Cross‐species hybridization of a Borrelia burgdorferi DNA array reveals infection‐ and culture‐associated genes of the unsequenced genome of the relapsing fever agent Borrelia hermsii

• Published in: Molecular microbiology Vol. 51; no. 3; pp. 729 - 748
• Main Authors: Zhong, Jianmin, Barbour, Alan G.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.02.2004; Blackwell Science; Blackwell Publishing Ltd
• Subjects: Animals; Bacterial diseases; Bacteriology; Biological and medical sciences; Borrelia - genetics; Borrelia burgdorferi; Borrelia burgdorferi - genetics; Borrelia hermsii; Borrelia infections; Borrelia Infections - microbiology; DNA arrays; DNA, Bacterial - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Genome, Bacterial; Human bacterial diseases; Infectious diseases; Medical sciences; Mice; Mice, Inbred BALB C; Microbiology; Miscellaneous; Molecular Sequence Data; Nucleic Acid Hybridization; Oligonucleotide Array Sequence Analysis; Open Reading Frames; Plasmids - genetics; Regression Analysis; Relapsing Fever - microbiology; Sensitivity and Specificity; Species Specificity; Tropical bacterial diseases; Borrelia burgdorferi; Spirochaetaceae; Spirochaetales; Microbiology; Borrelia infection; Infection; Gene; Spirochaetosis; Bacteriosis; Bacteria; Relapsing fever; Genome; Borrelia hermsii
• ISSN: 0950-382X; 1365-2958
• DOI: 10.1046/j.1365-2958.2003.03849.x

Summary The known genome sequence of Borrelia burgdorferi, an agent of Lyme borreliosis, was used to study the genetic content and gene expression in B. hermsii, another spirochete pathogen and a cause of relapsing fever. Cross‐species hybridization of a DNA array representing 1628 open reading frames (ORF) of B. burgdorferi with genomic DNA of B. hermsii indicated that the latter organism has at least 81% of the chromosomal genes and 43% of the plasmid genes of B. burgdorferi. We then carried out quantitative hybridization of the arrays with multiple replicates of cDNA produced from B. hermsii cells growing in the blood of infected mice or in culture medium that was adjusted to the same pH, temperature and a spirochete density as infected blood. Of 642 B. burgdorferi ORFs hybridized by all replicates under both conditions, 12 (1.9%) demonstrated differential expression by a regularized t‐test and stringent criteria. BBP07 and BBG30, two plasmid‐borne ORFs with the greatest measurable difference in expression between in vivo and in vitro conditions, putatively encode proteins of unknown function. Orthologues of BBP07 in B. hermsii were identified, and increased expression in infected mice was demonstrated by quantitative reverse‐transcriptase polymerase chain reaction.