Changing pattern of bacterial susceptibility to antibiotics in hematopoietic stem cell transplant recipients

Abstract

Summary:Adequate infection prophylaxis and empirical antibiotic therapy are of critical importance after hematopoietic stem cell transplantation (HSCT). We examined the evolution of bacterial susceptibility to antibiotics in 492 patients (198 allografts and 294 autografts) transplanted between 1982 and 1999 and evaluated whether ciprofloxacin prophylaxis and an empirical antibiotic regimen (glycopeptide + third-generation cephalosporin) were still valid. We collected all susceptibility tests performed during the initial hospitalization on blood cultures as well as routine surveillance cultures and analyzed susceptibility to ciprofloxacin and to major antibiotics used in our unit. Gram-positive cocci rapidly became resistant to ciprofloxacin (susceptibility around 70% in 1990 to less than 20% in 1998) but sensitivity to glycopeptides remained unaltered. There was a rapid decline in the number of patients colonized with Gramnegative bacilli in the early years of ciprofloxacin prophylaxis. However, susceptibility to ciprofloxacin fell sharply from around 90% in 1990 to around 30% in 1999. In parallel, susceptibility to ceftazidime also decreased to less than 80% in recent years. Piperacillin (؎ tazobactam) did not show any variation over time and its efficacy remained too low (about 60%). Imipenem as well as recently introduced cefepim and meropenem showed stable and excellent profiles (Ͼ90% susceptibility). In conclusion: (1) quinolone prophylaxis has now lost most of its value; (2) the choice of a thirdgeneration cephalosporin for empirical antibiotic therapy may no longer be the best because of the emergence of Gram-negative strains resistant to ␤-lactamases, such as Enterobacter sp. More appropriate regimens of empirical antibiotic therapy in HSCT recipients may be based on the use of a carbapenem or fourth-generation cephalosporin.

Characterization of Bacterial Infections in Allogeneic Hematopoietic Stem Cell Transplant Recipients Who Received Prophylactic Levofloxacin With Either Penicillin or Doxycycline

“…22,23 Rates of VRE colonization are increasingly reported in those who undergo HSCT, ranging from 10% to as high as 40% at some centers 24,25 ; however, numerous epidemiologic studies have noted a marginal (<5%) incidence of VRE infection in the HSCT patient population. 12,15,19 Although the earlier time period of our study is consistent with these trends, a few concerning features were identified. First, 5 VRE infections occurred in 2007, which could represent either a contained outbreak or a more generalized trend of increased VRE prevalence in our allogeneic HSCT patient population.…”

“…[16][17][18][19] Fluoroquinolone-resistant and MDR P aeruginosa and E coli were frequently identified in our allogeneic HSCT patients who received fluoroquinolonebased combination antimicrobial prophylaxis. These findings are consistent with a recent study describing prophylactic fluoroquinolone use as a risk factor for the isolation of MDR E coli in a broad neutropenic population.…”

Pretransplant serum ferritin and C-reactive protein as predictive factors for early bacterial infection after allogeneic hematopoietic cell transplantation

“…[3][4][5] Recently, the widespread emergence of FQ-resistant or multidrug-resistant microorganisms in hematologyoncology units has been suggested to compromise the effectiveness of routine antibacterial prophylaxis with FQs in patients undergoing cytotoxic chemotherapy or HCT. [6][7][8][9][10][11][12][13][14] In our center, the isolation rate of FQ-resistant Gramnegative bacilli was high (57.1%) during a period when FQs were routinely administered as antibacterial prophylactic agents; in particular, among isolated Enterobacteriaceae strains, 66.7, 33.3 and 22.2% were resistant to levofloxacin, piperacillin and ceftazidime, respectively. 8 In an attempt to reduce the emergence of antibiotic-resistant microorganisms, we stopped using any antibacterial prophylaxis in both autologous and allogeneic HCT recipients in 2004, 8 and found that this discontinuation of FQ prophylaxis, even in the setting of myeloablative allogeneic HCT did not significantly affect early mortality after transplantation.…”

Early vancomycin-resistant enterococcus (VRE) bacteremia after allogeneic bone marrow transplantation is associated with a rapidly deteriorating clinical course

“…1 There has been a concomitant trend toward antimicrobial resistance in both Gram-positive and Gram-negative bacteria. [1][2][3] The development of vancomycin resistance in enterococci has been a difficult challenge for both the clinician and the infection control practitioner. 4 In one outbreak involving leukemic patients, the mortality rate was 73%.…”