Galactomannan Research Articles

Comparison of β-D-Glucan and Galactomannan in Serum for Detection of Invasive Aspergillosis: Retrospective Analysis with Focus on Early Diagnosis.

The early diagnosis of invasive aspergillosis (IA) relies mainly on computed tomography imaging and testing for fungal biomarkers such as galactomannan (GM). We compared an established ELISA for the detection of GM with a turbidimetric assay for detection of the panfungal biomarker β-D-glucan (BDG) for early diagnosis of IA. A total of 226 serum specimens from 47 proven and seven probable IA cases were analysed. Sensitivity was calculated for samples obtained closest to the day of IA-diagnosis (d0). Additional analyses were performed by including samples obtained during the presumed course of disease. Most IA cases involved the respiratory system (63%), and Aspergillus fumigatus was the most frequently isolated species (59%). For proven cases, sensitivity of BDG/GM analysis was 57%/40%. Including all samples dating from –6 to +1 weeks from d0 increased sensitivities to 74%/51%. Sensitivity of BDG testing was as high as or higher than GM testing for all subgroups and time intervals analysed. BDG testing was less specific (90–93%) than GM testing (99–100%). Combining BDG and GM testing resulted in sensitivity/specificity of 70%/91%. Often, BDG testing was positive before GM testing. Our study backs the use of BDG for diagnosis of suspected IA. We suggest combining BDG and GM to improve the overall sensitivity.

Use of cashew gum combined with galactomannan for encapsulation of Rosmarinus officinalis essential oil

Encapsulating matrices are important to maintain the properties, promote the low and controlled release, and avoid these bioactive compounds' undesirable reactions. This study's objective was to evaluate cashew gum (CG) use combined with galactomannan (GAL) in the rosemary essential oil encapsulation by atomization. During the emulsification, the polysaccharides were crosslinked with sodium trimetaphosphate. The particles obtained after encapsulation were evaluated for moisture, solubility, particle size, encapsulation efficiency, morphology, antimicrobial activity, and chemical composition of the essential oil volatiles. GAL/CG blend showed higher encapsulation efficiency and lower oil release than the cashew gum matrix. Undoubtedly, galactomannan combined with cashew gum improved the microparticles' characteristics due to the galactomannan's high emulsifying property even in low concentration. Essential oil maintained its antimicrobial and chemical properties practically after the encapsulation procedure.

Actuating, shape reconstruction, and reinforcement of galactomannan-based hydrogels by coordination bonds induced metal ions capture

Application of abundant hemicelluloses polysaccharides on functional materials are of much interest. In this work, galactomannan (GM) hydrogels were prepared by dual hydrogen bonding interactions with polymerized poly-acrylic acid (AA) and poly-N-isopropylacrylamide (NIPAM). The hydrogels showed a series of novel and distinctive properties through in situ metal ions immersion. Highly improved ductility with a tensile strain of 230% and tensile stress of 390 kPa were exhibited by PAN-GM-Cu and PAN-GM-Fe respectively. More interestingly, the spontaneous metal ions capture into the network successfully actuated the sensitive curving and shape reconstruction behaviors of the hydrogels to varying degrees, which were tuned by the concentration of the metal ions. X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) proved the formation of new coordination bonds between Cu2+/Fe3+ and carboxylates/hydroxyls groups that reinforced and swelled the networks into different curving states. After the curving, PAN-GM-Cu exhibited more satisfied mechanical properties due to the distinctive morphological distribution of Cu2+ on the pores layers of the hydrogels. The intelligent hydrogels proposed in this work would provide new strategies for effective metal ions adsorption, which can be potentially applied on devices actuating, metal ions pollution water treatments, self-reinforcement and shape reconstruction.

