Volume 19, Number 1—January 2013
Dispatch
Novel Epidemic Clones of Listeria monocytogenes, United States, 2011
, and AuthorsTable
Characteristics of Listeria monocytogenes isolates representing 1 novel outbreak strain and 2 newly defined epidemic clones, ECVI and ECVII, United States, 2011*
| Isolate† | Agency | Outbreak year, location, source (type of source) | Serotype | MLST ST (CC) | MVLST VT (EC) | UP PT | DOWN PT |
|---|---|---|---|---|---|---|---|
| PFGE profile1‡ | |||||||
|
L2624 |
CDC | 2011, US, cantaloupe (C) | 1/2b | 5 (5) | 63 (VI) | – | – |
|
LIS0075 |
FDA | 2011, US, cantaloupe (F) | 1/2b | 5 (5) | 63 (VI) | – | – |
|
LIS0078 |
FDA | 2011, US, cantaloupe (E) | 1/2b | 5 (5) | 63 (VI) | – | – |
|
233 |
USDA | 2002, US, chicken plant A (F) | 1/2b | 5 (5) | 63 (VI) | – | – |
|
466 |
USDA | 2006, US, chicken plant B (F) | 1/2b | 5 (5) | 63 (VI) | – | 11 |
|
10–0810 |
NML | 1996, Canada, imitation crabmeat (C) | 1/2b | 5 (5) | 63 (VI) | 11 | 11 |
|
10–0811 |
NML
|
1996, Canada, imitation crabmeat (F)
|
1/2b
|
5 (5)
|
63 (VI)
|
11
|
11
|
| PFGE profile 2 | |||||||
|
L2625 |
CDC
|
2011, US, cantaloupe (C)
|
1/2a
|
29 (29)
|
74
|
–
|
–
|
| PFGE profile 3 | |||||||
|
L2626 |
CDC | 2011, US cantaloupe (C) | 1/2a | 561 (7)§ | 56 (VII) | – | – |
|
LIS0077 |
FDA
|
2011 US, cantaloupe (E)
|
1/2a
|
561 (7)
|
56 (VII)
|
–
|
–
|
| PFGE profile 4 | |||||||
|
L2676 |
CDC | 2011, US, cantaloupe (C) | 1/2a | 7 (7) | 56 (VII) | 18 | 13 |
|
LIS0072 |
FDA | 2011, US, cantaloupe (F) | 1/2a | 7 (7) | 56 (VII) | 18 | 13 |
|
LIS0087 |
FDA | 2011, US, cantaloupe (E) | 1/2a | 7 (7) | 56 (VII) | 18 | 13 |
|
261 |
USDA | 2002, US, chicken plant A (E) | 1/2a | 7 (7) | 56 (VII) | 18 | 13 |
|
498 |
USDA | 2006, US, chicken plant B (E) | 1/2a | 7 (7) | 56 (VII) | – | 10 |
|
10–813 |
NML | 2000 Canada, whipping cream (C) | 1/2a | 7 (7) | 56 (VII) | – | 13 |
|
10–812 |
NML | 2000 Canada, whipping cream (F) | 1/2a | 7 (7) | 56 (VII) | – | 13 |
*For comparison, additional molecular subtype data from unrelated foodborne outbreaks in Canada were obtained (4). PFGE, pulsed-field gel electrophoresis; CDC, Centers for Disease Control and Prevention; FDA, Food and Drug Administration; USDA, US Department of Agriculture; NML, National Microbiology Laboratory of Canada, Division of the Public Health Agency of Canada; MLST ST (CC), multilocus sequence typing, sequence type (clonal complex); MVLST VT (EC), multivirulence locus sequence typing, virulence type (epidemic clone); UP PT, upstream comK prophage type; DOWN PT, downstream comK prophage type; –, no PCR amplification of junction fragment.
†The numbering of outbreak strain used differs from the FDA’s final update on the outbreak (www.fda.gov/Food/FoodSafety/CORENetwork/ucm272372.htm#report).
‡PFGE profiles based on CDC and FDA analysis of isolates from cantaloupe-associated outbreak.
§ST561 differs from ST7 by 1 nonsynonymous single nucleotide polymorphism (G/A) in lhkA.
