Proper treatment of bloodstream infections requires rapid, early determination of appropriate antibiotic agents, emphasizing the need for more rapid drug susceptibility testing. The Drug ...Susceptibility Testing Microfluidic (DSTM) device represents a novel method in which a small amount of bacterial suspension is injected into the microchip-like device and cultured for 3 h. However, it remains unknown whether the DSTM method can directly determine antibiotic susceptibilities from positive blood cultures. Here, we developed a new approach to directly assess drug susceptibility, using the DSTM method for positive blood cultures. We compare the utility and accuracy of DSTM with those of conventional susceptibility testing methods. Fifty positive blood cultures identified as gram-negative bacilli were used herein. The outcomes of drug susceptibility and resistance assays for positive blood cultures were compared to those of conventional susceptibility testing methods to evaluate their utility and accuracy. Method agreement rates between DSTM and standard methods often exceed 90%, suggesting a high positive correlation with conventional methods. Furthermore, our results show that a combination of multiple drugs in the DSTM device helps identify extended-spectrum β-lactamase (ESBL)- and AmpC-β-lactamase (AmpC-)-producing microorganisms. In conclusion, DSTM method enables effective drug susceptibility and resistance screening within 3 h from positive blood cultures and is suitable for the rapid and personalized determination of the antimicrobial regimen.
The ability to non-invasively monitor tumor-infiltrating T cells in vivo could provide a powerful tool to visualize and quantify tumor immune infiltrates. For non-invasive evaluations in vivo, an ...anti-CD3 mAb was modified with desferrioxamine (DFO) and radiolabeled with zirconium-89 (Zr-89 or 89Zr). Radiolabeled 89Zr-DFO-anti-CD3 was tested for T cell detection using positron emission tomography (PET) in both healthy mice and mice bearing syngeneic bladder cancer BBN975. In vivo PET/CT and ex vivo biodistribution demonstrated preferential accumulation and visualization of tracer in the spleen, thymus, lymph nodes, and bone marrow. In tumor bearing mice, 89Zr-DFO-anti-CD3 demonstrated an 11.5-fold increase in tumor-to-blood signal compared to isotype control. Immunological profiling demonstrated no significant change to total T cell count, but observed CD4+ T cell depletion and CD8+ T cell expansion to the central and effector memory. This was very encouraging since a high CD8+ to CD4+ T cell ratio has already been associated with better patient prognosis. Ultimately, this anti-CD3 mAb allowed for in vivo imaging of homeostatic T cell distribution, and more specifically tumor-infiltrating T cells. Future applications of this radiolabeled mAb against CD3 could include prediction and monitoring of patient response to immunotherapy.
In this study, we analyze the sequential decisions on product positioning of two firms in the presence of network externalities. One commonly accepted phenomena in a market where a network ...externality arises is the first-mover advantage, in which the first entrant into a market can earn a higher profit than later entrants. However, in some recent online services markets, we see that the second mover earns a higher profit than the first mover. This occurs because the second mover strengthens its variety of available functions and services markedly, thereby facilitating consumers’ work and communication with its main product, which we call network externality intensity. Based on this observation, we analyze sequential positioning in Hotelling’s framework by incorporating an asymmetric network externality intensity between firms. We show that unlike the results of previous related studies, both first- and second-mover advantages can appear in the equilibrium depending on the relationship of the network externality intensity between firms; further, they do not change monotonically with the level of network externality intensity.