Development and in vitro evaluation of microparticles of fluoxetine in galactomannan against biofilms of S. aureus methicilin resistant

The emergence of multidrug-resistant (MDR) bacteria is a global problem, by reducing the effectiveness of traditional antibiotics and decreasing the therapeutic arsenal to treat bacterial infections. This has led to an increase in researches about how to overcome this resistance to antibiotics. One strategy is the repositioning (or repurposing) of existing drugs not previously used to combat microorganisms, rather than the development of new drugs. Fluoxetine (FLX) is a selective serotonin reuptake inhibitor (SSRIs) and is considered one of the first highly selective antidepressants of the monoamine neurotransmitter serotonin (5-HT). The objective of this study is to prepare and physically characterize fluoxetine microparticles with galactomannan and evaluate their efficacy against strains of Staphylococcus aureus sensitive and resistant to methicillin. The microparticles were analyzed by differential scanning calorimetry (DSC), infrared analysis (IR) and X-ray diffraction (XRD). In addition, the percentage of encapsulation efficiency (EE%) and drug release kinetics were determined in vitro, along with the determination of the minimum inhibitory concentration (MIC) and evaluation of the action against biofilms. Physical tests were conducted to characterize galactomannan (GAL), FLX, oxacillin (OXA) and the galactomannan/fluoxetine microparticles (GFM). The EE% value was 98 % and, in regard the release, tests with the microparticles released about 60 % of the drug in 200 min. The isolated MIC results for FLX (255 μg/mL) and OXA MIC (1.97–15.62 μg/mL) showed that the strains were resistant. Furthermore, in the biofilms, microparticles showed statically significant improvement for all concentrations used. The study revealed that fluoxetine encapsulated in microparticles has the potential to act as an effective antimicrobial agent.

Aspergillosis infection over 20\u2009years: a case report of probable vascular invasion in central nervous system

BackgroundAspergillosis infection of central nervous system (CNS) is rare and fatal. Diagnosis of invasive aspergillosis remains difficult. Aspergillosis of CNS can be an acute, subacute, or chronic onset, and the longest course of the disease was currently reported to be 4 years. Here, we report a case with recurrent headache over 20 years.Case presentationA 54-year-old man was admitted to our neurological disease ward due to intermittent throbbing headache lasting for more than 20 years that had grown notably worse over the past week. The headache was localized to the side of his head blown by a cold wind. He also experienced nausea and vomiting when the headache became severe. The headache usually lasted for 3–4 h after he was blown by the cold wind, though he had no fever. The neurological examination was normal. Magnetic resonance imaging (MRI) of the brain was negative for parenchymal and meningeal lesions. However, the case had increased intracranial pressure (ICP), and elevated protein level in the cerebrospinal fluid (CSF). Aspergillus fumigatus was found in CSF by nanopore targeted sequencing (NTS) and in blood by enzyme-linked immunosorbent assay (ELISA). Aspergillus fumigatus-specific antibody IgG was 104.62 AU/mL, aspergillus galactomannan (GM) antigen was 3.27 μg/L, D-dimer was 3.25 mg/L and fibrinogen degradation product was 11.50 mg/L, which were markedly higher than the normal levels. The patient was prescribed by voriconazole. After the treatment of 14 days, the ICP, CSF protein level, Aspergillus fumigatus-specific antibody IgG, GM antigen, D-dimer and fibrinogen degradation product returned normal. Aspergillus was disappeared by NTS test of CSF. His headache has never occurred again after blowing by a cold wind.ConclusionsThis report reveals that aspergillosis infection of CNS can last for more than 20 years and the major symptom is only intermittent throbbing headache in an immunocompetent patient. Vascular invasion is probably the mechanism of headache in our case with CNS aspergillosis infection. Performing high-throughput gene sequencing technology in CSF is important when the pathogen is not determined for the patients with suspected CNS infection.

Performance of the Bronchoalveolar Lavage Fluid Aspergillus Galactomannan Lateral Flow Assay With Cube Reader for Diagnosis of Invasive Pulmonary Aspergillosis: A Multicenter Cohort Study.

