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AMPylation is a post-translational modification in which AMP is added to the amino acid side chains of proteins1,2. Here we show that, with ATP as the ligand and actin as the host activator, the effector protein LnaB of Legionella pneumophila exhibits AMPylase activity towards the phosphoryl group of phosphoribose on PRR42-Ub that is generated by the SidE family of effectors, and deubiquitinases DupA and DupB in an E1- and E2-independent ubiquitination process3-7. The product of LnaB is further hydrolysed by an ADP-ribosylhydrolase, MavL, to Ub, thereby preventing the accumulation of PRR42-Ub and ADPRR42-Ub and protecting canonical ubiquitination in host cells. LnaB represents a large family of AMPylases that adopt a common structural fold, distinct from those of the previously known AMPylases, and LnaB homologues are found in more than 20 species of bacterial pathogens. Moreover, LnaB also exhibits robust phosphoryl AMPylase activity towards phosphorylated residues and produces unique ADPylation modifications in proteins. During infection, LnaB AMPylates the conserved phosphorylated tyrosine residues in the activation loop of the Src family of kinases8,9, which dampens downstream phosphorylation signalling in the host. Structural studies reveal the actin-dependent activation and catalytic mechanisms of the LnaB family of AMPylases. This study identifies, to our knowledge, an unprecedented molecular regulation mechanism in bacterial pathogenesis and protein phosphorylation.
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Monofosfato de Adenosina , Proteínas de Bactérias , Legionella pneumophila , Fosfotirosina , Transdução de Sinais , Humanos , Actinas/metabolismo , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , ADP-Ribosilação , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Hidrólise , Legionella pneumophila/enzimologia , Legionella pneumophila/metabolismo , Legionella pneumophila/patogenicidade , Ligantes , Modelos Moleculares , N-Glicosil Hidrolases/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Tirosina/metabolismo , Tirosina/química , Ubiquitina/metabolismo , Ubiquitinação , Enzimas Desubiquitinantes/metabolismo , Dobramento de Proteína , Fosfotirosina/química , Fosfotirosina/metabolismoRESUMO
INTRODUCTION/AIMS: Ultrasound (US) studies have demonstrated patchy enlargement of spinal and peripheral nerves in Guillain-Barré syndrome (GBS). However, whether ultrasound yields useful information for early classification of GBS has not been established. We aimed to evaluate nerve ultrasound in patients with GBS in northern China and compare the sonographic characteristics between demyelinating and axonal subtypes. METHODS: Between November 2018 and October 2019, 38 hospitalized GBS patients within 3 wk of disease onset and 40 healthy controls were enrolled. Ultrasonographic cross-sectional areas (CSA) of the peripheral nerves, vagus nerve, and cervical nerve roots were prospectively recorded in GBS subtypes and controls. RESULTS: Ultrasonographic CSA exhibited significant enlargement in most patients' nerves compared with healthy controls, most prominent in cervical nerves. The CSA tended to be larger in acute inflammatory demyelinating polyneuropathy (AIDP) than in acute motor axonal neuropathy (AMAN)/acute motor and sensory axonal neuropathy (AMSAN), especially in cervical nerves (C5: 5.9 ± 1.6 mm2 vs. 7.0 ± 1.7 mm2 , p = .042; C6: 10.5 ± 1.8 mm2 vs. 12.0 ± 2.1 mm2 , p = .033). The chi-squared test revealed significant differences in nerve enlargement in C5 (p < .001), C6 (p < .001), the proximal median nerve (p < .001), and the vagus nerve (p = .003) between GBS and controls. The vagus nerve was larger in patients with autonomic dysfunction than in patients without it (2.3 ± 1.0 mm2 vs. 1.4 ± 0.5 mm2 , p = .003). DISCUSSION: The demyelinating subtype presented with more significant cervical nerve enlargement in GBS. Vagus nerve enlargement may be a useful marker for autonomic dysfunction.
