title: Genome-based study of a spatio-temporal cluster of invasive meningococcal disease due to Neisseria meningitidis serogroup C, clonal complex 11.
abstract: To describe a spatio-temporal cluster of invasive meningococcal disease (IMD) due to serogroup C meningococci, occurred in a restricted area of Tuscany between January and October 2015, and the results of whole genome sequencing (WGS).
  
  
  
  Surveillance activities and public health measures were implemented in the Region. Bacterial isolates from IMD cases were characterized by the National Reference Laboratory of the Istituto Superiore di Sanità (ISS), and WGS was performed on available strains. The kSNP software was used to identify core genome SNPs.
  
  
  
  Overall, 28 IMD cases due to meningococcus C were identified up to 31st October, 2015. Of them, 26 were due to meningococcus C:P1.5-1,10-8: F3-6:ST-11 (cc11) and 2 to C:P1.5-1,10-8: F3-6:ST-2780 (cc11). WGS of 13 meningococci isolated during the outbreak occurred in Tuscany in 2015 showed higher similarity when compared with those of 47 C: P1.5-1,10-8: F3-6:ST-11 (cc11) invasive strains from sporadic cases previously detected in Italy.
  
  
  
  A highly aggressive meningococcal C strain was involved in the cluster of severe IMD occurred in Tuscany, a Region with high vaccine coverage among children. Whether this was due to low herd immunity related to the short duration of vaccine protection needs further investigation.
authors.affiliation: Department of Infectious, Parasitic & Immuno-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy. Electronic address: paola.stefanelli@iss.it.
authors.forename: P
authors.initials: P
authors.lastname: Stefanelli
authors.affiliation: Department of Infectious, Parasitic & Immuno-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Fazio
authors.affiliation: Department of Infectious, Parasitic & Immuno-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Neri
authors.affiliation: Molecular Biology Section, Army Medical and Veterinary Research Center, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Ciammaruconi
authors.affiliation: Living Environment, Food and Veterinary Prevention and Safety Office, Tuscany Region, Florence, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Balocchini
authors.affiliation: Molecular Biology Section, Army Medical and Veterinary Research Center, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Anselmo
authors.affiliation: Laboratory of Immunology and Infectious Diseases, Anna Meyer Children's University Hospital, University of Florence, Florence, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Azzari
authors.affiliation: Department of Medical Biotechnologies, University of Siena, Italy; Department of Experimental and Clinical Medicine, University of Florence, Italy; Microbiology and Virology Unit, Florence Careggi University Hospital, Italy.
authors.forename: G M
authors.initials: GM
authors.lastname: Rossolini
authors.affiliation: Department of Infectious, Parasitic & Immuno-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Vacca
authors.affiliation: Molecular Biology Section, Army Medical and Veterinary Research Center, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Fortunato
authors.affiliation: Molecular Biology Section, Army Medical and Veterinary Research Center, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Palozzi
authors.affiliation: Molecular Biology Section, Army Medical and Veterinary Research Center, Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Fillo
authors.affiliation: Molecular Biology Section, Army Medical and Veterinary Research Center, Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Lista
authors.affiliation: Laboratory of Immunology and Infectious Diseases, Anna Meyer Children's University Hospital, University of Florence, Florence, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Moriondo
authors.affiliation: Laboratory of Immunology and Infectious Diseases, Anna Meyer Children's University Hospital, University of Florence, Florence, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Nieddu
authors.affiliation: Department of Infectious, Parasitic & Immuno-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Rezza
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000276:immunology; D002648:Child; D004196:Disease Outbreaks; D062665:Epidemiological Monitoring; D005260:Female; D016680:Genome, Bacterial; D006801:Humans; D032521:Immunity, Herd; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology; D022401:Meningococcal Vaccines / Q000276:immunology; D008875:Middle Aged; D038542:Neisseria meningitidis, Serogroup C / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013029:Space-Time Clustering; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D022401:Meningococcal Vaccines
keywords: Meningococci; Neisseria meningitidis; Surveillance; Whole genome sequencing; cc11