The Aspergillus Galactomannan Lateral Flow Assay (LFA) is a rapid test for the diagnosis of invasive aspergillosis (IA) that has been almost exclusively evaluated in patients with hematologic malignancies. An automated digital cube reader that allows for quantification of results has recently been added to the test kits. We performed a retrospective multicenter study on bronchoalveolar lavage fluid (BALF) samples obtained from 296 patients with various underlying diseases (65% without underlying hematological malignancy) who had BALF galactomannan (GM) ordered between 2013 and 2019 at the University of California, San Diego, the Medical University of Graz, Austria, and the Mannheim University Hospital, Germany. Cases were classified as proven (n = 2), probable (n = 56), putative (n = 30), possible (n = 45), and no IA (n = 162). The LFA showed an area under the curve (AUC) of 0.865 (95% confidence interval [CI] .815-.916) for differentiating proven/probable or putative IA versus no IA, with a sensitivity of 74% and a specificity of 83% at an optical density index cutoff of 1.5. After exclusion of GM as mycological criterion for case classification, diagnostic performance of the LFA was highly similar to GM testing (AUC 0.892 vs 0.893, respectively). LFA performance was consistent across different patient cohorts and centers. In this multicenter study the LFA assay from BALF demonstrated good diagnostic performance for IA that was consistent across patient cohorts and locations. The LFA may serve a role as a rapid test that may replace conventional GM testing in settings where GM results are not rapidly available.

Microfluidic fluorescence immunosensor using ZnONFs for invasive aspergillosis determination

Galactomannan (GM) is a polysaccharide cell-wall component released by Aspergillus species, used as a biological marker for invasive aspergillosis (IA) screening. A fluorescence microfluidic immunosensor for GM detection was developed by using ZnO nanoflowers (ZnONFs) synthesized by a wet chemical method and characterized by scanning electron microscopy and energy dispersive spectrometry. The ZnONFs were covalently linked to the microfluidic channel through a silanization process with 3-aminopropyl triethoxysilane and then used as a bioaffinity nanoplatform for the immobilization of monoclonal anti-GM antibodies, which react specifically with the GM present in human serum samples.Subsequently, the GM amount that reacted was quantified by an HRP-anti-GM antibody (type sandwich immunoassay), which in the presence of H2O2 catalyzes the oxidation of 10-acetyl-3,7-dihydroxyphenoxacine to a highly fluorescent resorufin, which was measured by a laser-induced fluorescence (LIF) detector (excitation at 561 nm and emission at 585 nm).The measured fluorescence is directly proportional to the concentration of GM present in the patient serum sample. The fluorescence method was compared with a previously published electrochemical method, and a commercial ELISA test, showing outstanding properties. This immunosensor can be applied to the IA early diagnosis since it offers several attractive advantages such as high selectivity and sensitivity.

Epidemiology, laboratory diagnosis and clinical aspects of fungal pulmonary infections in 384 patients hospitalized in pulmonary units in Guilan province, Iran.

Background and Objectives:The respiratory tract is the most common site for developing fungal infections. People who have a weakened immune system are more susceptible to respiratory system involvement with fungi. Fungal infections of the respiratory tract are largely unrecognized and their true burden is elusive. Therefore, the aim of the current study was to evaluate the clinical spectrum, demographic characteristics, risk factors, and etiology of fungal respiratory infections in 384 patients hospitalized in pulmonary units of Razi hospital, Guilan province, Iran.Materials and Methods:A total of 384 lung specimens (192 Bronchoalveolar lavages (BAL) and 192 sputa) were obtained from patients who met the inclusion criteria. All samples were analyzed by direct microscopy and culture. Fungal identification was accomplished by internal transcribed spacer (ITS) and beta-tubulin sequencing. Also, in patients suspected to invasive pulmonary aspergillosis BAL specimens were tested for galactomannan (GM) antigen. According to the host factors (clinical symptoms, radiology findings and predisposing factors which were defined as inclusion criteria), and the positive results in direct examination, culture and serology (GM for aspergillosis) the infection was confirmed.Results:Fungal respiratory infection was confirmed in 137 cases (35.67%) including 86 (62.77%) males and 51 (37.23%) females and the highest prevalence of infection was found in the age group of 46–72 years (n=75, 54.74%). Cough (n=129, 94.16%), dyspnea (n=111, 81.02%), purulent sputum (n=85, 62.04%) and weight loss (n=77, 56.2%) were the predominant symptoms. Tuberculosis (n=34, 24.81%), taking chemotherapy regimen (n=30, 21.89%) and diabetes mellitus (n=27, 19.70%) were the predominant underlying conditions. Candida albicans (37.22%) and Candida tropicalis (21.89%) represent the two most commonly isolated species in the current study. Furthermore, according to revised EORTC/MSG (2008) definitions for invasive fungal infections, from 5 cases of pulmonary aspergillosis, 2 (40%) cases of probable invasive pulmonary aspergillosis (IPA) and 3 (60%) cases of possible IPA were diagnosed.Conclusion:According to the results of this study, infected infants with congenital CMV infection could identify at early stage by testing Guthrie cards (within 21 days of life). Furthermore, since there is a lack of CMV knowledge in our population, educating and effective counseling by obstetricians/gynecologists to the pregnant women are recommended.

