Previous Article | Next Article 
Journal of Clinical Microbiology, September 2000, p. 3484-3488, Vol. 38, No. 9
0095-1137/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Identification of DT104 and U302 Phage Types among
Salmonella enterica Serotype Typhimurium Isolates by
PCR
Lori C.
Pritchett,1,*
Michael E.
Konkel,2
John M.
Gay,1 and
Thomas E.
Besser3
Field Disease Investigation Unit, College of
Veterinary Medicine,1 Department of
Microbiology, College of Sciences,2 and
Department of Veterinary Microbiology and
Pathology,3 College of Veterinary Medicine,
Washington State University, Pullman, Washington 99164
Received 2 March 2000/Returned for modification 24 April
2000/Accepted 21 June 2000
 |
ABSTRACT |
A DNA sequence was identified in isolates of Salmonella
enterica serotype Typhimurium definitive type 104 (DT104). The
PCR amplification of an internal segment of this sequence identified DT104 and the closely related U302 phage type among 146 isolates of
S. enterica serotype Typhimurium tested, thus providing a
tool for rapid identification of DT104 and related isolates.
 |
TEXT |
An epidemic strain of
Salmonella enterica serotype Typhimurium definitive type 104 (DT104) rose to prominence when this multidrug-resistant (R-type
ACSSuT) pathogen was identified as a major cause of salmonellosis in
people and farm animals in Britain (12) and in people in the
United States (5). The epidemic strain of DT104 was defined by British researchers based upon Salmonella serovar
Typhimurium phage type 104, the R-type ACSSuT, and a plasmid profile
consisting of a single ~60-MDa plasmid (12).
Antimicrobial susceptibility tests to determine R-type (2)
and plasmid profile analyses (10) are widely available in U.S. laboratories, but identification of S. enterica
serotype Typhimurium phage types requires the maintenance of a phage
library and specially trained personnel. Thus, phage typing will likely always be limited to a few centralized laboratories. In addition, some
isolates cannot be assigned a phage type with the available phage
library. These difficulties hinder the progress of epidemiological investigations. We describe in this note the identification of a DNA
sequence that is unique to the DT104 and U302 phage types among
S. enterica serotype Typhimurium isolates, and the
development of a PCR assay to identify isolates containing this
sequence. This PCR assay can be used to rapidly screen suspect samples
or isolates for further testing and identification.
The PCR amplification of the 16S-to-23S spacer region of bacterial rRNA
genes has been used to detect polymorphisms in bacterial species and to
identify strains of S. enterica serotype Typhimurium associated with disease outbreaks (8, 9). Using this
technique on bovine isolates of S. enterica serotype
Typhimurium, the DT104 isolates demonstrated a unique band compared to
other phage types (Fig. 1). This unique
band was purified from the agarose gel and sequenced by the Laboratory
for Bioanalysis at Washington State University. The sequence data are
in boldface in Fig. 2.

View larger version (60K):
[in this window]
[in a new window]
|
FIG. 1.
PCR amplification products of isolates of S. enterica serotype Typhimurium obtained with primers to the
conserved regions of the 16S and 23S ribosomal genes as described by
Kostman et al. (8) and analyzed by 2% agarose gel
electrophoresis and staining with ethidium bromide. Lanes: 1 to 3, DT104; 4, 123-bp DNA ladder (Life Technologies, Gaithersburg, Md.); 5, phage type 1; 6, phage type 193. The ~550-bp polymorphism of the
DT104 isolates is indicated by the arrow.
|
|

View larger version (55K):
[in this window]
[in a new window]
|
FIG. 2.
The 1,767-bp sequence identified in S. enterica serotype Typhimurium DT104. Boldface bases indicate the
sequence identified as a polymorphism in Fig. 1 that was the result of
the primers to the rRNA gene sequences annealing to nonribosomal
sequences (identified by dotted arrows
[·········>]). The positions of
primers DT104F and DT104R are indicated by solid arrows
( ). The positions of additional primers designed to
extend the sequence are indicated by dashed arrows
(--->).
|
|
The original sequence was extended in both the 5' and 3' directions by
using sequence-specific primers (Fig. 2) and a kit designed to
facilitate genomic walking (The Vectorette System; Genosys, The
Woodlands, Tex.). A search of the nucleotide sequence databases did not
produce any matches to known ribosomal sequences, demonstrating that
the amplified polymorphism identified in Fig. 1 was the result of the
annealing of the primers to nonribosomal sequences. The possible
locations of the annealing sites are indicated on the sequence in Fig.
