic fibrosis.
J. Antimicrob. Chemother.
34:
353-361
[Abstract/Free Full Text].
11.
Johnson, W.,
S. Tyler, and
K. Rozee.
1994.
Linkage analysis of geographic and clinical clusters in Pseudomonas cepacia infections by
multilocus enzyme electrophoresis and ribotyping.
J. Clin. Microbiol.
32:
924-930
[Abstract/Free Full Text].
From the Authors:
From September 1993 to February 1995 we observed transmission of a Bukholderia species between adult patients with
cystic fibrosis in Green Lane Hospital (1). On the basis of biochemical, fatty acid analysis, and ribotyping results available
in 1995 the isolate was identified as B. gladioli. The first patient described in the outbreak had recently returned from a
trip to England where she had been hospitalized and attended
outpatient clinics. We corresponded with the hospital concerned
as well as with their reference laboratory at the Central Public
Health Laboratory, Colindale, United Kingdom. Our records
show that we sent the outbreak isolates to the Central Public
Health Laboratory in September 1995. We have however not
received notification of their arrival nor other feedback.
Over the past four years several publications have added to
our understanding of the taxonomy and nomenclature of
Burkholderia isolates (2, 3). In 1998 therefore we re-examined
the original isolates by means of whole cell protein electrophoresis analysis. These results showed that the strain reported in our original article as B. gladioli is, by current nomenclature, B. cepacia genomovar III. The correspondence
from Clode and colleagues confirms our results. We agree
with Clode and colleagues that the separation of isolates by
means of phenotypic tests is extremely difficult. In originally
describing the organism as B. gladioli we put weight on the
fatty acid analysis results. More recent work has shown that
these phenotypic characteristics are not as reliable as previously thought in being able to distinguish between Burkholderia species (2). It is probable that strains within this genus are
often not identified correctly. The occurrence of strains with
phenotypic characteristics of both B. cepacia and B. gladioli
only adds to the identification problem (3). Currently, accurate identification of genomovars and species within the genus
can be cumbersome. Unusual results warrant clarification by
genomic methods. However, although PCR methods offer
many advantages over classical identifications methods, much
more data are required before we know just how sensitive and
specific they are for species and strains of Burkholderia.
The additional results of Clode and coworkers showing the
Auckland strain to be indistinguishable from the UK "epidemic" strain (4) are noteworthy. They strongly suggest that
the strain was introduced into our hospital by the patient who
was our Case 1 after it was acquired in London before her returning to New Zealand. It would appear it is time to stop
talking of the "UK epidemic strain" as this ET12 lineage has
been known to be present in Canada, the United States, and
Europe for many years (5). It also appears to have been introduced into New Zealand in 1993 but its transmission ceased in
1995 upon the death of the last infected patient (1).
Finally, it needs to be reiterated that the outbreak occurred
despite procedures designed to prevent nosocomial transmission of respiratory pathogens. We need to retain awareness of
the danger posed by such agents and remain motivated to prevent their transmission in this vulnerable patient group.
MARGARET L. WILSHER
JOHN KOLBE
ARTHUR J. MORRIS
Departments of Respiratory Medicine
and Microbiology
Green Lane Hospital
Auckland, New Zealand
DAVID F. WELCH
Microbiology Laboratory
Laboratory Corporation of America
Dallas, Texas
PETER A. R. VANDAMME
Laboratorium voor Microbiology
Universiteit Gent
Gent, Belgium
1.
Wilsher, M. L.,
J. Kolbe,
A. J. Morris, and
D. F. Welch.
1997.
Nosocomial
acquisition of Burkholderia gladioli in patients with cystic fibrosis.
Am.
J. Respir. Crit. Care Med.
155:
1436-1440
.
2.
Vandamme, P.,
B. Holmes,
M. VanCanneyt,
T. Coenye,
B. Hoste,
R. Coopman,
H. Revets,
S. Lauwers,
M. Gillis,
K. Kersters, and
J. Govan.
1997.
Occurrence of multiple genomovars of Burkholderia cepacia in
cystic fibrosis patients: proposal of Burkholderia multivorans sp. nov.
Int. J. Syst. Bacteriol.
47:
1188-1200
.
3.
Baxter, I. A.,
P. A. Lambert, and
I. N. Simpson.
1997.
Isolation from clinical sources of Burkholderia cepacia possessing characteristics of Burkholderia gladioli.
J. Antimicrobial. Chemother.
39:
169-175
[Abstract/Free Full Text].
4.
Pitt, T. L.,
M. E. Kaufmann,
P. S. Patel,
L. C. A. Benge,
S. Gaskin, and
D.
M. Livermore.
1996.
Type characterisation and antibiotic susceptibility
of Burkholderia (Pseudomonas) cepacia isolates from patients with cystic fibrosis in the United Kingdom and the Republic of Ireland.
J. Med.
Microbiol.
44:
203-210
.
5.
Govan, J. R. W.,
J. E. Hughes, and
P. Vandamme.
1996.
Burkholderia cepacia: medical, taxonomic and ecological issues.
J. Med. Microbiol.
45:
395-407
[Abstract/Free Full Text].