Fungal Isolates of the Respiratory Tract in Symptomatic Patients Hospitalized in Pulmonary Units: A Mycological and Molecular Epidemiologic Study.

IntroductionFungal respiratory infections are being recognized with increasing frequency in parallel with an expanding population of immunocompromised patients. In most cases, colonization is the first step in the progression to pulmonary fungal infection. This study was designed to evaluate the distribution of fungal elements in the respiratory tract of symptomatic patients hospitalized in pulmonary units.MethodsThis descriptive cross-sectional study was carried out over a period of two years, from October 2017 to October 2019 in Guilan province, located in Iran’s northern region. In the current study, bronchoalveolar lavage or sputum specimens were collected. All samples were analyzed by direct microscopy using KOH 10% and culture. Fungal identification was accomplished by internal transcribed spacer (ITS) and beta-tubulin sequencing. Also, in patients suspected of invasive pulmonary aspergillosis, BAL specimens were tested for galactomannan (GM) antigen.ResultsA total of 384 lung specimens (192 bronchoalveolar lavage (BAL) and 192 sputum samples) were obtained from symptomatic patients hospitalized in pulmonary units. Of these, 137 (35.67%) were positive in direct examination and culture. Among the 137 positive cases, most isolates were from male patients 86 (62.77%) and most of them were between 46 and 72 years. Candida albicans (37.22%) and Candida tropicalis (21.89%) represent the two most commonly isolated species in the current study. Cough (94.16%), dyspnea (81.02%), purulent sputum (62.04%) and weight loss (56.2%) were the predominant symptoms and tuberculosis (24.81%), chemotherapy (21.89%) and diabetes mellitus (19.70%) were the predominant underlying conditions. Also, 5 cases of invasive pulmonary aspergillosis and 1 case of mucormycosis were diagnosed.ConclusionCandida albicans was the most common fungal species isolated from symptomatic patients hospitalized in pulmonary units. Tuberculosis, chemotherapy and diabetes mellitus were important underlying conditions for pulmonary fungal colonization and/or infection.

High prevalence of peribronchial focal lesions of airway invasive aspergillosis in hematological cancer patients with prolonged neutropenia.

The aim of this study is to characterize chest CT findings of neutropenic patients with proven/probable invasive pulmonary aspergillosis (IPA). Hematological cancer patients admitted to our institution (2007-2017) were retrospectively enrolled if the diagnostic criteria of proven/probable IPA during the neutropenia were met (EORTC/MSG). Galactomannan (GM) was routinely measured in serum and chest CT-scan was routinely performed in case of recurrent/persistent fever. Bronchoscopy was performed in case of chest CT-scan abnormalities. Chest CT-scan and GM dosage were analyzed at the time of IPA suspicion. Chest lesions were classified using a clinical report form by two expert radiologists. 35 patients were identified. Peribronchial focal lesions were observed in 29 IPA (82.9%) by the first radiologist and in 31 (88.5%) by the second (k = 0.768). 12 weeks mortality was 20%. Peribronchial focal lesions are a common finding in early-IPA whatever the GM value during neutropenia and our findings reinforce the efficiency of a preemptive approach. Peribronchial focal lesions, which are classically described in airway invasive aspergillosis, are a common finding in early-IPA in hematological cancer patients with prolonged neutropenia regardless of the GM value, and such peribronchial lesions should reinforce the possibility of IPA.

