scholarly journals An In Silico Target Fishing Approach to Identify Novel Ochratoxin A Hydrolyzing Enzyme

Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 258 ◽  
Author(s):  
Luca Dellafiora ◽  
Christoph Gonaus ◽  
Barbara Streit ◽  
Gianni Galaverna ◽  
Wulf-Dieter Moll ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
In Silico ◽  
Fungal Species ◽  
Mitigation Strategies ◽  
Carboxypeptidase B ◽  
Enzymatic Assays ◽  
Food And Feed ◽  
Hydrolyzing Enzymes ◽  
Feed Safety

Ochratoxin A (OTA), a mycotoxin that is of utmost concern in food and feed safety, is produced by fungal species that mainly belong to the Aspergillus and Penicillium genera. The development of mitigation strategies to reduce OTA content along the supply chains is key to ensuring safer production of food and feed. Enzyme-based strategies are among the most promising methods due to their specificity, efficacy, and multi-situ applicability. In particular, some enzymes are already known for hydrolyzing OTA into ochratoxin alpha (OTα) and phenylalanine (Phe), eventually resulting in detoxification action. Therefore, the discovery of novel OTA hydrolyzing enzymes, along with the advancement of an innovative approach for their identification, could provide a broader basis to develop more effective mitigating strategies in the future. In the present study, a hybrid in silico/in vitro workflow coupling virtual screening with enzymatic assays was applied in order to identify novel OTA hydrolyzing enzymes. Among the various hits, porcine carboxypeptidase B was identified for the first time as an effective OTA hydrolyzing enzyme. The successful experimental endorsement of findings of the workflow confirms that the presented strategy is suitable for identifying novel OTA hydrolyzing enzymes, and it might be relevant for the discovery of other mycotoxin- mitigating enzymes.

scholarly journals 170 Trends in mycotoxin contamination in the united states corn

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 93-94 ◽  
Author(s):  
Shelby Curry ◽  
Erika G Hendel ◽  
Paige Gott ◽  
G R Murugesan ◽  
Ursula Hofstetter-Schähs
Keyword(s):  
Animal Health ◽  
The United States ◽  
Fungal Species ◽  
Mitigation Strategies ◽  
Fungal Metabolites ◽  
Mycotoxin Contamination ◽  
Increased Risk ◽  
Food And Feed ◽  
Type A Trichothecenes ◽  
Feed Safety

Abstract Mycotoxins are harmful secondary fungal metabolites and are of key concern to food and feed safety globally. In addition to compromised performance, mycotoxins negatively impact animal health. Although classic signs such as decreased feed intake and vomiting are known in the field as indicators for exposure, mycotoxins act as predisposing factors for diseases by immune suppression, causing inflammation, and modulating the gastrointestinal environment, even at low levels. This survey presents mycotoxin levels of corn samples from the 2018 harvest and compares these levels with those in previous years. New crop corn samples from various sources, were submitted starting from mid-August 2018, and consisted of corn (70%), corn silage (18%), and corn byproduct (12%). Samples were analyzed utilizing the liquid chromatography and tandem mass spectrometry (LC-MS/MS) method for six major mycotoxin groups: aflatoxins (Afla), type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin-A (OTA). Data are presented for major mycotoxin classes in Table 1. The majority of samples contained at least 1 detectable mycotoxin with co-occurrence (≥ 2 mycotoxins) similar to 2017, and less than 2016. Prevalence of B-Trich has decreased compared with previous years, but average ppb is similar to 2017. Prevalence and average ppb of ZEN are similar to 2017, while FUM has increased in both prevalence and average ppb. Alfa prevalence has increased and average ppb is numerically higher than the previous two years. The preliminary results from the 2018 corn harvest suggest a continued risk from mycotoxins produced by Fusarium fungal species, and a potential increased risk of Afla compared to previous years. Because of the risk of multi-mycotoxin contamination in corn samples thus far, multiple mitigation strategies are needed beyond just adsorption, including biotransformation support of the immune system and liver function.