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Síndrome de Guillain-Barré , China , Síndrome de Guillain-Barré/diagnóstico por imagem , Humanos , Condução Nervosa/fisiologia , Nervos Periféricos/diagnóstico por imagem , Nervos Espinhais/diagnóstico por imagem , UltrassonografiaRESUMO
BACKGROUND: Imported malaria parasites with anti-malarial drug resistance (ADR) from Africa is a serious public health challenge in non-malarial regions, including Wuhan, China. It is crucial to assess the ADR status in African Plasmodium falciparum isolates from imported malaria cases, as this will provide valuable information for rational medication and malaria control. METHODS: During 2017-2019, a cross-sectional study was carried out in Wuhan, China. Peripheral blood 3 ml of returned migrant workers from Africa was collected. The target fragments from pfcrt, pfmdr1, and k13 propeller (pfk13) genes were amplified, sequenced, and analysed. RESULTS: In total, 106 samples were collected. Subsequently, 98.11% (104/106), 100% (106/106), and 86.79% (92/106) of these samples were successfully amplified and sequenced for the pfcrt (72-76), pfmdr1, and pfk13 genes, respectively. The prevalence of the pfcrt 76 T, pfmdr1 86Y, and pfmdr1 184F mutations was 9.62, 4.72, and 47.17%, respectively. At codons 72-76, the pfcrt locus displayed three haplotypes, CVMNK (wild-type), CVIET (mutation type), CV M/I N/E K/T (mixed type), with 87.50%, 9.62%, and 2.88% prevalence, respectively. For the pfmdr1 gene, NY (wild type), NF and YF (mutant type), N Y/F, Y Y/F, and N/Y Y/F (mixed type) accounted for 34.91, 43.40, 3.77, 15.09, 0.94, and 1.89% of the haplotypes, respectively. A total of 83 isolates with six unique haplotypes were found in pfcrt and pfmdr1 combined haplotypes, of which NY-CVMNK and NF-CVMNK accounted for 40.96% (34/83) and 43.37% (36/83), respectively. Furthermore, 90 cases were successfully sequenced (84.91%, 90/106) at loci 93, 97, 101, and 145, and 78 cases were successfully sequenced (73.58%, 78/106) at loci 343, 353, and 356 for pfcrt. However, the mutation was observed only in locus 356 with 6.41%. For pfk13, mutations reported in Southeast Asia (at loci 474, 476, 493, 508, 527, 533, 537, 539, 543, 553, 568, 574, 578, and 580) and Africa (at loci 550, 561, 575, 579, and 589) were not observed. CONCLUSIONS: The present data from pfcrt and pfmdr1 demonstrate that anti-malarial drugs including chloroquine, amodiaquine, and mefloquine, remain effective against malaria treatment in Africa. The new mutations in pfcrt related to piperaquine resistance remain at relatively low levels. Another source of concern is the artemether-lumefantrine resistance-related profiles of N86 and 184F of pfmdr1. Although no mutation in pfk13 is detected, molecular surveillance must continue.
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Proteínas de Membrana Transportadoras/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Mutação , Plasmodium falciparum/genética , Polimorfismo Genético , Proteínas de Protozoários/genética , África , Antimaláricos/uso terapêutico , China , Doenças Transmissíveis Importadas/tratamento farmacológico , Estudos Transversais , Malária Falciparum/tratamento farmacológico , Proteínas de Membrana Transportadoras/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Mutação/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Polimorfismo de Nucleotídeo Único , Proteínas de Protozoários/metabolismoRESUMO
Since 2012, there has been a noticeable upward trend in the global incidence of inclusion body hepatitis (IBH) cases, leading to substantial economic losses in the poultry industry. In response to this trend, the current study aimed to investigate the phylogenetic information, genetic mutations, and pathogenicity of the highly pathogenic fowl adenovirus (FAdV) strain HN1472, which was isolated from liver samples obtained from a laying flock affected by IBH. This investigation was carried out using 1-day-old specific pathogen-free (SPF) chickens. Recombination and phylogenetic analyses confirmed that HN1472 is a recombinant strain derived from FAdV-8a and FAdV-8b, and exhibited significant genetic divergence in the hexon, fiber, and ORF19 genes. Notably, the phylogenetic analysis identified recombination events in these regions. Furthermore, animal experiments revealed that HN1472 is a highly pathogenic isolate, causing 80% mortality and manifesting clinical signs of IBH in SPF chickens. Furthermore, the recombinant FAdV serotype 8b (FAdV-8b) was found to be widely distributed in various tissues, with a higher concentration in the livers and gizzard tissue at 3 d postchallenge (dpc). Collectively, these findings contribute to our current understanding of the factors influencing the pathogenicity and genetic diversity of FAdV serotype 8b (FAdV-8b) in China.