Extra-intestinal pathogenic
Escherichia coli
(ExPEC) is one of the world’s leading causes of bloodstream infections with high mortality. Sequence type 410 (ST410) is an emerging ExPEC clone resistant ...to a wide range of antibiotics. In this study, we investigated the epidemiology of 21 ST410
E. coli
isolates from two Ghanaian hospitals. We also investigated the isolates within a global context to provide further insight into the dissemination of this highly pathogenic clone. A phylogenetic tree of the 21 isolate genomes, along with 102 others from global collection, was constructed representing the ensuing clades and sub-clades of the ST: A/H53, B2/H24R, B3/H24Rx, and B4/H24RxC. The carbapenem-resistant sub-clade B4/H24RxC is reported to have emerged in the early 2000s when ST410 acquired an IncX3 plasmid carrying a
bla
OXA–
181
carbapenemase gene, and a second carbapenemase gene,
bla
NDM–
5
, on a conserved IncFII plasmid in 2014. We identified, in this study, one
bla
OXA–
181
–carrying isolate belonging to B4/H24RxC sub-lineage and one carrying
bla
NDM–
1
belonging to sub-lineage B3/H24Rx. The
bla
OXA–
181
gene was found on a 51kb IncX3 plasmid; pEc1079_3. The majority (12/21) of our Ghanaian isolates were clustered with international strains described by previous authors as closely related strains to B4/H24RxC. Six others were clustered among the ESBL-associated sub-lineage B3/H24Rx and three with the globally disseminated sub-lineage B4/H24RxC. The results show that this highly pathogenic clone is disseminated in Ghana and, given its ability to transmit between hosts, it poses a serious threat and should be monitored closely.
•Acidic alteration and high-temperature hot springs surround several Quaternary volcanoes within the Sengan area.•Quaternary intrusive granitic-dioritic rocks are distributed beneath the Sengan ...area.•Sengan area subsurface temperature was estimated based on temperature logging data.•Several high-temperature zones are scattered above sea level in the Sengan area.•The granitic-dioritic magma contributes to the formation of geothermal systems in the Sengan area.
Geological data were used to explore the geological structure and hydrothermal alteration distribution of the Sengan area, Northeast Japan. Acidic alteration and high-temperature hot springs surround several Quaternary volcanoes within the Sengan area. Quaternary intrusive granitic-dioritic rocks are distributed beneath the Kakkonda, Matsukawa, and Matsuo-Hachimantai geothermal fields. In particular, the Kakkonda granite, a heat source in the Kakkonda geothermal field, has a high temperature exceeding 500 °C inside the body. The temperature structure of the Sengan area was investigated using temperature logging data (WD-1a and 53 wells) collected as part of the temperature recovery test conducted in the geothermal wells. The temperature structure was estimated based on temperature extrapolation, a 2-D temperature distribution created with the thin-plate spline method, and a 3-D temperature distribution obtained by combining the horizontal 2-D temperature data. High-temperature zones above 200 °C are distributed at sea level in Nyuto (eastern Lake Tazawa), Kakkonda, Matsukawa, Matsuo-Hachimantai (Hachimantai), and Mt. Akita-Yakeyama, as predicted using the temperature structure estimation method. The granitic-dioritic magma penetrates the pre-Tertiary basement units and the Neogene beneath several fields to form a high-temperature zone in the shallow depth, contributing to the formation of geothermal systems in the Sengan area. However, the linear extrapolation of the subsurface temperature tended to over-estimate the temperature in the greater depth and was valid only at a depth shallower than 3 or 4 km below sea level. This study delineated several high-temperature zones exceeding 200 °C above sea level in the Sengan area.
Renal carcinoma is a common and aggressive malignancy whose histopathogenesis is incompletely understood and that is largely resistant to cytotoxic chemotherapy. We present two mouse models of kidney ...cancer that recapitulate the genomic alterations found in human papillary (pRCC) and clear cell RCC (ccRCC), the most common RCC subtypes. MYC activation results in highly penetrant pRCC tumours (MYC), while MYC activation, when combined with Vhl and Cdkn2a (Ink4a/Arf) deletion (VIM), produce kidney tumours that approximate human ccRCC. RNAseq of the mouse tumours demonstrate that MYC tumours resemble Type 2 pRCC, which are known to harbour MYC activation. Furthermore, VIM tumours more closely simulate human ccRCC. Based on their high penetrance, short latency, and histologic fidelity, these models of papillary and clear cell RCC should be significant contributions to the field of kidney cancer research.
Here, we assessed the utility of a polymerase chain reaction-based open reading frame typing assay for investigating the clonality of Clostridioides difficile isolates. This assay has a higher ...discriminatory power than multi-locus sequence typing for molecular epidemiological analysis of C. difficile isolates and can provide additional information about toxin genotypes.