scholarly journals IN SILICO STUDY OF THE ANTIMICROBIAL PROFILE OF β-CITRONELLOL: POTENTIAL AS AN ANTIFUNGAL

2019 ◽  
Vol 16 (32) ◽  
pp. 894-898
Author(s):  
D. F. SILVA ◽  
H. D. NETO ◽  
M. D. L. FERREIRA ◽  
A. A. O. FILHO ◽  
E. O. LIMA
Keyword(s):  
In Silico ◽  
Fungal Infections ◽  
In Silico Analysis ◽  
Fungal Species ◽  
In Silico Study ◽  
Pass Online ◽  
Therapeutic Alternatives ◽  
Bioactivity Profile ◽  
Silico Analysis

β-citronellol (3,7-dimethyl-6-octen-1-ol) has been exhibiting a number of pharmacological effects that creates interest about its antimicrobial potential, since several substances of the monoterpene class have already demonstrated to possess activity in this profile. In addition, the emergence of fungal species resistant to current pharmacotherapy poses a serious challenge to health systems, making it necessary to search for new effective therapeutic alternatives to deal with this problem. In this study, the antimicrobial profile of β-citronellol was analyzed. The Prediction of Activity Spectra for Substances (PASS) online software was used to study the antimicrobial activity of the β-citronellol molecule by the use of in silico analysis. In contrast, an in vitro antifungal study of this monoterpene was carried out. For this purpose, the Minimum Inhibitory Concentration (MIC) was determined by the microdilution technique in 96-well plates in Saboraud Dextrose Broth/RPMI against sensitive strains of Candida albicans, and this assay was performed in duplicate. In the in silico analysis of the antimicrobial profile, it was revealed that the monoterpene β-citronellol had a diverse antimicrobial bioactivity profile. For the antifungal activity, it presented a percentage value with Pa: 58.4% (predominant) and its MIC of 128 μg/mL, which was equivalent for all strains tested. The in silico study of the β-citronellol molecule allowed us to consider that the monoterpenoid is very likely to be bioactive against agents that cause fungal infections.

Aryloxy Triester Phosphoramidates as Phosphoserine Biocleavable Masking Motifs

2019 ◽  
Author(s):  
Ageo Miccoli ◽  
Binar A. Dhiani ◽  
Peter J. Thornton ◽  
Olivia A. Lambourne ◽  
Edward James ◽  
...  
Keyword(s):  
Small Molecules ◽  
Protein Interactions ◽  
In Silico ◽  
Parent Compound ◽  
Cellular Protein ◽  
Carboxypeptidase Y ◽  
Protein Protein Interactions ◽  
Enzymatic Assays ◽  
Specific Targeting

Many cellular protein-protein interactions (PPIs) are mediated by phosphoserine. The specific targeting of these PPIs by phosphoserine-containing small molecules has been scarce due to the dephosphorylation of phosphoserine and its charged nature at physiological pH, which hinders its uptake into cells. To address these issues, we herein report the masking of the phosphate group of phosphoserine with biocleavable aryloxy triester phosphoramidate groups. A combination of <i>in vitro</i> enzymatic assays and <i>in silico</i> studies, using carboxypeptidase Y and Hint-1 respectively, showed that the phosphate masking groups are metabolized to release phosphoserine. To probe the applicability of this phosphoserine masking approach, it was applied to a phosphoserine-containing inhibitor of 14-3-3 dimerization, and this generated molecules with improved pharmacological activity in cells compared to their unmasked phosphoserine-containing parent compound. Collectively, the data showcases the masking of phosphoserine with biocleavable aryloxy triester phosphoramidate masking groups as an efficient intracellular delivery system for phosphoserine-containing molecules.

scholarly journals PSII-22 Trends in Mycotoxin Contamination in United States Corn

