The Epidemiology of Non-Enteric Escherichia Coli Infections: Prevalence of Serological Groups*

Abstract

Escherichia coli is an 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, although they are frequently isolated in infected sites closely related to the gastrointestinal tract, such as the appendix, gall bladder, and peritoneal cavity, little is known about the serological specificity of coliform bacteria in non-enteric infections, particularly those involving the urinary tract. Ewing (1) has emphasized that complete serological typing of E. coli should provide accurate information concerning the incidence of specific strains associated with disease and permit evaluation of nosocomial spread.The concept that some strains of gram-negative organisms may be associated with infection more often than others is not new. Kauffman (2) advanced the hypothesis that certain coliform serotypes are more prevalent in appendicitis, and he also noted that strains of certain serological groups were more frequently isolated from the urine than from feces. Others have reported that strains of certain serological groups are more commonly isolated from infected sites than from fecal specimens (3). Vahlne (4) and Sjdstedt (5) that the majority of non-enteric E. coli infections are caused by strains of a few specific serological groups, but did not support the idea that specific strains have a marked predilection for renal tissue (7). This report is an extension of these original observations and offers additional evidence that certain serological groups of E. coli are responsible for the majority of non-enteric infections because of their increased prevalence in the environment. METHODS OrganismsThe organisms included in this study were obtained from the following sources: 1) Five hundred and twentytwo strains of E. coli were isolated from patients with non-enteric infections hospitalized at King County Hospital (KCH) and University of Washington Hospital (UW) in Seattle, Johns Hopkins Hospital (JH) in Baltimore, and Salt Lake General Hospital (SL) in Salt Lake City. The isolates obtained from KCH were from consecutive patients in whom E. coli was of known pathogenic significance (292 strains from 276 patients). The majority of strains was of urinary origin. 2) Eighty-seven strains were cultured from urine samples of consecutive catheterized pregnant women with low bacterial counts (< 1,000 bacilli per ml). These were considered to represent urethral contamination. 3) Thirty-five strains were isolated from consecutive untreated patients hospitalized with overt urinary tract infections characterized by significant bacteriuria (100,000 bacilli per ml), from whom simultaneous stool specimens were obtained by rectal swab. Bacteriology A modified method of Edwards and Ewing (8) was used for group differentiation of Enterobacteriaceae by biochemical tests. All ...

Genomic identity of pyelonephritogenic Escherichia coli isolated from blood, urine and faeces of children with urosepsis

“…Therefore, the old theory ± based on phenotypic markers of E. coli [16] ± that the gut is the primary reservoir of these uropathogenic bacteria has NT, O antigen non-typable. Ã Growth on the ®rst streaking area papG class II positive; ®ve separate colonies papG-negative.…”

Role of special pathogenicity versus prevalence theory in pathogenesis of acute cystitis caused by Escherichia coli

“…prevalence versus special pathogenicity. Typically, the infecting urinary strain during cystitis is the predominant faecal and vaginal E. coli strain of the host (Yamamoto et al, 1997;Turck & Petersdorf, 1962); thus, highlighting the rationale behind studying concurrent urinary, vaginal and faecal E. coli isolates from women with acute cystitis. Furthermore, by studying the aforementioned concurrent E. coli isolates each woman also serves as her own control.…”

“…As for the mechanism of infection there are two conflicting hypotheses: (1) special pathogenicity, which states that some E. coli possess an enhanced ability to cause infection by virtue of specific virulence factors [i.e. uropathogenic E. coli (UPEC)]; and (2) prevalence, according to this hypothesis mass action or the high prevalence of E. coli at the right place and at the right time causes infection (Plos et al, 1995;Turck & Petersdorf, 1962).…”

Characteristics of Antibiotic-Resistant Escherichia Coli In the Rectum of Healthy School-Children

“…The bowel is an important reservoir for strains of Escherichia coli that infect the urinary tract (Turck, Petersdorf and Fournier, 1962). During the treatment of patients with UTI the selective pressure of antibacterial agents may profoundly influence the gut flora (Winberg et al, 1973).…”