Publications by authors named "Liliana Rocha"

20 Publications

  • Page 1 of 1

Genetic atypical hemolytic uremic syndrome in children: a 20-year experience from a tertiary center.

J Bras Nefrol 2021 May 12. Epub 2021 May 12.

Centro Hospitalar Universitário do Porto, Centro Materno-Infantil do Norte, Unidade de Nefrologia Pediátrica, Porto, Portugal.

Introduction: Atypical hemolytic uremic syndrome (aHUS) is a rare disorder characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury, which primarily affects preschool-aged children. This study's aim was to describe the clinical profile, management, and long-term outcome of the genetic aHUS patients admitted to a tertiary care pediatric nephrology center during 20 years.

Methods: We performed a retrospective analysis of the clinical records of all aHUS patients younger than 18 years with identified genetic mutations. Data on clinical features, genetic study, therapeutic interventions, and long-term outcomes were reviewed.

Results: Five cases of aHUS with an identified genetic mutation were included; all were inaugural cases with the youngest being 4 months old. Complement factor H gene mutation was identified in four patients. Therapeutic plasma exchange was performed for acute management in 4 patients, one of whom also needed acute renal replacement therapy (peritoneal dialysis). All patients went on complete remission, 2 had more than one relapse but only 1 of these progressed to chronic kidney disease during the follow-up period (median (25th-75th percentile), 136 (43.5-200.5) months).

Conclusion: In children, the prognosis of renal function seems to be strongly dependent on the genetic background, thus being crucial to perform genetic study in all aHUS cases. In our cohort, 2 patients presented genetic mutations not previously described. Recent innovations on the genetic field leading to the identification of new mutations has lead to a better understanding of aHUS pathogenesis, but further studies, focusing on the genotype-phenotype correlation, with longer follow-up periods, are needed.
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http://dx.doi.org/10.1590/2175-8239-JBN-2020-0199DOI Listing
May 2021

Wild rice (O. latifolia) from natural ecosystems in the Pantanal region of Brazil: Host to Fusarium incarnatum-equiseti species complex and highly contaminated by zearalenone.

Int J Food Microbiol 2021 May 3;345:109127. Epub 2021 Mar 3.

Department of Food Science, Food Engineering Faculty, University of Campinas, Campinas, Brazil. Electronic address:

We assessed the mycobiota diversity and mycotoxin levels present in wild rice (Oryza latifolia) from the Pantanal region of Brazil; fundamental aspects of which are severely understudied as an edible plant from a natural ecosystem. We found multiple fungal species contaminating the rice samples; the most frequent genera being Fusarium, Nigrospora and Cladosporium (35.9%, 26.1% and 15%, respectively). Within the Fusarium genus, the wild rice samples were mostly contaminated by the Fusarium incarnatum-equiseti species complex (FIESC) (80%) along with Fusarium fujikuroi species complex (20%). Phylogenetic analysis supported multiple FIESC species and gave support to the presence of two putative new groups within the complex (LN1 and LN2). Deoxynivalenol (DON) and zearalenone (ZEN) chemical analysis showed that most of the isolates were DON/ZEN producers and some were defined as high ZEN producers, displaying abundant ZEN levels over DON (over 19 times more). Suggesting that ZEN likely has a key adaptive role for FIESC in wild rice (O. latifolia). Mycotoxin determination in the rice samples revealed high frequency of ZEN, and 85% of rice samples had levels >100 μg/kg; the recommended limit set by regulatory agencies. DON was only detected in 5.2% of the samples. Our data shows that FIESC species are the main source of ZEN contamination in wild rice and the excessive levels of ZEN found in the rice samples raises considerable safety concerns regarding wild rice consumption by humans and animals.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2021.109127DOI Listing
May 2021

Characterization of the Fusarium sambucinum species complex and detection of multiple mycotoxins in Brazilian barley samples.

Food Res Int 2020 10 19;136:109336. Epub 2020 May 19.