2.
To determine the association of this sequence with S. enterica serotype Typhimurium DT104, primers were designed for PCR
amplification of an internal segment of the sequence. Figure 2
illustrates the locations of the primers DT104F
(5'-GTCAGCAGTGTATGGAGCGA-3') and DT104R
(5'-AGTAGCGCCAGGACTCGTTA-3'), which were designed to amplify a 162-bp segment. In addition, primers INVA-1
(5'-ACAGTGCTCGTTTACGACCTGAAT-3') and INVA-2
(5'-AGACGACTGGTACTGATCGATAAT-3'), which amplify a 243-bp segment of the Salmonella invA gene (4, 11), were
included in the PCR assay as a positive control for sample preparation and the amplification reaction.
To evaluate the multiplex PCR, 239 Salmonella isolates
representing a wide range of serotypes and sources were selected from a
bank of Salmonella isolates maintained by the Field Disease Investigation Unit (FDIU), College of Veterinary Medicine, Washington State University, Pullman, Wash. These isolates were associated with
clinical cases of salmonellosis and were collected by the FDIU or
submitted to the Washington Animal Diseases Diagnostic Laboratory
between 1986 and 1997. All isolates were serogrouped and tested for
antimicrobial susceptibility (2) by the FDIU. Serotypes were
determined by the National Veterinary Services Laboratory (NVSL), U.S.
Department of Agriculture, Ames, Iowa. Phage typing was performed with
57 of the 146 isolates of S. enterica serotype Typhimurium
by the National Laboratory for Enteric Pathogens, Health Canada,
Ottawa, Canada (6), or the NVSL. Plasmid profiles (10) for 21 isolates of S. typhimurium phage type
104 were determined by the FDIU to confirm these isolates were of the
epidemic strain.
Cell lysates for each isolate were prepared in duplicate by suspending
a single bacterial colony in 300 µl of sterile distilled water in a
microcentrifuge tube and boiling for 20 min. Cell lysates were stored
at
20°C until amplified. Aliquots (5 µl) of cell lysates were
each amplified in a 25-µl reaction mixture with 1 µM (each) primers
INVA-1, INVA-2, DT104F, and DT104R; 200 µM (each) deoxynucleoside
triphosphates (dNTP), 2 mM MgCl2, 20 mM Tris-HCl (pH 8.4),
50 mM KCl, and 1.25 U of Taq DNA polymerase (Life
Technologies, Gaithersburg, Md.). Amplification was performed in 0.2-ml
microreaction tubes in a RapidCycler (Idaho Technology, Idaho Falls,
Idaho) as follows: denaturation at 96°C for 1 min; 30 cycles of
96°C for 30 s, 60°C for 30 s, and 72°C for 35 s;
and 1 final extension cycle at 72°C for 30 s. The PCR products
were visualized on ethidium bromide-stained agarose gels (Fig.
3).

View larger version (30K):
[in this window]
[in a new window]
|
FIG. 3.
Multiplex PCR amplification of isolates of
Salmonella analyzed by 2% agarose gel electrophoresis. (A)
Lanes: 1 and 19, 100-bp DNA Step Ladder (Promega Corp., Madison, Wis.);
2 to 18, isolates of S. enterica serotype Typhimurium with
phage types 1, 2, 3, 10, 51, 66, 80, 104, 121, 132, 160, 193, 208, 274, U302, 771, and 811, respectively. (B) Lanes: 1 and 8, 100-bp DNA Step
ladder; 2 to 7, isolates of S. enterica serotypes B
(Brandenburg), C (Lille), C2 (Muenchen), D (Dublin), D
(Enteritidis), and B (Typhimurium DT104), respectively. The 243-bp
amplification product of the Salmonella invA gene and the
162-bp amplification product of the newly identified sequence are
indicated.
|
|
Table 1 illustrates the variety of
serogroups, serotypes, and sample sources tested by the multiplex PCR
assay. In addition to the S. typhimurium DT104 isolates, 15 isolates of other serotypes produced the 162-bp product after PCR
amplification, including S. enterica serotype Brandenburg (1 of 1), S. enterica serotype Lille (3 of 3), S. enterica serotype Muenchen (1 of 2), S. enterica serotype Dublin (9 of 9), and S. enterica serotype
Enteritidis (1 of 3). The amplification product from one representative
isolate of each positive serotype was purified and sequenced. The
sequence data in Fig. 4 demonstrate the
PCR assay amplifies a similar 162-bp segment of DNA in these diverse
serotypes.
