Enhanced pyruvate production in <Emphasis Type="Italic">Candida glabrata</Emphasis> by overexpressing the <Emphasis Type="Italic">CgAMD1</Emphasis> gene to improve acid tolerance

Objectives

To enhance acid tolerance of Candida glabrata for pyruvate production by engineering AMP metabolism.

Results

The physiological function of AMP deaminase in AMP metabolism from C. glabrata was investigated by deleting or overexpresseing the corresponding gene, CgAMD1. At pH 4, CgAMD1 overexpression resulted in 59 and 51% increases in biomass and cell viability compared to those of wild type strain, respectively. In addition, the intracellular ATP level of strain Cgamd1Δ/CgAMD1 was down-regulated by 22%, which led to a 94% increase in pyruvate production. Further, various strengths of CgAMD1 expression cassettes were designed, thus resulting in a 59% increase in pyruvate production at pH 4. Strain Cgamd1Δ/CgAMD1 _(H) was grown in a 30 l batch bioreactor at pH 4, and pyruvate reached 46.1 g/l.

Conclusion

CgAMD1 overexpression plays an active role in improving acid tolerance and pyruvate fermentation performance of C. glabrata at pH 4.

     

Metabolic response of porcine colon explants to in vitro infection by <Emphasis Type="Italic">Brachyspira hyodysenteriae</Emphasis>: a leap into disease pathophysiology

Introduction

Swine dysentery caused by Brachyspira hyodysenteriae is a production limiting disease in pig farming. Currently antimicrobial therapy is the only treatment and control method available.

Objective

The aim of this study was to characterize the metabolic response of porcine colon explants to infection by B. hyodysenteriae.

Methods

Porcine colon explants exposed to B. hyodysenteriae were analyzed for histopathological, metabolic and pro-inflammatory gene expression changes.

Results

Significant epithelial necrosis, increased levels of l-citrulline and IL-1α were observed on explants infected with B. hyodysenteriae.

Conclusions

The spirochete induces necrosis in vitro likely through an inflammatory process mediated by IL-1α and NO.

     

Iridoid and phenylethanoid/phenylpropanoid metabolite profiles of <Emphasis Type="Italic">Scrophularia</Emphasis> and <Emphasis Type="Italic">Verbascum</Emphasis> species used medicinally in North America

Introduction

Botanicals containing iridoid and phenylethanoid/phenylpropanoid glycosides are used worldwide for the treatment of inflammatory musculoskeletal conditions that are primary causes of human years lived with disability, such as arthritis and lower back pain.

Objectives

We report the analysis of candidate anti-inflammatory metabolites of several endemic Scrophularia species and Verbascum thapsus used medicinally by peoples of North America.

Methods

Leaves, stems, and roots were analyzed by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) and partial least squares-discriminant analysis (PLS-DA) was performed in MetaboAnalyst 3.0 after processing the datasets in Progenesis QI.

Results

Comparison of the datasets revealed significant and differential accumulation of iridoid and phenylethanoid/phenylpropanoid glycosides in the tissues of the endemic Scrophularia species and Verbascum thapsus.

Conclusions

Our investigation identified several species of pharmacological interest as good sources for harpagoside and other important anti-inflammatory metabolites.

     

<Emphasis Type="Italic">massPix</Emphasis>: an R package for annotation and interpretation of mass spectrometry imaging data for lipidomics

Introduction

Mass spectrometry imaging (MSI) experiments result in complex multi-dimensional datasets, which require specialist data analysis tools.

Objectives

We have developed massPix—an R package for analysing and interpreting data from MSI of lipids in tissue.

Methods

massPix produces single ion images, performs multivariate statistics and provides putative lipid annotations based on accurate mass matching against generated lipid libraries.

Results

Classification of tissue regions with high spectral similarly can be carried out by principal components analysis (PCA) or k-means clustering.

Conclusion

massPix is an open-source tool for the analysis and statistical interpretation of MSI data, and is particularly useful for lipidomics applications.

     

<Emphasis Type="Italic">Toxoplasma gondii</Emphasis> seroprevalence in breeding pigs in Estonia

Background

Toxoplasma gondii is a widespread occurring parasite infecting warm-blooded animals, including pigs and humans. The aims of this study were to estimate the prevalence of anti-T. gondii antibodies and to evaluate risk factors for T. gondii seropositivity in breeding pigs raised in Estonia. Sera from 382 pigs were tested with a commercial direct agglutination test, using a cut-off titer of 40 for seropositivity, for the presence of anti-T. gondii immunoglobulin G antibodies.

Results

Twenty-two (5.8%) of the 382 pigs tested seropositive for T. gondii, and 6 of the 14 herds had at least one seropositive pig. The proportion of seropositive pigs within the herds ranged between 0 and 43%. Gender appeared as a significant factor, with sows having 5.6 times higher odds to be seropositive to T. gondii than boars. Seroprevalence did not increase with age.

