Novel Variant and Known Mutation in 23S rRNA Gene of Mycoplasma pneumoniae, Northern Vietnam, 2023.

During a 2023 outbreak of Mycoplasma pneumoniae-associated community-acquired pneumonia among children in northern Vietnam, we analyzed M. pneumoniae isolated from nasopharyngeal samples. In almost half (6 of 13) of samples tested, we found known A2063G mutations (macrolide resistance) and a novel C2353T variant on the 23S rRNA gene.

Uterine torsion in pregnancy: A case report.

INTRODUCTION AND IMPORTANCE: Uterine torsion are extremely rare in pregnancy as few cases have been reported. Torsion of the pregnant uterus is defined as the rotation more than 45 degrees around the long axis of the uterus. It has been referred as, once-in-a-lifetime diagnosis by obstetricians and gynecologists. This paper reports a case of uterine torsion and velamentous cord insertion from our obstetrical practice, along with a review of reported cases. CASE PRESENTATION: The 30-year-old patient (G2P1) at 38 weeks' gestation with a singleton pregnancy, was admitted to the Obstetrical Unit with uterine cramping and decreased fetal movement. Her prior obstetrical history included one uncomplicated term Cesarean section (2016), the current pregnancy had been velamentous cord insertion at 20 weeks' gestation and intra-uterine growth restriction at the 33rd -week gestation until the presentation date. Emergency Cesarean section was performed the 90 degrees uterine torsion and was diagnosed intra-operatively. This patient and her baby recovered and were discharged home on the fifth post-operative day. CLINICAL DISCUSSION: Uterine torsion, a rare pregnancy complication, should be considered when evaluating acute abdominal pain or performing a Cesarean delivery, especially in cases of abnormal fetal presentation, pelvic adhesions, uterine fibroids, malformations, or ovarian tumors. Early diagnosis and proper treatment are crucial due to the negative prognosis for both mother and baby. CONCLUSION: Uterine torsion along with velamentous cord insertion is difficult to diagnosis due to its rarity. It is essential to focus on uterine malformations during ultrasound examinations in the first, second, and third trimesters.

Structures and bioactivities of monomeric and dimeric carvotacetones from Sphaeranthus africanus.

Four previously undescribed carvotacetones including one monomeric (1) and three dimeric (8, 9, 10) derivatives, together with six known compounds were isolated from the n-hexane extract of the aerial parts of Sphaeranthus africanus L. The structures of the previously undescribed compounds were elucidated as 3-angeloyloxy-5-isobutanoyloxy-7-hydroxycarvotacetone (1), 7,7'-oxybis{3-angeloyloxy-5-[(2R*,3R*)-2,3-dihydroxy-2-methylbutanoyloxy]carvotacetone} (8), (2″S*,3″R*)-7-{3-angeloyloxy-5-[(2R*,3R*)-2,3-dihydroxy-2-methylbuta-noyloxy]carvotaceton-7-yloxy}-3-angeloyloxy-5-(2,3-dihydroxy-2-methylbutanoyloxy)carvo-tacetone (9), and 7,7'-oxybis{3-angeloyloxy-5-[(2S*,3R*)-2,3-dihydroxy-2-methylbutanoyl-oxy]carvotacetone} (10). The three dimeric derivatives (8-10) showed potent anti-proliferative activity against human cancer cell lines (CCRF-CEM, MDA-MB-231, U-251, HCT-116) with IC50 values ranging from 0.2 to 2.0 µM. Caspases 3 and 7 were found to be activated by all compounds, indicating apoptosis induction activity. Monomers exhibited a specific inhibition of NO production in BV2 and RAW 264.7 cells with IC50 values ranging from 4.2 to 6.8 µM which were 2-3.5-fold lower than IC50 values causing cytotoxicity. In addition, the carvotacetones reduced NF-κB1 (p105) mRNA expression at concentrations of 10 and 2.5 µM. Altogether, the results indicate that carvotacetones may be interesting lead structures for the development of anti-cancer and anti-inflammatory drugs.

