Expansion and transmission dynamics of high risk carbapenem-resistant Klebsiella pneumoniae subclones in China: An epidemiological, spatial, genomic analysis.

AIMS: Carbapenem-resistant Klebsiella pneumonia (CRKP) is a global threat that varies by region. The global distribution, evolution, and clinical implications of the ST11 CRKP clone remain obscure. METHODS: We conducted a multicenter molecular epidemiological survey using isolates obtained from 28 provinces and municipalities across China between 2011 and 2021. We integrated sequences from public databases and performed genetic epidemiology analysis of ST11 CRKP. RESULTS: Among ST11 CRKP, KL64 serotypes exhibited considerable expansion, increasing from 1.54% to 46.08% between 2011 and 2021. Combining our data with public databases, the phylogenetic and phylogeography analyses indicated that ST11 CRKP appeared in the Americas in 1996 and spread worldwide, with key clones progressing from China's southeastern coast to the inland by 2010. Global phylogenetic analysis showed that ST11 KL64 CRKP has evolved to a virulent, resistant clade with notable regional spread. Single-nucleotide polymorphism (SNP) analysis identified BMPPS (bmr3, mltC, pyrB, ppsC, and sdaC) as a key marker for this clade. The BMPPS SNP clade is associated with high mortality and has strong anti-phagocytic and competitive traits in vitro. CONCLUSIONS: The high-risk ST11 KL64 CRKP subclone showed strong expansion potential and survival advantages, probably owing to genetic factors.

Global genetic diversity and Asian clades evolution: a phylogeographic study of Staphylococcus aureus sequence type 5.

Staphylococcus aureus sequence type (ST) 5 has spread worldwide; however, phylogeographic studies on the evolution of global phylogenetic and Asian clades of ST5 are lacking. This study included 368 ST5 genome sequences, including 111 newly generated sequences. Primary phylogenetic analysis suggested that there are five clades, and geographical clustering of ST5 methicillin-resistant S. aureus (MRSA) was linked to the acquisition of S. aureus pathogenicity islands (SaPIs; enterotoxin gene island) and integration of the prophage φSa3. The most recent common ancestor of global S. aureus ST5 dates back to the mid-1940s, coinciding with the clinical introduction of penicillin. Bayesian phylogeographic inference allowed to ancestrally trace the Asian ST5 MRSA clade to Japan, which may have spread to major cities in China and Korea in the 1990s. Based on a pan-genome-wide association study, the emergence of Asian ST5 clades was attributed to the gain of prophages, SaPIs, and plasmids, as well as the coevolution of resistance genes. Clade IV displayed greater genomic diversity than the Asian MRSA clades. Collectively, our study provides in-depth insights into the global evolution of S. aureus ST5 mainly in China and the United States and reveals that different S. aureus ST5 clades have arisen independently in different parts of the world, with limited geographic dispersal across continents.

Global trends in the burden of chronic kidney disease attributable to type 2 diabetes: An age-period-cohort analysis.

AIM: To assess temporal trends of chronic kidney disease (CKD) attributable to type 2 diabetes (T2D) globally and in five sociodemographic index (SDI) regions. MATERIALS AND METHODS: We extracted the population data and CKD burden attributable to T2D from the Global Burden of Disease Study 2019. We evaluated the trends of disability-adjusted life years (DALYs), mortality, prevalence and incidence through age-period-cohort modelling, and calculated net drifts (overall annual percentage changes), local drifts (annual percentage changes in each age group), longitudinal age curves (fitted longitudinal age-specific rates), period relative risks (RRs) and cohort RRs. RESULTS: From 1990 to 2019, the global burden of CKD attributable to T2D showed increasing trends in general. The burden of CKD attributable to T2D was highest in the middle SDI region and lowest in the low SDI region. Age effects increased with age, and peaked at the ages of 75-79 and 80-84 years for incidence and prevalence, respectively. Period RRs in the burden of CKD attributable to T2D increased, with the high SDI being the most remarkable in DALYs and mortality, and the middle SDI being the most notable in incidence. Cohort RRs showed unfavourable trends in incidence and prevalence among recent cohorts. CONCLUSIONS: After a lengthy period of multi-initiative diabetes management, the high-middle SDI region exhibited improvement. However, unresolved issues and improvement gaps were still remarkable. Future efforts to reduce the burden of CKD attributable to T2D in the population should prioritize addressing the unfavourable patterns identified.

