Epidemiology And Antibiotic Resistance Of Bacterial Isolations In Children With Acute Leukemia And Bloodstream Infections: Observational Study

Background: Inmunocompromised patients pose an increased risk of bacteremia due to their underlying diseases and their treatment. AIM: To compare microorganisms isolated and to describe their antimicrobial susceptibility patterns in episodes of bacteremia (ep-b) registered in children with acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML). Methods & Materials: Observational descriptive study. Between July/2014 and June/2017. Ep-b of patients with ALL and AML admitted at a children hospital with positive blood cultures were included. Patients with bone-marrow transplant and those with microorganisms considered contaminants were excluded. Clinical, epidemiological and microbiological variables were compared between ep-b occurred in ALL and AML. Chi2 test was used for statistical analysis. Results: N = 311 ep-b. ALL: 209 ep-b, 226 isolations, median age 68 months (IQR: 39-120), 56% male. In 138 (66%) ep-b, neutropenia was found and 65 (31%) had severe neutropenia. Catheter-related bacteremia was diagnosed in 70 (34%) ep-b. AML: 102 ep-b, 108 isolations, median age 72 months (IQR: 24-103), 57% male. Eighty-five (83%) were neutropenic and 30 (29%) had severe neutropenia. Catheter-related bacteremia was diagnosed in 24 (24%) ep-b. Frequency of microorganisms (ALL vs. AML) was: Enterobacteriaceae (EB) 85 (38%) vs. 39 (36%) p = 0.38, P.aeruginosa 26 (12%) vs. 3 (3%) p < 0.01, S.aureus 10 (4%) vs. 6 (6%) p = 0.4, coagulase-negative staphylococci (CNS) 36 (16%) vs. 8 (7%) p < 0.01, viridans streptococci group (VS) 19 (8%) vs. 32 (30%) p < 0.01, other gram-positive cocci 13 (6%) vs. 9 (8%) p = 0.2, yeasts 11 (5%) vs. 4 (4%) p = 0.4 and other microorganisms 26 (11%) vs. 7 (6%) p = 0.1. We detected the presence of ESBL in 16/85 vs 7/39 EB and carbapenemases in 5/85 vs. 1/39 EB; 3/3 vs. 4/8 E.faecium were vancomycin-resistant; 9/19 vs. 17/32 VS were not susceptible to penicilin and 2/19 vs. 10/32 were not susceptible to ceftriaxone in ALL and AML respectively. Three of 26 isolates of P.aeruginosa were resistant to carbapenems and 2/10 S.aureus were methicillin-resistant in ALL. All CNS were methicillin-resistant in ALL and AML. Conclusion: P.aeruginosa and CNS was significantly associated to ALL while VS to AML. Low frecuency of EB and P.aeruginosa antibiotic-resistant were observed. Most staphylococci were methicillin-resistant, most E.faecium were vancomycin-resistant and half of VS were not susceptible to penicillin. These findings should be taken into account for the choice of empirical treatments.