View this table:
[in this window]
[in a new window]
|
TABLE 1.
Serogroup, serotype, antibiotic susceptibility, PCR
assay, and source of 239 isolates of Salmonella used in
this study
|
|

View larger version (32K):
[in this window]
[in a new window]
|
FIG. 4.
Comparison of the sequences of the 162-bp product
generated by the PCR amplification of an isolate of each positive
serotype by using primers DT104F and DT104R. Nucleotides that differ
from the consensus sequence are highlighted.
|
|
Table 2 illustrates that among the 54 isolates of S. enterica serotype Typhimurium with phage
typing data, all 21 DT104 isolates tested by this multiplex PCR
produced the 162-bp amplification product. In addition, three isolates
with phage type U302 produced the 162-bp amplification product, and
U302 is considered an offspring of the DT104 strain (R. D. Khakhria, personal communication). None of the 15 other defined phage
types of S. enterica serotype Typhimurium tested produced
the 162-bp product following PCR. Three isolates of multidrug-resistant
S. enterica serotype Typhimurium submitted for phage typing
could not be assigned a defined phage type, and these isolates also did
not produce the 162-bp product following PCR.
A sequence identity search (1) produced a closely matched
alignment (98% identity) between bases 1645 and 1716 of the newly identified sequence in S. enterica serotype Typhimurium
DT104 and 71 of 72 bases of an unfinished fragment of S. enterica serotype Typhi (microbial genome BLAST database accession
no. Sanger_601). An additional alignment (80% identity) was identified
for 382 bp of the newly identified sequence with a cDNA clone from a
mouse blastocyst that is described as being similar to replication
protein 14 from bacteriophage
80 (GenBank accession no. AA574821).
Recent studies have described PCR assays to detect S. enterica serotype Typhimurium DT104 based upon amplification of
regions of antibiotic resistance genes (3, 7). Our data
indicate that the sequence we have identified in DT104 is not
associated with the R-type ACSSuT. Fifteen isolates among other
serotypes yield an amplification product similar to DT104, but these
isolates were predominantly sensitive to one or more of the antibiotics that distinguish multidrug-resistant DT104. There was no common resistance pattern among these non-Typhimurium-positive isolates, and 5 of the 15 isolates were sensitive to all five antibiotics. Also, five
isolates of S. enterica serotype Typhimurium
one phage type
10, one phage type 771, and three isolates that could not be phage
typed
all have the R-type ACSSuT and do not yield an amplification
product in our PCR assay (Table 2).
In conclusion, we have identified a 1,767-bp sequence in S. enterica serotype Typhimurium DT104 and developed a PCR assay to
amplify an internal segment of this sequence. This multiplex PCR assay,
in combination with serotype data, identifies the DT104 and U302 phage
types. Furthermore, the similarity of the 162-bp amplification products
among different serotypes of Salmonella and the alignment of
a portion of the extended sequence with an unfinished fragment of
S. enterica serotype Typhi suggest the possibility of the
horizontal transfer of DNA.
Nucleotide sequence accession number.
The sequence of DT104
has been submitted to GenBank under accession no. AF275268.
 |
ACKNOWLEDGMENTS |
This work was funded by a grant from the American Veterinary
Medical Foundation and the USDA Fund for Rural America.
 |
FOOTNOTES |
*
Corresponding author. Mailing address: Field Disease
Investigation Unit, College of Veterinary Medicine, Washington State University, Pullman, WA 99164. Phone: (509) 335-0808. Fax: (509) 335-0880. E-mail: lcp{at}vetmed.wsu.edu.
 |
REFERENCES |
| 1.
|
Altschul, S. F.,
T. L. Madden,
A. A. Schäffer,
J. Zhang,
W. Miller, and D. J. Lipman.
1997.
Gapped BLAST and PSI-BLAST: a new generation of protein database search programs.
Nucleic Acids Res.
25:3389-3402[Abstract/Free Full Text].
|
| 2.
|
Bauer, A. W.,
W. M. M. Kirby,
J. C. Sherris, and M. Turck.
1966.
Antibiotic susceptibility testing by a standardized single disk method.
Am. J. Clin. Pathol.
36:493-496.
|
| 3.
|
Carlson, S. A.,
L. F. Bolton,
C. E. Briggs,
H. S. Hurd,
V. K. Sharma,
P. J. Fedorka-Cray, and B. D. Jones.
1999.
