title: Identification of high-risk Listeria monocytogenes serotypes in lineage I (serotype 1/2a, 1/2c, 3a and 3c) using multiplex PCR.
abstract: OBJECTIVE
  Using molecular subtyping techniques, Listeria monocytogenes is divided into three major phylogenetic lineages, and a multiplex PCR method can differentiate five L. monocytogenes subgroups: 1/2a-3a, 1/2c-3c, 1/2b-3b-7, 4b-4d-4e and 4a-4c. In this study, we conducted genome comparisons and evaluated serotype-associated genes for their utility as a multiplex PCR-based method for distinguishing high-risk serotypes 1/2a and 1/2c in lineage I from low-risk serotypes 3a and 3c.
  
  
  RESULTS
  Primer sets were developed that are specific for serotype 1/2c (LMOSLCC2372_0308) and serotype 3a (LMLG_0742). These primers were then tested in a multiplex format with primers specific for serotype 1/2a (flaA) to separate serotypes 1/2a, 1/2c, 3a and 3c using 25 strains of lineage I L. monocytogenes.
  
  
  CONCLUSIONS
  Here, for the first time, we report primers specific for L. monocytogenes serotype 1/2c and serotype 3a, and we demonstrate a multiplex PCR method for separating the four serotypes of lineage I L. monocytogenes.
  
  
  CONCLUSIONS
  The described multiplex PCR assay consistently showed successful separation of 1/2a and 1/2c strains from 3a and 3c strains. PCR is routinely performed in many diagnostic and epidemiologic investigations for L. monocytogenes, and these primers should increase the feasibility and accessibility of L. monocytogenes serotyping.
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA.
authors.forename: S W
authors.initials: SW
authors.lastname: Nho
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA.
authors.forename: H
authors.initials: H
authors.lastname: Abdelhamed
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA.
authors.forename: S
authors.initials: S
authors.lastname: Reddy
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA.
authors.forename: A
authors.initials: A
authors.lastname: Karsi
authors.affiliation: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Lawrence
mesh_terms: D017931:DNA Primers / Q000235:genetics; D006801:Humans; D008089:Listeria monocytogenes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D008088:Listeriosis / Q000382:microbiology*; D008969:Molecular Sequence Data; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D010802:Phylogeny; D012703:Serotyping / Q000379:methods*
chemical_list: D017931:DNA Primers
keywords: Listeria monocytogenes; PCR; diagnosis; serotype; virulence