Molecular subtypes of Adenovirus-associated acute respiratory infection outbreak in children in Northern Vietnam and risk factors of more severe cases.

BACKGROUND: Under the pressure of Human Adenovirus (HAdV)-associated acute respiratory infection (ARI) outbreak in children in Northern Vietnam in the end of 2022, this study was initiated to identify the HAdV subtype(s) and examine the associated clinical features and risk factors of more severe cases. METHODS: This study evaluated pediatric patients with ARI which had tested positive for HAdV between October and November 2022 using a multiplex real-time PCR panel. Nasopharyngeal aspirates or nasal swab samples were used for sequencing to identify HAdV subtypes. Clinical data were collected retrospectively. RESULTS: Among 97 successfully sequenced samples, the predominant subtypes were HAdV-B3 (83%), HAdV-B7 (16%) and HAdV-C2 (1%). Lower respiratory manifestations were found in 25% of the patients of which 5% were diagnosed with severe pneumonia. There was no significant association between HAdV subtype and clinical features except higher white blood cell and neutrophil counts in those detected with HAdV-B3 (p<0.001). Co-detection of HAdV with ≥1 other respiratory viruses was found in 13/24(54%) of those with lower respiratory manifestations and 4/5(80%) of those with severe pneumonia (odds ratio (95% confidence interval) vs. those without = 10.74 (2.83, 48.17) and 19.44 (2.12, 492.73) respectively after adjusting for age, sex, birth delivery method, day of disease). CONCLUSION: HAdV-B3 and HAdV-B7 were predominant in the outbreak. Co-detection of HAdV together with other respiratory viruses was a strong risk factor for lower respiratory tract illnesses and severe pneumonia. The findings advocate the advantages of multi-factor microbial panels for the diagnosis and prognosis of ARI in children.

Effects of MAT1-2 Spore Ratios on Fruiting Body Formation and Degeneration in the Heterothallic Fungus Cordyceps militaris.

The medicinal mushroom Cordyceps militaris is widely exploited in traditional medicine and nutraceuticals in Asian countries. However, fruiting body production in C. militaris is facing degeneration through cultivation batches, and the molecular mechanism of this phenomenon remains unclear. This study showed that fruiting body formation in three different C. militaris strains, namely G12, B12, and HQ1, severely declined after three successive culturing generations using the spore isolation method. PCR analyses revealed that these strains exist as heterokaryons and possess both the mating-type loci, MAT1-1 and MAT1-2. Further, monokaryotic isolates carrying MAT1-1 or MAT1-2 were successfully separated from the fruiting bodies of all three heterokaryotic strains. A spore combination of the MAT1-1 monokaryotic isolate and the MAT1-2 monokaryotic isolate promoted fruiting body formation, while the single monokaryotic isolates could not do that themselves. Notably, we found that changes in ratios of the MAT1-2 spores strongly influenced fruiting body formation in these strains. When the ratios of the MAT1-2 spores increased to more than 15 times compared to the MAT1-1 spores, the fruiting body formation decreased sharply. In contrast, when MAT1-1 spores were increased proportionally, fruiting body formation was only slightly reduced. Our study also proposes a new solution to mitigate the degeneration in the heterokaryotic C. militaris strains caused by successive culturing generations.

Enhanced podophyllotoxin production of endophyte Fusarium proliferatum TQN5T by host extract and phenylalanine.