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Infecções por Adenoviridae , Aviadenovirus , Galinhas , Filogenia , Doenças das Aves Domésticas , Animais , Doenças das Aves Domésticas/virologia , Infecções por Adenoviridae/veterinária , Infecções por Adenoviridae/virologia , Aviadenovirus/genética , Aviadenovirus/patogenicidade , Aviadenovirus/classificação , Aviadenovirus/fisiologia , Organismos Livres de Patógenos Específicos , Virulência , China/epidemiologia , Hepatite Viral Animal/virologiaRESUMO
Defect-engineered metal-organic frameworks (DEMOFs) are emerging advanced materials. The construction of DEMOFs is of great significance; however, DEMOF-based catalysis remains unexplored. (E)-vinylboronates, an important building block for asymmetric synthesis, can be synthesized via the hydroboration of alkynes. However, the lack of high-performance catalysts considerably hinders their synthesis. Herein, a series of DEHKUST-1 (HKUST = Hong Kong University of Science and Technology) (Da-f) catalysts with missing occupation of linkers at Cu nodes were designed by partially replacing benzene-1,3,5-tricarboxylate (H3BTC) with defective connectors of pyridine-3,5-dicarboxylate (PYDC) to efficiently promote the hydroboration of alkynes. Results showed that the Dd containing 0.8 doping ratio of PYDC exhibited remarkable catalytic activity than the defect-free HKUST-1. This originated from the improved accessibility for reactants towards the Lewis acid active Cu sites of DEHKUST-1 due to the presence of plenty of rooms next to the Cu sites and enhanced coordination ability in such 'defective' HKUST-1. Dd had high selectivity (>99 %) and yield (>96 %) for (E)-vinylboronates and extensive functional group compatibility for terminal alkynes. Density functional theory (DFT) calculations were performed to elucidate the mechanism of hydroboration. Compared with that of defect-free HKUST-1, the low energy barrier of DEHKUST-1 can be attributed to the lower coordination number of Cu sites and enhanced accessibility of Cu active sites towards reagents.
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Drug resistance surveillance is a major integral part of malaria control programs. Molecular methods play a pivotal role in drug resistance detection and related molecular research. This study aimed to develop a rapid and accurate detection method for drug resistance of Plasmodium falciparum (P. falciparum). A quantitative real-time PCR (qPCR) assay has been developed that identifies the mutation at locus A256T in the P.falciparum multi-drug resistance(pfmdr1) gene producing amino acid change at position 86. The results of 198 samples detected by qPCR were consistent with nested PCR and sequencing, giving an accuracy of 94.3%. The sensitivity, specificity, positive and negative predictive value of qPCR were 85.7%, 97.6%, 90.0% and 96.4%, respectively. The results of qPCR are basically consistent with the nested PCR, which is expected to replace the nested PCR as a new molecular biological method for drug resistance detection, providing reliable technical support for global malaria prevention and control.
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Malária Falciparum , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Plasmodium falciparum , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Plasmodium falciparum/genética , Humanos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Malária Falciparum/parasitologia , Malária Falciparum/diagnóstico , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Mutação , Resistência a Medicamentos/genéticaRESUMO
Cerebral malaria (CM), caused by Plasmodium falciparum, is the primary cause of death from severe malaria. Even after immediate parenteral therapy with antimalarial drugs, the mortality rate remains 15 to 25%. Currently, no effective therapeutic agents are available for the radical treatment of CM. Thus, further in-depth explorations of adjuvant therapies in combination with antimalarial drugs are urgently needed. The experimental cerebral malaria (ECM) model was established by infecting C57BL/6 mice with Plasmodium berghei ANKA. Subsequently, infected mice were continuously treated with dihydroartemisinin (DHA) in combination with rapamycin (RAP) and atorvastatin (AVA) for 5 days at different time points, including day 0, day 3, and day 6 postinfection (p.i.). Treatment efficacy was evaluated by comparing behavioral scores, body weight, parasitemia, survival rate, blood-brain barrier (BBB) integrity, and histopathology. The optimal combination therapy of DHA, RAP, and AVA on day 3 p.i. was selected for ECM. This strategy significantly improved survival rate, reduced parasitemia, improved the rapid murine coma and behavioral scale scores and permeability of the BBB, attenuated cerebrovascular and hepatic central venous obstruction and hemozoin deposition in the liver, and decreased the red pulp area of the spleen, which effectively ameliorated neurological damage in ECM. It also improved histopathology and neurological damage caused by ECM. In this study, the optimal therapeutic strategy for ECM was selected, which is expected to be a potential therapy for human CM. IMPORTANCE Although artemisinin-based combination therapies (ACTs) have greatly improved the clinical outcome of cerebral malaria (CM) as a fatal disease that can permanently disable a significant proportion of children even if they survive, new treatment options are needed as Plasmodium falciparum develops resistance to antimalarial drugs. Recent reports suggest that basal treatment with artemisinin derivatives often fails to protect against cell death, neurological damage, and cognitive deficits. In this study, the combination of dihydroartemisinin with rapamycin and atorvastatin improved the current antimalarial outcomes by overcoming the limitations of current antimalarials for CM morbidity and neurological sequelae. This combination offers a new adjunctive treatment for the clinical treatment of human CM in susceptible populations, including children under 5 years old and pregnant women.
