Leukemia and risk of recurrent Escherichia coli bacteremia: genotyping implicates E. coli translocation from the colon to the bloodstream

Abstract

In patients with leukemia, the portal(s) and reasons for the persistence of an Escherichia coli recurrent bacteremia remain unclear. Adult Hematology Clinic (AHC) databases at the State Clinical Hospital in Gdańsk were reviewed to evaluate the frequency of E. coli bacteremia between 2002 and 2005. Blood and bowel E. coli strains were obtained and the genetic relatedness of the strains was analyzed. The rate of E. coli bacteremia per 1,000 admissions at the AHC was higher (85.0) than in the other clinics of the hospital (2.9), p < 0.001. A higher mortality was observed in patients with a history of E. coli versus non-E. coli bacteremia [30/95 (31 %) vs. 53/430 (12 %), p < 0.001]; 72.8 % of patients with leukemia had an unknown source of bacteremia. In 2005, 6 out of 25 (24 %) patients with leukemia had ≥2 episodes of E. coli-positive blood cultures. These gastrointestinal E. coli isolates were replaced within 3–8 weeks with a new E. coli H genotype. A recurrent episode of bacteremia was usually caused by an infection with a transient E. coli H genotype identical to that found in the subject’s bowel. Consistent with the definition of bowel/blood translocation, the bowel appeared to be a portal for E. coli in these subjects and, hence, a clear source for their recurring bacteremia.

Fecal Microbiota Transplantation in Patients With Blood Disorders Inhibits Gut Colonization With Antibiotic-Resistant Bacteria: Results of a Prospective, Single-Center Study

“…There have been recent reports of the negative effect of decreases in the heterogeneity of the gut microbiome on survival related to increased transplant-related mortality [19], and these observations may have a causal relationship. It is also clear that gut colonization in patients with hematological diseases is associated with an increased rate of life-threatening systemic infections [9][10][11][12]. We postulated that restoration of the physiological composition of gut flora using FMT may benefit individuals with blood disorders and clear the gut from ARB.…”

“…Colonized patients pose an epidemiological threat to other hospitalized individuals and to members of their households [6,7] but are also in danger of developing systemic infections with gut-colonizing microorganisms [8,9]. This is especially the case for patients with blood disorders due to suppression of their innate and/or acquired immunity.…”

“…This is especially the case for patients with blood disorders due to suppression of their innate and/or acquired immunity. It has been reported that 70% of cases of bacteremia in individuals with hemato-oncological diseases are derived from the gut [9]. Systemic infections with antibiotic-resistant bacteria (ARB; eg, carbapenem-resistant Acinetobacter baumannii and carbapenem-resistant Pseudomonas aeruginosa) in patients who have undergone allogeneic hematopoietic cell transplantation (alloHCT) are associated with a mortality rate of 36%-95% [10][11][12].…”

Gut microbiota modulation of chemotherapy efficacy and toxicity

“…Translocation describes the process through which commensal or pathogenic bacteria pass across the gut barrier into the systemic milieu, where they can contribute to the morbidity of chemotherapy 21 . Although it was first described in the 1960s 22 , and risk factors for its presence were established, the microbial and host mechanisms that drive this event are not fully defined.…”

Murine Model of Chemotherapy-Induced Extraintestinal Pathogenic Escherichia coli Translocation

“…In 85% of these patients, the infection originates from microorganisms that comprise the patient's own microbiome, especially those that inhabit the gastrointestinal (GI) tract (6). Indeed, of the potentially 500 to 1,000 different species of bacteria that inhabit the GI tract, only a handful seem capable of causing such infections, with Escherichia coli being the Gram-negative organism most frequently isolated from the blood of bacteremic patients (7) and a serious cause of life-threatening infection in those with cancer (8). Such strains are referred to as ExPEC (extraintestinal pathogenic E. coli) strains.…”