Fermentation technology using endophytes is considered a potential alternative approach for producing pharmaceutical compounds like podophyllotoxin (PTOX). In this study, fungus TQN5T (VCCM 44284) was selected from endophytic fungi isolated from Dysosma versipellis in Vietnam for PTOX production through TLC. The presence of PTOX in TQN5T was further confirmed by HPLC. Molecular identification indicated TQN5T as Fusarium proliferatum with 99.43% identity. This result was asserted by morphological characteristics such as white cottony, filamentous colony, layer and branched mycelium, and clear hyphae septa. Cytotoxic assay indicated both biomass extract and culture filtrate of TQN5T presented strong cytotoxicity on LU-1 and HepG2 with IC50 of 0.11, 0.20, 0.041, and 0071, respectively, implying anti-cancer compounds were accumulated in the mycelium and secreted into the medium. Further, the production of PTOX in TQN5T was investigated in the fermentation condition supplemented with 10 µg/ml of host plant extract or phenylalanine as elicitors. The results revealed a significantly higher amount of PTOX in the PDB + PE and PDB + PA at all studied time points in comparison with PDB (control). Especially, after 168 h of culture, PTOX content in the PDB with plant extract reached the peak with 314 µg/g DW which is 10% higher than the best yield of PTOX in previous studies, denoting F. proliferatum TQN5T as a promising PTOX producer. This is the first study on enhancing the PTOX production in endophytic fungi by supplementing phenylalanine-a precursor for PTOX biosynthesis in plants into fermented media, suggesting a common PTOX biosynthetic pathway between host plant and endophytes. KEY POINTS: • Fusarium proliferatum TQN5T was proven for PTOX production. • Both mycelia extract and spent broth extract of Fusarium proliferatum TQN5T presented strong cytotoxicity on cancer cell lines LU-1 and HepG2. • The supplementation of 10 µg/ml host plant extract and phenylalanine into fermentation media of F. proliferatum TQN5T improved the yield of PTOX.

A newly constructed Agrobacterium-mediated transformation system based on the hisB auxotrophic marker for genetic manipulation in Aspergillus niger.

The filamentous fungus Aspergillus niger is widely exploited as an industrial workhorse for producing enzymes and organic acids. So far, different genetic tools, including CRISPR/Cas9 genome editing strategies, have been developed for the engineering of A. niger. However, these tools usually require a suitable method for gene transfer into the fungal genome, like protoplast-mediated transformation (PMT) or Agrobacterium tumefaciens-mediated transformation (ATMT). Compared to PMT, ATMT is considered more advantageous because fungal spores can be used directly for genetic transformation instead of protoplasts. Although ATMT has been applied in many filamentous fungi, it remains less effective in A. niger. In the present study, we deleted the hisB gene and established an ATMT system for A. niger based on the histidine auxotrophic mechanism. Our results revealed that the ATMT system could achieve 300 transformants per 107 fungal spores under optimal transformation conditions. The ATMT efficiency in this work is 5 - 60 times higher than those of the previous ATMT studies in A. niger. The ATMT system was successfully applied to express the DsRed fluorescent protein-encoding gene from the Discosoma coral in A. niger. Furthermore, we showed that the ATMT system was efficient for gene targeting in A. niger. The deletion efficiency of the laeA regulatory gene using hisB as a selectable marker could reach 68 - 85% in A. niger strains. The ATMT system constructed in our work represents a promising genetic tool for heterologous expression and gene targeting in the industrially important fungus A. niger.

An efficient Agrobacterium-mediated system based on the pyrG auxotrophic marker for recombinant expression in the filamentous fungus Penicillium rubens.

OBJECTIVES: This work aimed to construct a versatile, effective, and food-grade Agrobacterium tumefaciens-mediated transformation (ATMT) system for recombinant expression in the filamentous fungus Penicillium rubens (also known as Pencillium chrysogenum). RESULTS: In this study, the wild-type P. chrysogenum VTCC 31172 strain was re-classified as P. rubens by a multilocus sequencing analysis. Further, the pyrG gene required for uridine/uracil biosynthesis was successfully deleted in the VTCC 31172 strain by homologous recombination to generate a stable uridine/uracil auxotrophic mutant (ΔpyrG). The growth of the P. rubens ΔpyrG strain could be restored by uridine/uracil supplementation, and a new ATMT system based on the uridine/uracil auxotrophic mechanism was established for this strain. The optimal ATMT efficiency could reach 1750 transformants for 106 spores (equivalent to 0.18%). In addition, supplementation of uridine/uracil at the concentrations of 0.005-0.02% during the co-cultivation process significantly promoted transformation efficiency. Especially, we demonstrated that the pyrG marker and the amyB promoter from the koji mold Aspergillus oryzae were fully functional in P. rubens ΔpyrG. Expression of the DsRed reporter gene under the regulation of the A. oryzae amyB promoter lighted up the mycelium of P. rubens with a robust red signal under fluorescence microscopy. Furthermore, genomic integration of multiple copies of the Aspergillus fumigatus phyA gene under the control of the amyB promoter significantly enhanced phytase activity in P. rubens. CONCLUSIONS: The ATMT system developed in our work provides a safe genetic platform for producing recombinant products in P. rubens without using drug resistance markers.