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Background: It has been proposed that bacterial lysates may serve as a suitable immunomodulatory oral medication to improve and control asthma symptoms. However, the difference in its efficacy in adults and children remains unclear. Methods: Randomized controlled trials (RCTs) evaluating OM-85 add-on therapy in asthma patients up to December 2021 were searched using PubMed, Scopus, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang database, and WP (WeiPu) database. Risk of bias was evaluated using the Cochrane risk of bias assessment tool. Results: A total of 36 studies were included. The results showed that OM-85 add-on treatment provided a 24% improvement in asthma symptom control [relative rates (RR) =1.24, 95% confidence intervals (CI): 1.19-1.30], and also significantly improved lung function, increased numbers of T-lymphocytes and the subtypes, and elevated levels of interferon-γ (IFN-γ), interleukin-10 (IL-10), and IL-12. Levels of serum immunoglobulin E (IgE), eosinophil cationic protein (ECP) and pro-inflammatory cytokines (including IL-4 and IL-5) were suppressed in the OM-85 add-on treatment group. Moreover, OM-85 add-on treatment showed more prominent effects in asthmatic children than in asthmatic adults. Conclusions: OM-85 add-on therapy showed important clinical benefits for patients with asthma, especially asthmatic children. Further studies focusing on the immunomodulatory function of OM-85 in personalized asthma treatment are warranted.
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Highly pathogenic fowl adenovirus serotype 4 (FAdV-4) is an acute infectious disease with severe economic impact, causing chicken hepatitis hydropericardium syndrome (HHS) and high mortality. In the present study, we evaluated the immunogenicity of the recombinant Fiber2-knob protein (F2-Knob) as an FAdV-4 candidate subunit vaccine in 14-day-old SPF chickens. The knob domain is the functional region of the viral surface protein Fiber2. The protein was expressed in Escherichia coli and was administered a single immunization with different vaccine doses. The protective efficacy was evaluated by mortality, clinical symptoms, virus shedding and histopathological examinations after challenged with the FAdV-4. The results showed that the level of ELISA antibodies of the chickens immunized with Fiber2-knob protein was significantly higher than that of the chickens immunized with an inactivated vaccine against FAdV-4. The antibody value of the immunized Fiber2-knob protein was positively correlated with the increase in immunization dose. The challenge experiment showed that the F2-Knob protein provided full protection against virulent FAdV-4 challenge and significantly reduced viral shedding. These results suggest that F2-Knob protein could be a novel vaccine candidate provide insights to control FAdV-4.
