Cureus. 2026 Jul 2;18(7):e111932. doi: 10.7759/cureus.111932. eCollection 2026 Jul.
ABSTRACT
Antimicrobial resistance is an important clinical challenge in patients with hematologic malignancies, who are highly susceptible to severe infections due to prolonged neutropenia, disrupted mucosal barriers, intensive chemotherapy, and hematopoietic stem-cell transplantation. This systematic review synthesizes available international evidence on pathogen distribution, antimicrobial resistance patterns, and clinical outcomes in hemato-oncology settings. This systematic review searched PubMed, Scopus, and Google Scholar for English-language studies published from January 2014 to 15 November 2025. Studies reporting microbiologically confirmed infections in patients with hematologic malignancies, with extractable antimicrobial susceptibility or resistance data, were included. Due to substantial clinical, microbiological, methodological, and epidemiological heterogeneity, findings were synthesized qualitatively. Seventeen studies met the inclusion criteria. Gram-negative bacteria predominated across most settings, although pathogen distribution varied by region, age group, infection type, and denominator unit. Extended-spectrum β-lactamase (ESBL)-producing Enterobacterales, carbapenem-resistant Gram-negative bacteria, multidrug-resistant Gram-negative organisms, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant Enterococcus were reported across included studies. Where extractable study-level data were available, ESBL-related estimates ranged from 40% to 78%, while carbapenem-resistance estimates varied widely by organism group and study setting, from low carbapenem resistance among Enterobacteriaceae in one pediatric oncology cohort to 38.2% carbapenem-resistant Gram-negative bacteria in an Indian adult febrile neutropenia cohort. Mortality outcomes were heterogeneously reported and were not pooled. In comparative studies, resistant or multidrug-resistant bloodstream infections were associated with worse outcomes, including increased mortality and ICU admission, although causality cannot be inferred from the predominantly observational evidence. Antimicrobial resistance is a clinically important problem in patients with hematologic malignancies, particularly due to resistant Gram-negative pathogens. The findings support strengthened hemato-oncology-specific surveillance, local antibiogram-guided empirical therapy, antimicrobial stewardship, and standardized reporting of resistance phenotypes and clinical outcomes.
PMID:42542874 | PMC:PMC13428191 | DOI:10.7759/cureus.111932