•POT method can determine C. difficile toxin genotype.•POT method exhibits higher discriminatory power than MLST for C. difficile typing.•POT method is a useful tool for the epidemiological investigations of C. difficile.
RalGTPase-activating protein (RalGAP) is an important negative regulator of small GTPases RalA/B that mediates various oncogenic signaling pathways in various cancers. Although the Ral pathway has ...been implicated in prostate cancer (PCa) development and progression, the significance of RalGAP in PCa has been largely unknown. We examined RalGAPα2 expression using immunohistochemistry on two independent tissue microarray sets. Both datasets demonstrated that the expression of RalGAPα2 was significantly downregulated in PCa tissues compared to adjacent benign prostatic epithelia. Silencing of RalGAPα2 by short hairpin RNA enhanced migration and invasion abilities of benign and malignant prostate epithelial cell lines without affecting cell proliferation. Exogenous expression of wild-type RalGAP, but not the GTPase-activating protein activity-deficient mutant of RalGAP, suppressed migration and invasion of multiple PCa cell lines and was phenocopied by pharmacological inhibition of RalA/B. Loss of Ralgapa2 promoted local microscopic invasion of prostatic intraepithelial neoplasia without affecting tumor growth in a Pten-deficient mouse model for prostate tumorigenesis. Our findings demonstrate the functional significance of RalGAP downregulation to promote invasion ability, which is a property necessary for prostate carcinogenesis. Thus, loss of RalGAP function has a distinct role in promoting progression from prostatic intraepithelial neoplasia to invasive adenocarcinoma.
Tens of thousands of cases of invasive meningococcal diseases (IMD) with thousands of deaths are reported annually worldwide; however, only approximately 40 cases occur each year in Japan. Therefore, ...the majority of medical technologists in Japan have never performed or prepared for analyses of the causative agent, Neisseria meningitidis. Since IMD outbreaks have been reported at mass gathering events, the risk of IMD will increase in Japan in 2021 because of the Olympics. In the present study, we developed a new simple gel-based duplex PCR method that may be employed by the majority Japanese clinical laboratories. It is simple to perform and time- and cost-effectively identifies encapsulated and unencapsulated N. meningitidis by detecting the encapsulated N. meningitidis-specific ctrB and N. meningitidis-specific ggt genes. We consider this simple and cost-effective identification method to compensate for the lack of experience and resource-poor conditions in most Japanese laboratories in which N. meningitidis has rarely been examined.
Global dissemination of New Delhi metallo-β-lactamase (NDM)-producing bacteria has become a major health threat. However, there are few reports regarding the identification and characterisation of ...NDM-producing bacteria from West Africa, including Ghana. An Escherichia coli strain with resistance to meropenem was isolated from the Tamale Teaching Hospital in Ghana. Its identification and determination of antibiotic susceptibility profile were carried out using commercial systems. The antibiotic resistance mechanism was analysed by phenotypic detection kits, PCR, and DNA sequencing. Conjugation experiments, S1 nuclease pulsed field gel electrophoresis, and Southern blotting were performed. Finally, the NDM-1-harbouring plasmid was characterised using next-generation sequencing and phylogenetic analysis. The meropenem-resistant Escherichia coli strain EC2189 harboured blaNDM-1 and belonged to sequence type 410. blaNDM-1 was located on the IncHI type transferrable plasmid p2189-NDM (248,807 bp long), which co-carried multiple resistance genes, such as blaCTX-M-15, aadA1, aac(6')-Ib, sul3, dfrA12, and cmlA1. p2189-NDM phylogenetically differed from previously identified blaNDM-1-positive IncHI type plasmids. A truncated Tn125 containing blaNDM-1 was bracketed by an ISSm-1-like insertion sequence upstream and by a site-specific integrase downstream. To the best of our knowledge, we have, for the first time identified and molecularly characterised an NDM-1-producing Enterobacteriaceae strain in Ghana with blaNDM-1 that had a novel genetic structure. Our findings indicate a possibility of NDM-1 dissemination in Ghana and underscore the need for constant monitoring of carbapenemase-producing bacteria.
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