Novel intertypic recombination of Echovirus 11 in the Enterovirus species B.

Enteroviruses (EVs), single-stranded, positive-sense RNA viruses, can be classified into four species (A-D), which have previously been linked to a diverse range of disease manifestations and infections affecting the central nervous system. In the Enterovirus species B (EV-B), Echovirus type 11 (E11) has been observed to occasionally circulate in Taiwan, which was responsible for an epidemic of enterovirus infections in 2018. Here, 48 clinical specimens isolated in 2003, 2004, 2009, and 2018 were collected for the high-throughput sequencing. Notably, we identified 2018 Taiwanese strains having potential recombinations in the 3D gene, as well as one 2003 strain having a double recombination with E6 and Coxsackievirus B5 in the P2 and P3 regions, respectively. Additionally, one amino acid signature mutated from the Histidine (H) in throat swab specimens to the Tyrosine (Y) in cerebral spinal fluid specimens was detected at position 1496 (or 57) of the genomic coordinate (or 3A gene) to further demonstrate intra-host evolution in different organs. In conclusion, this study identifies potential intertypic recombination events and an intra-host signature mutation in E11 strains, isolated during a 2018 neurological disease outbreak in Taiwan, contributing to our understanding of its evolution and pathogenesis.

CO2-Responsive Water-Soluble Conjugated Polymers as a Multifunctional Fluorescent Probe for Bioimaging Applications.

We describe important progress in the synthesis and development of gas-responsive water-soluble conjugated polymers (WSCPs) with potential as multifunctional fluorescent materials for biomedical imaging and probes. A water-soluble WSCP (I-PT) composed of a hydrophobic fluorescent polythiophene backbone and a hydrophilic imidazole side chain was successfully prepared through a facile and efficient two-step synthetic route. Owing to the repulsive force between the hydrophilic and hydrophobic segments and the highly sensitive carbon dioxide (CO2)- and nitrogen (N2)-responsive imidazole groups in its structure, I-PT can spontaneously self-assemble into spherical-like nanoparticles in an aqueous environment, and thus exhibits unique light absorption and fluorescence properties as well as rapid responsiveness to CO2 and N2. In addition, its structure, optical absorption/fluorescence behavior, and surface potential can be quickly turned on and off through alternating cycles of CO2 and N2 bubbling and exhibit controllable cyclic switching stability, thereby allowing effective manipulation of its hierarchical structure and chemical-physical characteristics. More importantly, a series of in vitro cell experiments confirmed that, compared to the significant cytotoxicity of pristine and N2-treated I-PT nanoparticles, CO2-treated I-PT nanoparticles exhibit extremely low cytotoxicity in normal and cancer cells and undergo greatly accelerated cellular uptake, resulting in a significant increase in the intensity and stability of their fluorescence signal in the intracellular environment. Overall, this newly discovered CO2/N2-responsive system provides new insights to effectively enhance the biocompatibility, cellular internalization, and intracellular fluorescence characteristics of WSCPs and holds great potential for biomedical imaging/sensing applications.

Impact of lymph node retrieval on prognosis in elderly and non-elderly patients with T3-4/N+ rectal cancer following neoadjuvant therapy: a retrospective cohort study.

PURPOSE: The optimal number of lymph nodes to be resected in patients with rectal cancer who undergo radical surgery after neoadjuvant therapy remains controversial. This study evaluated the prognostic variances between elderly and non-elderly patients and determined the ideal number of lymph nodes to be removed in these patients. METHODS: The Surveillance, Epidemiology, and End Results (SEER) datasets were used to gather information on 7894 patients diagnosed with stage T3-4/N+ rectal cancer who underwent neoadjuvant therapy from 2010 to 2019. Of these patients, 2787 were elderly and 5107 were non-elderly. A total of 152 patients from the Longyan First Affiliated Hospital of Fujian Medical University were used for external validation. Overall survival (OS) and cancer-specific survival (CSS) were evaluated to determine the optimal quantity of lymph nodes for surgical resection. RESULTS: The study found significant differences in OS and CSS between elderly and non-elderly patients, both before and after adjustment for confounders (P < 0.001). The removal of 14 lymph nodes may be considered a benchmark for patients with stage T3-4/N+ rectal cancer who undergo radical surgery following neoadjuvant therapy, as this number provides a more accurate foundation for the personalized treatment of rectal cancer. External data validated the differences in OS and CSS and supported the 14 lymph nodes as a new benchmark in these patients. CONCLUSION: For patients with T3-4/N+ stage rectal cancer who undergo radical surgery following neoadjuvant therapy, the removal of 14 lymph nodes serves as a cutoff point that distinctly separates patients with a favorable prognosis from those with an unfavorable one.

