Bacterial ecology of sepsis in febrile neutropenics on hematology-oncology services

Introduction: Febrile neutropenia is a hematologic emergency that develops following treatment of hematologic malignancies. It exposes patients to the risk of sepsis, which is a major cause of morbidity and mortality. Currently, coagulase-negative staphylococci are the most common bloodborne isolates while enterobacteria are isolated less frequently. The objective of our study is to determine the epidemiological, bacteriological and antibiotic susceptibility profile of strains isolated from blood cultures collected from febrile neutropenic patients at Hassan II University Hospital, Fez. Materials and methods: This is a prospective study, over a period of 4 years (January 2019 - December 2022) including 83 patients with bacteremia hospitalized in the department of hemato-oncology. Identification and detection of antibiotic resistance was performed according to conventional bacteriology methods and CA-SFM/EUCAST recommendations. Results: Among 524 blood cultures received, we diagnosed 83 cases of bacteremia. The average age of the patients was 55 years. The average age of the patients was 55 years. The predominance of women was noted, with a sex ratio of 0.88. The majority of the episodes, 94.87%, occurred in patients followed for a neoplastic pathology. Hematological malignancies were the most responsible with a rate of 61.54% against 33.33% of solid tumors. Gram-positive bacteria represent 56.6%, and 43.4% of Gram-negative bacteria. The proportions of the different bacterial classes (BGN / CG+) have remained stable over the last 4 years, Staphylococcus epidermidis was the most frequent isolated Gram-positive bacteria 24.1℅(n=29) then Staphylococcus aureus 24.6% (n=18), followed by Gram-negative bacteria of enterobacteria type especially Escherichia coli which was the most frequently isolated pathogen (16.86%), followed by Klebsiella pneumoniae (10.84℅) and non-fermenting Gram-negative bacteria such as Pseudomonas aeruginosa (8.4) and Acinetobacter baumanii (6℅). Bacteria of clinical interest have shown increasingly worrisome levels of beta-lactam resistance, with extended-spectrum beta-lactamase (ESBL)-producing strains of Klebsiella pneumoniae accounting for 4, 8% with only one case of carbapenemase, meticillin-resistant Staphylococcus aureus was 3.61% while no imipenem-resistant Pseudomonas aeruginosa or vancomycin-resistant enterococci were found. While Acinetobacter baumanii isolates (n=5) showed increased resistance to the majority of antibiotics tested, especially to imipenem which was 100%. Discussion and conclusion: Gram-positive bacteremia of the genus coagulase-negative staphylococcus is the most common type of infection in febrile neutropenias showing an increasingly resistant profile to first-line antibiotics. However, Gram-negative infections have shown decreased susceptibility compared to previous years. A regular study of the bacterial ecology of blood culture isolates and a determination of antibiotic susceptibility are necessary to optimize the probabilistic antibiotic therapy of bacteremia.