Alternative strategies need to be explored in the future to improve the antibiofilm characteristics of these antibiotics. These in vitro findings suggest that AMP nisin may significantly improve the antibacterial and antibiofilm activities of many antibiotics, and further, antibiotics in combination with nisin have considerable potential for use in the inhibition of drug-resistant pathogens. Over 2500 serotypes have been reported in Salmonella, and most of them result in diarrhea. Within these serotypes, Salmonella enterica serovar Typhi and Paratyphi, can lead to systemic infections in humans, known as typhoid and paratyphoid fever. These diseases cause epidemics in Asia, MK-1775 Africa and Latin America. Before the 1990s, S. Typhi was the main causative agent of enteric fever in southeast Asia and in China, but in the mid-1990s, the number of cases caused by S. Paratyphi A started to increase, and paratyphoid fever subsequently became the major enteric fever. The whole genomes of some S. Typhi and S. Paratyphi A strains have been sequenced. Genetically monomorphic genomes and relatively low sequence diversity were found, which may be the result of a high restriction of host adaption. Multilocus sequence typing and pulsed-field gel electrophoresis were used to generate phylogenetic information and obtain a population variance analysis, and for S. Typhi and S. Paratyphi A genotyping. Genomic sequencing and a single nucleotide polymorphism analysis provided high-throughput and high-resolution genome variation methodology, and were applied for the epidemic analysis of S. Typhi strains. All of the results showed a low level of genetic variation in S. Paratyphi A, and a high clonality of strains involved in epidemics. A genome comparison among different strains is used to identify the core genome and pan genome. The core genome includes the core, conserved genes and surviving characteristics which keep the microorganism evolving. In contrast, the pan genome includes newly transferred genes, and demonstrates the diversity of the organism. Genome comparisons help investigators discover the divergence of the same genes between different organisms. However, a genome analysis cannot show the differences in the protein levels, which are the actual determinants of the growth and survival of the organism. Proteomic studies can illustrate the expression levels of various gene products under given culture conditions, discover the responses to different biological systems and uncover protein modifications and protein-protein interactions. A comparison of the proteomes of different strains can indicate their shared and unique features. Besides the shared proteins, it may also help identify newly acquired gene products. Many technologies for proteome analysis are in use. In this study, we conducted a comparative proteomics analysis for four strains with different geospatial and temporal characteristics by performing 2-DE, and obtained their core and pan proteomes.