title: Sequencing of the grxB gene of Cronobacter spp. and the development of a PCR assay for its identification.
abstract: Cronobacter spp. (formerly Enterobacter sakazakii), a foodborne pathogen linked to powdered infant formula, is a rare cause of invasive infection with a high mortality rate in neonates. In this study, the Cronobacter sakazakii ATCC 29544 and C. muytjensii ATCC 51329 glutaredoxin 2 (grxB) genes were cloned and sequenced. Based on the unique regions of the Cronobacter grxB genes, two primers were synthesized to develop and optimize a Cronobacter-specific polymerase chain reaction (PCR) method. The PCR assay amplified a 378-bp DNA product from all positive controls, which are composed of 45 strains of Cronobacter spp., but not from any of 45 non-Cronobacter bacterial strains. The detection limits of this method are 10(4) colony-forming units (CFU)/mL of Cronobacter spp. in infant formula directly and 10(0) CFU/mL after an 8-h enrichment step. In summary, we have developed a PCR assay based on the grxB sequence. Combined with enrichment culturing, this technique offers a rapid and sensitive method for the detection of Cronobacter spp.
authors.affiliation: School of Medical Laboratory, Tianjin Medical University, Tianjin, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Dong
authors.forename: Qingping
authors.initials: Q
authors.lastname: Wu
authors.forename: Jumei
authors.initials: J
authors.lastname: Zhang
authors.forename: Shuping
authors.initials: S
authors.lastname: Mo
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Kou
authors.forename: Weipeng
authors.initials: W
authors.lastname: Guo
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D015169:Colony Count, Microbial; D044083:Cronobacter sakazakii / Q000235:genetics* / Q000302:isolation & purification*; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D054477:Glutaredoxins / Q000235:genetics*; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000737:chemistry; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D054477:Glutaredoxins