These include looking for the presence or absence of antigens, phage typing, molecular fingerprinting and biotyping, where serovars are differentiated by which nutrients they are able to ferment.

[12] In November 2016, a new strain of extensively drug resistant (XDR) Salmonella enterica serovar Typhi emerged in Pakistan, primarily from the cities of Hyderabad and Karachi.

[14] These XDR strains are resistant to all antibiotic treatment options: chloramphenicol, ampicillin, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporins.

[16] Originally in the 1880s, Salmonella species were named after the disease, host, or geological location they were associated with; however, this taxonomic characterization was contested due to genus members being categorized incompatibly with their genetic similarities.

In the 1980s, the emergence of nucleotide sequencing and DNA hybridization led many established bacteriologists such as Le Minor and Popoff (1987), Euzéby (1999), and Ezaki and Yabuuchi (2000) to put forth their proposals for nomenclature changes.

[21] The World Health Organization characterizes salmonellosis as a foodborne disease whose symptoms include diarrhea, fever, nausea, vomiting, and in severe cases death.

[22] Salmonellosis has been assessed to primarily occur in human hosts due to bacterial colonization of the intestinal tract after the consumption of contaminated food or water, but it is also known to spread from person-to-person via the fecal-oral route.

[24] It has become increasingly difficult to mitigate the presence of salmonellosis infections across the human population due to the unique nature of multidrug-resistant serovars as a result of the counterproductive effects to use antibiotics as a broad spectrum treatment.

[25] Key host immune deficiencies associated with HIV, malaria and malnutrition have contributed to a wide spread of this disease and the need to use expensive antimicrobial drugs in the poorest health services in the world.

[26] But also bacterial factors, such as upregulated activity of the virulence gene pgtE, due to a single nucleotide polymorphism (SNP) in its promoter region, have been shown to have a great impact upon the pathogenesis of this particular Salmonella sequence type.