Pancreatic fistula and biliary fistula after laparoscopic pancreatoduodenectomy: 500 patients at a single institution.

Background: Pancreatic fistula (PF) and biliary fistula (BF) are two major leakage complications after pancreatoduodenectomy (PD). The aim of this study is to investigate the risk factors of PF and BF after laparoscopic PD (LPD). Materials and Methods: We conducted a retrospective analysis of 500 patients who underwent LPD from 1 April 2015 to 31 March 2020. Clinical data from patients were analysed using multivariate logistic regression analysis. Results: PF occurred in 86 (17.2%) patients. Univariate and multivariate analysis indicated that the soft texture of the pancreas (P = 0.001) was the independent risk factor for PF. BF occurred in 32 (6.4%) patients. Univariate and multivariate analysis indicated that history of cardiovascular disease (P < 0.001), surgical time (P = 0.005), pre-operative CA125 (P = 0.036) and pre-operative total bilirubin (P = 0.044) were independent risk factors for BF. Conclusion: The texture of the pancreas was an independent risk factor for PF after LPD, which was consistent with the literatures. In addition, history of cardiovascular disease, surgical time, pre-operative CA125 and pre-operative total bilirubin were new independent risk factors for BF after LPD. Therefore, patients with high-risk factors of BF should be informed that they are at a high risk for this complication.

Epidemiology of pancreatic cancer: New version, new vision.

Pancreatic cancer (PC) is a devastating malignancy with an extremely high mortality rate and poses significant challenges to healthcare systems worldwide. The prevalence of PC risk factors spiked over the years, leading to a global increase in PC incidence rates. The contribution of different risk factors, however, varied from region to region due to genetic predisposition, environmental, social, and political factors underlying disease prevalence in addition to public health strategies. This comprehensive review aims to provide a thorough analysis of the epidemiology of PC, discussing its incidence, risk factors, screening strategies and socioeconomic burden. We compiled a wide range of seminal studies as well as epidemiological investigations to serve this review as a comprehensive guide for researchers, healthcare professionals, and policymakers keen for a more profound understanding of PC epidemiology. This review highlights the essentiality of persistent research efforts, interdisciplinary collaboration, and public health initiatives to address the expanding burden of this malignancy.

Human airway lineages derived from pluripotent stem cells reveal the epithelial responses to SARS-CoV-2 infection.

There is an urgent need to understand how SARS-CoV-2 infects the airway epithelium and in a subset of individuals leads to severe illness or death. Induced pluripotent stem cells (iPSCs) provide a near limitless supply of human cells that can be differentiated into cell types of interest, including airway epithelium, for disease modeling. We present a human iPSC-derived airway epithelial platform, composed of the major airway epithelial cell types, that is permissive to SARS-CoV-2 infection. Subsets of iPSC-airway cells express the SARS-CoV-2 entry factors angiotensin-converting enzyme 2 (ACE2), and transmembrane protease serine 2 (TMPRSS2). Multiciliated cells are the primary initial target of SARS-CoV-2 infection. On infection with SARS-CoV-2, iPSC-airway cells generate robust interferon and inflammatory responses, and treatment with remdesivir or camostat mesylate causes a decrease in viral propagation and entry, respectively. In conclusion, iPSC-derived airway cells provide a physiologically relevant in vitro model system to interrogate the pathogenesis of, and develop treatment strategies for, COVID-19 pneumonia.

Identification of multiple transfer units and novel subtypes of tmexCD-toprJ gene clusters in clinical carbapenem-resistant Enterobacter cloacae and Klebsiella oxytoca.