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Infecções por Adenoviridae , Doenças das Aves Domésticas , Vacinas Virais , Animais , Infecções por Adenoviridae/prevenção & controle , Infecções por Adenoviridae/veterinária , Sorogrupo , Galinhas , Anticorpos Antivirais , Adenoviridae , Proteínas RecombinantesRESUMO
Background/aim: Patients with elevated intracranial pressure (ICP) tend to have optic disc edema and a thicker optic nerve sheath diameter (ONSD). However, the cut-off value of the optic disc height (ODH) for evaluating elevated ICP is not clear. This study was conducted to evaluate ultrasonic ODH and to investigate the reliability of ODH and ONSD for elevated ICP. Methods: Patients suspected of having increased ICP and who underwent a lumbar puncture were recruited. ODH and ONSD were measured before lumbar puncture. Patients were divided according to elevated and normal ICP. We analyzed the correlations between ODH, ONSD, and ICP. ODH and ONSD cut-off points for the identification of elevated ICP were determined and compared. Results: There were a total of 107 patients recruited for this study, 55 patients with elevated ICP and 52 with normal ICP. Both ODH and ONSD in the elevated ICP group were higher than in the normal group [ODH: median 0.81 (range 0.60-1.06) mm vs. 0.40 [0-0.60] mm, p < 0.001; ONSD: 5.01 ± 0.37 mm vs. 4.20 ± 0.38 mm, p < 0.001]. ICP was positively correlated with ODH (r = 0.613; p < 0.001) and ONSD (r = 0.792; p < 0.001). The cut-off values of ODH and ONSD for evaluating elevated ICP were 0.63 mm and 4.68 mm, respectively, with 73% and 84% sensitivity and 83% and 94% specificity, respectively. ODH combined with ONSD showed the highest value under the receiver operating characteristic curve of 0.965 with a sensitivity of 93% and a specificity of 92%. Conclusion: Ultrasonic ODH combined with ONSD may help monitor elevated ICP non-invasively.
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A transcriptome profiles the expression levels of genes in cells and has accumulated a huge amount of public data. Most of the existing biomarker-related studies investigated the differential expression of individual transcriptomic features under the assumption of inter-feature independence. Many transcriptomic features without differential expression were ignored from the biomarker lists. This study proposed a computational analysis protocol (mqTrans) to analyze transcriptomes from the view of high-dimensional inter-feature correlations. The mqTrans protocol trained a regression model to predict the expression of an mRNA feature from those of the transcription factors (TFs). The difference between the predicted and real expression of an mRNA feature in a query sample was defined as the mqTrans feature. The new mqTrans view facilitated the detection of thirteen transcriptomic features with differentially expressed mqTrans features, but without differential expression in the original transcriptomic values in three independent datasets of lung cancer. These features were called dark biomarkers because they would have been ignored in a conventional differential analysis. The detailed discussion of one dark biomarker, GBP5, and additional validation experiments suggested that the overlapping long non-coding RNAs might have contributed to this interesting phenomenon. In summary, this study aimed to find undifferentially expressed genes with significantly changed mqTrans values in lung cancer. These genes were usually ignored in most biomarker detection studies of undifferential expression. However, their differentially expressed mqTrans values in three independent datasets suggested their strong associations with lung cancer.
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Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/diagnóstico , Perfilação da Expressão Gênica , Transcriptoma/genética , Biomarcadores , RNA Mensageiro/genéticaRESUMO
Rodent malaria caused by Plasmodium yoelii 17XL (Py 17XL) is an ideal animal model for human malaria studies. Although the gut microbiota plays an important role in the occurrence and development of infectious diseases, the gut microbiota associated with Py 17XL infection remains unclear. In the current study, the gut microbiota composition of infected BALB/c mice was surveyed. Mouse fecal samples were collected at 0, 2, 5 days post-infection (dpi), and the gut microbiota was characterized by 16S rRNA sequencing. Operational taxonomic units (OTUs) were 634 ± 26 on average. Firmicutes and Bacteroidetes were typically predominant in the gut microbiota composition at the phylum level. Compared with the Ctrl, Firmicutes was significantly decreased after infection, while Bacteroidetes was notably increased. The most dominant family was Lactobacillaceae in all samples. The alpha diversity index showed that compared with that of the Ctrl, the observed OTU number was decreased at 2 dpi and then slightly increased at 5 dpi. LEfSe analysis revealed several bacterial taxa were notably related to Py-infected mice at the phylogenetic level. Several bacterial genera, such as Lactobacillus, were overrepresented in the Py-infected fecal microbiota at 2 dpi, while Muribaculaceae was overrepresented at 5 dpi. Moreover, Alistipes and Helicobacter were overrepresented at 5 dpi compared with 2 dpi. The results indicated Py infection could alter the gut microbiota composition of mice. Besides, biomarkers could serve as direct targets to elucidate their roles in the progression and pathogenesis of malaria and provide insights into studies of antimalarial drugs and malaria vaccines.
