title: Multilocus Sequence Typing of Cronobacter Strains Isolated from Retail Foods and Environmental Samples.
abstract: Cronobacter spp. are bacterial pathogens that affect children and immunocompromised adults. In this study, we used multilocus sequence typing (MLST) to determine sequence types (STs) in 11 Cronobacter spp. strains isolated from retail foods, 29 strains from dust samples obtained from vacuum cleaners, and 4 clinical isolates. Using biochemical tests, species-specific polymerase chain reaction, and MLST analysis, 36 strains were identified as Cronobacter sakazakii, and 6 were identified as Cronobacter malonaticus. In addition, one strain that originated from retail food and one from a dust sample from a vacuum cleaner were identified on the basis of MLST analysis as Cronobacter dublinensis and Cronobacter turicensis, respectively. Cronobacter spp. strains isolated from the retail foods were assigned to eight different MLST sequence types, seven of which were newly identified. The strains isolated from the dust samples were assigned to 7 known STs and 14 unknown STs. Three clinical isolates and one household dust isolate were assigned to ST4, which is the predominant ST associated with neonatal meningitis. One clinical isolate was classified based on MLST analysis as Cronobacter malonaticus and belonged to an as-yet-unknown ST. Three strains isolated from the household dust samples were assigned to ST1, which is another clinically significant ST. It can be concluded that Cronobacter spp. strains of different origin are genetically quite variable. The recovery of C. sakazakii strains belonging to ST1 and ST4 from the dust samples suggests the possibility that contamination could occur during food preparation. All of the novel STs and alleles for C. sakazakii, C. malonaticus, C. dublinensis, and C. turicensis determined in this study were deposited in the Cronobacter MLST database available online ( http://pubmlst.org/cronobacter/).
authors.affiliation: 1 Institute of Animal Physiology and Genetics , Academy of Sciences of the Czech Republic, Prague, Czech Republic .|2 Department of Microbiology, Nutrition, and Dietetics, Czech University of Life Sciences Prague , Prague, Czech Republic .
authors.forename: Jiří
authors.initials: J
authors.lastname: Killer
authors.affiliation: 2 Department of Microbiology, Nutrition, and Dietetics, Czech University of Life Sciences Prague , Prague, Czech Republic .
authors.forename: Eva
authors.initials: E
authors.lastname: Skřivanová
authors.affiliation: 3 Department of Biochemistry and Microbiology, University of Chemistry and Technology , Prague, Czech Republic .
authors.forename: Igor
authors.initials: I
authors.lastname: Hochel
authors.affiliation: 2 Department of Microbiology, Nutrition, and Dietetics, Czech University of Life Sciences Prague , Prague, Czech Republic .|4 Institute of Animal Science , Prague, Czech Republic .
authors.forename: Milan
authors.initials: M
authors.lastname: Marounek
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D059126:Cronobacter / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism; D044083:Cronobacter sakazakii / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism; D018153:Czech Republic; D004391:Dust; D004756:Enterobacteriaceae Infections / Q000382:microbiology; D004783:Environmental Microbiology; D005516:Food Microbiology; D006801:Humans; D058889:Molecular Typing; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D001426:Bacterial Proteins; D004391:Dust