Emergence and Persistent Dominance of SARS-CoV-2 Omicron BA.2.3.7 Variant, Taiwan.

Since April 2022, waves of SARS-CoV-2 Omicron variant cases have surfaced in Taiwan and spread throughout the island. Using high-throughput sequencing of the SARS-CoV-2 genome, we analyzed 2,405 PCR-positive swab samples from 2,339 persons and identified the Omicron BA.2.3.7 variant as a major lineage within recent community outbreaks in Taiwan.

Targeting influenza A virus by splicing inhibitor herboxidiene reveals the importance of subtype-specific signatures around splice sites.

BACKGROUND: The association between M segment splicing and pathogenicity remains ambiguous in human influenza A viruses. In this study, we aimed to investigate M splicing in various human influenza A viruses and characterize its physiological roles by applying the splicing inhibitor, herboxidiene. METHODS: We examined the M splicing of human H1N1 and H3N2 viruses by comparing three H1N1 and H3N2 strains, respectively, through reverse transcriptase-polymerase chain reaction (RT-PCR) analyses. We randomly selected M sequences of human H1N1, H2N2, and H3N2 viruses isolated from 1933 to 2020 and examined their phylogenetic relationships. Next, we determined the effects of single nucleotide variations on M splicing by generating mutant viruses harboring the 55C/T variant through reverse genetics. To confirm the importance of M2 splicing in the replication of H1N1 and H3N2, we treated infected cells with splicing inhibitor herboxidiene and analyzed the viral growth using plaque assay. To explore the physiological role of the various levels of M2 protein in pathogenicity, we challenged C57BL/6 mice with the H1N1 WSN wild-type strain, mutant H1N1 (55T), and chimeric viruses including H1N1 + H3wt and H1N1 + H3mut. One-tailed paired t-test was used for virus titer calculation and multiple comparisons between groups were performed using two-way analysis of variance. RESULTS: M sequence splice site analysis revealed an evolutionarily conserved single nucleotide variant C55T in H3N2, which impaired M2 expression and was accompanied by collinear M1 and mRNA3 production. Aberrant M2 splicing resulted from splice-site selection rather than a general defect in the splicing process. The C55T substitution significantly reduced both M2 mRNA and protein levels regardless of the virus subtype. Consequently, herboxidiene treatment dramatically decreased both the H1N1 and H3N2 virus titers. However, a lower M2 expression only attenuated H1N1 virus replication and in vivo pathogenicity. This attenuated phenotype was restored by M replacement of H3N2 M in a chimeric H1N1 virus, despite low M2 levels. CONCLUSIONS: The discrepancy in M2-dependence emphasizes the importance of M2 in human influenza A virus pathogenicity, which leads to subtype-specific evolution. Our findings provide insights into virus adaptation processes in humans and highlights splicing regulation as a potential antiviral target.

Efficacy of agomelatine with cognitive behavioral therapy for delayed sleep-wake phase disorder in young adults: A randomized controlled study.

BACKGROUND: Delayed sleep-wake phase disorder (DSWPD) is common and easily misdiagnosed in young people, and to date, there is no evidence-based treatment. PURPOSE: A nonblinded randomized controlled study evaluated the effect of agomelatine therapy (AT) and cognitive behavior therapy (CBT) on DSWPD in young adults. METHODS: Sixty adolescents and young adults (range = 19-24 years, mean = 22 years, 52% female) diagnosed with DSWPD were randomized to receive 4 weeks of agomelatine therapy with or without cognitive behavior therapy. Sleep diaries, Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Insomnia Severity Index (ISI), and World Health Organization wellbeing questionnaire (WHO-5) were measured pre-treatment and post-treatment. RESULTS: Agomelatine therapy for 4 weeks shifted the sleep-wake rhythm (p < .001) forward in both groups at the week 4 assessment. There were no significant differences in sleep onset (p = .099) and sleep offset (p = .959) between the CBT group and the no treatment (NT) group at the follow-up visits. However, significant differences were found in sleep duration (p = .002), sleep quality (p=0.005), sleep difficulties (p < .001), daytime sleepiness (p = .001), and wellbeing (p = .007) between groups. CONCLUSIONS: The improvements were received largely through the sleep-promoting effects of agomelatine therapy, and combining with cognitive behavior therapy on maintenance of altered sleep rhythms might be feasible.