Whole-genome sequencing of antimicrobial-resistant Salmonella enterica isolates from a Cairina moschata carcass.

Salmonella enterica is one of the most common agents of foodborne bacterial illness with poultry being an important reservoir. The indiscriminate use of antimicrobial compounds in poultry farming increasingly leads to antimicrobial-resistant (AMR) which threatens the health of both animals and humans. Antimicrobial-resistant Salmonella enterica from the poultry can spread to human through the direct contact with infected poultry or fecal contaminated environments. Antimicrobial-resistant S. enterica, especially fluoroquinolone-resistant nontyphoidal Salmonella is in the list of global health concern stated by the World Health Organization (WHO). Here we report the whole-genome sequencing data and de novo genome assemble of antimicrobial-resistant S. enterica strains S8 and S9 from the C. moschata carcass collected in Vietnam. Genomic DNA of S. enterica were extracted and subjected to whole-genome sequencing using Illumina MiSeq platform. The genome size of antimicrobial-resistant S. enterica strain S8 is 4,707,459 bp with a GC-content of 52.38%, containing 10 antimicrobial resistant genes. The genome size of antimicrobial-resistant Samonella enterica strain S9 is 4,923,944 bp with a GC-content of 52,39%, containing 10 antimicrobial resistance genes. Our data provided the insights on antimicrobial resistant genes of S. enterica isolates from the C. moschata carcass, which help to understand the infection mechanism of antimicrobial-resistant S. enterica in human.

Cytotoxicity of Carvotacetones from Sphaeranthus africanus Against Cancer Cells and Their Potential to Induce Apoptosis.

Three carvotacetones (1 - 3: ) isolated from Sphaeranthus africanus were screened in 60 cancer cell lines at the National Cancer Institute (NCI) within the Developmental Therapeutics Program (DTP). At the concentration of 10-5 M, compound 1: (3,5-diangeloyloxy-7-hydroxycarvotacetone) turned out to be the most active compound against ACHN and UO-31 renal cancer cell lines with growth percent values of - 100% (all cells dead). Compound 2: (3-angeloyloxy-5-[2″,3″-epoxy-2″-methylbutanoyloxy]-7-hydroxycarvotacetone) showed strong effects in SK-MEL-5 melanoma and ACHN renal cancer cells with inhibition values of 93% and 97%, respectively. Compound 3: (3-angeloyloxy-5-[3″-chloro-2″-hydroxy-2″-methylbutanoyloxy]-7-hydroxy-carvotacetone) exhibited a quite strong effect on renal cancer cells with a growth inhibitory effect of 96% against ACHN and UO-31 cells. When treated with five different concentrations of 1: (1 × 10-8, 1 × 10-7, 1 × 10-6, 1 × 10-5, and 1 × 10-4 M), HOP-92 cells were found to be most sensitive with GI50, TGI, and LC50 values of 0.17, 0.40, and 0.96 µM, respectively. When using the ApoTox-Glo triplex assay to evaluate the apoptosis inducing effects of seven carvotacetones isolated from S. africanus in CCRF-CEM cells, compounds 1:  - 6: increased caspase-3/7 activity with 1, 2: , and 4: (3-angeloyloxy-5,7-dihydroxycarvotacetone) exhibiting the highest activitiy, indicating induction of caspase-dependent apoptosis.

Simultaneously induced mutations in eIF4E genes by CRISPR/Cas9 enhance PVY resistance in tobacco.