Department of Food Science, Food Engineering Faculty, University of Campinas - UNICAMP, SP, Brazil. Electronic address:

This study investigated the fungal diversity in Brazilian barley samples, focusing on the Fusarium sambucinum species complex and the presence of multiple mycotoxins: aflatoxins B1, B2, G1, G2 beauvericin (BEA), enniatins (ENNs) A, A1, B, and B1, deoxynivalenol (DON), fumonisins (FB) B1 and B2, HT-2 and T-2 toxins, nivalenol (NIV) and ochratoxin A (OTA) from two different regions, São Paulo (SP) and Rio Grande do Sul (RS). The majority of the isolates belonged to the Fusarium sambucinum species complex (FSAMSC), with F. graminearum s.s. characterized as the major contaminant. F. meridionale and F. poae were the second most frequent fungi isolated from SP and RS, respectively. All of the F. graminearum s.s. isolates demonstrated 15-ADON genotype, whereas F. poae and F. meridionale were all NIV. The majority of the F. cortaderiae isolates were NIV, with only one 3-ADON genotype. Mycotoxin analysis revealed that none of the samples were contaminated by aflatoxins, OTA, FB2 and type A trichothecenes, however, all of the samples were contaminated with at least one Fusarium toxin. Contamination by DON, ZEA, ENNB and ENNB1 levels were significantly higher in RS. Co-contamination of BEA, DON, ENNs, NIV and ZEA in 18.5% and 24.2% of the analyzed samples was observed, from SP and RS respectively. More than 20% of the samples from RS presented DON and ZEA levels above the regulations established by Europe and Brazil. The results provide further information on the FSAMSC from South America and detected multiple Fusarium toxins in barley samples. This highlights the importance for further studies on the possible interactions of these mycotoxins in order to determine potential risks to animal health.
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http://dx.doi.org/10.1016/j.foodres.2020.109336DOI Listing
October 2020

NIR spectroscopy and chemometric tools to identify high content of deoxynivalenol in barley.

Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2020 Sep 27;37(9):1542-1552. Epub 2020 Jul 27.

Department of Food Science, School of Food Engineering, State University of Campinas , Campinas, São Paulo, Brazil.

Deoxynivalenol (DON) is one of the mycotoxins produced mainly by the species complex in small grain cereals, including barley. This toxin can cause alimentary disorders, immune function depression and gastroenteritis. The negative health effects associated with DON coupled to the increasing concern about green and rapid methods of analysis motivated this study. In this context, near infrared (NIR) spectroscopy data were applied for exploratory analysis to distinguish barley with high and low levels of DON contamination (> or <1250 µg/kg according to the European Union threshold), by Partial Least Squares-Discriminant Analysis (PLS-DA), and to verify the performance of Partial Least Squares-Regression (PLS-R) to predict DON concentration in barley samples. Maximum values of specificity and sensitivity were achieved in the calibration set; 90.9% and 81.9% were observed in the cross-validation set for the PLS-DA classification model. PLS-R quantification of DON in barley presented low values of error (RMSEC = 101.94 µg/kg and RMSEP = 160.76 µg/kg). Thus, we found that NIR in combination with adequate chemometric tools could be applied as a green technique to monitor DON contamination in barley.
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http://dx.doi.org/10.1080/19440049.2020.1778189DOI Listing
September 2020

Pathogenic, Morphological, and Phylogenetic Characterization of f. sp. Isolates From Cucurbits in Almería Province, Spain.

Plant Dis 2020 May 19;104(5):1465-1476. Epub 2020 Mar 19.

IFAPA Centro La Mojonera, La Mojonera, Almería 04745, Spain.

f. sp. (syn. ) is one of the most devastating soilborne pathogens affecting the production of cucurbits worldwide. Since its first detection in Almería Province in Spain in the spring of 2007, it has become one of the main soilborne pathogens affecting zucchini production. It has also been reported on melon, watermelon, and squash rootstocks in Spain, representing a high risk of dissemination in the area. The objectives of this study were to investigate the incidence and distribution of this disease in southeastern Spain and characterize isolates collected over 5 years. These strains were characterized on the basis of greenhouse aggressiveness assays on a range of cucurbit hosts, morphological characteristics, and elongation factor 1-α and RNA polymerase II second largest subunit phylogenies. All pathogenic isolates were highly aggressive on zucchini plants, causing a high mortality rate a few weeks after inoculation. The rest of the cucurbit hosts showed differential susceptibility to the pathogen, with cucumber being the least susceptible. Plants belonging to other families remained asymptomatic. Morphological characterization revealed the formation of verticilate monophialides and chlamydospores forming long chains, characteristics not described for this forma specialis. Phylogenetic studies of both the individual loci and combined datasets revealed that all pathogenic isolates clustered together with strong monophyletic support, nested within clade 3 in the species complex.
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http://dx.doi.org/10.1094/PDIS-09-19-1954-REDOI Listing
May 2020

Effect of temperature on growth, gene expression, and aflatoxin production by Aspergillus nomius isolated from Brazil nuts.