OBJECTIVES: Tigecycline is a last-resort antibiotic used to treat lethal infections caused by carbapenem-resistant Enterobacterales; however, plasmid-borne tigecycline resistance tmexCD-toprJ gene clusters can confer tigecycline resistance. The aim of the study was to identify novel subtypes and the spread of tmexCD-toprJ. METHODS: Five non-duplicate isolates of different species, carrying tmexCD-toprJ gene clusters or novel subtypes, were isolated from patients across China between November 2018 and June 2019. WGS was performed using Illumina and Nanopore platforms. A phylogenetic tree was constructed using a dataset of 77 sequences carrying the tmexCD-toprJ gene clusters, 72 of which were downloaded from NCBI with a blastn identity cut-off of 95%. RESULTS: We detected six different transfer units and two novel subtypes (tmexC1D1.2-toprJ1 and tmexC2D2.2-toprJ2) of the tmexCD-toprJ gene clusters. Among the six transfer units, three were mediated by IS26, while the rest were presumably mediated by Tn5393, hypothetical integrases (xerD-hp clusters-umuC-integrases-tnfxB2-tmexC2D2-toprJ2-umuC) and hypothetical units (hp-hp-hp-tnfxB2-tmexC2D2.2-toprJ2-ΔTn5393-Tn6292). Moreover, two tmexCD-toprJ-like gene clusters co-located on the same plasmid with blaNDM in five isolates. Phylogenetic analysis revealed that tmexCD-toprJ gene clusters may have originated in Pseudomonas spp., being mainly distributed in Pseudomonas spp. and Klebsiella spp. (64/77). Most tmexCD-toprJ gene clusters in Enterobacterales were located on plasmids, indicating that the gene clusters have a high inter-species transfer risk after transfer to Enterobacterales. CONCLUSIONS: In summary, to the best of our knowledge, this is the first report of tmexCD-toprJ gene clusters being isolated from Enterobacter cloacae and Klebsiella oxytoca, revealing that these multiple transfer units should be further studied because of their clinical significance.

Mapping hole hopping escape routes in proteins.

A recently proposed oxidative damage protection mechanism in proteins relies on hole hopping escape routes formed by redox-active amino acids. We present a computational tool to identify the dominant charge hopping pathways through these residues based on the mean residence times of the transferring charge along these hopping pathways. The residence times are estimated by combining a kinetic model with well-known rate expressions for the charge-transfer steps in the pathways. We identify the most rapid hole hopping escape routes in cytochrome P450 monooxygenase, cytochrome c peroxidase, and benzylsuccinate synthase (BSS). This theoretical analysis supports the existence of hole hopping chains as a mechanism capable of providing hole escape from protein catalytic sites on biologically relevant timescales. Furthermore, we find that pathways involving the [4Fe4S] cluster as the terminal hole acceptor in BSS are accessible on the millisecond timescale, suggesting a potential protective role of redox-active cofactors for preventing protein oxidative damage.

Downregulation of estrogen receptor-α36 expression attenuates metastasis of hepatocellular carcinoma cells.

This study aimed to examine the role of estrogen receptor (ER)-α36 in the metastasis of hepatocellular carcinoma (HCC) and in the epithelial-mesenchymal transition (EMT). HCC HepG2 and Huh7 cells with the knocked-down level of ER-α36 expression were established. Cell growth and migration of the HepG2 and Huh7 cell variants were studied using MTS, transwell, and wound-healing assays, and the metastatic abilities of HepG2 cell variants were examined using a tail-vein injection model in nude mice. Levels of EMT markers, Src phosphorylation in HepG2 and Huh7 cell variants, and tumors formed by HepG2 cell variants in the nude mice were examined using Western blot and immunohistochemistry. We found that the growth and metastatic abilities of HepG2 and Huh7 cells with the knocked-down level of ER-α36 expression (HepG2/Si36 and Huh7/Si36) were significantly reduced, with increased levels of cytokeratin and E-Cadherin expression, and decreased levels of Vimentin, Snail, Slug and the Src phosphorylation, compared to the HCC cells transfected with an empty vector (HepG2/Vector and Huh7/Vector). We also found ER-α36 knockdown suppressed the lung metastasis of HepG2 cells with the involvement of EMT and the Src pathway in vivo. The Src inhibitor PP2 suppressed the growth and migration of HepG2/Vector and Huh7/Vector cells with decreased Vimentin, Snail, and Slug and increased cytokeratin and E-Cadherin expressions, but failed to induce the migration and the EMT markers in HepG2/Si36 and Huh7/Si36 cells. ER-α36 is involved in the metastasis of HCC cells through the regulation of EMT and the Src signaling pathway.

