The BAX PCR assay for screening Listeria monocytogenes targets a partial putative gene lmo2234.
The BAX PCR for screening Listeria monocytogenes is a commercial PCR assay for specifically targeting L. monocytogenes, a foodborne pathogen that can contaminate a variety of foods and cause a potentially fatal disease, listeriosis, among high-risk populations. The high specificity (> 98%) of this PCR assay is achieved by targeting a species-specific genomic region (approximately 400 bp) presumably found only in L. monocytogenes. In this study, the identity of the BAX PCR-targeted genomic region was determined by using PCR cloning, DNA sequencing, and basic local alignment search tool (BLAST) analysis of the amplicon sequences of an L. monocytogenes serotype 1/2a strain. BLAST analysis identified the BAX PCR amplicon (GenBank accession no. AY364605) as a 423-bp genomic region between nucleotides 224,409 and 224,831 in the genome of L. monocytogenes (serotype 1/2a strain EGD-e), including a 145-bp noncoding region and a 278-bp partial coding sequence of a putative gene, lmo2234. The translated amino acid sequence (92 amino acids) of this partial coding region is highly conserved between L. monocytogenes and Listeria innocua (93% homology). Reverse-position-specific BLAST analysis identified a conserved domain in Lmo2234 that was similar (95.3% aligned, E value = 9E-18) to the consensus amino acid sequence of sugar phosphate isomerases/epimerases (National Center for Biotechnology Information conserved domain database accession no. COG 1082.1, IolE), indicating that Lmo2234 might be involved in bacterial carbohydrate transport and metabolism.
Department of Food Science, Pennsylvania State University, University Park, Pennsylvania 16802-2504, USA.
Wei
W
Zhang
Allison
A
Hughes
Grier
G
Wilt
Stephen J
SJ
Knabel
D000595:Amino Acid Sequence; D004269:DNA, Bacterial / Q000032:analysis*; D005784:Gene Amplification; D005798:Genes, Bacterial; D008089:Listeria monocytogenes / Q000235:genetics* / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D020539:Sequence Analysis, Protein; D013045:Species Specificity
D004269:DNA, Bacterial