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 172-173
Author(s):  
Erika Hendel ◽  
Shelby Ramirez ◽  
Paige Gott ◽  
G Raj Murugesan ◽  
Ursula Hofstetter
Keyword(s):  
Animal Health ◽  
Corn Silage ◽  
Mitigation Strategies ◽  
Fungal Metabolites ◽  
Mycotoxin Contamination ◽  
Food And Feed ◽  
Type A Trichothecenes ◽  
Low Levels ◽  
Feed Safety ◽  
New Crop

Abstract Mycotoxins are harmful secondary fungal metabolites and are of key concern to food and feed safety globally. These toxins are detrimental to animal health and can compromise animal performance even at low levels. Classic signs such as decreased feed intake and vomiting used as indicators for exposure overlook other costs of mycotoxicosis, including increasing the frequency and severity of disease via immune suppression, inciting inflammation, and modulating the gastrointestinal environment. This survey examines initial samples of the 2019 crop with previous year trends. New crop corn samples were submitted from September 2019 and consisted of corn (46%), corn silage (50%), and corn byproduct (4%). Samples were analyzed utilizing the liquid chromatography and tandem mass spectrometry (LC-MS/MS) method for six major mycotoxin groups: aflatoxins (Afla), type A trichothecenes (A-Trich), type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN), and ochratoxin-A (OTA). Data are presented for major mycotoxin classes in Table 1. Fewer samples are available thus far compared to the fall of 2018 (50 samples in 2019 vs. 135 samples in 2018), thus risk profile of this crop year is likely to change as the sample pool expands. Co-occurrence (≥ 2 mycotoxins) has decreased compared to 2018. The prevalence of B-Trich decreased compared with previous years, but levels are similar to 2018. Prevalence and levels of ZEN decreased from 2018, and are similar to 2017, while FUM is similar in prevalence to 2018, but average ppb numerically increased. As of yet, no Alfa has been detected; however, corn stored with higher moisture content has increased the risk for storage toxins. Mycotoxin risk of this harvest season is still coming into focus as harvest delays have affected sample submission. Due to continued risk of multi-mycotoxin contamination, multiple mitigation strategies are needed beyond just adsorption, including biotransformation, support of the immune system and liver function.

Degradation of ochratoxin A by supernatant and ochratoxinase of Aspergillus niger W-35 isolated from cereals

2020 ◽  
Vol 13 (2) ◽  
pp. 287-298
Author(s):  
M. Zhao ◽  
X.Y. Wang ◽  
S.H. Xu ◽  
G.Q. Yuan ◽  
X.J. Shi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Promising Strategy ◽  
Ochratoxin Α ◽  
Food And Feed ◽  
Commercial Feeds ◽  
Penicillium Spp

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus spp. and Penicillium spp. and poses a threat to food safety. Biodegradation may be a promising strategy for reducing the OTA contamination in the future. In this study, Aspergillus niger strain W-35 was isolated from cereals and studied for its ability to degrade OTA. Results showed that the supernatant of W-35 could degrade OTA both in vitro and in commercial feeds after incubation at 37 °C for 12 h by 78.0 and 37.0%, respectively. Ochratoxin α (OTα) was assayed as a degradation product by HPLC-FLD. Furthermore, an enzyme specific for OTA degradation (ochratoxinase, OTase) obtained from W-35 was successfully expressed in Escherichia coli BL21, and degraded OTA at a rate of 85.1% for 12 h. These results indicated that this OTA degradation is enzymatic and that the responsible enzyme is extracellular OTase. Reliable degradation of OTA has the potential for wide-ranging applications in the food and feed industries.

scholarly journals Rat Tumour Histopathology Associated with Experimental Chronic Dietary Exposure to Ochratoxin A in Prediction of the Mycotoxin’s Risk for Human Cancers

Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 205
Author(s):  
Diana Herman ◽  
Peter Mantle
Keyword(s):  
Ochratoxin A ◽  
Dietary Exposure ◽  
Male Rats ◽  
Balkan Endemic Nephropathy ◽  
Tract Cancer ◽  
Food And Feed ◽  
Endemic Nephropathy ◽  
Experimental Findings ◽  
Human Nephropathy