Enterovirus A71 Induces Neurological Diseases and Dynamic Variants in Oral Infection of Human SCARB2-Transgenic Weaned Mice.

Enterovirus A71 (EV-A71) and many members of the Picornaviridae family are neurotropic pathogens of global concern. These viruses are primarily transmitted through the fecal-oral route, and thus suitable animal models of oral infection are needed to investigate viral pathogenesis. An animal model of oral infection was developed using transgenic mice expressing human SCARB2 (hSCARB2 Tg), murine-adapted EV-A71/MP4 virus, and EV-A71/MP4 virus with an engineered nanoluciferase gene that allows imaging of viral replication and spread in infected mice. Next-generation sequencing of EV-A71 genomes in the tissues and organs of infected mice was also performed. Oral inoculation of EV-A71/MP4 or nanoluciferase-carrying MP4 virus stably induced neurological symptoms and death in infected 21-day-old weaned mice. In vivo bioluminescence imaging of infected mice and tissue immunostaining of viral antigens indicated that orally inoculated virus can spread to the central nervous system (CNS) and other tissues. Next-generating sequencing further identified diverse mutations in viral genomes that can potentially contribute to viral pathogenesis. This study presents an EV-A71 oral infection murine model that efficiently infects weaned mice and allows tracking of viral spread, features that can facilitate research into viral pathogenesis and neuroinvasion via the natural route of infection. IMPORTANCE Enterovirus A71 (EV-A71), a positive-strand RNA virus of the Picornaviridae, poses a persistent global public health problem. EV-A71 is primarily transmitted through the fecal-oral route, and thus suitable animal models of oral infection are needed to investigate viral pathogenesis. We present an animal model of EV-A71 infection that enables the natural route of oral infection in weaned and nonimmunocompromised 21-day-old hSCARB2 transgenic mice. Our results demonstrate that severe disease and death could be stably induced, and viral invasion of the CNS could be replicated in this model, similar to severe real-world EV-A71 infections. We also developed a nanoluciferase-containing EV-A71 virus that can be used with this animal model to track viral spread after oral infection in real time. Such a model offers several advantages over existing animal models and can facilitate future research into viral spread, tissue tropism, and viral pathogenesis, all pressing issues that remain unaddressed for EV-A71 infections.

Prevalence and Antimicrobial Resistance of Ureaplasma urealyticum and Mycoplasma hominis in Patients with Genital Tract Infection in Jiangsu, China.

BACKGROUND: The aim of this study was to investigate the infection and antimicrobial resistance of Ureaplasma urealyticum (U. urealyticum) and Mycoplasma hominis (M. hominis) in patients with genital tract diseases in Jiangsu, China. METHODS: A total of 3,321 patients suspected with genital tract infectious diseases were enrolled in this study from September 2017 to September 2020. The Mycoplasma detection and antimicrobial susceptibility were tested using the commercially available Mycoplasma kit. RESULTS: Among the 3,321 specimens tested, 1,503 (45.3%) were positive for Mycoplasmas, and the proportion of mono-infection of U. urealyticum is highest (79.5%). The overall infection rate has been increasing in the past 3 years. The positive rate in females (68.7%) was higher than in males (25.0%), and the main infection age group was 20 - 39 (81.2%). Besides, U. urealyticum and M. hominis displayed relative lower resistance rates to gatifloxacin, josamycin, minocycline, and doxycycline (6.0%, 6.5%, 3.1%, and 3.2%, respectively). However, the antimicrobial resistance rates to azithromycin, clindamycin, roxithromycin, sparfloxacin, and ofloxacin were relatively high (45.4%, 42.1%, 34.9, 36.0, and 65.5%, respectively). Antimicrobial resistance of U. urealyticum and M. hominis to these 14 drugs have been changing in the past 3 years. CONCLUSIONS: In total, these preliminary data showed the prevalence and antimicrobial resistance status of U. urealyticum and M. hominis in patients suspected with genital tract infectious diseases, which has use for reference on both prevention and treatment of diseases caused by them.

