Multilocus Sequence Typing as a Replacement for Serotyping in Salmonella enterica

Salmonella enterica subspecies enterica is traditionally subdivided into serovars by serological and nutritional characteristics. We used Multilocus Sequence Typing (MLST) to assign 4,257 isolates from 554 serovars to 1092 sequence types (STs). The majority of the isolates and many STs were grouped into 138 genetically closely related clusters called eBurstGroups (eBGs). Many eBGs correspond to a serovar, for example most Typhimurium are in eBG1 and most Enteritidis are in eBG4, but many eBGs contained more than one serovar. Furthermore, most serovars were polyphyletic and are distributed across multiple unrelated eBGs. Thus, serovar designations confounded genetically unrelated isolates and failed to recognize natural evolutionary groupings. An inability of serotyping to correctly group isolates was most apparent for Paratyphi B and its variant Java. Most Paratyphi B were included within a sub-cluster of STs belonging to eBG5, which also encompasses a separate sub-cluster of Java STs. However, diphasic Java variants were also found in two other eBGs and monophasic Java variants were in four other eBGs or STs, one of which is in subspecies salamae and a second of which includes isolates assigned to Enteritidis, Dublin and monophasic Paratyphi B. Similarly, Choleraesuis was found in eBG6 and is closely related to Paratyphi C, which is in eBG20. However, Choleraesuis var. Decatur consists of isolates from seven other, unrelated eBGs or STs. The serological assignment of these Decatur isolates to Choleraesuis likely reflects lateral gene transfer of flagellar genes between unrelated bacteria plus purifying selection. By confounding multiple evolutionary groups, serotyping can be misleading about the disease potential of S. enterica. Unlike serotyping, MLST recognizes evolutionary groupings and we recommend that Salmonella classification by serotyping should be replaced by MLST or its equivalents

Review of \u3ci\u3e Archaeology, History, and Custer\u27s Last Battle: The Little Big Horn Reexamined\u3c/i\u3e by Richard Allan Fox, Jr

Already the subject of official inquiry, interviews, innumerable articles, books, symposia, movies, recreations, demonstrations, and undoubtedly more than one barroom fight-one could legitimately ask: is there anything new left to be said about Custer\u27s\u27 \u27Last Stand at the battle of the Little Big Horn? To the delight of some and the dismay of others, this book answers forthrightly in the affirmative and it does so convincingly. Fox\u27s contribution to previous efforts (both scholarly and otherwise) derives from the field of archaeology-a relative newcomer to the discussion surrounding the events of June 25, 1876. Using the material remains of the battle (bullets, cartridge cases, and grave markers), Fox concentrates on constructing what happened step-by-step during the course of the conflict. In doing so, he leads the reader carefully and skillfully through the artifactual data and the inferences necessary to bring meaning to these mute objects. While his immediate goal is to deduce the behavior and movements of combatants on that fateful day, it is also his intent to show more broadly why the study of artifactual remains and those of historical accounts, archaeography and historiography respectively-should be linked as different ways of knowing the past. Historians may occasionally take exception with, and my fellow archaeologists feel some embarrassment over, the diligence with which Fox presses this issue in the book-but it is exactly this point which most needs to be made to the respective disciplines and to those interested in Custer\u27s Last Stand as both myth and reality