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Table 1 Case 3 – Molecular Analysis of S. Typhimurium PT Untypable, ASSuT isolates in NSRL databases.

From: Role of subtyping in detecting Salmonella cross contamination in the laboratory

Isolate no Year Lab Source PFGE MLVA
     XbaI BlnI  
03–0407 2003 D Human B A 05-02-07-14-02
05–0802 2005 E Human A A 04-03-10-02-02
05–0900 2005 E Dairy product B A 04-04-11-00-02
05–0902 2005 E Swine B A 04-04-11-00-02
07–0146 2007 E Dairy product A B 04-03-11-02-02
07–0237 2007 E Swine A B 04-03-11-02-02
07–0200 2007 L Pork C C 05-02-07-00-02
07–0201 2007 L Unknown B A 04-03-07-02-02
07–0204 2007 L Unknown A A 04-04-16-21-02
07–0028 2007 L Pork A A 04-03-10-02-02
07–0060 2007 L Pork A A 04-03-10-02-02
07–0174 2007 L Swine A A 04-03-11-02-02
  1. Investigation of a suspected contamination incident involving 07–0146, a S. Typhimurium, PT Untypable, resistance profile ASSuT, isolated from a dairy product involved molecular analysis of all isolates sharing this isolates phenotype (n = 12). PFGE with XbaI digestion showed the isolates to be closely related, e.g. patterns A and B were 92.8% similar while C was 89% similar to A. All isolates were indistinguishable with BlnI digestion apart from 07–0146 and 07–0237 (86% similarity) and 07–0200. MLVA provided further evidence that the Salmonella isolated from the dairy product was in fact contamination from swine isolate 07–0237.
  2. The 2005 Lab E dairy isolate (05–0900) differed from 07–0146 but was indistinguishable from a swine isolate (05–0902) from Lab E which was isolated at the same time.