Biomimetic galactomannan/bentonite/graphene oxide film with superior mechanical and fire retardant properties by borate cross-linking

With the great demand for high-strength integrated materials in various industries, products from renewable resources were expected to replace petroleum-based materials. Inspired by the hierarchical structure of nacre, in this work, bentonite and graphene oxide (GO) were incorporated into the galactomannan (GM) matrix to prepare a ternary nanocomposite, which was further cross-linked and strengthened with borate. The chemical structure of the composite was analyzed with SEM, FTIR, XPS and XRD, revealing a co-assembly reaction between GO, bentonite and GM, accompanied by the borate crosslinking. This synergistic strengthen effect resulted in a composite possessing a maximum tensile stress and toughness of 231.16 MPa and 4.53 MJ/m3, respectively, harder than most of the previously reported hemicellulose composites. Moreover, the nanocomposites showed excellent fire retardant property with a limiting oxygen index of 46.8 % due to the introduction of bentonite and GO, which shows potential application in fire-protective insulation, packaging and coating.

Serum galactomannan level for the diagnosis of invasive pulmonary aspergillosis in hospitalized patients with chronic obstructive pulmonary disease (COPD): Meta-analysis

Background: The serum galactomannan (GM) assay is used to diagnose invasive pulmonary aspergillosis (IPA). We conducted a meta-analysis to assess the overall accuracy of the serum GM test for detecting IPA in critically ill COPD patients. Methods: The web of science, Pubmed, Embase, China National Knowledge Infrastructure, WanFang, Weipu (VIP) Science China databases were searched for all the eligible studies, including randomized controlled trials and prospective studies up to February 2019. We selected and assessed articles that reported diagnostic data related to serum GM for diagnosis of invasive fungal disease in hospitalized COPD patients. Additionally, pooled sensitivity (SEN), specificity (SPE), true positive (TP), false positive (FP), true negative (TN), false negative (FN) were estimated for summarizing overall test performance. Results: Of 1104 articles screened, 14 studies were involved in the meta-analysis with 1127 patients in the COPD serum sample. The pooled serum GM assay results with cutoff value of 0.5 were as follows: DOR: 15 (95% CI, 6–38), sensitivity: 0.57 (95% CI, 0.37–0.75), specificity: 0.92 (95%,CI, 0.85–0.96), and the SROC was 0.89 (95% CI, 0.86–0.91). When the cutoff value was 1, the results were as follows: DOR: 33 (95% CI, 15–70), sensitivity: 0.57 (95% CI, 0.39–0.73), specificity: 0.96 (95% CI, 0.93–0.98), and SROC was 0.95 (95% CI, 0.92–0.96). Conclusion: Serum GM can be used to assist in diagnosis of IPA in critically ill COPD patients. When cutoff value was set as 1, serum GM had better diagnostic value compared to those with cutoff of 0.5.

Galactomannan detection in bronchoalveolar lavage fluids: A diagnostic approach for fungus ball in patients with pulmonary tuberculosis?

Several previous studies have shown cavitary lung lesions in old pulmonary tuberculosis (PTB) increase the risk of fungus ball. Detection of galactomannan (GM) in bronchoalveolar lavage (BAL) is also proposed as a diagnostic approach for the fungus ball. We evaluated the diagnosis of fungus balls and GM levels in BAL samples in PTB patients. A total of 110 PTB patients were evaluated for fungus ball during 2017-2019. The patients were evaluated for radiological, histopathological results and mycological findings of BAL including GM detection and culture. The sensitivity, specificity and positive and negative predictive value for GM test were calculated. The optimal cut-off for BAL GM testing was determined by receiver operating characteristic (ROC). Of 110 PTB patients, nine (8.18%) showed fungus ball, all with old PTB. The molecularly confirmed Aspergillus species were A. flavus, A. fumigatus and A. ochraceus. The sensitivity and specificity of BAL GM ≥ 0.5 in old PTB patients with fungus ball were 100%, 41.5%, respectively. The statistical analysis of the mean ± SEM of BAL GM levels was demonstrated a higher levels of GM in patients with fungus ball/aspergilloma compared to old PTB patients without fungus ball/aspergilloma. The optimal cut-off value for BAL GM was determined as 0.50 by ROC curve analysis. According to our results, we can recommend the detection of GM in BAL samples as a diagnostic approach for fungus ball in PTB patients.