Conclusions

Anti-T. gondii antibodies were present in a substantial proportion of breeding pig herds in Estonia. On the other hand, the presence of herds without seropositive pigs illustrates that porcine T. gondii infections can be avoided even in a country where the parasite is endemic and common in several other host species.

     

Secreted expression of truncated capsid protein from porcine circovirus type 2 in <Emphasis Type="Italic">Pichia pastoris</Emphasis>

Objective

To achieve secreted expression of the truncated capsid protein from porcine circovirus type 2 (PCV2) in Pichia pastoris.

Results

A truncated cap gene (tcap) with a deleted N-terminal nuclear localization signal was optimized and synthesized. Effective secreted expression was achieved in P. pastoris GS115. The high-productive recombinant strain for tCap was grown in a 5 l bioreactor and the productivity of tCap in supernatant reached 250 μg/ml. Furthermore, serum antibody test demonstrated that adjuvant-assisting tCap induced a significant increase of specific PCV2-Cap antibody over time in mice and a similar antibody level in pigs compared with a commercial Cap-based subunit vaccine.

Conclusion

This work establishes a secreted expression strategy in P. pastoris for the production of PCV2 Cap with superior bioactivity, and this strategy might provide potential uses in developing Cap-based subunit vaccine in the future.

     

<Emphasis Type="Italic">Streptococcus pyogenes</Emphasis>-purpura fulminans as an invasive form of group A streptococcal infection

Background

Streptococcus pyogenes is an uncommon pathogen of purpura fulminans, and the pathogenesis of S. pyogenes-purpura fulminans remains unclear because of paucity of cases. We reported a pediatric case of S. pyogenes-purpura fulminans with literature review of the disease.

Case presentation

A 3-year-old boy showed limping, lethargy and acral gangrene within 24 h. A diagnosis of S. pyogenes-purpura fulminans was made for bacterial isolation from throat and peripheral blood. Intensive therapy led to a survival with amputation of the left distal metatarsal bone, and normal development. The isolated M12 carried no mutation of csrS/R or rgg. Thrombophilia or immunodeficiency was excluded.

Discussion

Twelve-reported cases (9 pediatric and 3 elderly) of S. pyogenes-purpura fulminans started with shock and coagulopathy. Five patients age <?8 years had no underlying disease and survived. One youngest and two immunocompromised patients died.

Conclusion

Streptococcus pyogenes-acute infectious purpura fulminans is a distinctive rare form of aggressive GAS infections.

     

Physiological indicators of stress and meat and carcass characteristics in tail bitten slaughter pigs

Background

Tail biting is a common welfare problem in pig production and in addition to being a sign of underlying welfare problems, tail biting reduces welfare in itself. The aim of this study was to evaluate the effects of tail biting on different pre and post mortem indicators of stress in slaughter pigs and on carcass and meat characteristics. A total of 12 tail bitten (TB) and 13 control (C) pigs from a farm with a long-term tail biting problem were selected for salivary cortisol analyses before and after transport to the slaughterhouse. After stunning, samples were taken for the analysis of serum cortisol, blood lactate, intestinal heat shock protein 70 (HSP70), and meat quality characteristics. In addition, body temperature immediately after and muscle temperature 35 min after stunning were measured, as well as lean meat percentage and carcass weight.

Results

TB pigs showed a lower cortisol response to the transport-induced stress than C pigs and also had a lower serum cortisol concentration after stunning. HSP70 content in the small intestine was higher in the TB pigs than in C pigs. TB pigs had a considerably lower carcass weight therefore produced a lower total amount of lean meat per carcass than C pigs.

Conclusions

This study suggests that prolonged or repeated stress in the form of tail biting causes a blunted stress response, possibly a sign of hypocortisolism. In addition, it underlines the importance of reducing tail biting, both from an animal welfare and an economic point-of-view.

     

Plant growth-promoting bacterium <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis> FR1 secrets a novel type of extracellular polyhydroxybutyrate polymerase involved in abiotic stress response in plants

Objectives

Identification of novel microbial factors contributing to plant protection against abiotic stress.

Results

The genome of plant growth-promoting bacterium Pseudomonas fluorescens FR1 contains a short mobile element encoding a novel type of extracellular polyhydroxybutyrate (PHB) polymerase (PhbC) associated with a type I secretion system. Genetic analysis using a phbC mutant strain and plants showed that this novel extracellular enzyme is related to the PHB production in planta and suggests that PHB could be a beneficial microbial compound synthesized during plant adaptation to cold stress.

Conclusion

Extracellular PhbC can be used as a new tool for improve crop production under abiotic stress.