A Case of Psoas Muscle Abscess With Hematuria, Detected Initially by Point-of-Care Ultrasound in the Emergency Department.

BACKGROUND: Psoas muscle abscess (PMA) is a collection of pus in the psoas muscle. It is considered a rare clinical entity and is often misdiagnosed due to highly vague symptoms. We report that point-of-care ultrasound (POCUS) serves as a useful and noninvasive tool for early detection of PMA. CASE REPORT: Our patient was a 35-year-old man without any past medical illness who visited the emergency department due to right lower back pain and hematuria for 8 months. He denied fever, trauma, or recreational drug use. On arrival, the patient's vital signs were stable and had no fever. Laboratory tests showed white blood cell count 12,800/µL with neutrophil segment 83.2%, C-reactive protein 0.2 mg/dL, and normal renal function. Urine routine showed red blood cells > 100/high-power field. Kidney-ureter-bladder radiograph revealed a positive psoas sign on the right. POCUS showed a mixed echogenic mass adjacent to the right kidney. Subsequently, contrast abdominal computed tomography revealed T10-T11 collapsed vertebral bodies with disc erosion and right psoas muscle abscess at the right kidney level. The patient received open drainage of psoas muscle abscess and T11-T12 laminectomy. He was discharged 13 days post admission. Why ShouldanEmergency PhysicianBe Aware of This? Early and accurate diagnosis of PMA is important because, if left untreated, mortality rate can reach 100%. A potential pitfall in our case is the presence of hematuria with flank pain that could lead to incorrect diagnosis of renal calculi, a much more common condition. This case illustrates the importance of using POCUS in any patient with back or flank pain, with or without hematuria.

Genotyping and Drug Resistance Profile of Clinical Isolates of Candida albicans from Vulvovaginal Candidiasis in the Eastern China.

A total of 244 Candida albicans isolates recovered from vulvovaginal candidiasis (VVC) patients in Suzhou, Eastern China, were investigated. According to CLSI documents M27-A4 and M59-3ed/M60-2ed, the MIC geometric means of nine antifungals in increasing order were micafungin (0.048 mg/L), anidulafungin (0.132 mg/L), caspofungin (0.19 mg/L), itraconazole (0.23 mg/L), posaconazole (0.25 mg/L), voriconazole (0.28 mg/L), 5-flucytosine (0.44 mg/L), amphotericin B (0.49 mg/L) and fluconazole (2.01 mg/L) respectively. Of note, 6.5% (16/244) C. albicans isolates showed resistance mainly to anidulafungin (mono-echinocandin resistance), while voriconazole had the lowest susceptibility rate of 34.8% (85/244), followed by fluconazole 59.4% (145/244), respectively. All isolates were genotyped by allelic combination of 3 microsatellite markers (CEF3, CAIII and LOC4). A total of 129 different allelic genotypes were identified, in which seven different clades were recognized with a discriminatory power of 0.96. Genotypes A-D were present in 35% of the isolates. In conclusion, decrease in antifungal drug susceptibility to C. albicans isolates from VVC is alarming. Our findings revealed the genetic diversity of C. albicans isolates among VVC patients and provided insights into the molecular epidemiology of Candida infections in China.

Metal-Organic Framework-Encapsulated CoCu Nanoparticles for the Selective Transfer Hydrogenation of Nitrobenzaldehydes: Engineering Active Armor by the Half-Way Injection Method.

A novel armor-type composite of metal-organic framework (MOF)-encapsulated CoCu nanoparticles with a Fe3 O4 core (Fe3 O4 @SiO2 -NH2 -CoCu@UiO-66) has been designed and synthesized by the half-way injection method, which successfully serves as an efficient and recyclable catalyst for the selective transfer hydrogenation. In this half-way injection approach, the pre-synthetic Fe3 O4 @SiO2 -NH2 -CoCu was injected into the UiO-66 precursor solution halfway through the MOF budding period. The formed MOF armor could play a role of providing significant additional catalytic sites besides CoCu nanoparticles, protecting CoCu nanoparticles, and improving the catalyst stability, thus facilitating the selective transfer hydrogenation of nitrobenzaldehydes into corresponding nitrobenzyl alcohols in high selectivity (99 %) and conversion (99 %) rather than nitro group reduction products. Notably, this method achieves the precise assembly of a MOF-encapsulated composite, and the ingenious combination of MOF and nanoparticles exhibits excellent catalytic performance in the selective hydrogen transfer reaction, implementing a "1+1>2" strategy in catalysis.