Risk factors for mortality in patients with pulmonary mucormycosis.

Pulmonary mucormycosis (PM) represents a serious burden in terms of morbidity and mortality in immunocompromised patients. Studies of prognostic factors in patients with PM are limited and have involved small numbers of patients. Adult patients diagnosed with proven and probable PM according to the modified definitions of the EORTC/MSG 2008 in a tertiary hospital in Seoul, South Korea, between 2008 and 2019 were retrospectively enrolled. A total of 49 patients including 31 (63%) with proven PM and 18 (37%) with probable PM were enrolled. The 90-day mortality rate was 49% (24/49). Neutropenia, thrombocytopenia, use of voriconazole at clinical suspicion, positivity of non-sterile culture, use of steroid and treatment without surgery were more common in fatal cases than non-fatal cases. Voriconazole use at clinical suspicion for invasive mould pneumonia (OR 6.91, P=.01) and prolonged neutropenia (OR 4.86, P=.03) were independent risk factors for mortality. Voriconazole use at clinical suspicion was associated with positive galactomannan (GM) assay (OR 5.93, P=.02) and history of invasive pulmonary aspergillosis (OR, 6.88, P=.05). About half of the patients with PM died within 90days of diagnosis, and fatal outcomes were common in patients with prolonged neutropenia and empirical voriconazole use. Caution is needed in using voriconazole even in patients with positive GM results and prior histories of invasive pulmonary aspergillosis in whom PM cannot be ruled out by differential diagnosis.

Routine comprehensive Aspergillus screening of bronchoalveolar lavage samples in lung transplant recipients.

Invasive aspergillosis is a significant cause of morbidity and mortality in lung transplant recipients (LTRs). Early diagnosis may improve outcome, yet is challenging. We assessed the diagnostic yield of a routine, comprehensive, prospectively employed Aspergillus screening strategy in LTRs. During a 6-month period, all bronchoalveolar lavage (BAL) samples (including post-transplant surveillance) obtained from LTRs at our center were routinely tested for Aspergillus PCR, galactomannan (GM), and fungal culture. Invasive aspergillosis (IA) was defined using EORTC/MSG and ISHLT criteria for proven and probable aspergillosis. Ninety-five consecutive BAL samples were tested. PCR, GM, and fungal culture were positive in 28.4%, 30.6%, and 7.4%, respectively. Five cases of IA (two proven, three probable) were identified. Fungal culture failed to detect 40% of IA cases, which were detected by a positive PCR and/or GM. However, the majority of positive PCR samples represented colonization (59.3%). Sensitivity of PCR, GM, and culture for IA was 80%, 60%, and 60%, respectively, and specificity was 74%, 71%, and 96%. In LTRs, a routine prospectively employed screening strategy in which all BAL samples were screened for Aspergillus PCR and GM, detected aspergillosis cases that were otherwise missed by a false-negative fungal culture, but resulted in more cases of colonization being detected. Clinical judgment is thus warranted to avoid unnecessary treatment of colonization.

Late Onset Invasive Pulmonary Aspergillosis in Lung Transplant Recipients in the Setting of a Targeted Prophylaxis/Preemptive Antifungal Therapy Strategy.