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Since single nucleotide polymorphisms (SNPs) have attracted attention, there have been many explorations and improvements in screening and detection methods for SNPs. Traditional methods are complex and time-consuming and rely on expensive instruments. Therefore, there is an urgent need for a low-cost, simple, and accurate method that is convenient for use in resource-poor areas. Thus, a platform based on allele-specific PCR (AS-PCR) and a gold nanoparticle-based lateral flow assay (LFA) was developed, optimized, and used to detect the SNPs of the drug resistance gene pfmdr1. Subsequently, the system was assessed on clinical isolates and compared with nested PCR followed by Sanger sequencing. The sensitivity and specificity of the AS-PCR-LFA platform were up to 99.43% and 100%, respectively, based on the clinical isolates. The limit of detection is approximately 150 fg/µL for plasmid DNA as the template and 50 parasites/µL for dried filter blood spots from clinical isolates. The established and optimized AS-PCR-LFA system is more adaptable and rapidly translated to SNP analysis of other drug resistance genes and genetic diseases. In addition, while actively responding to the point-of-care testing policy, it also contributes to the Global Malaria Eradication Program. IMPORTANCE Rapid detection of single nucleotide polymorphisms (SNPs) is essential for malaria treatment. Based on the techniques of allele-specific PCR (AS-PCR) and lateral flow assay (LFA), an accurate and powerful platform for SNP detection of pfmdr1 was developed and evaluated with plasmid and clinical isolates. It offers a useful tool to identify antimalarial drug resistance and can support the effort to eliminate malaria globally.
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Antimaláricos , Nanopartículas Metálicas , Plasmodium falciparum , Alelos , Antimaláricos/farmacologia , Resistência a Medicamentos/genética , Ouro/uso terapêutico , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Mutação , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Reação em Cadeia da Polimerase , Proteínas de Protozoários/genéticaRESUMO
Cerebral malaria (CM) caused by Plasmodium falciparum is a fatal neurological complication of malaria, resulting in coma and death, and even survivors may suffer long-term neurological sequelae. In sub-Saharan Africa, CM occurs mainly in children under five years of age. Although intravenous artesunate is considered the preferred treatment for CM, the clinical efficacy is still far from satisfactory. The neurological damage induced by CM is irreversible and lethal, and it is therefore of great significance to unravel the exact etiology of CM, which may be beneficial for the effective management of this severe disease. Here, we review the clinical characteristics, pathogenesis, diagnosis, and clinical therapy of CM, with the aim of providing insights into the development of novel tools for improved CM treatments.
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Malária Cerebral , Malária Falciparum , Criança , Pré-Escolar , Humanos , Malária Cerebral/diagnóstico , Malária Cerebral/terapia , Malária Falciparum/diagnóstico , Malária Falciparum/tratamento farmacológico , Plasmodium falciparumRESUMO
BACKGROUND: Molecular markers for monitoring resistance could help improve malaria treatment policies. Delayed clearance of Plasmodium falciparum by artemisinin-based combination therapies (ACTs) has been reported in several countries. In addition to PfKelch13 (pfk13), new drug resistance genes, P. falciparum ubiquitin-specific protease 1 (pfubp1) and the eadaptor protein complex 2 mu subunit (pfap2mu), have been identified as being linked to ACTs. This study investigated the prevalence of single-nucleotide polymorphisms (SNPs) in clinical P. falciparum isolates pfubp1 and pfap2mu imported from Africa and Southeast Asia (SEA) to Wuhan, China, to provide baseline data for antimalarial resistance monitoring in this region. METHODS: Peripheral venous blood samples were collected in Wuhan, China, from August 2011 to December 2019. The Pfubp1 and pfap2mu SNPs of P. falciparum were determined by nested PCR and Sanger sequencing. RESULTS: In total, 296 samples were collected. Subsequently, 92.23% (273/296) were successfully amplified and sequenced for Pfubp1. There were 60.07% (164/273) wild-type strains and 39.93% (109/273) mutant strains. The pfap2mu gene was divided into three fragments for amplification, and 82.77% (245/296), 90.20% (267/296) and 94.59% (280/296) were sequenced successfully. Genotypes reportedly associated with ACTs resistance detected in this study included pfubp1 D1525E as well as E1528D and pfap2mu S160N. The mutation prevalence rates were 10.99% (30/273), 13.19% (36/273) and 11.24% (30/267), respectively. These are all focused on Congo, Nigeria and Angola. Known delayed-clearance parasite mutations have also been found in SEA. CONCLUSIONS: The existence of mutation sites of known clearance genes detected in the isolates in this study, including D1525E and E1528D in the pfubp1 gene and S160N in the pfap2mu gene, further proved the risk of ACTs resistance. Constant vigilance is therefore needed to protect the effectiveness of ACTs and to prevent the spread of drug-resistant P. falciparum. Further studies in malaria-endemic countries are needed to further validate potential genetic markers for monitoring parasite populations in Africa and SEA.
