Molecular characterisation ofSalmonellastrains isolated from outbreaks and sporadic cases of diarrhoea occurred in Paraná State, South of Brazil

Abstract

SUMMARYA total of 46 strains ofSalmonellaisolated from patients with sporadic diarrhoea or involved in foodborne outbreaks were analysed by PCR for genus identification and serotyping. Subtyping was performed using pulsed-field gel electrophoresis (PFGE) and multiple amplification of phage locus typing (MAPLT) for seven variable loci. Bacteria were identified as belonging to serotype Enteritidis (33 strains; 71·7%) or Typhimurium (13 strains; 28·3%). A high similarity coefficient (94·6%) was observed in theSalmonellaEnteritidis group for which were found three related PFGE profiles and only one MAPLT; strains representing profile PA/P1/MI were prevalent (27; 81·8%). TwoSalmonellaTyphimurium isolates were untypeable by PFGE. The remaining 11 strains had eight PFGE and three MAPLT profiles. The discriminatory power of MAPLT was lower than that of PFGE.SalmonellaEnteritidis of clonal nature is predominant in Paraná State, with the most prevalent profile PA/P1/M1 associated with sporadic diarrhoea and with seven of nine reported outbreaks. In conclusion, PFGE shows higher discriminatory power amongSalmonellastrains.