SPINK1 as a plasma marker for tumor hypoxia and a therapeutic target for radiosensitization

Hypoxia is associated with tumor radioresistance; therefore, a predictive marker for tumor hypoxia and a rational target to overcome it have been sought to realize personalized radiotherapy. Here, we show that serine protease inhibitor Kazal type I (SPINK1) meets these 2 criteria. SPINK1 expression was induced upon hypoxia (O2 < 0.1%) at the transcription initiation level in a HIF-dependent manner, causing an increase in secreted SPINK1 levels. SPINK1 proteins were detected both within and around hypoxic regions of xenografted and clinical tumor tissues, and their plasma levels increased in response to decreased oxygen supply to xenografts. Secreted SPINK1 proteins enhanced radioresistance of cancer cells even under normoxic conditions in EGFR-dependent and nuclear factor erythroid 2–related factor 2–dependent (Nrf2-dependent) manners and accelerated tumor growth after radiotherapy. An anti-SPINK1 neutralizing antibody exhibited a radiosensitizing effect. These results suggest that SPINK1 secreted from hypoxic cells protects the surrounding and relatively oxygenated cancer cells from radiation in a paracrine manner, justifying the use of SPINK1 as a target for radiosensitization and a plasma marker for predicting tumor hypoxia

Multicenter evaluation of Verigene Enteric Pathogens Nucleic Acid Test for detection of gastrointestinal pathogens

We investigated the efficiency of the Verigene Enteric Pathogens Nucleic Acid Test (Verigene EP test), which is an automated microarray-based assay system that enables rapid and simultaneous genetic detection of gastrointestinal pathogens and toxins, including those in the Campylobacter　Group, Salmonella species, Shigella species, the Vibrio Group, Yersinia enterocolitica, Shiga toxin 1 and 2, norovirus GI/GII, and rotavirus A. Three clinical laboratories evaluated the Verigene EP test, using 268 stool samples for bacterial and toxin genes and 167 samples for viral genes.Culture-based reference methods were used for the detection of bacteria and toxins, while a different molecular assay was used for viral detection. The overall concordance rate between the Verigene EP test and the reference methods for the 1940 assays was 99.0%. The overall sensitivity and specificity of the Verigene EP test were 97.0% and 99.3%, respectively. Of the 19 samples with discordant results, 13 samples were false positives and six were false negatives. The Verigene EP test simultaneously detected two targets in 11 samples; overall, the test demonstrated high efficiency in detecting crucial diarrheagenic pathogens, indicating its suitability for clinical practice

Had COVID-19 spread in the community before the first confirmed case in Nagasaki, Japan?

This retrospective study evaluated stored nasopharyngeal swab samples from Japanese patients with influenza-like illness during the 2019/2020 season. We aimed to determine whether COVID-19 had spread in the community before the first confirmed case. The period of influenza season during 2019/2020 in Nagasaki was shorter than in previous influenza seasons. When the first COVID-19 case was reported in Nagasaki prefecture, the number of influenza cases were very low. No positive results for SARS-CoV-2 were detected in 182 samples that were obtained from adult outpatients. Our results revealed no large-scale spread of COVID-19 in the community before the first confirmed case

Clinical evaluation of a fully automated and high-throughput molecular testing system for detection of influenza virus

Introduction: We investigated the performance of the cobas® 6800 system and cobas SARS-CoV-2 & Influenza A/B, a fully automated molecular testing system for influenza viruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This enabled an assay in a batch of 96 samples in approximately 3 h. Methods: An assay was performed using the cobas SARS-CoV-2 & Influenza A/B on the cobas 6800 system for samples collected in four facilities between November 2019 and March 2020 in our previous study. The results were compared with those obtained using the reference methods.Results: Of the 127 samples analyzed, the cobas SARS-CoV-2 & Influenza A/B detected influenza A virus in 75 samples, of which 73 were positive using the reference methods. No false negative results were observed. The overall positive and negative percent agreement for influenza A virus detection were 100.0% and 96.3%, respectively. There were no positive results for the influenza B virus or SARS-CoV-2.Conclusion: The cobas 6800 system and cobas SARS-CoV-2 & Influenza A/B showed high accuracy for influenza A virus detection and can be useful for clinical laboratories, especially those that routinely assay many samples

Fluoroquinolone resistance in extended-spectrum β-lactamase-producing Klebsiella pneumoniae in a Japanese tertiary hospital: silent shifting to CTX-M-15-producing K. pneumoniae

