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The physical map of Campylobacter jejuni TGH9011 (ATCC 43430) was constructed by mapping the three restriction enzyme sites SacII (CCGCGG), SalI (GTCGAC), and SmaI (CCCGGG) on the genome of C. jejuni by using pulsed-field gel electrophoresis and Southern hybridization. A total of 25 restriction enzyme sites were mapped onto the C. jejuni chromosome. The size of the genome was reevaluated and was shown to be 1,812.5 kb. Ten C. jejuni genetic markers that have been isolated in our laboratory were mapped to specific restriction enzyme fragments. Furthermore, we have accurately mapped one of the three rRNA operons (rrnA) and have demonstrated a separation of the 16S and 23S rRNA-encoding sequences in one of the rRNA operons.

The three rRNA gene loci of Campylobacter jejuni TGH9011 (ATCC 43431) were cloned. All three rRNA operons were shown to possess a contiguous 16S-23S structure and contain intercistronic tRNA(Ala) and tRNA(Ile). The three RNA operons and additional 14 genetic markers were mapped in the updated genomic map of C. jejuni TGH9011, which now has a total of 24 genetic markers.

A physical map of Campylobacter upsaliensis ATCC 43954 was constructed from DNA fragments generated by Sall(5' GlTCGAC), Narl(5' GWCGCC) and BssHll (5' GKGCGC) restriction digests separated using pulsed-field gel electrophoresis. The size of the C. upsaliensis genome was approximately 2000 kb, providing evidence of the largest Campylobacter genome sized to date. Twenty-one fragments created from these restriction digests were assembled into a physical map using a combination of complementary met hods including cross-Sout hern hybridization, hybridization fingerprint analysis and hybridization with homologous and heterologous (from Campylobacter jejuni) gene probes. The position of ten genetic loci, including that of the iron-uptake regulatory (fur) gene, were localized to the physical map. A genomic library of C. upsaliensis ATCC 43954 was constructed in lambda Gem-I1 vector. Fifty thousand recombinants with an average size of 16 kb represent a library about 200 times the size of the genome. Using C. jejuni DNA probes, clones representing C. upsaliensis flaA, fur and &sZ genes were isolated and localized to the physical map.