Invasive pulmonary aspergillosis (IPA) is a significant cause of morbidity and mortality in lung transplant recipients (LTRs). It is unclear how a targeted prophylaxis/ preemptive antifungal therapy strategy impacts the incidence of IPA beyond the first-year posttransplant. This is a retrospective cohort of LTRs from January 2010 to December 2014. We included all LTRs who survived beyond the first year and followed them until death or 4 years postoperatively. Incidence of probable/proven IPA and Aspergillus colonization were assessed as per International Society for Heart and Lung Transplantation (ISHLT) criteria. Patients with risk factors, positive Aspergillus cultures, or galactomannan (GM) received targeted prophylaxis/preemptive therapy within the first-year posttransplant. During the study period, 350 consecutive LTRs underwent 1078 bronchoscopies. Positive bronchoalveolar lavage for GM or Aspergillus cultures was reported for 15% (52/350) of LTRs between 2 and 4 years after transplantation. Among them, the median time to positive Aspergillus culture or GM positivity was 703 days (interquartile range, 529-754 d). The incidence rate of IPA and Aspergillus colonization was 30 of 1000 patient-y, and 63 of 1000 patient-y, respectively. The mortality rate was significantly higher in patients with IPA than without IPA (107/1000 patient-years versus 18/1000 patient-years; P < 0.0001). Rate of first-year colonization and IPA was 33% and 9%, respectively. Among the 201 patients who had a negative bronchoscopy during the first year posttransplant, only 6 (3%) developed IPA during the follow-up. A targeted prophylaxis/preemptive therapy strategy within the first-year posttransplant resulted in 4% incidence of IPA at 4-years after transplantation. However, IPA was associated with higher mortality.

Evolutionary rate variation among genes involved in galactomannan biosynthesis in Coffea canephora.

The endosperm cell walls of mature coffee seeds accumulate large amounts of mannan storage polysaccharides, which serve as nutrient reserve for embryo and contribute to beverage quality. Our study investigated the evolutionary patterns of key galactomannan (GM) biosynthesis genes using d N/d S ratio, synteny, and phylogenetic analysis and detected heterogeneity in rate of evolution among gene copies. Selection ratio index revealed evidence of positive selection in the branch editing gene Coffea canephora alpha (α) galactosidase (Cc‐alpha Gal) at Cc11_g15950 copy (ω = 1.12), whereas strong purifying selection on deleterious mutations was observed in the Coffea canephora uridine diphosphate (UDP)‐glucose 4′‐epimerase (Cc‐UG4E) and Coffea canephora mannose‐1P guanylytransferase (Cc‐MGT) genes controlling the crucial nucleotide carbon sugar building blocks flux in the pathway. Relatively low sequence diversity and strong syntenic linkages were detected in all GM pathway genes except in Cc‐alpha Gal, which suggests a correlation between selection pressure and nucleotide diversity or synteny analysis. In addition, phylogenetic analysis revealed independent evolution or expansion of GM pathway genes in different plant species, with no obvious inferable clustering patterns according to either gene family or congruent with evolutionary plants lineages tested due to high dynamic nature and specific biochemical cell wall modification requirements. Altogether, our study shows a significant high rate of evolutionary variation among GM pathway genes in the diploid C. canephora and demonstrates the inherent variation in evolution of gene copies and their potential role in understanding selection rates in a homogenously connected metabolic pathway.

Purification and characterization of pectins from Abelmoschus esculentus (okra pods) and Citrus limetta (citrus peels) and in silico binding study of pectin and pectic polysaccharides with galectin-1

Galectins are a class of animal lectins that bind to β-galactoside residues through a conserved carbohydrate recognition domain of about 130 amino acids. The carbohydrate-binding specificity of mammalian galectins revealed its affinity toward lactose, related beta-galactosides, and any glycoconjugates with a nonreducing galactoside terminus. Recent studies have indicated that galectin-1 upregulation impacts progression of tumor through its pleiotropic roles such as cell transformation and proliferation, angiogenesis, adhesion, and invasiveness and immunosuppression. Several galectin-1 inhibitors such as thiodigalactoside, Anginex GM-CT-01 and GR-MD-02 have been designed for applications in cancer therapy. GM-CT-01 (DAVANAT), a modified polysaccharide, composed of mannose and galactose (galactomannan) and a variant of DAVANAT, GR-MD-02, which is a polysaccharide with a backbone of rhamnogalacturonate and branches that terminate with galactose and arabinose residues are produced from chemically processed and modified industrial-grade apple pectin are also found to be beneficial in therapy toward cancer as well as nonalcoholic steatohepatitis. Various reports have also presented evidence that galectin-1-targeted therapy will play a major role to reduce the distribution of tumor cells, inhibit angiogenesis, and restrict tumor growth, thus seeing the importance of pectins and pectin polysaccharides in cancer therapy, we purified and characterized pectins from okra pods (Abelmoschusesculentus) and citrus peels (Citruslimetta) and studied the residual protein content, total carbohydrate content, characteristic properties using Fourier-transform infrared, galacturonic acid content, equivalent weight, and methoxyl content and methyl esterification of extracted okra and citrus pectins. We further performed insilico binding study of pectin and pectic polysaccharides with Galectin-1.