Tobacco is an important commercial crop and a rich source of alkaloids for pharmaceutical and agricultural applications. However, its yield can be reduced by up to 70% due to virus infections, especially by a potyvirus Potato virus Y (PVY). The replication of PVY relies on host factors, and eukaryotic translation initiation factor 4Es (eIF4Es) have already been identified as recessive resistance genes against potyviruses in many plant species. To investigate the molecular basis of PVY resistance in the widely cultivated allotetraploid tobacco variety K326, we developed a dual guide RNA CRISPR/Cas9 system for combinatorial gene editing of two clades, eIF4E1 (eIF4E1-S and eIF4E1-T) and eIF4E2 (eIF4E2-S and eIF4E2-T) in the eIF4E gene family comprising six members in tobacco. We screened for CRISPR/Cas9-induced mutations by heteroduplex analysis and Sanger sequencing, and monitored PVYO accumulation in virus challenged regenerated plants by DAS-ELISA both in T0 and T1 generations. We found that all T0 lines carrying targeted mutations in the eIF4E1-S gene displayed enhanced resistance to PVYO confirming previous reports. More importantly, our combinatorial approach revealed that eIF4E1-S is necessary but not sufficient for complete PVY resistance. Only the quadruple mutants harboring loss-of-function mutations in eIF4E1-S, eIF4E1-T, eIF4E2-S and eIF4E2-T showed heritable high-level resistance to PVYO in tobacco. Our work highlights the importance of understanding host factor redundancy in virus replication and provides a roadmap to generate virus resistance by combinatorial CRISPR/Cas9-mediated editing in non-model crop plants with complex genomes.

A nationwide web-based survey of factors associated with depressive symptoms among Japanese workers.

BACKGROUND: Precarious employment has affected mental health, and limited data are available on the association of low stress tolerance with depressive symptoms among Japanese workers. AIMS: This study aimed to examine the relationship between stress tolerance and depressive symptoms among Japanese workers, including company employees, civil servants and self-employed persons in various industries. METHODS: We conducted a nationwide cross-sectional study. From March 26 to April 6, 2020, we performed a web-based survey of Japanese workers. The questionnaire included questions on socioeconomic factors, the SOC scale that assesses stress tolerance, the CES-D, and the EQ-5D-5L. Multivariate regression analyses were performed to determine the factors associated with depressive symptoms. RESULTS: We included 3,001 participants in the analysis. A high SOC score, adequate sleeping time and frequency of exercise were associated with higher depressive symptoms. Employment status and long working hours were not associated with depressive symptoms. Younger workers had lower SOC scores than older workers. An inverse correlation between the SOC score and CES-D score was found among Japanese workers. CONCLUSIONS: Improving stress tolerance among younger workers is needed to prevent worsening mental health regardless of employment status for Japanese workers.

Invasive Meningococcal Disease Remains a Health Threat in Vietnam People's Army.

OBJECTIVE: Despite strict surveillance, Neisseria meningitidis still causes life-threatening invasive meningococcal disease (IMD). The study aimed to describe the prevalence, clinical and subclinical features, and treatment outcomes of IMD among young soldiers of the Vietnam People's Army. METHODS: A prospective, population-based surveillance study was conducted in all Vietnamese military hospitals from January 2014 to June 2021. The presence of Neisseria meningitidis was confirmed by PCR or culture from blood or/and CSF. Epidemiological indices (incidence, serogroups, and distribution of cases by length of service), medical history, clinical and sub-clinical features, and treatment outcomes were documented and analyzed. RESULTS: There were 69 IMD cases (91% serogroup B) documented, mainly in conscripts (91%). The highest annual incidence was 3.33/100,000 soldiers per year. Of these cases, 44% were meningitis (n=30), 19% septicemia (n=13), and 38% meningococcemia (n=26). The most common clinical symptoms were neck stiffness (61 cases, 88%), petechial rash (51%), and shock (20 cases, 29%). Laboratory findings showed leukocytosis in 96% of IMD cases, PCT >0.05 (ng/mL) in 100%, elevated leukocyte count (>1,000/mm3) in 71%, and high protein >1 g/L in 70%. The overall mortality rate was 9%. Two cases were found to be resistant to ceftriaxone. Prognostic factors of severity included petechial rash (OR = 9.82, p < 0.001), septicemia (OR = 5.83, p < 0.001), meningococcemia (OR = 6.22, p < 0.001), low platelet count, prolonged prothrombin time; high PCT (AUC = 0.84, p < 0.001), and increased creatinine (AUC = 0.86, p < 0.001). CONCLUSION: IMD remains a health threat in the armed forces in Vietnam, especially among new recruits. To the best of our knowledge, this is the first study in Vietnam describing ceftriaxone resistance in Neisseria meningitidis and suggests the need to reconsider standard empiric therapy for IMD.

