Epidemiology and emerging resistance in bacterial bloodstream infections in patients with hematologic malignancies.
BACKGROUND
The objective of this study was determine the frequency of bloodstream infections (BSIs) and the causative bacteria and their resistance patterns in patients with hematological malignancies (HMs) in a large tertiary care university hospital in Turkey over a 5-year period.


METHODS
A total of 2098 patients with HMs with 3703 neutropenic episodes were included. Patients were classified as high-risk (n = 843) and low-risk (n = 1255) groups and evaluated for frequency of BSIs, causative bacteria, and their resistance patterns.


RESULTS
The frequency of BSIs was 14.5%. The frequency of gram-negative BSIs in high-risk and low-risk groups was 10.7% and 5.4% (p < 0.001), respectively. The frequency of gram-positive BSIs in high-risk and low-risk groups was 7.0% and 3.9% (p < 0.001), respectively. Gram-negative bacteria predominated (52.6%), with Escherichia coli (17.3%) and Klebsiella spp. (11.0%) as the most frequent organisms. Coagulase-negative staphylococci (10.4%) and Corynebacterium spp. (6.3%) were the most common gram-positive bacteria (35.8%). The rate of extended-spectrum beta-lactamase (ESBL) production was 45% for E. coli and 58% for Klebsiella spp. Quinolone resistance was 58% for E. coli and 11% for Klebsiella spp.. The overall frequency of ceftazidime resistance in Pseudomonas aeruginosa was 28%, and 87% of Acinetobacter spp. were multidrug-resistant. Of Staphylococcus aureus isolates, 24.8% were resistant to methicillin.


CONCLUSION
The dominating causes of BSIs in patients with HMs in our hospital are resistant gram-negative bacteria, which has made empirical antimicrobial choice a highly challenging issue in this patient population.
['Kara|Özgür|Ö|', 'Zarakolu|Pinar|P|', 'Aşçioğlu|Sibel|S|', 'Etgül|Sezgin|S|', 'Uz|Burak|B|', 'Büyükaşik|Yahya|Y|', 'Akova|Murat|M|']
D000150:Acinetobacter D000293:Adolescent D000328:Adult D000368:Aged D000369:Aged, 80 and over D000900:Anti-Bacterial Agents D016470:Bacteremia D024881:Drug Resistance, Bacterial D004926:Escherichia coli D005260:Female D006090:Gram-Negative Bacteria D006094:Gram-Positive Bacteria D019337:Hematologic Neoplasms D006801:Humans D007709:Klebsiella D008297:Male D008826:Microbial Sensitivity Tests D008875:Middle Aged D009503:Neutropenia D011550:Pseudomonas aeruginosa D013211:Staphylococcus aureus D062606:Tertiary Care Centers D013997:Time Factors D014421:Turkey D055815:Young Adult
Bloodstream infection hematologic malignancy antimicrobial resistance bacteremia neutropenia