Summer Hospitalization and Bronchial Asthma Make Treatment of Respiratory Syncytial Virus Infection Difficult: A Retrospective Study in Japan.

In recent years, epidemics of respiratory syncytial virus (RSV) have been seen in the summer in Japan. Patients hospitalized in the summer used a high-flow oxygen administration device more frequently than patients hospitalized in the winter. This study was a retrospective study to examine the variables associated with duration of oxygen therapy and severe cases. Subjects were pediatric patients diagnosed with RSV infection and hospitalized for treatment during the 5 years from April 2014 to March 2019. Data from 292 patients were analyzed. Duration of oxygen therapy was significantly associated with bronchial asthma (partial regression coefficient: 0.897, P = .004). Hospitalization in summer was significantly associated with severe condition (adjusted odds ratio: 4.07, 95% confidence interval: 1.16-14.27). The present study showed that bronchial asthma is a risk factor for prolonged oxygen therapy and infection in summer is a risk factor for progression to severe condition in cases of RSV infection.

A novel neuropilin-1-binding sequence in the human T-cell lymphotropic virus type 1 envelope glycoprotein.

Entry of human T-cell lymphotropic virus type 1 (HTLV-1) into host cells is mainly mediated by interactions between the viral envelope glycoprotein surface unit (SU) and three host receptors: glucose transporter type 1, heparin/heparan sulfate proteoglycan, and neuropilin-1 (Nrp1). Here, we analyzed the interaction between HTLV-1 SU and Nrp1 using nuclear magnetic resonance and isothermal titration calorimetry. We found that two SU peptides, residues 85-94 and residues 304-312, bound directly to the Nrp1 b1 domain with affinities of 7.4 and 17.7 µM, respectively. The binding modes of both peptides were almost identical to those observed for Tuftsin and vascular endothelial growth factor A binding to the Nrp1 b1 domain. These results suggest that the C-terminal region of HTLV-1 SU contains a novel site for direct binding of virus to the Nrp1 b1 domain. Our biophysical characterization of the SU peptides may help in developing inhibitors of HTLV-1 entry.

Efficacy of non-carbapenem antibiotics for pediatric patients with first febrile urinary tract infection due to extended-spectrum beta-lactamase-producing Escherichia coli.

Although carbapenem is the recommended for urinary tract infection (UTI) caused by extended-spectrum beta-lactamase (ESBL)-producing organisms, non-carbapenems have been reported to be effective for adult patients with UTI caused by ESBL-producing organisms. The purpose of this study was to evaluate the efficacy of non-carbapenems for pediatric patients with UTI due to ESBL-producing Escherichia coli (E. coli) based on the microbiologic and clinical outcomes. Fifteen children, who were treated for first febrile UTI caused by ESBL-producing E. coli were enrolled in this study. Antimicrobial susceptibilities and ESBL production were determined according to the Clinical and Laboratory Standards Institute guidelines. To detect CTX-M genes, polymerase chain reaction was performed with specific primers for blaCTX-M detection. Of the 15 enrolled patients, 10 (66.7%) were boys and 5 (33.3%) were girls, with a median age of four months. VUR was detected in six patients (40%). For detection of blaCTX-M by PCR, CTX-M-3, CTX-M-8, CTX-M-14, and CTX-M-15 were detected in five, one, eight, and one patient, respectively. Overall, 14 of the 15 isolates (93.3%) were susceptible for fosfomycin (FOM), and all isolates were susceptible for cefmetazole (CMZ), flomoxef (FMOX), and imipenem/cilastatin (IPM/CS). Of the 15 patients, 12 (80%) clinically improved without the use of carbapenems. In conclusion, even if isolates of ESBL-producing E. coli are multidrug resistant based on MIC assessment, clinical susceptibility to non-carbapenems, such as CMZ, FMOX, and FOM, is possible. Accordingly, carbapenems may not be required all the time for treatment of pediatric UTI in clinical practice.