Estrogen receptor-α36 is involved in diallyl sulfide-induced inhibition of malignant growth of HepG2 and Huh7 hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is a highly malignant disease that currently lacks effective treatment. Epidemiological studies have suggested the preventive role of raw garlic intake in different tumors, such as HCC. Although diallyl sulfide (DAS), the main component of garlic extracts, has been reported to inhibit the growth of HCC cells, the underlying mechanism remains elusive. This study aimed to investigate the inhibitory effect of DAS on the growth of HepG2 and Huh7 hepatocellular carcinoma cells and its underlying mechanism. HepG2 and Huh7 cells were treated with DAS and nude mice were intrahepatically injected with human HCC HepG2 cells and maintained with or without DAS administration for 28 days. MTS and clonogenic assays revealed that DAS inhibited the growth and clonogenicity of HepG2 and Huh7 hepatocellular carcinoma cells. Furthermore, DAS inhibited the growth of xenograft tumors accompanied by a decreased rate of pathological karyomitosis as observed by H&E staining. The expression levels of estrogen receptor-α36 (ER-α36) and epidermal growth factor receptor (EGFR) in HepG2 and Huh7 cells and in xenograft tumors derived from HepG2 cells after DAS treatment were detected by immunohistochemistry and western blotting. We found that DAS disrupted the positive regulatory loop between ER-α36 and EGFR, and decreased the phosphorylation of AKT at Ser 473 both in vivo and in vitro. DAS also induced cell apoptosis, as evidenced by Hoechst and TUNEL staining. Western blotting revealed activation of caspase3, increased BAX and decreased Bcl-2 expression. However, the ER-α36 expression knockdown attenuated DAS-induced ERK and AKT phosphorylation in HCC cells. DAS was also able to inhibit ER-α36-mediated activation of the MAPK/ERK signaling induced by estrogen. Thus, our results indicate that ER-α36 signaling is involved in DAS-induced inhibition of HCC cell growth both in vitro and in vivo.

Machine Learning Approaches for Metalloproteins.

Metalloproteins are a family of proteins characterized by metal ion binding, whereby the presence of these ions confers key catalytic and ligand-binding properties. Due to their ubiquity among biological systems, researchers have made immense efforts to predict the structural and functional roles of metalloproteins. Ultimately, having a comprehensive understanding of metalloproteins will lead to tangible applications, such as designing potent inhibitors in drug discovery. Recently, there has been an acceleration in the number of studies applying machine learning to predict metalloprotein properties, primarily driven by the advent of more sophisticated machine learning algorithms. This review covers how machine learning tools have consolidated and expanded our comprehension of various aspects of metalloproteins (structure, function, stability, ligand-binding interactions, and inhibitors). Future avenues of exploration are also discussed.

Identification of a Novel Hybrid Plasmid Encoding KPC-2 and Virulence Factors in Klebsiella pneumoniae Sequence Type 11.

Recent emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) coharboring blaKPC-2 and pLVPK-like virulence plasmids represented a novel clinical challenge. In the present study, we characterized a blaKPC-2 and virulence hybrid plasmid, designated pCRHV-C2244, from a clinical ST11-K64 CRKP strain. pCRHV-C2244 was non-self-transmissible due to incomplete conjugative elements but mobilizable together with a conjugative helper. Enhanced virulence and stable maintenance without significant fitness loss in its original host were confirmed in vitro and in vivo.

Clinical Evaluation of an Improved Metagenomic Next-Generation Sequencing Test for the Diagnosis of Bloodstream Infections.

