The chapter discusses the genomic diversity and organization of enteric microorganisms, particularly focusing on the conservation and unique gene clusters in *Escherichia coli* and *Salmonella enterica*. The conserved genes are believed to reflect the basic lifestyle of these bacteria, while the unique gene clusters contribute to their adaptation to specific environments and pathogenicity. The pseudogene complement of *S. typhi* highlights the host restriction of this organism and raises questions about its eradication potential. The methods section details the isolation and sequencing of *Salmonella typhi* CT18, a strain isolated from a patient with typhoid fever in Vietnam. The genome sequence was obtained using a combination of whole-genome shotgun libraries and M13mp18 libraries, with coverage ranging from 1.2× to 7.9×. The genome was assembled, finished, and annotated using various tools, including Artemis and a custom-trained genefinder for *S. typhi*. The sequence was compared to other *S. typhimurium* and *E. coli* genomes to identify deletions and insertions, and inactivating mutations were identified and verified. The acknowledgements section thanks various institutions and individuals for their contributions to the project, including the Sanger Centre, Washington University, and the Danish National Research Foundation. The sequences have been submitted to EMBL with specific accession numbers.The chapter discusses the genomic diversity and organization of enteric microorganisms, particularly focusing on the conservation and unique gene clusters in *Escherichia coli* and *Salmonella enterica*. The conserved genes are believed to reflect the basic lifestyle of these bacteria, while the unique gene clusters contribute to their adaptation to specific environments and pathogenicity. The pseudogene complement of *S. typhi* highlights the host restriction of this organism and raises questions about its eradication potential. The methods section details the isolation and sequencing of *Salmonella typhi* CT18, a strain isolated from a patient with typhoid fever in Vietnam. The genome sequence was obtained using a combination of whole-genome shotgun libraries and M13mp18 libraries, with coverage ranging from 1.2× to 7.9×. The genome was assembled, finished, and annotated using various tools, including Artemis and a custom-trained genefinder for *S. typhi*. The sequence was compared to other *S. typhimurium* and *E. coli* genomes to identify deletions and insertions, and inactivating mutations were identified and verified. The acknowledgements section thanks various institutions and individuals for their contributions to the project, including the Sanger Centre, Washington University, and the Danish National Research Foundation. The sequences have been submitted to EMBL with specific accession numbers.