Escherichia coli bacteremia: Clinical features, risk factors and clinical implication of antimicrobial resistance

Escherichia coli is an important cause of both community acquired (CA) and hospital acquired (HA) bacteremia. A prospective study was conducted at a tertiary care University Hospital from January, 2012 to July 2014, to compare the clinical features, risk factors, outcomes and antimicrobial resistance between E. coli bacteremia acquired from the community (CA) versus E. coli bacteremia acquired from the hospital (HA). Clinical and laboratory data of 171 adult patients with at least one positive blood culture of E. coli were analyzed. Data were collected from patients with significant blood stream infection, using medical and laboratory record files and information from treating medical staff. The overall incidence of extended spectrum beta lactamase (ESBL) infection was high, 67/171 (77.4%). Thirty-eight (40.9%) of the CA isolates were found to produce ESBL, while 28 (35.9%) of the HA isolates were ESBL producers. Patients with CA bacteremia tend to be older than those with HA bacteremia (0.003). Neoplastic diseases (hematological malignancy (<0.001), solid tumors (<0.001)), renal transplantation end stage renal disease (ESRD) (<0.006), and wound infection (<0.001) were the most commonly associated conditions in patients with HA bacteremia. Patients from the community are more likely to present with UTI (<0.001), fever and pyelonephritis (0.001). Both CA and HA E. coli isolates showed the highest sensitivity to imipenem, meropenem and amikacin followed by gentamicin and tazocin. The CA isolates are more susceptible to amikacin, tazocin and ciprofloxacin than the HA isolates. No significant difference in the mortality rate between patients with CA bacteremia and patients who acquire the bacteremia in a hospital setting (0.836) was observed. Clinicians need to be aware of the risk factors and changing pattern of antimicrobial resistance of this pathogen and should consider adequate empirical therapy with coverage of these pathogens for patients with risk factors