Bacterial factors required for Streptococcus pneumoniae coinfection with influenza A virus.

BACKGROUND: Streptococcus pneumoniae is a common cause of post-influenza secondary bacterial infection, which results in excessive morbidity and mortality. Although 13-valent pneumococcal conjugate vaccine (PCV13) vaccination programs have decreased the incidence of pneumococcal pneumonia, PCV13 failed to prevent serotype 3 pneumococcal disease as effectively as other vaccine serotypes. We aimed to investigate the mechanisms underlying the co-pathogenesis of influenza virus and serotype 3 pneumococci. METHODS: We carried out a genome-wide screening of a serotype 3 S. pneumoniae transposon insertion mutant library in a mouse model of coinfection with influenza A virus (IAV) to identify the bacterial factors required for this synergism. RESULTS: Direct, high-throughput sequencing of transposon insertion sites identified 24 genes required for both coinfection and bacterial infection alone. Targeted deletion of the putative aminotransferase (PA) gene decreased bacterial growth, which was restored by supplementation with methionine. The bacterial burden in a coinfection with the PA gene deletion mutant and IAV in the lung was lower than that in a coinfection with wild-type pneumococcus and IAV, but was significantly higher than that in an infection with the PA gene deletion mutant alone. These data suggest that IAV infection alters host metabolism to benefit pneumococcal fitness and confer higher susceptibility to pneumococcal infection. We further demonstrated that bacterial growth was increased by supplementation with methionine or IAV-infected mouse lung homogenates. CONCLUSIONS: The data indicates that modulation of host metabolism during IAV infection may serve as a potential therapeutic intervention against secondary bacterial infections caused by serotype 3 pneumococci during IAV outbreaks in the future.

Methods for detection and study of virus-derived small RNAs produced from the intramolecular base-pairing region of the picornavirus genome.

There is conclusive evidential support for the existence of virus-derived small RNA (vsRNA) in mammals. Two types of vsRNA have been reported from picornaviruses. The first is virus-derived short-interfering RNA (vsiRNA) that is processed from viral double-stranded RNA intermediates during RNA replication. The other is small RNA derived from the highly base-paired single-stranded genomic region, e.g. the internal ribosome entry site (IRES) of picornaviruses. vsiRNA interacts with the Argonaute protein to control viral RNA replication through the process of RNA interference. However, the function of structure-based vsRNA is largely unknown. We previously identified vsRNA1 generated from the enterovirus-A71 (EV-A71) IRES region by the endogenous enzyme Dicer. Exogenous vsRNA1 can inhibit IRES activity both in vivo and in vitro, hence viral replication is inhibited. Here we describe key methods used to characterize vsRNA, including annotation by next-generation sequencing, abundance measurement by Northern blotting, determination of Dicer-dependence by gel-shift assay and in vitro cleavage assay, and the inhibitory effect on IRES activity via in vitro translation assay.

Bilateral pulmonary embolism without deep venous thrombosis was observed after knee arthroscopy: a case report.

BACKGROUND: Symptomatic pulmonary embolism (PE) after knee arthroscopy is extremely rare. If the embolism is not treated promptly, the patient may die. Bilateral pulmonary embolism with associated pulmonary infarct without concomitant deep vein thrombosis has never been reported following routine knee arthroscopy. CASE PRESENTATION: A 50-year-old female patient with no other risk factors other than hypertension, obesity, varicose veins in the ipsilateral lower extremities and elevated triglyceride (TG) presented to our ward. She had experienced sudden chest tightness, polypnea and fainting after going to the bathroom the morning of the second postoperative day and received emergency medical attention. Colour ultrasonography of the extremities showed no deep vein thrombosis. Lung computed tomography angiography (CTA) showed multiple embolisms scattered in both pulmonary artery branches. Thus, emergency interventional thrombolysis therapy was performed, followed by postoperative symptomatic treatment with drugs with thrombolytic, anticoagulant and protective activities. One week later, lung CTA showed a significant improvement in the PEs compared with those in the previous examination. Since the aetiology of PE and no obvious symptoms were discerned, the patient was discharged. CONCLUSION: Although knee arthroscopy is a minimally invasive and quick procedure, the risk factors for PE in the perioperative period should be considered and fully evaluated to enhance PE detection. Moreover, a timely diagnosis and effective treatment are important measures to prevent and cure PE after knee arthroscopy. Finally, clear guidelines regarding VTE thromboprophylaxis following knee arthroscopy in patients with a low risk of VTE development are needed.