Social Media Insights During the COVID-19 Pandemic: Infodemiology Study Using Big Data.

BACKGROUND: The COVID-19 pandemic is still undergoing complicated developments in Vietnam and around the world. There is a lot of information about the COVID-19 pandemic, especially on the internet where people can create and share information quickly. This can lead to an infodemic, which is a challenge every government might face in the fight against pandemics. OBJECTIVE: This study aims to understand public attention toward the pandemic (from December 2019 to November 2020) through 7 types of sources: Facebook, Instagram, YouTube, blogs, news sites, forums, and e-commerce sites. METHODS: We collected and analyzed nearly 38 million pieces of text data from the aforementioned sources via SocialHeat, a social listening (infoveillance) platform developed by YouNet Group. We described not only public attention volume trends, discussion sentiments, top sources, top posts that gained the most public attention, and hot keyword frequency but also hot keywords' co-occurrence as visualized by the VOSviewer software tool. RESULTS: In this study, we reached four main conclusions. First, based on changing discussion trends regarding the COVID-19 subject, 7 periods were identified based on events that can be aggregated into two pandemic waves in Vietnam. Second, community pages on Facebook were the source of the most engagement from the public. However, the sources with the highest average interaction efficiency per article were government sources. Third, people's attitudes when discussing the pandemic have changed from negative to positive emotions. Fourth, the type of content that attracts the most interactions from people varies from time to time. Besides that, the issue-attention cycle theory occurred not only once but four times during the COVID-19 pandemic in Vietnam. CONCLUSIONS: Our study shows that online resources can help the government quickly identify public attention to public health messages during times of crisis. We also determined the hot spots that most interested the public and public attention communication patterns, which can help the government get practical information to make more effective policy reactions to help prevent the spread of the pandemic.

Psychological impact of the state of emergency over COVID-19 for non-permanent workers: a Nationwide follow-up study in Japan.

BACKGROUND: The outbreak of COVID-19 has caused mental health problems and increased unemployment due to the economic recession. This survey aimed to assess the psychological impact of the state of emergency. We estimated changes in mental health, quality of life, and unemployment experience for general workers during the first COVID-19 outbreak in Japan. METHODS: We conducted a nationwide follow-up study. During the periods of March 26 to April 6, 2020 and June 26 to July 2, 2020, we used the internet to survey general workers aged 15 to 59 years in Japan. The questionnaire items covered employment status and socioeconomic factors, and we used the Center for Epidemiologic Studies Depression Scale (CES-D) and EQ-5D-5L to assess depression and health-related quality of life (HR-QOL), respectively. The differences in outcomes of permanent and non-permanent workers were analyzed using propensity score analysis. A multiple linear regression analysis was performed to examine the relationship between unemployment and CES-D scores. RESULTS: We included 2351 subjects in the analysis. Changes in both CES-D scores and utility were not significantly different between the two groups. However, a significant difference was found regarding the rate of unemployment, which was associated with higher CES-D scores. CONCLUSIONS: The present study demonstrated that the mental health of non-permanent workers was not negatively affected following the state of emergency due to COVID-19 in Japan. Unemployment is an important factor that influences the mental health of general workers.

An Efficient Hairy Root System for Validation of Plant Transformation Vector and CRISPR/Cas Construct Activities in Cucumber (Cucumis sativus L.).