Detection of multiresistant Salmonella typhimurium DT104 using multiplex and fluorogenic PCR.
Mol. Cell. Probes
13:213-222[CrossRef][Medline].
|
| 4.
|
Chiu, C.-H., and J. T. Ou.
1996.
Rapid identification of Salmonella serovars in feces by specific detection of virulence genes, invA and spvC, by an enrichment broth culture-multiplex PCR combination assay.
J. Clin. Microbiol.
34:2619-2622[Abstract].
|
| 5.
|
Glynn, M. K.,
C. Bopp,
W. Dewitt,
P. Dabney,
M. Mokhtar, and F. J. Angulo.
1998.
Emergence of multidrug-resistant Salmonella enterica serotype typhimurium DT104 infections in the United States.
N. Engl. J. Med.
338:1333-1338[Abstract/Free Full Text].
|
| 6.
|
Khakhria, R. D.,
D. Woodward,
W. M. Johnson, and C. Poppe.
1997.
Salmonella isolated from humans, animals and other sources in Canada, 1983-92.
Epidemiol. Infect.
119:15-23[CrossRef][Medline].
|
| 7.
|
Khan, A. A.,
M. S. Nawaz,
S. A. Khan, and C. E. Cerniglia.
2000.
Detection of multidrug-resistant Salmonella typhimurium DT104 by multiplex polymerase chain reaction.
FEMS Microbiol. Lett.
182:355-360[CrossRef][Medline].
|
| 8.
|
Kostman, J. R.,
T. D. Edlind,
J. J. LiPuma, and T. L. Stull.
1992.
Molecular epidemiology of Pseudomonas cepacia determined by polymerase chain reaction ribotyping.
J. Clin. Microbiol.
30:2084-2087[Abstract/Free Full Text].
|
| 9.
|
Natasi, A., and C. Mammima.
1995.
Epidemiological evaluation by PCR ribotyping of sporadic and outbreak-associated strains of Salmonella enterica serotype typhimurium.
Res. Microbiol.
146:99-106[Medline].
|
| 10.
|
Portnoy, D. A.,
S. L. Moseley, and S. Falkow.
1981.
Characterization of plasmids and plasmid-associated determinants of Yersinia enterocolitica pathogenesis.
Infect. Immun.
31:775-782[Abstract/Free Full Text].
|
| 11.
|
Rahn, K.,
S. A. DeGrandis,
R. C. Clarke,
S. A. McEwen,
J. E. Gal'an,
C. Ginochhio,
R. Curtiss, and C. L. Gyles.
1992.
Amplification of an invA gene sequence of Salmonella typhimurium by polymerase chain reaction as a specific method of detection of salmonella.
Mol. Cell. Probes
6:271-290[CrossRef][Medline].
|
| 12.
|
Wall, P. G.,
D. Morgan,
K. Lamden,
M. Ryan,
M. Griffin,
E. J. Threlfall,
L. R. Ward, and B. Rowe.
1994.
A case control study of infection with an epidemic strain of multiresistant Salmonella typhimurium DT 104 in England and Wales.
Commun. Dis. Rep. CDR Rev.
4:R130-R135[Medline].
|
Journal of Clinical Microbiology, September 2000, p. 3484-3488, Vol. 38, No. 9
0095-1137/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Apanavicius, C. J., Powell, K. L., Vester, B. M., Karr-Lilienthal, L. K., Pope, L. L., Fastinger, N. D., Wallig, M. A., Tappenden, K. A., Swanson, K. S.
(2007). Fructan Supplementation and Infection Affect Food Intake, Fever, and Epithelial Sloughing from Salmonella Challenge in Weanling Puppies. J. Nutr.
137: 1923-1930
[Abstract]
[Full Text]
-
Selke, M., Meens, J., Springer, S., Frank, R., Gerlach, G.-F.
(2007). Immunization of Pigs To Prevent Disease in Humans: Construction and Protective Efficacy of a Salmonella enterica Serovar Typhimurium Live Negative-Marker Vaccine. Infect. Immun.
75: 2476-2483
[Abstract]
[Full Text]
-
Yokoyama, E., Maruyama, S., Kabeya, H., Hara, S., Sata, S., Kuroki, T., Yamamoto, T.
(2007). Prevalence and Genetic Properties of Salmonella enterica Serovar Typhimurium Definitive Phage Type 104 Isolated from Rattus norvegicus and Rattus rattus House Rats in Yokohama City, Japan. Appl. Environ. Microbiol.