Mammalian animal toxicity of ochratoxin A (OTA) has focused largely in the past half-century on pigs because of initial recognition of it as a principal cause of intermittent growth suppression and renal disease caused by mouldy feed. Subsequent classical toxicology has used laboratory rodents because renal pathology in pigs raised questions concerning possible involvement in the human idiopathic bilateral renal atrophy of Balkan endemic nephropathy for which OTA was a focus of attention for human nephropathy through 1980s and into 2000s. Emphasis on human nephropathy has more recently concerned the plant metabolite aristolochic acid. Recognition that agricultural management can often minimise food and feed-stuff spoilage by OTA-producing Aspergilli and Penicillia has moderated some of the risks for animals. Legislation for human food safety combined with sophisticated analysis generally provides safety in the developed world. Chronic experimental exposure of male rats, in the absence of clinical dis-ease, specifically causes renal cancer. The possibility of this as a unique model for the human has generated considerable experimental evidence which may be more directly relevant for carcinogenesis in the complex kidney than that obtained from biochemical toxicities in vitro. Nevertheless, there does not appear to be any case of human renal or urinary tract cancer for which there is verified etiological proof for causation by OTA, contrary to much claim in the literature. To contribute to such debate, histopathology review of OTA/rat renal cancers, augmented where appropriate by immune profiles, has been completed for all remaining tumours in our research archive. Overall consistency of positivity for vimentin, is matched with occasional positives either for CD10 or the cytokeratin MNF 116. The current situation is discussed. Suggestion that OTA could cause human testicular cancer has also been challenged as unsupported by any experimental findings in rats, where the Leydig cell tumour immune profile does not match that of human germ cell neoplasms.

scholarly journals Fungal Genomic Resources for Strain Identification and Diversity Analysis of 1900 Fungal Species

2021 ◽  
Vol 7 (4) ◽  
pp. 288
Author(s):  
Mir Asif Iquebal ◽  
Sarika Jaiswal ◽  
Vineet Kumar Mishra ◽  
Rahul Singh Jasrotia ◽  
Ulavappa B. Angadi ◽  
...  
Keyword(s):  
Genome Sequence ◽  
In Silico ◽  
Sequence Data ◽  
Fungal Species ◽  
Genomic Research ◽  
Whole Genome Sequence ◽  
Strain Identification ◽  
Diversity Analysis ◽  
Whole Genome

Identification and diversity analysis of fungi is greatly challenging. Though internal transcribed spacer (ITS), region-based DNA fingerprinting works as a “gold standard” for most of the fungal species group, it cannot differentiate between all the groups and cryptic species. Therefore, it is of paramount importance to find an alternative approach for strain differentiation. Availability of whole genome sequence data of nearly 2000 fungal species are a promising solution to such requirement. We present whole genome sequence-based world’s largest microsatellite database, FungSatDB having >19M loci obtained from >1900 fungal species/strains using >4000 assemblies across globe. Genotyping efficacy of FungSatDB has been evaluated by both in-silico and in-vitro PCR. By in silico PCR, 66 strains of 8 countries representing four continents were successfully differentiated. Genotyping efficacy was also evaluated by in vitro PCR in four fungal species. This approach overcomes limitation of ITS in species, strain signature, and diversity analysis. It can accelerate fungal genomic research endeavors in agriculture, industrial, and environmental management.

scholarly journals 91 Electronic probes for assessment of changes in gastrointestinal microbiome in nursery pigs

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 25-26
Author(s):  
Scott D Carter ◽  
Kitty Cardwell ◽  
Andres Espindola Camacho ◽  
Ishtar Silva Lara
Keyword(s):  
Gut Microbiota ◽  
Relative Abundance ◽  
In Silico ◽  
Pathogenic Bacteria ◽  
Mitigation Strategies ◽  
Commensal Bacteria ◽  
Metagenomic Sequencing ◽  
Metagenomic Sequence ◽  
Nursery Pigs

