Characterization Of Fecal Coliform Isolates By Electrophoretic Analysis Of Pili

Escherichia coli bacteria isolated from the stool of normal, healthy individuals, a variety of other warm bloodied animals, and from the environment, were characterized according to a hemagglutination (HA) sequence and by electrophoresis of surface components. The hemagglutination method was rapid, inexpensive, and amendable to the analysis of many isolates. A total of 1280 isolates were analyzed by HA. The data revealed that E.coli strains exhibited a finite number (60 of 243) of HA combinations, but that isolates from different animals and environmental samples commonly produced the same HA pattern. The conclusion was that a more specific HA procedure, consisting of additional blood types, and analysis of non-finbriae associated HA, needed verification. Techniques used to isolate and purify pili were conducted on 112 isolates. The time required for bacterial growth and pili extraction were lengthy; only 4 isolates could be examined per week. Pili digests, separated by SDS-Page electrophoresis, demonstrated that isolates differed according to the number and the molecular weight of gel bands. Many protein bands outside the MW of pili were observed, indicating that the extraction procedure accumulated other contaminating surface proteins. As predicted by the HA method, pili analysis will require a more detailed procedure to be able to differentiate between individual isolates. Funding: NOAA Office of Sea Grant; grant number: NA81AA-D-00050; Funding: Mississippi Sea Grant Consortium; project number: R/ER-12;