Incidence of bacteremia and antimicrobial resistance, and associated factors among patients transferred from long-term care hospital

Dissemination of an international high-risk clone of Escherichia coli ST410 co-producing NDM-5 and OXA-181 carbapenemases in Seoul, Republic of Korea

The rapid increase in carbapenemase-producing Enterobacterales is a global health concern. During 2017-2020, a total of 44 Escherichia coli isolates co-harbouring bla_NDM-5 and bla_OXA-181 were collected from patients at 17 hospitals in Seoul and characterized based on antimicrobial susceptibility, resistance genes and plasmid replicons detected using polymerase chain reaction (PCR). Clonal relatedness was estimated using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). All isolates had an identical multidrug resistance profile, including resistance to carbapenems, cephalosporins, ciprofloxacin, tetracycline, and trimethoprim/sulfamethoxazole, and susceptibility to amikacin, colistin, and tigecycline. Resistance genes (bla_CTX-M-15, bla_CMY-2, bla_TEM-1B, bla_OXA-1, aac(6')-Ib-cr, and qnrS) and plasmid replicons (IncFIA, IncFIB, and IncX3) was observed in almost all isolates. All isolates belonged to ST410 and were genetically similar (>88% similarity), with some PFGE types shared among isolates from different hospitals. Analysis of the whole genome revealed that the isolates clustered together with other strains of the international high-risk clone ST410 B4/H24RxC from other countries. These findings underline the ongoing spread of the high-risk clone of NDM-5- and OXA-181-producing E. coli ST410 B4/H24RxC among hospitals in Seoul. Continuous monitoring and implementation of infection control measures are crucial to track and prevent further spread of these resistant strains.

Procalcitonin as a marker of Gram-negative bloodstream infections in hematological patients with febrile neutropenia

The aim of this study was to explore the predictive value of procalcitonin (PCT) in Gram-negative bloodstream infections (BSIs) in hematological patients with febrile neutropenia. A total of 1466 samples (396 blood culture (BC)-positive, 1052 BC-negative, and 18 contaminated specimens) were included, comprising 268 Gram-negative, 88 Gram-positive, 19 fungal, and 21 polymicrobial BSIs. Median PCT value (0.72 ng/mL; IQR: 0.23-3.87) was significantly higher in Gram-negative than Gram-positive (0.34 ng/mL; IQR: 0.14-2.23; p < .01), or fungal (0.27 ng/mL; IQR: 0.13-0.40; p < .01) BSIs. In mono-microbial BSIs, the best PCT cutoff distinguishing Gram-negative BSIs from all other fever causes was 0.56 ng/ml, with a specificity of 76.8%. PCT levels were significantly higher in BSIs from multidrug-resistant (MDR) Gram-negative strains than from non-MDR (p < .01). This study confirms that elevated PCT may predict Gram-negative BSIs in hematological patients with febrile neutropenia, and demonstrates higher PCT levels in MDR Gram-negative BSIs in these patients.