Mycotoxin Res 2020 May 11;36(2):173-180. Epub 2019 Dec 11.

Laboratory of Mycotoxins and Toxigenic Fungi, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil.

Aspergillus nomius is a potent producer of aflatoxins B and G and is one of the most common species of fungi found in Brazil nuts. Temperature is considered a major abiotic factor that influences fungal colonization and aflatoxin production in nuts during pre- and post-harvest. Therefore, assessment of the response of aflatoxigenic species to different temperatures is important to add information about the understanding of aflatoxin production by Aspergillus nomius and may help in the development of new strategies to prevent aflatoxin contamination. The aim of this study was to evaluate the effect of temperature (25, 30, and 35 °C) on the radial growth, aflatoxin production (B and G), and aflatoxin gene expression of seven A. nomius strains isolated from Brazil nuts. The optimal temperature for growth was 30 °C and was also the best condition for the expression of the aflR, aflD, and aflQ genes. However, maximum production of aflatoxins B and G occurred at 25 °C. Interestingly, high expression of the structural gene aflQ was observed in the maximum aflatoxin production condition (25 °C). The present study demonstrates that temperature may influence aflatoxin production by A. nomius. The combination of molecular and physiological data aids the understanding of the aflatoxigenic species response to different temperatures and can assist in predicting the driving environmental factors that influence aflatoxin contamination of Brazil nuts.
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http://dx.doi.org/10.1007/s12550-019-00380-wDOI Listing
May 2020

Complex Evolutionary Origins of Specialized Metabolite Gene Cluster Diversity among the Plant Pathogenic Fungi of the Fusarium graminearum Species Complex.

Genome Biol Evol 2019 11;11(11):3106-3122

Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchatel, Switzerland.

Fungal genomes encode highly organized gene clusters that underlie the production of specialized (or secondary) metabolites. Gene clusters encode key functions to exploit plant hosts or environmental niches. Promiscuous exchange among species and frequent reconfigurations make gene clusters some of the most dynamic elements of fungal genomes. Despite evidence for high diversity in gene cluster content among closely related strains, the microevolutionary processes driving gene cluster gain, loss, and neofunctionalization are largely unknown. We analyzed the Fusarium graminearum species complex (FGSC) composed of plant pathogens producing potent mycotoxins and causing Fusarium head blight on cereals. We de novo assembled genomes of previously uncharacterized FGSC members (two strains of F. austroamericanum, F. cortaderiae, and F. meridionale). Our analyses of 8 species of the FGSC in addition to 15 other Fusarium species identified a pangenome of 54 gene clusters within FGSC. We found that multiple independent losses were a key factor generating extant cluster diversity within the FGSC and the Fusarium genus. We identified a modular gene cluster conserved among distantly related fungi, which was likely reconfigured to encode different functions. We also found strong evidence that a rare cluster in FGSC was gained through an ancient horizontal transfer between bacteria and fungi. Chromosomal rearrangements underlying cluster loss were often complex and were likely facilitated by an enrichment in specific transposable elements. Our findings identify important transitory stages in the birth and death process of specialized metabolism gene clusters among very closely related species.
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http://dx.doi.org/10.1093/gbe/evz225DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6836718PMC
November 2019

Mycotoxins Stability during the Malting and Brewing Processes.

Toxins (Basel) 2019 05 7;11(5). Epub 2019 May 7.

Research Institute of Brewing and Malting, Malting Institute Brno, Mostecká 7, 614 00 Brno, Czech Republic.

Mycotoxins are widely studied by many research groups in all aspects, but the stability of these compounds needs further research for clarification. The objective of this study is to evaluate deoxynivalenol and zearalenone stability during all steps of the malting and brewing processes. The levels of these compounds decreased significantly during the production process (barley to beer). During the malting process, the DON levels decreased significantly in the steeping, germination, and malting steps (62%, 51.5%, and 68%, respectively). Considering ZEN, when the levels were compared between barley and the last step of the process, a significant decrease was observed. Most of the mycotoxins produced were transferred to the rootlets and spent grains, which is advantageous considering the final product. Furthermore, the mycotoxin dietary intake estimation was included in this study. The results proved that if the concentrations of target mycotoxins in raw material are under the limits established by the regulations, the levels decrease during the malting and brewing processes and make the beer secure for consumers. The quality of the five commodities involved in the beer process plays a decisive role in the creation of a safe final product.
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http://dx.doi.org/10.3390/toxins11050257DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6563223PMC
May 2019

Assessment of Toxigenic Fusarium Species and Their Mycotoxins in Brewing Barley Grains.