Hairy root induction system has been applied in various plant species as an effective method to study gene expression and function due to its fast-growing and high genetic stability. Recently, these systems have shown to be an effective tool to evaluate activities of CRISPR/Cas9 systems for genome editing. In this study, Rhizobium rhizogenes mediated hairy root induction was optimized to provide an effective tool for validation of plant transformation vector, CRISPR/Cas9 construct activities as well as selection of targeted gRNAs for gene editing in cucumber (Cucumis sativus L.). Under the optimized conditions including OD650 at 0.4 for infection and 5 days of co-cultivation, the highest hairy root induction frequency reached 100% for the cucumber variety Choka F1. This procedure was successfully utilized to overexpress a reporter gene (gus) and induce mutations in two Lotus japonicus ROOTHAIRLESS1 homolog genes CsbHLH66 and CsbHLH82 using CRISPR/Cas9 system. For induced mutation, about 78% of transgenic hairy roots exhibited mutant phenotypes including sparse root hair and root hair-less. The targeted mutations were obtained in individual CsbHLH66, CsbHLH82, or both CsbHLH66 and CsbHLH82 genes by heteroduplex analysis and sequencing. The hairy root transformation system established in this study is sufficient and potential for further research in genome editing of cucumber as well as other cucumis plants.

Antimicrobial and Efflux Pump Inhibitory Activity of Carvotacetones from Sphaeranthus africanus Against Mycobacteria.

Carvotacetones (1-7) isolated from Sphaeranthus africanus were screened for their antimycobacterial and efflux pump (EP) inhibitory potential against the mycobacterial model strains Mycobacterium smegmatis mc2 155, Mycobacterium aurum ATCC 23366, and Mycobacterium bovis BCG ATCC 35734. The minimum inhibitory concentrations (MICs) of the carvotacetones were detected through high-throughput spot culture growth inhibition (HT-SPOTi) and microbroth dilution assays. In order to assess the potential of the compounds 1 and 6 to accumulate ethidium bromide (EtBr) in M. smegmatis and M. aurum, a microtiter plate-based fluorometric assay was used to determine efflux activity. Compounds 1 and 6 were analyzed for their modulating effects on the MIC of EtBr and the antibiotic rifampicin (RIF) against M. smegmatis. Carvotacetones 1 and 6 had potent antibacterial effects on M. aurum and M. bovis BCG (MIC ≤ 31.25 mg/L) and could successfully enhance EtBr activity against M. smegmatis. Compound 1 appeared as the most efficient agent for impairing the efflux mechanism in M. smegmatis. Both compounds 1 and 6 were highly effective against M. aurum and M. bovis BCG. In particular, compound 1 was identified as a valuable candidate for inhibiting mycobacterial efflux mechanisms and as a promising adjuvant in the therapy of tuberculosis or other non-tubercular mycobacterial infections.

Anti-inflammatory and antiproliferative compounds from Sphaeranthus africanus.

