The growing threat of multidrug-resistant Gram-negative infections in patients with hematologic malignancies

Abstract

Prolonged neutropenia and chemotherapy-induced mucositis render patients with hematologic malignancies highly vulnerable to Gram-negative bacteremia. Unfortunately, multidrug-resistant (MDR) Gram-negative bacteria are increasingly encountered globally, and current guidelines for empirical antibiotic coverage in these patients may not adequately treat these bacteria. This expansion of resistance, coupled with traditional culturing techniques requiring 2-4 days for bacterial identification and antimicrobial susceptibility results, have grave implications for these immunocompromised hosts. This review characterizes the epidemiology, risk factors, resistance mechanisms, recommended treatments, and outcomes of the MDR Gram-negative bacteria that commonly cause infections in patients with hematologic malignancies. We also examine infection prevention strategies in hematology patients, such as infection control practices, antimicrobial stewardship, and targeted decolonization. Finally, we assess strategies to improve outcomes of infected patients, including gastrointestinal screening to guide empirical antibiotic therapy, new rapid diagnostic tools for expeditious identification of MDR pathogens, and use of two new antimicrobial agents, ceftolozane/tazobactam and ceftazidime/avibactam.

Multidrug Resistant Gram-Negative Bacteria in Community-Acquired Pneumonia

“…maltophilia is a motile, aerobic, non-fermentative Gram-negative bacillus with the ability to survive on any humid surface, form biofilm and colonize humid surfaces. It is an emerging opportunistic pathogen with multidrug resistance, which particularly affects immunocompromised patients (i.e., with malignances, post-organ transplantation) worldwide [41,42].…”

Antibiotic prophylaxis in neutropenic children with acute leukemia: Do the presently available data really support this practice?

“…Gram-negatives, represent the major threat for neutropenic patients because of a bad prognosis in the case of invasive disease. 23,[26][27][28][29][30][31][32][33] Even if the results of the major RCTs and meta-analyses suggest that administration of antibacterial prophylaxis for febrile neutropenia had no impact on the selection of resistant bacteria, it must be remembered that RCTs, and meta-analyses derived from them, should not be used for epidemiological purposes since a RCT generally did not collect data on infections occurring after the end of the study and in patients excluded from the trial itself. 1,34,35 Therefore, no data on patients (and on the environmental ecology) outside the study were available.…”

Long-term taxonomic and functional divergence from donor bacterial strains following fecal microbiota transplantation in immunocompromised patients

“…Multi-drug-resistant (MDR) bacteria are becoming increasingly common in patients with hematological malignancies, such as HCT recipients (Baker and Satlin 2016) . It has been previously shown that FMT is capable of reducing antibiotic resistance genes in immunocompetent patients being treated for CDAD (Millan et al 2016) .…”