Use of Whole Genome Sequencing and Patient Interviews To Link a Case of Sporadic Listeriosis to Consumption of Prepackaged Lettuce.
We report on a case of listeriosis in a patient who probably consumed a prepackaged romaine lettuce-containing product recalled for Listeria monocytogenes contamination. Although definitive epidemiological information demonstrating exposure to the specific recalled product was lacking, the patient reported consumption of a prepackaged romaine lettuce-containing product of either the recalled brand or a different brand. A multinational investigation found that patient and food isolates from the recalled product were indistinguishable by pulsed-field gel electrophoresis and were highly related by whole genome sequencing, differing by four alleles by whole genome multilocus sequence typing and by five high-quality single nucleotide polymorphisms, suggesting a common source. To our knowledge, this is the first time prepackaged lettuce has been identified as a likely source for listeriosis. This investigation highlights the power of whole genome sequencing, as well as the continued need for timely and thorough epidemiological exposure data to identify sources of foodborne infections.
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road N.E., Atlanta, Georgia 30329, USA. KAJackson1@cdc.gov.
K A
KA
Jackson
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road N.E., Atlanta, Georgia 30329, USA.
S
S
Stroika
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road N.E., Atlanta, Georgia 30329, USA.
L S
LS
Katz
Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993, USA.
J
J
Beal
Ohio Department of Health Laboratory, 8995 East Main Street, Building 22, Reynoldsburg, Ohio 43068, USA.
E
E
Brandt
National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba, Canada R3E 3R2.
C
C
Nadon
National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba, Canada R3E 3R2.
A
A
Reimer
Greater Toronto Area Laboratory, Canadian Food Inspection Agency, 2301 Midland Avenue, Scarborough, Ontario, Canada M1P 4R7.
B
B
Major
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road N.E., Atlanta, Georgia 30329, USA; Atlanta Research and Education Foundation, Suite 355, Atlanta, Georgia 30329, USA.
A
A
Conrad
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road N.E., Atlanta, Georgia 30329, USA.
C
C
Tarr
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road N.E., Atlanta, Georgia 30329, USA.
B R
BR
Jackson
Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road N.E., Atlanta, Georgia 30329, USA.
R K
RK
Mody
D016521:Electrophoresis, Gel, Pulsed-Field; D005516:Food Microbiology; D005517:Foodborne Diseases; D006801:Humans; D018545:Lactuca; D008089:Listeria monocytogenes / Q000235:genetics; D008088:Listeriosis