Toxins (Basel) 2019 01 10;11(1). Epub 2019 Jan 10.

Biotechnology Department, University of Sao Paulo, Av. Professor Lineu Prestes, Sao Paulo 2415, Brazil.

species threaten yield and quality of cereals worldwide due to their ability to produce mycotoxins and cause plant diseases. Trichothecenes and zearalenone are the most economically significant mycotoxins and are of particular concern in barley, maize and wheat. For this reason, the aim of this study was to characterize the isolates from brewing barley and to assess deoxynivalenol and zearalenone contamination in grains. Characterization of the strains was carried out by the phylogeny based on two loci (EF-1α and RPB2). Mycotoxin detection and quantification were performed by LC-MS. The results show that was the predominant genus. Phylogenetic study demonstrated that the majority of the strains clustered within the species complex followed by the species complex. The results revealed high incidence of deoxynivalenol (DON) and zearalenone (ZEA) contamination (90.6% and 87.5%, respectively). It was observed that 86% of the samples contaminated with ZEA were above the limits set by the EU and Brazilian regulations. These results may highlight the importance of controlling toxins in barley, mainly because of its use in the brewing industry and the resistance of various mycotoxins to food processing treatments.
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http://dx.doi.org/10.3390/toxins11010031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6357013PMC
January 2019

Incidence of toxigenic fungi and zearalenone in rice grains from Brazil.

Int J Food Microbiol 2018 Apr 3;270:5-13. Epub 2018 Feb 3.

University of Southern Santa Catarina (UNESC), Iparque-Scientific and Technological Park, Rod. Gov. Jorge Lacerda, 88807-400, Santa Catarina, Brazil.

Rice (Oryza sativa L.) is one of the most important food crops worldwide. In Brazil, the southern region is the area with the highest production of rice in the country and also has a high average daily intake of rice by the population. The mycoflora, mainly toxigenic Aspergillus and Fusarium species, the presence of AFB, DON and ZEA in rice grains, as well as daily intake estimates for the Southern Brazilian population were evaluated. The rice grain samples were collected during the 2017 crop from different harvest periods. According to the mycological tests, the samples presented a high count of fungal colonies in the pre and post-harvest, where the incidence of the F. graminearum species complex (52%) was significantly predominant. This group can be responsible for ZEA production, as found in this study in parboiled rice, mainly because most of the isolated strains were producers of high ZEA levels in the pre-harvest (77%) and post-harvest after natural (79%) and artificial (75%) drying of the rice. Only ZEA showed significant results in the rice grain analyzed (60%) at levels of 90.56 to 126.31 μg/kg, where 36% of the samples were significantly higher than the current maximum limit stipulated in Brazilian regulations and by the European Commission. Despite this, the dietary exposure of ZEA estimated for the southern Brazilian population was below the provisional maximum tolerable daily intake level of 0.5 μg/kg body weight/day set at international regulations.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2018.02.004DOI Listing
April 2018

Unrecognized Fibrinogen A α-Chain Amyloidosis: Results From Targeted Genetic Testing.

Am J Kidney Dis 2017 Aug 27;70(2):235-243. Epub 2017 Mar 27.

Department of Nephrology, Centro Hospitalar do Porto, Hospital de Santo António, Porto, Portugal; Unit for Multidisciplinary Research in Biomedicine, Instituto de Ciências Biomédicas Abel Salazar, University of Porto, Porto, Portugal.

Background: Fibrinogen A α-chain (AFib) amyloidosis results from autosomal-dominant mutations in the gene encoding AFib (FGA). Patients with this disorder typically present with proteinuria. Isolated cases of AFib amyloidosis, carrying the FGA p.Glu545Val variant, were identified in the district of Braga, in northwest Portugal. This observation led us to hypothesize that this disorder might be an unrecognized cause of kidney disease in that region and prompted us to carry out targeted genetic testing for the p.Glu545Val variant in the local hemodialysis population and family members of identified cases.