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Antimaláricos , Artemisininas , Malária Falciparum , Malária , Parasitos , Animais , Angola , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Artemisininas/farmacologia , Artemisininas/uso terapêutico , China/epidemiologia , Resistência a Medicamentos/genética , Malária/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Mutação , Plasmodium falciparum/genética , Polimorfismo de Nucleotídeo Único , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismoRESUMO
Single-nucleotide polymorphisms and genotyping related to genetic detection are several of the focuses of contemporary biotechnology development. Traditional methods are complex, take a long time, and rely on expensive instruments. Therefore, there is an urgent need for a rapid, simple, and accurate method convenient for use in resource-poor areas. Thus, a platform based on allele-specific PCR (AS-PCR) combined with a lateral flow assay (LFA) was developed, optimized, and used to detect the genotype of the Plasmodium falciparum chloroquine transporter gene (pfcrt). Subsequently, the system was assessed by clinical isolates and compared with Sanger sequencing. The sensitivity and specificity of the AS-PCR-LFA platform were 95.83% (115/120) and 100% (120/120), respectively, based on the clinical isolates. The detection limit of plasmid DNA was approximately 3.38 × 105 copies/µL. In addition, 100 parasites/µL were used for the dried filter blood spots from clinical isolates. The established rapid genotyping technique is not limited to antimalarial drug resistance genes but can also be applied to genetic diseases and other infectious diseases. Thus, it has realized the leap and transformation from scientific research theory to practical application and actively responds to the point-of-care testing policy. IMPORTANCE Accurate recognition of the mutation and genotype of genes are essential for the treatment of infectious diseases and genetic diseases. Based on the techniques of allele-specific PCR (AS-PCR) and a lateral flow assay (LFA), a rapid and useful platform for mutation detection was developed and assessed with clinical samples. It offers a powerful tool to identify antimalarial drug resistance and can support malaria control and elimination globally.
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Antimaláricos , Malária Falciparum , Alelos , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Cloroquina/farmacologia , Cloroquina/uso terapêutico , Resistência a Medicamentos/genética , Genótipo , Humanos , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/genética , Reação em Cadeia da Polimerase/métodos , Proteínas de Protozoários/genética , Proteínas de Protozoários/uso terapêuticoRESUMO
Posterior circulation cerebral infarction (PCCI) can lead to deceased infratentorial cerebral blood flow (CBF) and metabolism. Neural activity is closely related to regional cerebral blood flow both spatially and temporally. Transcranial Doppler (TCD) combined with quantitative electroencephalography (QEEG) is a technique that evaluates neurovascular coupling and involves synergy between the metabolic and vascular systems. This study aimed to monitor brain function using TCD-QEEG and estimate the efficacy of TCD-QEEG for predicting the prognosis of patients with PCCI. We used a TCD-QEEG recording system to perform quantitative brain function monitoring; we recorded the related clinical variables simultaneously. The data were analyzed using a Cox proportional hazards regression model. Receiver-operating characteristic (ROC) curve analysis was used to evaluate the cut-off for the diastolic flow velocity (VD) and (delta + theta)/(alpha + beta) ratio (DTABR). The area under the ROC curve (AUROC) was calculated to assess the predictive validity of the study variables. Forty patients (aged 63.7 ± 9.9 years; 30 men) were assessed. Mortality at 90 days was 40%. The TCD indicators of VD [hazard ratio (HR) 0.168, confidence interval (CI) 0.047-0.597, p = 0.006] and QEEG indicators of DTABR (HR 12.527, CI 1.637-95.846, p = 0.015) were the independent predictors of the clinical outcomes. The AUROC after combination of VD and DTABR was 0.896 and showed better predictive accuracy than the Glasgow Coma Scale score (0.75), VD (0.76), and DTABR (0.781; all p < 0.05). TCD-QEEG provides a good understanding of the coupling mechanisms in the brain and can improve our ability to predict the prognosis of patients with PCCI.