Preparation of MOF Film/Aerogel Composite Catalysts via Substrate-Seeding Secondary-Growth for the Oxygen Evolution Reaction and CO2 Cycloaddition.

Substrate-supported metal-organic frameworks (MOFs) films are desired to realize their potential in practical applications. Herein, a novel substrate-seeding secondary-growth strategy is developed to prepare composites of uniform MOFs films on aerogel walls. Briefly, the organic ligand is "pre-seeded" onto the aerogel walls, and then a small amount of metal-ion solution is sprayed onto the prepared aerogel. The sprayed solution diffuses along the aerogel walls to form a continuous thin layer, which confines the nucleation reaction, promoting the formation of uniform MOFs films on the aerogel walls. The whole process is simple in operation, highly efficient, and eco-friendly. The resulting hierarchical MOFs/aerogel composites have abundant accessible active sites and enable excellent mass transfer, which endows the composite with outstanding catalytic activity and stability in both liquid-phase CO2 cycloaddition and electrochemical oxygen evolution reaction (OER) process.

MiR-34a inhibits the proliferation, migration, and invasion of oral squamous cell carcinoma by directly targeting SATB2.

In various kinds of carcinomas, the special AT-rich sequence-binding protein 2 (SATB2) with its atypical expression promotes the metastasis and progression of the tumor, though in the oral squamous cell carcinoma (OSCC) its inherent mechanism and the status of SATB2 remain unclear. The role played by the SATB2 expression in the OSCC cell lines and tissue samples in the target of miR-34a downstream is the intended endeavor of this study. In te OSCCs the miR-34a expression was determined by quantitative real-time polymerase chain reaction (q-PCR), while the SATB2 expression in the cell lines and tissue samples in OSCC was analyzed with the q-PCR and the western blot. Studies in both in vitro and in vivo of the effects of miR-34a on the initiation of OSCC were conducted. As a direct target of the miR-34a the SATB2 was verified with the luciferase reporter assay. In cases where the miR-34a levels were low, the SATB2 in OSCCs seemed to be overexpressed. Besides, both in the in vitro and in vivo a suppression of migration, invasion, and cell growth was caused by miR-34a by down regulating the SATB2 expression. The SATB2 being a direct target of miR-34a was confirmed by the cotransfection of miR-34a mimics specifically the decrease in the expression of luciferase of SATB2-3'UTR-wt reporter. As a whole, our study confirmed the inhibition of miR-34a in the invasion, proliferation, and migration of the OSCCs, playing a potential tumor suppressor role with SATB2 as its downstream target.

Genomic Insight into the Spread of Meropenem-Resistant Streptococcus pneumoniae Spain23F-ST81, Taiwan.

Incidence of invasive pneumococcal disease caused by antimicrobial-resistant Streptococcus pneumoniae types not included in pneumococcal conjugate vaccines has increased, including a penicillin- and meropenem-resistant serotype 15A-ST63 clone in Japan. During 2013-2017, we collected 206 invasive pneumococcal isolates in Taiwan for penicillin and meropenem susceptibility testing. We found serotypes 15B/C-ST83 and 15A-ST63 were the most prevalent penicillin- and meropenem-resistant clones. A transformation study confirmed that penicillin-binding protein (PBP) 2b was the primary meropenem resistance determinant, and PBP1a was essential for high-level resistance. The rate of serotype 15B/C-ST83 increased during the study. All 15B/C-ST83 isolates showed an ermB macrolide resistance genotype. Prediction analysis of recombination sites revealed 12 recombination regions in 15B/C-ST83 compared with the S. pneumoniae Spain23F-ST81 genome. Pneumococcal clones rapidly recombine to acquire survival advantages and undergo local expansion under the selective pressure exerted by vaccines and antimicrobial drugs. The spread of 15B/C-ST83 is alarming for countries with high antimicrobial pressure.

Culture-Based Virus Isolation To Evaluate Potential Infectivity of Clinical Specimens Tested for COVID-19.