     

Brain microabscesses in a porcine model of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> sepsis

Background

Sepsis caused by Staphylococcus aureus often leads to brain microabscesses in humans. Animal models of haematogenous brain abscesses would be useful to study this condition in detail. Recently, we developed a model of S. aureus sepsis in pigs and here we report that brain microabscesses develop in pigs with such induced S. aureus sepsis.Twelve pigs were divided into three groups. Nine pigs received an intravenous inoculation of S. aureus once at time 0 h (group 1) or twice at time 0 h and 12 h (groups 2 and 3). In each group the fourth pig served as control. The pigs were euthanized at time 12 h (Group 1), 24 h (Group 2) and 48 h (Group 3) after the first inoculation. The brains were collected and examined histopathologically.

Results

All inoculated pigs developed sepsis and seven out of nine pigs developed brain microabscesses. The microabscesses contained S. aureus and were located in the prosencephalon and mesencephalon. Chorioditis and meningitis occurred from 12 h after inoculation.

Conclusions

Pigs with experimental S. aureus sepsis often develop brain microabscesses. The porcine brain pathology mirrors the findings in human sepsis patients. We therefore suggest the pig as a useful animal model of the development of brain microabscesses caused by S. aureus sepsis.

     

Study on the Clinical Features and Prognosis of <Emphasis Type="Italic">Penicilliosis marneffei</Emphasis> Without Human Immunodeficiency Virus Infection

Objective

To improve the diagnosis and treatment of Penicilliosis marneffei without human immunodeficiency virus infection.

Methods

Analyze and review the clinical features, diagnosis and treatment of six cases of P. marneffei without human immunodeficiency virus infection at The First Affiliated Hospital of Fujian Medical University.

Results

Two cases were diagnosed in the ENT Department, three cases in the respiratory department and one case in the dermatological department. Penicillium marneffei infection was confirmed by sputum culture, blood culture and tissue biopsy. After definite diagnosis, one refused further treatment, and others showed significant improvement.

Conclusion

Penicilliosis marneffei is insidious onset and easy to be escaped and misdiagnosed. To achieve early diagnosis and appropriate treatment, doubtful cases should be alerted for the diagnoses as P. marneffei.

     

Synthesis of rosmarinic acid analogues in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Objectives

To produce rosmarinic acid analogues in the recombinant Escherichia coli BLRA1, harboring a 4-coumarate: CoA ligase from Arabidopsis thaliana (At4CL) and a rosmarinic acid synthase from Coleus blumei (CbRAS).

Results

Incubation of the recombinant E. coli strain BLRA1 with exogenously supplied phenyllactic acid (PL) and analogues as acceptor substrates, and coumaric acid and analogues as donor substrates led to production of 18 compounds, including 13 unnatural RA analogues.

Conclusion

This work demonstrates the viability of synthesizing a broad range of rosmarinic acid analogues in E. coli, and sheds new light on the substrate specificity of CbRAS.

     

Biodegradation of saline phenolic wastewater in a biological contact oxidation reactor with immobilized cells of <Emphasis Type="Italic">Oceanimonas</Emphasis> sp.

Objective

To develop a method to treat saline phenolic wastewater in a biological contact oxidation reactor (BCOR) with immobilized cells of a marine microorganism, Oceanimonas sp., isolated from seawater.

Results

Cells were immobilized on fibre carriers in the BCOR. Saline wastewater with phenol at 1.5 g/l and NaCl at 6 % (w/v) was treated. In continuous assays, 99 % removal of phenol was achieved and a kinetic model for the phenol degradation is presented based on Monod’s equation.

Conclusion

The BOCR system using immobilized cells of Oceanimonas efficiently treats saline phenolic wastewaters without having decrease the salinity of the wastewater.

     

Does centrifugation matter? Centrifugal force and spinning time alter the plasma metabolome

Background

Centrifugation is an indispensable procedure for plasma sample preparation, but applied conditions can vary between labs.

Aim

Determine whether routinely used plasma centrifugation protocols (1500×g 10 min; 3000×g 5 min) influence non-targeted metabolomic analyses.

Methods

Nuclear magnetic resonance spectroscopy (NMR) and High Resolution Mass Spectrometry (HRMS) data were evaluated with sparse partial least squares discriminant analyses and compared with cell count measurements.

Results

Besides significant differences in platelet count, we identified substantial alterations in NMR and HRMS data related to the different centrifugation protocols.

Conclusion

Already minor differences in plasma centrifugation can significantly influence metabolomic patterns and potentially bias metabolomics studies.

