Editing Typhoid fever (section)

===Bacteria===
The [[Gram stain|Gram-negative]] bacterium that causes typhoid fever is ''Salmonella enterica'' subsp. enterica serovar Typhi. Based on the MLST subtyping scheme, the two main sequence types of the ''S.'' Typhi are ST1 and ST2, which are widespread globally.<ref name="Yap et al 2016">{{cite journal | vauthors = Yap KP, Ho WS, Gan HM, Chai LC, Thong KL | title = Global MLST of Salmonella Typhi Revisited in Post-genomic Era: Genetic Conservation, Population Structure, and Comparative Genomics of Rare Sequence Types | journal = Frontiers in Microbiology | volume = 7 | pages = 270 | date = 2016 | pmid = 26973639 | pmc = 4774407 | doi = 10.3389/fmicb.2016.00270 | doi-access = free }}</ref> Global phylogeographical analysis showed dominance of a haplotype 58 (H58), which probably originated in India during the late 1980s and is now spreading through the world with [[Multiple drug resistance|multi-drug resistance]].<ref>{{cite journal | vauthors = Wong VK, Baker S, Pickard DJ, Parkhill J, Page AJ, Feasey NA, Kingsley RA, Thomson NR, Keane JA, Weill FX, Edwards DJ, Hawkey J, Harris SR, Mather AE, Cain AK, Hadfield J, Hart PJ, Thieu NT, Klemm EJ, Glinos DA, Breiman RF, Watson CH, Kariuki S, Gordon MA, Heyderman RS, Okoro C, Jacobs J, Lunguya O, Edmunds WJ, Msefula C, Chabalgoity JA, Kama M, Jenkins K, Dutta S, Marks F, Campos J, Thompson C, Obaro S, MacLennan CA, Dolecek C, Keddy KH, Smith AM, Parry CM, Karkey A, Mulholland EK, Campbell JI, Dongol S, Basnyat B, Dufour M, Bandaranayake D, Naseri TT, Singh SP, Hatta M, Newton P, Onsare RS, Isaia L, Dance D, Davong V, Thwaites G, Wijedoru L, Crump JA, De Pinna E, Nair S, Nilles EJ, Thanh DP, Turner P, Soeng S, Valcanis M, Powling J, Dimovski K, Hogg G, Farrar J, Holt KE, Dougan G | title = Phylogeographical analysis of the dominant multidrug-resistant H58 clade of Salmonella Typhi identifies inter- and intracontinental transmission events | journal = Nature Genetics | volume = 47 | issue = 6 | pages = 632–9 | date = June 2015 | pmid = 25961941 | pmc = 4921243 | doi = 10.1038/ng.3281 }}</ref> A more detailed genotyping scheme was reported in 2016 and is now widely used. This scheme reclassified the nomenclature of H58 to genotype 4.3.1.<ref>{{cite journal | vauthors = Wong VK, Baker S, Connor TR, Pickard D, Page AJ, Dave J, Murphy N, Holliman R, Sefton A, Millar M, Dyson ZA, Dougan G, Holt KE | title = An extended genotyping framework for Salmonella enterica serovar Typhi, the cause of human typhoid | journal = Nature Communications | volume = 7 | issue = 1 | pages = 12827 | date = October 2016 | pmid = 27703135 | pmc = 5059462 | doi = 10.1038/ncomms12827 | doi-access = free | bibcode = 2016NatCo...712827W }}</ref>