Multidrug resistant bacteremia in hematopoietic stem cell transplant recipients

Bacteremia become fearsome in hematopoietic stem cell transplant (HSCT) recipients with the emergence of multidrug-resistant (MDR) strains.

Our purpose was to investigate the prevalence of MDR bacteremia in HSCT recipients at the Tunisian National Bone Marrow Transplant Center, associated factors and attributable mortality rate.

Our retrospective study (January 2010-December 2017) included all MDR bacteremia in the Hematology department. MDR rods were: extended spectrum beta-lactamase producing Enterobacterales (ESBL-E), P. aeruginosa and A. baumannii resistant to at least three families of antibiotics, methicillin-resistant S. aureus (MRSA) and vancomycin resistant E. faecium (VRE).

The prevalence of MDR bacteremia among HSCT recipients was 5.9% (48/816) with a stable trend over time (rs=0.18). Neutropenia, prior hospitalization, prior antibiotherapy and prior colonization with MDR pathogens were observed in 59%, 58%, 48% and 31% of cases, respectively. Imipenem was the most prescribed first-line antibiotic (50%). The attributable mortality rate was 13%. MDR bacteria (n=48) belonged to ESBL-E (60%), P. aeruginosa (19%), A. baumannii (13%), MRSA (4%) and VRE (4%). For ESBL-E and P. aeruginosa, the rates of antibiotic resistance were respectively, 17% and 44% to imipenem, 31% and 56% to amikacin and 15% and 0% to colistin. Strains of A. baumannii were susceptible only to colistin. The MRSA (n=2) were resistant to ciprofloxacin and gentamicin and susceptible to glycopeptides. The VRE (n=2) were susceptible to linezolid and tigecycline.

Low prevalence of MDR bacteremia in HSCT recipients but high attributable mortality rate, requiring reinforcement of hygiene measures.