Outbreak of Saprochaete clavata Sepsis in Hematology Patients: Combined Use of MALDI-TOF and Sequencing Strategy to Identify and Correlate the Episodes

IntroductionNew fungal species are increasingly reported in immunocompromised patients. Saprochaete clavata (S. clavata), an ascomycetous fungus formerly called Geotrichum clavatum, is intrinsically resistant to echinocandins and is often misidentified.ObjectiveWe describe a cluster of seven S. clavata infections in hospitalized hematology patients who developed this rare fungemia within a span of 11 months. Three of the seven patients died. Identification of the isolates was determined only with the Saramis database of VitekMS system and sequencing of the internal transcribed spacer (ITS) region. Clonal relatedness of the isolates was determined by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF) analysis; clonal correlation between the strains was investigated by means of phylogenetic analysis, based on single-nucleotide variants (SNPs). Clinical presentation, 1–3 β-D-glucan (BG) and galactomannan (GM) antigen results and analysis of possible sources of contamination are also described with a prospective case–control study of the outbreak.ResultsMALDI-TOF MS-Vitek (bioMerieux, Marcy l’Etoile, France) failed to identify the six isolates, while SARAMIS (bioMerieux, Marcy l’Etoile, France) identified the isolates as S. clavata. Initially, Vitek 2 identified the strains as Geotrichum capitatum in two of the seven cases. Molecular identification gave 99% homology with S. clavata. BG was positive in three out of six patients (range 159 to >523 pg/ml), GM results were always negative. All the isolates were resistant to echinocandins (anidulafungin, micafungin, and caspofungin) and Fluconazole, but susceptible to Flucytosine and Voriconazole. One isolate showed acquired resistance to Flucytosine and Amphotericin B during treatment. Both the correlation-based dendrograms obtained by MALDI-TOF MS (Bruker Daltonics) and MS-Vitek not only clustered six of the seven bloodstream infection (BSI) isolates in the same group, but also showed their strong relatedness. Phylogenetic analysis using SNPrelate showed that the seven samples recorded during the investigation period clustered together. We observed a split between one case and the remainder with a node supported by a z-score of 2.3 (p-value = 0.021) and 16 mutations unique to each branch.ConclusionThe use of proteomics for identification and evaluation of strain clonality in outbreaks of rare pathogens is a promising alternative to laborious and time-consuming molecular methods, even if molecular whole-genome sequencing (WGS) typing will still remain the reference method for rare emergent pathogens.

Robust galactomannan/graphene oxide film with ultra-flexible, gas barrier and self-clean properties

This study examines a facile technology to manufacture food packaging alternatives with superior mechanical, ultra-flexible, gas barrier and self-cleaning properties, based on green and benign starting materials. A novel galactomannan (GM) was isolated from the Sesbania cannabina seeds, which was used as a matrix for the fabrication of GM-based films. Inspired by the brick-and-mortar structure of natural nacre, a facile method was adopted to fabricate an artificial nacre based on the self-assembly of GM and borate crosslinked graphene oxide (GO). These GM/GO composites are ultra-flexible, which can be folded into various shapes. The tensile strength reached 135.54 MPa which is 2.40 times that of the pure GM film. In addition, after coating with the poly(dimethylsiloxane) (PDMS), these films became hydrophobic (WCA around 120°) with self-cleaning properties. Our study further revealed that the oxygen and water vapor permeabilities were improved with the introduction of GO and PDMS coating.