Integrative analysis of Salmonellosis in Israel reveals association of Salmonella enterica Serovar 9,12:l,v:- with extraintestinal infections, dissemination of endemic S. enterica Serovar Typhimurium DT104 biotypes, and severe underreporting of outbreaks.
Salmonella enterica is the leading etiologic agent of bacterial food-borne outbreaks worldwide. This ubiquitous species contains more than 2,600 serovars that may differ in their host specificity, clinical manifestations, and epidemiology. To characterize salmonellosis epidemiology in Israel and to study the association of nontyphoidal Salmonella (NTS) serovars with invasive infections, 48,345 Salmonella cases reported and serotyped at the National Salmonella Reference Center between 1995 and 2012 were analyzed. A quasi-Poisson regression was used to identify irregular clusters of illness, and pulsed-field gel electrophoresis in conjunction with whole-genome sequencing was applied to molecularly characterize strains of interest. Three hundred twenty-nine human salmonellosis clusters were identified, representing an annual average of 23 (95% confidence interval [CI], 20 to 26) potential outbreaks. We show that the previously unsequenced S. enterica serovar 9,12:l,v:- belongs to the B clade of Salmonella enterica subspecies enterica, and we show its frequent association with extraintestinal infections, compared to other NTS serovars. Furthermore, we identified the dissemination of two prevalent Salmonella enterica serovar Typhimurium DT104 clones in Israel, which are genetically distinct from other global DT104 isolates. Accumulatively, these findings indicate a severe underreporting of Salmonella outbreaks in Israel and provide insights into the epidemiology and genomics of prevalent serovars, responsible for recurring illness.
Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel Sackler Faculty of Medicine, Department of Epidemiology and Preventive Medicine, Tel Aviv University, Tel Aviv, Israel.
Alex
A
Marzel
Department of Microbiology and Molecular Genetics, University of California, Irvine, California, USA.
Prerak T
PT
Desai
Ministry of Health Central Laboratories, Jerusalem, Israel.
Israel
I
Nissan
Ministry of Health Central Laboratories, Jerusalem, Israel.
Yosef Ilan
YI
Schorr
Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel.
Jotham
J
Suez
Ministry of Health Central Laboratories, Jerusalem, Israel.
Lea
L
Valinsky
Ministry of Health Central Laboratories, Jerusalem, Israel.
Abraham
A
Reisfeld
Ministry of Health Central Laboratories, Jerusalem, Israel.
Vered
V
Agmon
U.S. Department of Agriculture, Athens, Georgia, USA.
Jean
J
Guard
Department of Microbiology and Molecular Genetics, University of California, Irvine, California, USA.
Michael
M
McClelland
Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel Galia.Rahav@sheba.health.gov.il Ohad.Gal-Mor@sheba.health.gov.il.
Galia
G
Rahav
Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel Galia.Rahav@sheba.health.gov.il Ohad.Gal-Mor@sheba.health.gov.il.
Ohad
O
Gal-Mor
D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008969:Molecular Sequence Data; D058889:Molecular Typing; D012480:Salmonella Infections / Q000453:epidemiology* / Q000382:microbiology*; D019779:Salmonella enterica / Q000145:classification* / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D065288:Serogroup
D004269:DNA, Bacterial