Escherichia coli O157:H7 in Feral Swine near Spinach Fields and Cattle, Central California Coast1
Michele T. Jay* , Michael Cooley‡, Diana Carychao‡, Gerald W. Wiscomb§, Richard A. Sweitzer¶, Leta Crawford-Miksza*, Jeff A. Farrar#, David K. Lau**, Janice O’Connell*, Anne Millington#, Roderick V. Asmundson**, Edward R. Atwill, and Robert E. Mandrell‡
Author affiliations: *California Department of Public Health, Richmond, California, USA; †University of California, Davis, California, USA; ‡US Department of Agriculture, Albany, California, USA; §US Department of Agriculture, Sacramento, California, USA; ¶University of North Dakota, Grand Forks, North Dakota, USA; #California Department of Public Health, Sacramento, California, USA; **US Food and Drug Administration, Alameda, California, USA;
Figure 2. Minimum spanning tree analysis of multilocus variable number tandem repeat analysis (MLVA) data of 76 Escherichia coli O157:H7 strains typed from 47 samples compared with the spinach-related outbreak strain (subtype E). A categorical coefficient and the BURST priority rule of the highest number of single-locus changes were used for the clustering (Bionumerics software version 4.601, Applied Maths, Austin, TX, USA). Circles representing unique MLVA types are designated by an alphanumeric value (Table 2). Numbers between circles represent summed tandem-repeat differences between MLVA types (10). The shaded areas (red, green, and blue) denote genetically related clusters with MLVA differences <3. Red circles indicate types comprising isolates that were indistinguishable from the spinach-related outbreak strain (subtype E) by pulsed-field gel electrophoresis (PFGE).
The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.