Abstract Gut microbiota play an important role in extraction, synthesis and absorption of nutrients. Commensal bacteria prevent pathogenic bacteria colonization and maintain intestinal epithelium integrity. The most common families of commensal bacteria in nursery pigs are Prevotellaceae, Clostridiaceae, Erysipelotrichaceae, Lachnospitaceae, Lactobacillaceae, Ruminicoccaceae and Streptoccocaceae. Understanding the microbial abundance shifts that causes health disruption leading to diarrhea and stunted growth performance can be of great benefit for developing mitigation strategies. Next generation sequencing (NGS) technology facilitates metagenomic approaches, developing sequencing profile representing any and all organisms within a sample. Electronic-probe Diagnostic Nucleic acid Analysis (EDNA) is a bioinformatic tool originally developed to detect species-specific plant pathogen targets in metagenomic databases. EDNA has been shown to reduce time to detect microbial signatures in large metagenomic sequence data. However, it has not previously been used as a metagenomic tool for assessing microbiome composition at the family level. Therefore, a metagenomic sequencing based in silico detection of gut microbiota using E-probes of the seven most common commensal families was developed and further validated in vitro. E-probes were designed from the selected families as follows, Prevotellaceae (89,565), Clostridiaceae (58,554), Erysipelotrichaceae (195), Lachnospitaceae (87), Lactobacillaceae (211,507), Ruminicoccaceae (14,575) and Streptoccocaceae (54,632). Fecal metagenomes of nursery pigs from 0, 7, 14, and 21 d were used to validate the E-probes. The hits were able to detect the relative abundance variations of the 4-time periods. The results between hits and reads were as follows, Prevotellaceae (r2 = 0.98), Clostridiaceae (r2 = 0.99), Erysipelotrichaceae (r2 = 0.99), Lachnospitaceae (r2 = 0.99), Lactobacillaceae (r2 = 0.91), Ruminicoccaceae (r2 = 0.99) and Streptoccocaceae (r2 = 0.98). These results validate in silico usage of E-probes to detect the relative abundance variations in gut microbiota. Further in vitro validation will be performed to assess the microbial changes related to diet in nursery pigs.

Aryloxy Triester Phosphoramidates as Phosphoserine Biocleavable Masking Motifs

2019 ◽  
Author(s):  
Ageo Miccoli ◽  
Binar A. Dhiani ◽  
Peter J. Thornton ◽  
Olivia A. Lambourne ◽  
Edward James ◽  
...  
Keyword(s):  
Small Molecules ◽  
Protein Interactions ◽  
In Silico ◽  
Parent Compound ◽  
Cellular Protein ◽  
Carboxypeptidase Y ◽  
Protein Protein Interactions ◽  
Enzymatic Assays ◽  
Specific Targeting

Many cellular protein-protein interactions (PPIs) are mediated by phosphoserine. The specific targeting of these PPIs by phosphoserine-containing small molecules has been scarce due to the dephosphorylation of phosphoserine and its charged nature at physiological pH, which hinders its uptake into cells. To address these issues, we herein report the masking of the phosphate group of phosphoserine with biocleavable aryloxy triester phosphoramidate groups. A combination of <i>in vitro</i> enzymatic assays and <i>in silico</i> studies, using carboxypeptidase Y and Hint-1 respectively, showed that the phosphate masking groups are metabolized to release phosphoserine. To probe the applicability of this phosphoserine masking approach, it was applied to a phosphoserine-containing inhibitor of 14-3-3 dimerization, and this generated molecules with improved pharmacological activity in cells compared to their unmasked phosphoserine-containing parent compound. Collectively, the data showcases the masking of phosphoserine with biocleavable aryloxy triester phosphoramidate masking groups as an efficient intracellular delivery system for phosphoserine-containing molecules.

Sign in / Sign up

Export Citation Format

Share Document