Study Design: Case series.

Setting & Participants: 3 groups of participants: (1) kidney biopsy registry, n=4; (2) hemodialysis facility, n=122 of 267 patients; and (3) genetically at-risk individuals; n=69 of 167 family members.

Outcomes: Kidney disease, kidney disease progression, and survival.

Results: The p.Glu545Val variant was identified in all 4 patients of the biopsy registry, 12 of 122 (9.8%) hemodialysis patients tested, and 34 of 69 (49%) relatives tested. These 50 cases belonged to 13 unrelated families with kidney disease or amyloidosis identified in 61% of probands. 35 individuals presented with hypertension at a mean of 51.0±10.4 years. Of these, 30 developed kidney disease at a mean of 56.7±12.0 years, and 21 initiated dialysis therapy at a mean of 61.4±11.3 years. Heart, liver, spleen, colon, and ileum were involved along the progression of the disease. Kidney disease was formerly attributed to hypertension in 25% of patients with AFib amyloidosis undergoing hemodialysis.

Limitations: Retrospective data collection for patients with amyloidosis previously diagnosed.

Conclusions: AFib amyloidosis appears to be an under-recognized disorder in Braga, Portugal, where we found a high frequency of the FGA p.Glu545Val variant. Due to the nonspecific nature of its major clinical features, the diagnosis of AFib amyloidosis should have a high index of suspicion, particularly in populations in which hypertension is prevalent.
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http://dx.doi.org/10.1053/j.ajkd.2017.01.048DOI Listing
August 2017

Fusarium verticillioides and fumonisin contamination in Bt and non-Bt maize cultivated in Brazil.

Mycotoxin Res 2017 May 6;33(2):121-127. Epub 2017 Mar 6.

Microbiology Department, Institute of Biomedical Sciences, University of Sao Paulo, Avenue Prof. Lineu Prestes, 1374, Laboratory 249, Sao Paulo, SP, 05508-000, Brazil.

Fusarium verticillioides is one of the main pathogens of maize, causing ear and stalk rots. This fungus is also able to produce high levels of fumonisins, which have been linked to various illnesses in humans and animals. Previous studies have shown that maize hybrids genetically modified with the cry genes from the bacterium Bacillus thuringiensis (Bt) presented lower incidence of F. verticillioides and fumonisin levels, presumably through the reduction of insects, which could act as vectors of fungi. The aim of this study was to assess the incidence of F. verticillioides and the concentration of fumonisins in Bt and isogenic non-Bt hybrids (2B710Hx, 30F35YG, 2B710, and 30F35, respectively). The samples of 2B710Hx and 30F35YG presented lower F. verticillioides frequency than 2B710 and 30F35 samples. However, there was no statistical difference between fumonisin contamination when Bt and non-Bt samples were compared (P > 0.05). The results suggest that other environmental parameters could possibly trigger fumonisin production during plant development in the field; consequently, other management strategies should be applied to aid controlling fumonisin contamination in maize.
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http://dx.doi.org/10.1007/s12550-017-0271-4DOI Listing
May 2017

Mycotoxin analysis of industrial beers from Brazil: The influence of fumonisin B and deoxynivalenol in beer quality.

Food Chem 2017 Mar 9;218:64-69. Epub 2016 Sep 9.

Biotecnology Department, University of Sao Paulo, Sao Paulo, Av. Professor Lineu Prestes 2415, Brazil; Microbiology Department, University of Sao Paulo, Sao Paulo, Av. Professor Lineu Prestes 1374, Brazil.

Worldwide, barley is the main source of carbohydrate in the brewing process. However, corn is often used as an adjunct to improve and accelerate the fermentation process. Considering that, these two substrates are susceptible to fungal contamination as well as mycotoxins. The objective of the current study is to determine the incidence of the mycotoxins deoxynivalenol (DON) and fumonisin B (FB) in industrial beers. The method applied for mycotoxin analyses included high performance liquid chromatography The mean levels for recovery experiments were 89.6% for DON and 93.3% for FB. DON was not detected in any of the analyzed samples whereas FB was found in 49% of the 114 samples. The current survey demonstrated levels of FB contamination in industrial beer, possibly due to the addition of contaminated adjuncts. It is necessary to establish maximum levels of mycotoxins in beer in Brazil and other countries in order to reduce health risks.
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http://dx.doi.org/10.1016/j.foodchem.2016.09.062DOI Listing
March 2017

FUM Gene Expression Profile and Fumonisin Production by Fusarium verticillioides Inoculated in Bt and Non-Bt Maize.