73: 2624-2630
[Abstract]
[Full Text]
-
Antunes, P., Machado, J., Peixe, L.
(2007). Dissemination of sul3-Containing Elements Linked to Class 1 Integrons with an Unusual 3' Conserved Sequence Region among Salmonella Isolates. Antimicrob. Agents Chemother.
51: 1545-1548
[Abstract]
[Full Text]
-
Antunes, P., Machado, J., Peixe, L.
(2006). Characterization of antimicrobial resistance and class 1 and 2 integrons in Salmonella enterica isolates from different sources in Portugal. J Antimicrob Chemother
58: 297-304
[Abstract]
[Full Text]
-
Chiu, C.-H., Su, L.-H., Chu, C.-H., Wang, M.-H., Yeh, C.-M., Weill, F.-X., Chu, C.
(2006). Detection of Multidrug-Resistant Salmonella enterica Serovar Typhimurium Phage Types DT102, DT104, and U302 by Multiplex PCR.. J. Clin. Microbiol.
44: 2354-2358
[Abstract]
[Full Text]
-
de la Torre, E., Tello, M., Mateu, E. M., Torre, E.
(2005). Use of Biochemical Kinetic Data To Determine Strain Relatedness among Salmonella enterica subsp. enterica Isolates. J. Clin. Microbiol.
43: 5419-5424
[Abstract]
[Full Text]
-
Hermans, A. P. H. M., Abee, T., Zwietering, M. H., Aarts, H. J. M.
(2005). Identification of Novel Salmonella enterica Serovar Typhimurium DT104-Specific Prophage and Nonprophage Chromosomal Sequences among Serovar Typhimurium Isolates by Genomic Subtractive Hybridization. Appl. Environ. Microbiol.
71: 4979-4985
[Abstract]
[Full Text]
-
Amavisit, P., Boonyawiwat, W., Bangtrakulnont, A.
(2005). Characterization of Salmonella enterica Serovar Typhimurium and Monophasic Salmonella Serovar 1,4,[5],12:i:- Isolates in Thailand. J. Clin. Microbiol.
43: 2736-2740
[Abstract]
[Full Text]
-
Ahmed, A. M., Nakano, H., Shimamoto, T.
(2005). Molecular characterization of integrons in non-typhoid Salmonella serovars isolated in Japan: description of an unusual class 2 integron. J Antimicrob Chemother
55: 371-374
[Abstract]
[Full Text]
-
Antunes, P., Machado, J., Sousa, J. C., Peixe, L.
(2005). Dissemination of Sulfonamide Resistance Genes (sul1, sul2, and sul3) in Portuguese Salmonella enterica Strains and Relation with Integrons. Antimicrob. Agents Chemother.
49: 836-839
[Abstract]
[Full Text]
-
Antunes, P., Machado, J., Sousa, J. C., Peixe, L.
(2004). Dissemination amongst humans and food products of animal origin of a Salmonella typhimurium clone expressing an integron-borne OXA-30 {beta}-lactamase. J Antimicrob Chemother
54: 429-434
[Abstract]
[Full Text]
-
Alvarez, J., Sota, M., Vivanco, A. B., Perales, I., Cisterna, R., Rementeria, A., Garaizar, J.
(2004). Development of a Multiplex PCR Technique for Detection and Epidemiological Typing of Salmonella in Human Clinical Samples. J. Clin. Microbiol.
42: 1734-1738
[Abstract]
[Full Text]
-
de la Torre, E., Zapata, D., Tello, M., Mejia, W., Frias, N., Garcia Pena, F. J., Mateu, E. M., Torre, E.
(2003). Several Salmonella enterica subsp. enterica Serotype 4,5,12:i:- Phage Types Isolated from Swine Samples Originate from Serotype Typhimurium DT U302. J. Clin. Microbiol.
41: 2395-2400
[Abstract]
[Full Text]
-
Carattoli, A., Filetici, E., Villa, L., Dionisi, A. M., Ricci, A., Luzzi, I.
(2002). Antibiotic Resistance Genes and Salmonella Genomic Island 1 in Salmonella enterica Serovar Typhimurium Isolated in Italy. Antimicrob. Agents Chemother.
46: 2821-2828
[Abstract]
[Full Text]
-
Gebreyes, W. A., Altier, C.
(2002). Molecular Characterization of Multidrug-Resistant Salmonella enterica subsp. enterica Serovar Typhimurium Isolates from Swine. J. Clin. Microbiol.
40: 2813-2822
[Abstract]
[Full Text]