FIG. 4.

Western Blot analysis of CPE expression by selected North American human GI disease isolates. The expression of CPE by sporulating cultures of control and disease isolates of C. perfringens was evaluated using a CPE-specific Western immunoblot procedure. Isolates were grown in sporulation media as described in the Materials and Methods and then sonicated. An aliquot (40 μl) of each sonicated sporulating culture lysate was then subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblotting with CPE antibodies. The blot was developed for chemiluminescence detection to identify immunoreactive species. Results for control isolates shown include 10239 (NCTC10239, a chromosomal cpe, food poisoning isolate) and F4969 (a plasmid cpe, non-food-borne human GI disease isolate). Results for representative North American human GI disease isolates shown include food poisoning isolates 537-5 and 538-1 and AAD isolates T34058 and W30554. Molecular mass markers are shown at left; the arrow at right indicates the migration of purified CPE.