Purpose. Fluoroquinolone resistance (FQ-r) in extended-spectrum β-lactamase (ESBL) producers is an urgent health concern in countries where ESBL-producing K. pneumoniae (ESBL-Kpn) is prevalent. We investigated FQ-r in Japan where ESBL-Kpn is less prevalent. Methodology. Clinical ESBL-Kpn isolates from 2011 to 2013 were collected in Nagasaki University Hospital. The ESBL genotypes included CTX-M-15, and the mechanisms of FQ-r through plasmid-mediated quinolone resistance (PMQR) and mutations in quinolone resistance-determining regions (QRDRs) were examined. Clonality was analysed by enterobacterial repetitive intergenic consensus (ERIC)-PCR and multi-locus sequence typing was performed on selected isolates. Results/Key findings. Thirty ESBL-Kpn isolates, including seven levofloxacin-resistant isolates, were obtained from different patients. An increase in CTX-M-15-producing strains was observed during the study period (0/11 in 2011, 3/8 in 2012, and 5/11 in 2013). PMQR was detected in 53.3?% of the isolates and aac-(6′)-Ib-cr was the most common (36.7?%). ST15 was observed in 60.0?% of the isolates, and for the most predominant ERIC-PCR profiles, 62.5?% of the isolates possessed the CTX-M-15 genotype and 71.4?% were levofloxacin-resistant. Levofloxacin-resistance was significantly more common in CTX-M-15 isolates (62.5?%) compared to non-CTX-M-15 isolates (9.1?%). Three QRDR mutations and aac(6′)-Ib-cr, but not qnrB and qnrS, were significantly enriched in the CTX-M-15 isolates (100.0?%) compared to the non-CTX-M-15 isolates (13.6?%). Conclusion. Cumulatively, these results indicate that the epidemic strain, the CTX-M-15-producing K. pneumoniae ST15, is covertly spreading even when ESBL producers are not prevalent. Monitoring these epidemic strains and ESBLs in general is important for quickly identifying health crises and minimizing future risks from FQ-r ESBL-Kpn

The surveillance of colistin resistance and mobilized colistin resistance genes in multidrug-resistant Enterobacteriaceae isolated in Japan

Background: The plasmid-mediated bacterial colistin-resistant gene, mcr, is of global concern in clini-cal healthcare. However, there are few reports of surveillance for mcr in Japan. The aim of this study was to assess the prevalence of colistin resistance by identifying nine mcr genes in extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae and carbapenem-resistant Enterobacteriaceae (CRE) isolates in Japan.Methods: A total of 273 ESBL and CRE clinical isolates were collected from patients in five tertiary hospi-tals from August 2016 to March 2017. Minimum inhibitory concentration (MIC) of colistin was measured using the microdilution method. Polymerase chain reaction (PCR) was performed to detect mcr-1 to mcr-9 genes in all strains. Whole-genome sequencing (WGS) analysis was conducted for any mcr-genes identi-fied that had not been previously reported in patients from Japan.Results: The rate of colistin resistance was 7.7% in all strains, with a higher rate in the CRE strains than in the ESBL-producing strains (20.4% versus 1.1%). The mcr-5 and mcr-9 gene were detected in one ESBL-producing Escherichia coli strain (1/273, 0.37%) and three CRE strains (3/273, 1.1%), respectively. As theESBL-producing E. coli strain was the first clinical strain with mcr-5 in Japan, WGS analysis was performed for the strain. The sequence type of the mcr-5-positive strain was ST1642 and it carried two distinct plasmids, ESBL gene-carrying pN-ES-6-1, and mcr-5.1-carrying pN-ES-6-2.Conclusions: The results of this study showed that the frequency of colistin resistance and mcr-positive strains is not high in Japan. As the MIC for colistin was low in the mcr-5.1 and mcr-9 gene-positive strain, continuous monitoring of mcr genes is necessary

Evaluation of FilmArray respiratory panel multiplex polymerase chain reaction assay for detection of pathogens in adult outpatients with acute respiratory tract infection

Although viruses are the major pathogen that causes upper respiratory tract infection (URTI) and acute bronchitis, antibiotics have been prescribed. This was a prospective observational study in influenza epidemics that enrolled adult outpatients who visited a hospital with respiratory tract infection symptoms. In this study, we evaluated the usefulness of FilmArray respiratory panel (RP). Fifty patients were enrolled. FilmArray RP detected the pathogens in 28 patients. The common pathogens were influenza virus (n = 14), respiratory syncytial virus (n = 6), and human rhinovirus (n = 6). Of the 14 patients with influenza virus, 6 were negative for the antigen test. The physicians diagnosed and treated the patients without the result of FilmArray in this study. Of the patients with positive FilmArray RP, 9 were treated with antibiotics; however, bacteria were detected in only 3 patients. By implementing FilmArray RP, URTI and acute bronchitis would be precisely diagnosed, and inappropriate use of antibiotics can be reduced