Genotypic characterization of Enterobacter sakazakii isolates by PFGE, BOX-PCR and sequencing of the fliC gene.
OBJECTIVE
Enterobacter sakazakii is an emerging food-borne pathogen that can cause rare but severe forms of neonatal meningitis, bacteraemia and necrotizing enterocolitis. A rapid typing method at the strain level is needed to determine the monoclonality or polyclonality of the isolates during outbreaks.


RESULTS
The BOX-PCR fingerprinting technique, which targets the repetitive BOX sequences, and sequencing of the flagellin gene, fliC, were evaluated against a panel of 27 Ent. sakazakii strains from clinical and environmental sources. The typeability and discriminatory power of the techniques were compared with those of pulsed-field gel electrophoresis (PFGE), the reference genotyping method. BOX-PCR results yielded 92% agreement with PFGE results, whereas fliC gene sequencing was poorly discriminative.


CONCLUSIONS
In our study, BOX-PCR and PFGE were similarly discriminatory to type Ent. sakazakii strains. The weak variability of the Ent. sakazakii fliC gene was related to the absence of the variable central domain present in most fliC genes of Enterobacteriaceae.


CONCLUSIONS
The BOX-PCR typing provides an accurate discrimination and a rapid answer to identify clonal isolates of Ent. sakazakii.
Proudy
I
I
Service de Microbiologie, EA 2128 Interactions Hôte et Microorganismes des Epithéliums, CHU Côte de Nacre, Université de Caen Basse-Normandie, Caen Cedex, France.
Bouglé
D
D
Coton
E
E
Coton
M
M
Leclercq
R
R
Vergnaud
M
M
D044083:Cronobacter sakazakii / Q000235:genetics*; D016172:DNA Fingerprinting / Q000379:methods; D004269:DNA, Bacterial / Q000032:analysis*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D004756:Enterobacteriaceae Infections / Q000175:diagnosis*; D005408:Flagellin / Q000235:genetics; D005516:Food Microbiology; D005838:Genotype; D006801:Humans; D007225:Infant Food; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length
D004269:DNA, Bacterial; D005408:Flagellin