Front Microbiol 2015 6;6:1503. Epub 2016 Jan 6.

Laboratório de Micotoxinas, Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo São Paulo, Brazil.

This study aimed to determine the levels of fumonisins produced by Fusarium verticillioides and FUM gene expression on Bt (Bacillus thuringiensis) and non-Bt maize, post harvest, during different periods of incubation. Transgenic hybrids 30F35 YG, 2B710 Hx and their isogenic (30F35 and 2B710) were collected from the field and a subset of 30 samples selected for the experiments. Maize samples were sterilized by gamma radiation at a dose of 20 kGy. Samples were then inoculated with F. verticillioides and analyzed under controlled conditions of temperature and relative humidity for fumonisin B1 and B2 (FB1 and FB2) production and FUM1, FUM3, FUM6, FUM7, FUM8, FUM13, FUM14, FUM15, and FUM19 expression. 2B710 Hx and 30F35 YG kernel samples were virtually intact when compared to the non-Bt hybrids that came from the field. Statistical analysis showed that FB1 production was significantly lower in 30F35 YG and 2B710 Hx than in the 30F35 and 2B710 hybrids (P < 0.05). However, there was no statistical difference for FB2 production (P > 0.05). The kernel injuries observed in the non-Bt samples have possibly facilitated F. verticillioides penetration and promoted FB1 production under controlled conditions. FUM genes were expressed by F. verticillioides in all of the samples. However, there was indication of lower expression of a few FUM genes in the Bt hybrids; and a weak association between FB1 production and the relative expression of some of the FUM genes were observed in the 30F35 YG hybrid.
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http://dx.doi.org/10.3389/fmicb.2015.01503DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4701941PMC
January 2016

Variation in type A trichothecene production and trichothecene biosynthetic genes in Fusarium goolgardi from natural ecosystems of Australia.

Toxins (Basel) 2015 Nov 5;7(11):4577-94. Epub 2015 Nov 5.

The Royal Botanic Gardens and Domain Trust, Mrs Macquaries Rd, Sydney, NSW 2000, Australia.

Fusarium goolgardi, isolated from the grass tree Xanthorrhoea glauca in natural ecosystems of Australia, is closely related to fusaria that produce a subgroup of trichothecene (type A) mycotoxins that lack a carbonyl group at carbon atom 8 (C-8). Mass spectrometric analysis revealed that F. goolgardi isolates produce type A trichothecenes, but exhibited one of two chemotypes. Some isolates (50%) produced multiple type A trichothecenes, including 4,15-diacetoxyscirpenol (DAS), neosolaniol (NEO), 8-acetylneosolaniol (Ac-NEO) and T-2 toxin (DAS-NEO-T2 chemotype). Other isolates (50%) produced only DAS (DAS chemotype). In the phylogenies inferred from DNA sequences of genes encoding the RNA polymerase II largest (RPB1) and second largest (RPB2) subunits as well as the trichothecene biosynthetic genes (TRI), F. goolgardi isolates were resolved as a monophyletic clade, distinct from other type A trichothecene-producing species. However, the relationships of F. goolgardi to the other species varied depending on whether phylogenies were inferred from RPB1 and RPB2, the 12-gene TRI cluster, the two-gene TRI1-TRI16 locus, or the single-gene TRI101 locus. Phylogenies based on different TRI loci resolved isolates with different chemotypes into distinct clades, even though only the TRI1-TRI16 locus is responsible for structural variation at C-8. Sequence analysis indicated that TRI1 and TRI16 are functional in F. goolgardi isolates with the DAS-NEO-T2 chemotype, but non-functional in isolates with DAS chemotype due to the presence of premature stop codons caused by a point mutation.
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http://dx.doi.org/10.3390/toxins7114577DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4663521PMC
November 2015

Multi-method approach for characterizing the interaction between Fusarium verticillioides and Bacillus thuringiensis subsp. Kurstaki.

PLoS One 2014 16;9(4):e92189. Epub 2014 Apr 16.

Department of Microbiology, Laboratory of Mycotoxins and Toxigenic Fungi, University of São Paulo, São Paulo, São Paulo, Brazil.

