title: Characterization of Listeria monocytogenes strains isolated during 2011-2013 from human infections in Switzerland.
abstract: Listeria monocytogenes, an emerging foodborne pathogen, can cause in the population at risk severe infections that are associated with high case fatality rates. A total of 93 L. monocytogenes strains isolated from different patients in Switzerland from July 2011 to September 2013 were further characterized. Septicemia was reported for 74.2% of the patients, meningitis for 10.8%, and abortion for 3.2%. The majority of the strains belonged to serotype 1/2a (n=58) followed by serotype 4b (n=28), 1/2b (n=5), and 1/2c (n=2). The strains represented 35 multilocus sequence typing sequence types, 8 of which were designated for the first time. Sequence analysis of the inlA gene in the 35 sequence types showed that most of the strains encoded full-length proteins. Screening for Listeriolysin S showed the presence of this virulence factor in 29 of the 33 genetic lineage I strains. By using ApaI and AscI for pulsed-field gel electrophoresis, most strains showed distinguishable patterns.
authors.affiliation: 1 Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich , Zurich, Switzerland .
authors.forename: Denise
authors.initials: D
authors.lastname: Althaus
authors.forename: Angelika
authors.initials: A
authors.lastname: Lehner
authors.forename: Sylvain
authors.initials: S
authors.lastname: Brisse
authors.forename: Mylène
authors.initials: M
authors.lastname: Maury
authors.forename: Taurai
authors.initials: T
authors.lastname: Tasara
authors.forename: Roger
authors.initials: R
authors.lastname: Stephan
mesh_terms: D000293:Adolescent; D000328:Adult; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism; D002648:Child; D016000:Cluster Analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005506:Food Contamination; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000382:microbiology; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006460:Hemolysin Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008089:Listeria monocytogenes / Q000145:classification / Q000302:isolation & purification*; D008088:Listeriosis / Q000453:epidemiology* / Q000382:microbiology; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D012703:Serotyping; D013557:Switzerland / Q000453:epidemiology; D037521:Virulence Factors; D055815:Young Adult
chemical_list: D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D037521:Virulence Factors; C038705:hlyA protein, Listeria monocytogenes