     

The bacterial community associated with rose-scented geranium (<Emphasis Type="Italic">Pelargonium graveolens</Emphasis>) leaves responds to anthracnose symptoms

Background

The fungus Colletotrichum is a plant pathogen that causes the anthracnose disease, resulting in huge losses in various crops including the rose-scented geranium (Pelargonium graveolens). Although the bacterial community associated with plants has an important role in the establishment of plant diseases, little is known about what happens in P. graveolens.

Aims

To increase the knowledge about the bacterial community associated with P. graveolens and its relationship with anthracnose disease symptoms.

Methods

Quantitative PCR and high-throughput sequencing were combined to determine the presence of the fungus Colletotrichum and to reveal the bacterial communities associated with different plant parts – root, stem and leaf – and in the rhizosphere and bulk soil, and also to determine the respective bacterial communities associated with P. graveolens leaves symptomatic and asymptomatic for anthracnose disease.

Results

The fungus Colletotrichum was detected in all plant parts and in the surrounding soil. Bacterial communities varied spatially in plants, and the disease symptoms also influenced the composition of the bacterial community. Abundances of operational taxonomic units (OTUs) assigned to the phylum Actinobacteria and to the genus Streptococcus were greatly increased in asymptomatic leaves.

Conclusions

The bacterial community associated to geranium leaves responds to anthracnose symptoms.

     

Exploring the cellular network of metabolic flexibility in the adipose tissue

Background

Metabolic flexibility is the ability of cells to change substrates for energy production based on the nutrient availability and energy requirement. It has been shown that metabolic flexibility is impaired in obesity and chronic diseases such as type 2 diabetes mellitus, cardiovascular diseases, and metabolic syndrome, although, whether it is a cause or an effect of these conditions remains to be elucidated.

Main body

In this paper, we have reviewed the literature on metabolic flexibility and curated pathways and processes resulting in a network resource to investigate the interplay between these processes in the subcutaneous adipose tissue. The adipose tissue has been shown to be responsible, not only for energy storage but also for maintaining energy homeostasis through oxidation of glucose and fatty acids. We highlight the role of pyruvate dehydrogenase complex–pyruvate dehydrogenase kinase (PDC-PDK) interaction as a regulatory switch which is primarily responsible for changing substrates in energy metabolism from glucose to fatty acids and back. Baseline gene expression of the subcutaneous adipose tissue, along with a publicly available obesity data set, are visualised on the cellular network of metabolic flexibility to highlight the genes that are expressed and which are differentially affected in obesity.

Conclusion

We have constructed an abstracted network covering glucose and fatty acid oxidation, as well as the PDC-PDK regulatory switch. In addition, we have shown how the network can be used for data visualisation and as a resource for follow-up studies.

     

Double product reflects the association of heart rate with MACEs in acute coronary syndrome patients treated with percutaneous coronary intervention

Background

There is little information about the prognostic value of double product (DP) for acute coronary syndrome (ACS) patients treated with percutaneous coronary intervention (PCI). The aim of this study was to investigate whether DP reflects the predictive power of heart rate (HR) or systolic blood pressure (SBP) in ACS patients treated with PCI.

Methods

A total of 7590 ACS patients who had undergone PCI, free from cardiac shock, were included. The follow-up duration was two years. The main adverse cardiovascular events (MACEs) included all-cause death, recurrent myocardial infarction and stroke.

Results

In the unadjusted model, significantly higher rates of MACEs were recorded in the high DP group (relative risk 1.41, 95%CI 1.08 to 1.83, p?=?0.012). However, in the full adjusted models, after including HR and SBP, the predictive value of DP was not significant (relative risk 0.86, 95%CI 0.55 to1.33, p?=?0.499). The predictive value of HR for MACEs was statistically significant (relative risk 1.74, 95% CI 1.33–2.28, p?<?0.001). It was worth noting that the history of hypertension was strongly associated with MACEs (relative risk 1.53, 95% CI 1.11–2.11, p?=?0.009).

Conclusion

High DP is associated with MACEs for ACS patients treated with PCI. However, the predictive value of DP weakened when adjusted for HR. Therefore, we have shown that DP may reflect the predictive power of HR for ACS patients treated with PCI.

     

Genetic improvement of <Emphasis Type="Italic">Magnetospirillum gryphiswaldense</Emphasis> for enhanced biological removal of phosphate

Objectives

To improve its phosphate accumulating abilities for phosphate recycling from wastewater, a magnetotactic bacterium, Magnetospirillum gryphiswaldense, was genetically modified to over-express polyphosphate kinase.

Results

Polyphosphate kinase was over-expressed in the bacterium. The recombinant strain accumulated ninefold more polyphosphate from synthetic wastewater compared to original wild type. The magnetic property of the recombinant M. gryphiswaldense strain was retained.

Conclusions

The recombinant M. gryphiswaldense can be used for phosphate removal and recovery in bioremediation.