[Risk factors and prognosis in 31 patients with extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae bloodstream infection]

Abstract

Objective: To investigate the risk factors, prognosis and resistance to antibiotics in patients with extended-spectrum b-lactamase (ESBLs)-producing Escherichia coli and Klebsiella pneumoniae bloodstream infection.

Methods: A retrospective study was conducted in patients with Escherichia coli and Klebsiella pneumoniae bloodstream infection isolated from Jan. 2004 to Dec. 2005 in Peking University Third Hospital. Those with ESBLs-producing sepsis were case patients, while non-ESBLs-producing sepsis were control patients. The unpaired Student's t-test or non-parametric test and Chi-square test was used for comparison of risk factors, prognosis and resistance to antibiotics between the two groups.

Results: A total of 265 (265/748, 35.4%) strains of ESBLs-producing Escherichia coli and 56 (56/266, 21.1%) strains of Klebsiella pneumoniae were isolated between 2004 and 2005, respectively. There were 15 patients with ESBLs-producing sepsis (M/F: 8/7, age 11 - 82 yr) and 16 with non-ESBLs-producing sepsis (M/F: 5/11, age 7 d-84 yr). The frequent origins of infection in the 2 groups were respiratory system, peritoneal cavity and reproductive system. No statistical difference was found between the 2 groups in clinical symptoms such as temperature, fever type, respiratory rate, heart rate, shock, white blood cells. Pitt bacteremia score and APACHE II score (all P > 0.05). No statistical difference was found between the 2 groups in risk factors such as length of hospital stay before pathogen isolation, length of ICU stay, use of mechanical ventilation, duration of mechanical ventilation, use of central venous catheter, glucocorticosteroids or immunosuppressants, histamine-2-receptor agonists, urinary catheter, operation, gastric tube, total parenteral nutrition, previous hospital admission, anemia and hypoalbuminemia (all P > 0.05). However, the number of use of third-generation cephalosporin given 2 weeks before strains isolation was 9 in case patients (9/11) and 3 in control patients (3/10, chi(2) = 5.743, P < 0.05). The antibiotic resistance rate of ESBLs-producing Escherichia coli and Klebsiella pneumoniae increased significantly, including piperacillin (9 vs. 5, chi(2) = 7.013, P < 0.01), cefepime (7, 0, chi(2) = 7.467, P < 0.01), ceftazidime (9, 1, chi(2) = 11.317, P < 0.01), cefoperazone/sulbactam (11, 2, chi(2) = 11.780, P < 0.01), levofloxacin (12, 7, chi(2) = 5.662, P < 0.05). Five in case patients (5/15) and 2 in control patients (2/16) died.

Conclusions: Use of third-generation cephalosporin is an important risk factor for ESBLs-producing Escherichia coli and Klebsiella pneumoniae bloodstream infection. It is of great clinical significance in supervising ESBLs epidemiology and the third-generation cephalosporin usage.