BACKGROUND: Metagenomic next-generation sequencing (mNGS) of plasma cell-free DNA has emerged as a promising diagnostic technology for bloodstream infections. However, a major limitation of current mNGS assays is the high rate of false-positive results due to contamination. METHODS: We made novel use of 3 control groups-external negative controls under long-term surveillance, blood samples with a negative result in conventional tests, and a group of healthy people-that were combined and dedicated to distinguishing contaminants arising from specimen collection, sample processing, and human normal flora. We also proposed novel markers to filter out false-positive interspecies calls. This workflow was applied retrospectively to 209 clinical plasma samples from patients with suspected bloodstream infections. Every pathogen identified by the mNGS test was reviewed to assess the diagnostic performance of the workflow. RESULTS: Our mNGS workflow showed clinical sensitivity of 87.1%, clinical specificity of 80.2%, positive predictive value of 77.9%, and negative predictive value of 88.6% compared with the composite reference standard. Notably, mNGS showed great improvement in clinical specificity compared with the current test while keeping clinical sensitivity at a high level. CONCLUSION: The mNGS workflow with multiple control groups dedicated to distinguishing nonpathogen microbes from real causal pathogens has reducing false-positive results. This contribution, with its optimization of workflow and careful use of controls, can help mNGS become a powerful tool for identifying the pathogens responsible for bloodstream infections.

Combining Gemcitabine-Loaded Macrophage-like Nanoparticles and Erlotinib for Pancreatic Cancer Therapy.

Pancreatic cancer is a lethal malignancy with a dismal prognosis. Gemcitabine is currently used to treat pancreatic cancer, but it is limited by significant toxicity. Clinical trials on the combination of gemcitabine and erlotinib reported unsatisfactory outcomes along with concerns of toxicity. The encapsulation of chemotherapy drugs in polylactic-co-glycolic acid (PLGA) nanoparticles (NPs) can alleviate toxicity through targeted delivery and sustained release. In addition, camouflaging the NPs with a macrophage membrane can evade the immune system and further improve tumor homing. We designed gemcitabine-loaded PLGA NPs with a macrophage membrane coating (MPGNPs) to reduce drug toxicity and increase the accumulation in the tumor. The combination of MPGNPs and erlotinib synergistically inhibited pancreatic cancer cell proliferation in vitro and in vivo by targeting the PI3K/AKT/mTOR and Ras/Raf/MEK/ERK signaling pathways. The MPGNPs were also able to evade phagocytosis and achieve passive targeting to the pancreatic tumors. The combination of MPGNPs and erlotinib showed synergistic anti-tumor efficacy in vitro and in vivo. This study provides a proof-of-concept for treating pancreatic cancer with a combination of MPGNPs and erlotinib.

Clinical and microbiological characteristics of adults with hospital-acquired pneumonia: a 10-year prospective observational study in China.

Hospital-acquired pneumonia (HAP) is a significant nosocomial infection; data on the distribution and antimicrobial resistance profiles of HAP in China are limited. We included 2827 adult patients with HAP from the Chinese Antimicrobial Resistance Surveillance of Nosocomial Infections network admitted in 15 Chinese teaching hospitals between 2007 and 2016. Clinical data and antimicrobial susceptibility of isolated pathogens were obtained from the medical records and central laboratory, respectively. Multivariable logistic regression was performed to determine the risk factors for mortality and multidrug resistance (MDR). A total of 386 (13.7%) patients died in the hospital, while 1181 (41.8%) developed ventilator-associated pneumonia (VAP). Active immunosuppressant therapy (OR 1.915 (95% CI 1.475-2.487)), solid tumor (OR 1.860 (95% CI 1.410-2.452)), coma (OR 1.783 (95% CI 1.364-2.333)), clinical pulmonary infection score ≥7 (OR 1.743 (95% CI 1.373-2.212)), intensive care unit stay (OR 1.652 (95% CI 1.292-2.111)), age ≥65 years (OR 1.621 (95% CI 1.282-2.049)), and tracheal cannula insertion (OR 1.613 (95% CI 1.169-2.224)) were independent risk factors for in-hospital mortality. Liver cirrhosis (OR 3.120 (95% CI 1.436-6.780)) and six other variables were independent predictors of MDR. Acinetobacter baumannii (25.6%), Pseudomonas aeruginosa (20.1%), Klebsiella pneumoniae (15.4%), and Staphylococcus aureus (12.6%) were the most common pathogens (MDR prevalence 64.9%). Isolates from VAP patients showed more A. baumannii and less K. pneumoniae and E. coli strains (p < 0.001, respectively) than those from patients without VAP. The proportion of methicillin-resistant S. aureus strains decreased; that of carbapenem-resistant A. baumannii and Enterobacterales strains increased. There had been changes in the antibiotic resistance profiles of HAP pathogens in China. Risk factors for mortality and MDR are important for the selection of antimicrobials for HAP in China.

