Studies on the epidemiology of Escherichia coli, 1960-1968.

Abstract

Escherichia coli is a ubiquitous microorganism which is found in the gastrointestinal tract of every individual, where it usually forms a part of the normal gut flora. Extensive epidemiological, clinical, and bacteriological observations have documented the pathogenic significance of certain serological strains of E. coli in infantile diarrhea. However, little heed was paid to the possible role of specific E. coli in the pathogenesis of urinary infections until 1960, when the late Dr. Lowell Rantz suggested that E. coli with certain groupspecific antigens are more invasive [1]. In all, although there are more than 140 specific 0-groups of E. coli, clinical disease is caused by relatively few. Early in 1961 we began a series of epidemiologic studies to ascertain the role of these organisms in urinary tract infections [2,3]. Most urinary tract infections were caused by E. coli of a few serologic groups, namely 04, 06, and 075. The other common 0-groups?01, 050, 07, and 025?were found less frequently. Not only were urinary tract infections more commonly associated with these strains, but these organisms were also more prevalent in extrarenal gram-negative infections; and even patients who turned out not to have significant bacteriuria more commonly carried these organisms. This epidemiologic pattern held for 2 different hospitals in Seattle which cater to markedly different populations. At the same time similar patterns were found in other hospitals in the United States, including the Johns Hopkins Hospital and the Salt Lake City General Hospital. Because E. coli make up an important part of the stool flora, it seemed reasonable to postulate that these E. coli came from the patient's own