title: Streptococcus suisserotype 2 strains isolated in Argentina (South America) are different from those recovered in North America and present a higher risk for humans.
abstract: BACKGROUND
  Streptococcus suisserotype 2 is an important swine pathogen and emerging zoonotic agent causing meningitis and septicemia/septic shock. Strains are usually virulent (Eurasia) or of intermediate/low virulence (North America). Very few data regarding human and swine isolates from South America are available.
  
  
  METHODS
  Seventeen new humanS. suiscases in Argentina (16 serotype 2 strains and a serotype 5 strain) are reported. Alongside, 14 isolates from pigs are analyzed: 12 from systemic disease, one from lungs and one from tonsils of a healthy animal. All human serotype 2 strains and most swine isolates are sequence type (ST) 1, as determined by multilocus sequence typing and present amrp+/epf+/sly+genotype typical of virulent Eurasian ST1 strains. The remaining two strains (recovered from swine lungs and tonsils) are ST28 and possess amrp+/epf-/sly-genotype typical of low virulence North American strains. Representative human ST1 strains as well as one swine ST28 strain were analyzed by whole-genome sequencing and compared with genomes from GenBank. ST1 strains clustered together with three strains from Vietnam and this cluster is close to another one composed of 11 strains from the United Kingdom.
  
  
  CONCLUSIONS
  Close contact with pigs/pork products, a good surveillance system, and the presence of potentially virulent Eurasian-like serotype 2 strains in Argentina may be an important factor contributing to the higher number of human cases observed. In fact, Argentina is now fifth among Western countries regarding the number of reported human cases after the Netherlands, France, the UK and Poland.
authors.affiliation: Instituto Nacional de Enfermedades Infecciosas, Buenos Aires, Argentina.
authors.forename: Raquel
authors.initials: R
authors.lastname: Callejo
authors.affiliation: Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control, Changping, Beijing, PR China.
authors.forename: Han
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing Key Laboratory of Emerging Infectious Diseases, Beijing, PR China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Du
authors.affiliation: Instituto Nacional de Enfermedades Infecciosas, Buenos Aires, Argentina.
authors.forename: Monica
authors.initials: M
authors.lastname: Prieto
authors.affiliation: Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control, Changping, Beijing, PR China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Xu
authors.affiliation: Instituto Nacional de Tecnologia Agropecuaria (INTA), Marcos Juárez, Córdoba, Argentina.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Zielinski
authors.affiliation: Swine and Poultry Infectious Disease Center, (CRIPA), Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Auger
authors.affiliation: Swine and Poultry Infectious Disease Center, (CRIPA), Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
keywords: Streptococcus suis serotype 2; multilocus sequence typing; sequencing; swine; virulence factors; zoonosis