Comparison of Radiation Dose and Image Quality Between Split-Filter Twin Beam Dual-Energy Images and Single-Energy Images in Single-Source Contrast-Enhanced Chest Computed Tomography.

OBJECTIVE: To compare image quality and radiation dose of split-filter TwinBeam dual-energy (SF-TBDE) with those of single-energy images (SECT) in the contrast-enhanced chest computed tomography (CT). METHODS: Two hundred patients who underwent SF-TBDE (n = 100) and SECT (n = 100) contrast-enhanced chest scanning were retrospectively analyzed. The contrast-to-noise ratio (CNR) and figure of merit (FOM)-CNR of 5 structures (lung, aorta, pulmonary artery, thyroid, and erector spinae) were calculated and subjectively evaluated by 2 independent radiologists. Radiation dose was compared using volume CT dose index and size-specific dose estimate. RESULTS: The CNR and FOM-CNR of lung and erector spinae in SF-TBDE were higher than those of SECT (P < 0.001). The differences in the subjective image quality between the 2 groups were not significant (P = 0.244). Volume CT dose index and size-specific dose estimate of SF-TBDE were lower than those of SECT (6.60 ± 1.56 vs 7.81 ± 3.02 mGy, P = 0.001; 9.25 ± 1.60 vs. 10.55 ± 3.54; P = 0.001). CONCLUSIONS: The SF-TBDE CT can provide similar image quality at a lower radiation dose compared with SECT.

Zinc is essential for the transcription function of the PGC-1α/Nrf2 signaling pathway in human primary endometrial stromal cells.

Zinc (Zn) has antioxidant effect in different types of organs and is closely associated with human health. Endometrial receptivity is one of the most important factors in the embryo implantation and development. However, the regulatory mechanism of Zn in endometrium tissue is still unclear. In the study, we found that plasma Zn level is significantly associated with female infertility, which severely affects female reproductive health. Primary endometrial stromal cells were isolated from female endometrium and cultured in the laboratory. Zn chelator TPEN treatment reduced the expression of stem cell markers CD73, CD90, and CD105 and generated reactive oxygen species in endometrial stromal cells. However, pretreatment of Zn (zinc sulfate) is able to prevent TPEN-induced oxidative stress in vitro. By transcriptional profiling and gene ontology analysis, we found that Zn increased the cellular pluripotency signaling and extracellular matrix-receptor interaction, but reduced autophagy, endocytosis, and the nitrogen metabolism pathway. We further discovered the antioxidant function of Zn through the peroxisome proliferator-activated receptor gamma coactivator 1α/nuclear factor erythroid-2-related factor signaling pathway in endometrial stromal cells. Zn supplementation may open up an effective therapeutic approach for patients with oxidative stress-related endometrial diseases.

Chemoprophylaxis Vaccination: Phase I Study to Explore Stage-specific Immunity to Plasmodium falciparum in US Adults.

BACKGROUND: Chemoprophylaxis vaccination with sporozoites (CVac) with chloroquine induces protection against a homologous Plasmodium falciparum sporozoite (PfSPZ) challenge, but whether blood-stage parasite exposure is required for protection remains unclear. Chloroquine suppresses and clears blood-stage parasitemia, while other antimalarial drugs, such as primaquine, act against liver-stage parasites. Here, we evaluated CVac regimens using primaquine and/or chloroquine as the partner drug to discern whether blood-stage parasite exposure impacts protection against homologous controlled human malaria infection. METHODS: In a Phase I, randomized, partial double-blind, placebo-controlled study of 36 malaria-naive adults, all CVac subjects received chloroquine prophylaxis and bites from 12-15 P. falciparum-infected mosquitoes (CVac-chloroquine arm) at 3 monthly iterations, and some received postexposure primaquine (CVac-primaquine/chloroquine arm). Drug control subjects received primaquine, chloroquine, and uninfected mosquito bites. After a chloroquine washout, subjects, including treatment-naive infectivity controls, underwent homologous, PfSPZ controlled human malaria infection and were monitored for parasitemia for 21 days. RESULTS: No serious adverse events occurred. During CVac, all but 1 subject in the study remained blood-smear negative, while only 1 subject (primaquine/chloroquine arm) remained polymerase chain reaction-negative. Upon challenge, compared to infectivity controls, 3/3 chloroquine arm subjects displayed delayed patent parasitemia (P = .01) but not sterile protection, while 3/11 primaquine/chloroquine subjects remained blood-smear negative. CONCLUSIONS: CVac-primaquine/chloroquine is safe and induces sterile immunity to P. falciparum in some recipients, but a single 45 mg dose of primaquine postexposure does not completely prevent blood-stage parasitemia. Unlike previous studies, CVac-chloroquine did not produce sterile immunity. CLINICAL TRIALS REGISTRATION: NCT01500980.

