Search

Background The dissemination of carbapenem-resistant Acinetobacter baumannii (CRAB) became an urgent public health concern. A specific sequence type (ST) of A. bauamannii has been reported to be associated with severity of disease or mortality. This study aimed to determine the genetic relatedness of CRAB blood isolates cultured from patients at a tertiary care hospital and to investigate clinical characteristics and outcome of CRAB bacteremia. Methods CRAB blood isolates were collected between June 2016 and December 2018, and their clinical data were obtained. Multi-locus sequence test (MLST) was performed using the Oxford scheme, and the STs were assigned using the MLST database. Results Of the 126 CRAB blood isolates, 123 isolates which could be typed by MLST all belonged to clonal complex (CC) 92. During the entire period, ST369 (42.3%) was the most dominant, followed by ST191 (32.5%), ST784 (13.8%) and ST451 (4.1%). ST369 was firstly introduced in August 2017. ST191 (61.4%) was the most abundant during June 2016 to July 2017, whereas ST369 (65.8%) replaced ST191 (16.5%) since August 2017. The time interval between intensive care unit admission and bacteremia was shorter in ST369 than ST191 in multivariate analysis (day, median (Q1, Q3), ST369 6 (3, 9.8), ST191 9 (6, 17), Odd Ratio 0.87 (95% CI 0.76–0.99) P = 0.048 logistic regression). According to the ST, the 7-day and 30-day mortality rates were as follows; 46% and 65% in ST191, 50% and 62% in ST369, and 10.7% and 46.4% in the other STs. Patients infected by ST191 or 369 had significant higher 7-day mortality rates (ST191/369, 48.3% vs. the other STs 10.7%, P = 0.001 by log-rank test) and 30-day mortality rates (ST191/369, 63.2% vs. the other STs, 46.4%, P = 0.045 by log-rank test). Conclusion This study demonstrates the clonal spread of two STs at a tertiary care hospital in South Korea over 2.5 years. After the introduction of ST369, it replaced ST 191 and widely disseminated within a hospital. Two predominant STs were associated with poor outcome. Continuous surveillance are necessary to monitor the dissemination of these strains. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]

Background Invasive aspergillosis is a major cause of infectious morbidity and mortality in immunocompromised patients.However, definitive diagnosis of invasive Aspergillus infection is still difficult due to the lack of a rapid, sensitive and specific diagnostic methods. In this studies, we investigated 2-deoxy-2-[18F]fluorosorbitol ([18F]FDS) which has been reported to be accumulated in Gram-negative bacteria but not in Gram-positive bacteria or healthy mammalian or cancer cells, for the imaging detection of Aspergullus fumigatus infections with PET in vivo. Methods [18F]FDS was synthesized by reduction of 2-deoxy-2-[18F]fluoro- d -glucose ([18F]FDG) using NaBH4. When the reaction was complete, the mixture was adjusted to a pH value to 6.5–7.5. Subsequently, the solution was filtered directly into a sterile product vial through a Sep-Pak Alumina N cartridge with a sterile filter. The probe uptake assay was performed by incubating bacterial cell and fungi with [18F]FDS (20 µCi) at 37°C for 2 h. Female BALB/c were immunosuppressed with cyclophosphamide and cortisone acetate prior to A. fumigatus intranasal, intramuscular, brain infection. The mircoPET images were obtained at 2 h after i.v. injection of [18F]FDS in infected mice. Results In vitro uptake test revealed significantly higher accumulation of [18F]FDS at 2 hin A. fumigatus, C. albicans and R. oryzae rather than with bacterial strains (Figure 1). PET imaging of BALB/c mice with pulmonary A. fumigatus infections showed obvious accumulation of [18F]FDS in the infected lungs compared with control (Figure 2). [18F]FDS PET imaging also detected A. fumigatus muscle and brain infection in mice. In infected shoulder muscle of mice, [18F]FDS PET imaging showed high legion-to-background ratio at 2 h. (4.05 ± 1.59, Figure 3). Conclusion [18F]FDS PET study demonstrated stable uptake in infected tissue with A. fumigatus and rapid clearance from the blood and other organs. [18F]FDS could be a useful imaging probe visualizing the invasive aspergillosis in vivo. Disclosures All authors: No reported disclosures. [ABSTRACT FROM AUTHOR]