Bacterial antagonists used as biocontrol agents represent part of an integrated management program to reduce pesticides in the environment. Bacillus thuringiensis is considered a good alternative as a biocontrol agent for suppressing plant pathogens such as Fusarium. In this study, we used microscopy, flow cytometry, indirect immunofluorescence, and high performance liquid chromatography to determine the interaction between B. thuringiensis subsp. kurstaki LFB-FIOCRUZ (CCGB) 257 and F. verticillioides MRC 826, an important plant pathogen frequently associated with maize. B. thuringiensis showed a strong in vitro suppressive effect on F. verticillioides growth and inhibited fumonisin production. Flow cytometry analysis was found to be adequate for characterizing the fungal cell oscillations and death during these interactions. Further studies of the antagonistic effect of this isolate against other fungi and in vivo testing are necessary to determine the efficacy of B. thuringiensis subsp. kurstaki in controlling plant pathogens. This is the first report on the use of flow cytometry for quantifying living and apoptotic F. verticillioides cells and the B. thuringiensis Cry 1Ab toxin.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0092189PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3989188PMC
January 2015

Post-transplantation encapsulating peritoneal sclerosis in a pediatric patient.

Pediatr Nephrol 2012 Sep 24;27(9):1583-8. Epub 2012 Apr 24.

Nephrology Department, Hospital Maria Pia, Centro Hospitalar do Porto, Rua da Boavista, 4050-111, Porto, Portugal.

Background: Encapsulating peritoneal sclerosis (EPS) is a serious complication of long-term peritoneal dialysis (PD), but only a few cases have been described in the pediatric patient population. There is no established medical treatment, and surgery has been reported with variable success. The number of reports of EPS being successfully treated with tamoxifen, based on its anti-fibrotic effects, are increasing. The role of sirolimus, an mTOR inhibitor with immunomodulatory and anti-proliferative properties, has been less well-defined.

Case-diagnosis/treatment: A 17-year-old kidney transplant recipient, with a previous cumulative time on PD of 8 years and 3 months, developed severe bowel obstruction 8 months after undergoing a second kidney graft. Her immunosuppressive regimen consisted of tacrolimus, mycophenolate mofetil, and prednisolone. The patient underwent laparotomy, which revealed multiple thick leathery adhesions with an encapsulated small bowel. Enterolysis was performed, and total parenteral nutrition was commenced after surgery to provide an adequate food intake. Treatment with tamoxifen was initiated, but the patient developed significant liver toxicity 2 weeks later, and the drug was withdrawn. The immunosuppressive regimen was changed to an increased dose of prednisolone, and tacrolimus was replaced with sirolimos. At 20 months of follow-up, the patient remains symptom-free, with a functioning kidney transplant.

Conclusion: Although EPS is a very rare condition in the pediatric population, it should be considered when a child or adolescent with a long-term history of PD presents with nonspecific gastrointestinal symptoms or with signs of bowel obstruction. There is an urgent need for alternative immunosuppressive protocols. The use of sirolimus in this group of patients remains controversial.
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http://dx.doi.org/10.1007/s00467-012-2176-yDOI Listing
September 2012

Mycoflora and co-occurrence of fumonisins and aflatoxins in freshly harvested corn in different regions of Brazil.

Int J Mol Sci 2009 Nov 24;10(11):5090-103. Epub 2009 Nov 24.

Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, SP, Brazil.

Natural mycoflora and co-occurrence of fumonisins (FB(1), FB(2)) and aflatoxins (AFB(1), AFB(2), AFG(1) and AFG(2)) in freshly harvested corn grain samples from four regions of Brazil were investigated. Fusarium verticillioides was predominant in all samples. Analysis of fumonisins showed that 98% of the samples were contaminated with FB(1) and 74.5% with FB(1) + FB(2), with toxin levels ranging from 0.015 to 9.67 microg/g for FB(1) and from 0.015 to 3.16 microg/g for FB(2). Twenty-one (10.5%) samples were contaminated with AFB(1), seven (3.5%) with AFB(2) and only one (0.5%) with AFG(1) and AFG(2) Co-contamination with aflatoxins and fumonisins was observed in 7% of the samples. The highest contamination of fumonisins and aflatoxins was observed in Nova Odessa (SP) and Várzea Grande (MT), respectively. The lowest contamination of these mycotoxins was found in Várzea Grande and Nova Odessa, respectively.
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http://dx.doi.org/10.3390/ijms10115090DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2808024PMC
November 2009