BACKGROUND: Sphaeranthus africanus has been used in traditional Vietnamese medicine to treat sore throat, and to relieve pain and swelling. However, the anti-inflammatory activity of this plant had not yet been investigated. Previously, we isolated five carvotacetones (1-5) from this plant that displayed cytotoxicity against several cancer cell lines. PURPOSE: The objective of this study was to isolate further constituents from S. africanus and to investigate the anti-inflammatory activity of all constituents. Furthermore, the anti-proliferative activity of the newly isolated compounds was evaluated. STUDY DESIGN AND METHODS: Compounds were isolated from the upper parts of S. africanus by chromatographic methods. Structures were determined using spectroscopic techniques, like NMR and MS. All nine compounds isolated from S. africanus were evaluated for inhibitory activity against COX-1 and COX-2 isoenzymes in-vitro, COX-2 mRNA expression and influence on NO production. The anti-proliferative activities of newly isolated compounds (6-9) were evaluated by XTT viability assay with four cancer cell lines, namely CCRF-CEM, MDA-MB-231, HCT-116, and U-251 cells. RESULTS: Two diastereomeric carvotacetones (3-angeloyloxy-5-[2″S,3″R-dihydroxy-2″-methyl-butanoyloxy]-7-hydroxycarvotacetone (6) and 3-angeloyloxy-5-[2″R,3″R-dihydroxy-2″-methyl-butanoyloxy]-7-hydroxycarvotacetone (7), asperglaucide (8) and chrysoplenol D (9) were isolated from S. africanus. COX-1 and COX-2 assays of compounds 1-9 revealed that compounds 1 and 2 possess potent and selective COX-2 inhibitory activity with IC50 values of 3.6 and 0.5 µM, respectively. COX-2 gene expression assay showed that some carvotacetones exhibited inhibitory effects on COX-2 gene expression in THP-1 macrophages. Compound 4 is the most active compound inhibiting the synthesis of COX-2 by 55% at 2.06 µM. In the iNOS assay, all seven carvotacetones inhibited NO production in BV2 and RAW cell lines with IC50 values ranging from 0.2 to 2.9 µM. Compound 4 showed potent inhibitory activity with IC50 values of 0.2 µM in both BV2 and RAW cell lines. Molecular docking studies revealed the binding orientations of 1 and 2 in the active sites of COX-2. XTT assay of the newly isolated compounds revealed that the two isomeric carvotacetones (6-7) exhibited considerable anti-proliferative activity against four cancer cell lines (CCRF-CEM, MDA-MB-231, HCT-116, U-251) with IC50 values ranging from 1.23 to 8 µM. CONCLUSION: For the first-time, the diastereomeric carvotacetones (6-7) were isolated as separate compounds, and their anti-proliferative activity was determined. Selective COX-2 inhibitory, COX-2 mRNA expression and NO production inhibitory activities by some of the major constituents of S. africanus supports the traditional medical application of this plant for the treatment of inflammation-related disorders.

A new and efficient approach for construction of uridine/uracil auxotrophic mutants in the filamentous fungus Aspergillus oryzae using Agrobacterium tumefaciens-mediated transformation.

Aspergillus oryzae is a filamentous fungus widely used in food industry and as a microbial cell factory for recombinant protein production. Due to the inherent resistance of A. oryzae to common antifungal compounds, genetic transformation of this mold usually requires auxotrophic mutants. In this study, we show that Agrobacterium tumefaciens-mediated transformation (ATMT) method is very efficient for deletion of the pyrG gene in different Aspergillus oryzae wild-type strains to generate uridine/uracil auxotrophic mutants. Our data indicated that all the obtained uridine/uracil auxotrophic transformants, which are 5- fluoroorotic acid (5-FOA) resistant, exist as the pyrG deletion mutants. Using these auxotrophic mutants and the pyrG selectable marker for genetic transformation via A. tumefaciens, we could get about 1060 transformants per 106 fungal spores. In addition, these A. oryzae mutants were also used successfully for expression of the DsRed fluorescent reporter gene under control of the A. oryzae amyB promoter by the ATMT method, which resulted in obvious red transformants on agar plates. Our work provides a new and effective approach for constructing the uridine/uracil auxotrophic mutants in the importantly industrial fungus A. oryzae. This strategy appears to be applicable to other filamentous fungi to develop similar genetic transformation systems based on auxotrophic/nutritional markers for food-grade recombinant applications.

Crystallographic snapshots of active site metal shift in E. coli fructose 1,6-bisphosphate aldolase.

Fructose 1,6-bisphosphate aldolase (FBA) is important for both glycolysis and gluconeogenesis in life. Class II (zinc dependent) FBA is an attractive target for the development of antibiotics against protozoa, bacteria, and fungi, and is also widely used to produce various high-value stereoisomers in the chemical and pharmaceutical industry. In this study, the crystal structures of class II Escherichia coli FBA (EcFBA) were determined from four different crystals, with resolutions between 1.8 Å and 2.0 Å. Native EcFBA structures showed two separate sites of Zn1 (interior position) and Zn2 (active site surface position) for Zn2＋ ion. Citrate and TRIS bound EcFBA structures showed Zn2＋ position exclusively at Zn2. Crystallographic snapshots of EcFBA structures with and without ligand binding proposed the rationale of metal shift at the active site, which might be a hidden mechanism to keep the trace metal cofactor Zn2＋ within EcFBA without losing it. [BMB Reports 2016; 49(12): 681-686].