Real-time reverse transcription-PCR (RT-PCR) is currently the most sensitive method to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19). However, the correlation between detectable viral RNA and culturable virus in clinical specimens remains unclear. Here, we performed virus culture for 60 specimens that were confirmed to be positive for SARS-CoV-2 RNA by real-time RT-PCR. The virus could be successfully isolated from 12 throat and nine nasopharyngeal swabs and two sputum specimens. The lowest copy number required for virus isolation was determined to be 5.4, 6.0, and 5.7 log10 genome copies/ml sample for detecting the nsp12, E, and N genes, respectively. We further examined the correlation of genome copy number and virus isolation in different regions of the viral genome, demonstrating that culturable specimens are characterized by high copy numbers with a linear correlation observed between copy numbers of amplicons targeting structural and nonstructural regions. Overall, these results indicate that in addition to the copy number, the integrity of the viral genome should be considered when evaluating the infectivity of clinical SARS-CoV-2 specimens.

Predicting Intraserotypic Recombination in Enterovirus 71.

Enteroviruses are well known for their ability to cause neurological damage and paralysis. The model enterovirus is poliovirus (PV), the causative agent of poliomyelitis, a condition characterized by acute flaccid paralysis. A related virus, enterovirus 71 (EV-A71), causes similar clinical outcomes in recurrent outbreaks throughout Asia. Retrospective phylogenetic analysis has shown that recombination between circulating strains of EV-A71 produces the outbreak-associated strains which exhibit increased virulence and/or transmissibility. While studies on the mechanism(s) of recombination in PV are ongoing in several laboratories, little is known about factors that influence recombination in EV-A71. We have developed a cell-based assay to study recombination of EV-A71 based upon previously reported assays for poliovirus recombination. Our results show that (i) EV-A71 strain type and RNA sequence diversity impacts recombination frequency in a predictable manner that mimics the observations found in nature; (ii) recombination is primarily a replicative process mediated by the RNA-dependent RNA polymerase; (iii) a mutation shown to reduce recombination in PV (L420A) similarly reduces EV-A71 recombination, suggesting conservation in mechanism(s); and (iv) sequencing of intraserotypic recombinant genomes indicates that template switching occurs by a mechanism that may require some sequence homology at the recombination junction and that the triggers for template switching may be sequence independent. The development of this recombination assay will permit further investigation on the interplay between replication, recombination and disease.IMPORTANCE Recombination is a mechanism that contributes to genetic diversity. We describe the first assay to study EV-A71 recombination. Results from this assay mimic what is observed in nature and can be used by others to predict future recombination events within the enterovirus species A group. In addition, our results highlight the central role played by the viral RNA-dependent RNA polymerase (RdRp) in the recombination process. Further, our results show that changes to a conserved residue in the RdRp from different species groups have a similar impact on viable recombinant virus yields, which is indicative of conservation in mechanism.

A Case of Right Renal Arteriovenous Malformation Mimicking the Symptoms of Urinary Tract Infection in the Emergency Department.

BACKGROUND: Renal arteriovenous malformation (AVM) is a rare cause of massive hematuria, and patients with renal AVM may present with symptoms like urinary tract infections in the emergency department. CASE REPORT: A 37-year-old woman presented to the emergency department with symptoms of hematuria, urinary hesitancy, and severe suprapubic pain that had been present for a few hours. A urine examination revealed no pyuria, but urine occult blood for 3+ and a red blood cell count of >100 per high-power field. Bedside echocardiography revealed right kidney hydronephrosis and a distended bladder with a blood clot. A 3-way Foley catheter was inserted and drained 800 mL of bloody urine. A contrast-enhanced computed tomography scan was ordered that showed a 1.1-cm hypervascular tumor in the lower pole of right kidney, with active bleeding and rupture into the adjacent collecting system. Active renal tumor bleeding or renal AVM was suspected. The patient was transferred to a tertiary medical center where right renal artery angiography was arranged and disclosed an AVM with aneurysm formation at the right renal lower pole. Transarterial embolization was performed immediately to embolize the 3 feeders of the AVM. WHY SHOULD EMERGENCY PHYSICIANS BE AWARE OF THIS?: Renal AVM is a rare but potentially life-threatening cause of massive hematuria. Delayed or missed diagnosis is possible because renal AVM may present with symptoms like urinary tract infection, especially in young females. Renal artery angiography is the diagnosis of choice, and emergent transarterial embolization is now the standard of treatment.