The human vascular endothelial cell line HUV-EC-C harbors the integrated HHV-6B genome which remains stable in long term culture.

Human herpes virus 6 (HHV-6) is a common human pathogen that is most often detected in hematopoietic cells. Although human cells harboring chromosomally integrated HHV-6 can be generated in vitro, the availability of such cell lines originating from in vivo tissues is limited. In this study, chromosomally integrated HHV-6B has been identified in a human vascular endothelial cell line, HUV-EC-C (IFO50271), derived from normal umbilical cord tissue. Sequence analysis revealed that the viral genome was similar to the HHV-6B HST strain. FISH analysis using a HHV-6 DNA probe showed one signal in each cell, detected at the distal end of the long arm of chromosome 9. This was consistent with a digital PCR assay, validating one copy of the viral DNA. Because exposure of HUV-EC-C to chemicals did not cause viral reactivation, long term cell culture of HUV-EC-C was carried out to assess the stability of viral integration. The growth rate was altered depending on passage numbers, and morphology also changed during culture. SNP microarray profiles showed some differences between low and high passages, implying that the HUV-EC-C genome had changed during culture. However, no detectable change was observed in chromosome 9, where HHV-6B integration and the viral copy number remained unchanged. Our results suggest that integrated HHV-6B is stable in HUV-EC-C despite genome instability.

Development and evaluation of immunochromatography to detect Gram-negative bacteria producing ArmA 16S rRNA methylase responsible for aminoglycoside resistance.

Rapid and reliable detection of aminoglycoside-resistant bacteria is an important infection-control measure and a crucial aspect of antimicrobial chemotherapy. The enzyme 16S rRNA methylase has been shown to mediate aminoglycoside resistance in bacteria. This study describes a newly developed immunochromatographic assay using novel monoclonal antibodies (mAbs) that recognize ArmA 16S rRNA methylase. Epitope mapping showed that these mAbs recognized amino acids 1-93 of ArmA, which consists of 257 amino acids. Evaluation of the assay using ArmA producing and non-producing bacterial species, as well as bacteria producing other types of 16S rRNA methylases, indicated that immunochromatographic detection of the ArmA-type 16S rRNA methylase was fully consistent with PCR analysis for armA genes, with all immunochromatographically positive strains being resistant to aminoglycosides (MIC≥128µg/mL). The detection limit of the assay was 12ng ArmA. These findings indicate that this assay can be used for the rapid and reliable detection of the production of ArmA 16S rRNA methylase by Gram-negative bacteria, including Acinetobacter baumannii and Escherichia coli.

[Comparison of the clinical effectiveness of three neuraminidase inhibitors for Japanese pediatric patients with influenza in the 2013/2014 season].

We investigated the clinical symptoms of 206 pediatric patients with influenza virus infection and compared them among oseltamivir-treated, zanamivir-treated, and laninamivir-treated groups in 2013/2014 influenza season. The drug compliance of each neuraminidase inhibitor was good in all three groups. Although the duration of fever after administration of the first dose of each neuraminidase inhibitor were significantly prolonged in the patient with influenza B infection than in the patient with influenza A infection, no statistically significant difference in the clinical efficacy and the side effect among three groups were found. The number of biphasic fever episodes in patients treated with neuraminidase inhibitor was rare (two episodes of oseltamivir-treated group and one episode of zanamivir-treated group). In conclusion, under the good drug compliance, the efficacy of all three neuraminidase inhibitor was the same for the treatment of influenza virus infection in children.