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The genus of Plasmodium parasites can cause malaria, which is a prevalent infectious disease worldwide, especially in tropical and subtropical regions. C57BL/6 mice infected with P. berghei ANKA (PbA) will suffer from experimental cerebral malaria (ECM). However, the gut microbiota in C57BL/6 mice has rarely been investigated, especially regarding changes in the intestinal environment caused by infectious parasites. P. berghei ANKA-infected (PbA group) and uninfected C57BL/6 (Ctrl group) mice were used in this study. C57BL/6 mice were infected with PbA via intraperitoneal injection of 1 × 106 infected red blood cells. Fecal samples of two groups were collected. The microbiota of feces obtained from both uninfected and infected mice was characterized by targeting the V4 region of the 16S rRNA through the Illumina MiSeq platform. The variations in the total gut microbiota composition were determined based on alpha and beta diversity analyses of 16S rRNA sequencing. The raw sequences from all samples were generated and clustered using ≥ 97% sequence identity into many microbial operational taxonomic units (OTUs). The typical microbiota composition in the gut was dominated by Bacteroidetes, Firmicutes, Proteobacteria, and Verrucomicrobia at the phylum level. Bacteroidetes and Verrucomicrobia were considerably decreased after PbA infection compared with the control group (Ctrl), while Firmicutes and Proteobacteria were increased substantially after PbA infection compared with Ctrl. The alpha diversity index showed that the observed OTU number was increased in the PbA group compared with the Ctrl group. Moreover, the discreteness of the beta diversity revealed that the PbA group samples had a higher number of OTUs than the Ctrl group. LEfSe analysis revealed that several potential bacterial biomarkers were clearly related to the PbA-infected mice at the phylogenetic level. Several bacterial genera, such as Acinetobacter, Lactobacillus, and Lachnospiraceae_NK4A136_group, were overrepresented in the PbA-infected fecal microbiota. Meanwhile, a method similar to gene coexpression network construction was used to generate the OTU co-abundance units. These results indicated that P. berghei ANKA infection could alter the gut microbiota composition of C57BL/6 mice. In addition, potential biomarkers should offer insight into malaria pathogenesis and antimalarial drug and malaria vaccine studies.
Assuntos
Microbioma Gastrointestinal , Malária , Animais , Camundongos , Camundongos Endogâmicos C57BL , Filogenia , Plasmodium berghei , RNA Ribossômico 16S/genéticaRESUMO
Background: The emerging Coronavirus Disease-2019 (COVID-19) has challenged the public health globally. With the increasing requirement of detection for SARS-CoV-2 outside of the laboratory setting, a rapid and precise Point of Care Test (POCT) is urgently needed. Methods: Targeting the nucleocapsid (N) gene of SARS-CoV-2, specific primers, and probes for reverse transcription recombinase-aided amplification coupled with lateral flow dipstick (RT-RAA/LFD) platform were designed. For specificity evaluation, it was tested with human coronaviruses, human influenza A virus, influenza B viruses, respiratory syncytial virus, and hepatitis B virus, respectively. For sensitivity assay, it was estimated by templates of recombinant plasmid and pseudovirus of SARS-CoV-2 RNA. For clinical assessment, 100 clinical samples (13 positive and 87 negatives for SARS-CoV-2) were tested via quantitative reverse transcription PCR (RT-qPCR) and RT-RAA/LFD, respectively. Results: The limit of detection was 1 copies/µl in RT-RAA/LFD assay, which could be conducted within 30 min at 39°C, without any cross-reaction with other human coronaviruses and clinical respiratory pathogens. Compared with RT-qPCR, the established POCT assay offered 100% specificity and 100% sensitivity in the detection of clinical samples. Conclusion: This work provides a convenient POCT tool for rapid screening, diagnosis, and monitoring of suspected patients in SARS-CoV-2 endemic areas.