Genetic and epigenetic aberrations of ABCB1 synergistically boost the acquisition of taxane resistance in esophageal squamous cancer cells.

Taxanes are applied as potent chemotherapeutic agents in the treatment of patients with esophageal cancer, but their usefulness is limited, partly because of acquisition of chemoresistance. In our previous study, we established three taxane resistant esophageal cancer cell lines; significant ABCB1 upregulations were found in all three. However, the responsible mechanism(s) still remains an open question. In this study, we explored possible mechanisms that might contribute to upregulation of ABCB1 in taxane resistant cells. ABCB1 gene amplification was found in taxane resistant cell line RTE-1P, but expressional upregulation cannot be explained only by gene amplification, because gene amplification is one order of magnitude or less whereas gene expression is more than two orders of magnitude. In the parental TE-1, ABCB1 expression was upregulated after treatment with 5-azadeoxycytidine and/or trichostatin A; epigenetic mechanisms may be deeply involved. ABCB1 has two promoters; a downstream promoter was found to play the dominant role in taxane resistant esophageal cancer cell lines. Analyses of CpG islands demonstrated that taxane resistant cells showed unmethylated CGI whereas parental cells were dominantly methylated. In conclusion, we propose that both the ABCB1 gene amplification and aberrations in epigenetic mechanisms are responsible for acquisition of taxane resistance in esophageal cancer cells.

Evolution of hypervirulence in carbapenem-resistant Klebsiella pneumoniae in China: a multicentre, molecular epidemiological analysis.

OBJECTIVES: Carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) have been increasingly reported in China. Here, a multicentre, longitudinal surveillance study on CR-hvKP is described. METHODS: We retrospectively investigated carbapenem-resistant K. pneumoniae (CRKP) in 56 centres across China during 2015-17 and screened the virulence genes (iucA, iroN, rmpA and rmpA2) for the presence of virulence plasmids. Hypermucoviscosity, serum killing and Galleria mellonella lethality experiments were conducted to identify CR-hvKP among strains with all four virulence genes. Capsule typing, fitness and plasmid features of CR-hvKP were also investigated. RESULTS: A total of 1052 CRKP were collected. Among these, 34.2% (360/1052) carried virulence genes and 72 of them had all four of the virulence genes tested. Fifty-five (76.4%) were considered to be CR-hvKP using the G. mellonella infection model, with KPC-2-producing K64-ST11 being the most common type (80%, 44/55). Prevalence of CR-hvKP differed greatly between regions, with the highest in Henan (25.4%, 17/67) and Shandong (25.8%, 25/97). A significant increase in CR-hvKP among KPC-2-producing ST11 strains was observed, from 2.1% (3/141) in 2015 to 7.0% (23/329) in 2017 (P=0.045). Alarmingly, compared with classic CRKP, no difference in growth was found among CR-hvKP (P=0.7028), suggesting a potential risk for dissemination. The hybrid virulence and resistance-encoding plasmid evolved from pLVPK and the resistance plasmid harbouring blaKPC-2, indicating evolution existed between the hypervirulence and hyper-resistance plasmid. CONCLUSIONS: CR-hvKP were more frequently detected than previously assumed, especially among KPC-2-producing ST11. Dissemination of hypervirulence could be extremely rapid due to limited fitness cost. Also, the evolution of resistance genes into hypervirulence plasmids was identified, presenting significant challenges for public health and infection control.