RESUMO
BACKGROUND: Brazil produces approximately 63 million tons of corn kernels annually, which is commonly contaminated with fungi and mycotoxins. The objective of this study was to evaluate the efficacy of gaseous allyl isothiocyanate (AITC) to inhibit the growth of Aspergillus parasiticus and Fusarium verticillioides, and mycotoxin production (aflatoxins B1 , B2 , G1 and G2 , fumonisins B1 and B2 ) in corn during 180 days of storage. RESULTS: AITC at 50 µL L-1 resulted in a significant reduction of the fungal population (P < 0.05) after 180 days, decreasing 3.17 log(CFU g-1 ) and 3.9 log(CFU g-1 ) of A. parasiticus and F. verticillioides respectively in comparison with the control. In addition, 10 and 50 µL L-1 treatments prevented the production of fumonisin B1 for the whole period. Aflatoxins were not detected in either control or treated groups. Residual levels of AITC in corn treated with 10 µL L-1 and 50 µL L-1 were detected up to 14 days and 30 days respectively. CONCLUSION: Prophylactic treatment with AITC reduced the fungal population and inhibited fumonisin B1 production in stored corn, exhibiting great potential to be applied in corn silos to prevent fungi contamination and minimize mycotoxin levels. © 2018 Society of Chemical Industry.
Assuntos
Aspergillus/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Isotiocianatos/farmacologia , Micotoxinas/metabolismo , Zea mays/microbiologia , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Contaminação de Alimentos/análise , Armazenamento de Alimentos , Fungicidas Industriais/química , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Isotiocianatos/químicaRESUMO
Corynebacterium pseudotuberculosis causes significant loss to goat and sheep farmers because it is the causal agent of the infectious disease caseous lymphadenitis, which may lead to outcomes ranging from skin injury to animal death (Ruiz et al., 2011) [1]. This bacterium was grown under osmotic (2 M), acid (pH) and heat (50 °C) stress and under control (Normal-BHI brain heart infusion) conditions, which simulate the conditions faced by the bacteria during the infectious process. Subsequently, cDNA of each condition was sequenced by the SOLiD3 Plus platform using the RNA-Seq technique [2], [3], [4]. The data produced was processed to evaluate the differential gene expression, which is helpful to understand the adaptation mechanisms during the infection in the host. The sequencing data of all conditions are available in the European Bioinformatics Institute (EBI) repository under accession number E-MTAB-2017.
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Lactococcus lactis subsp. lactis NCDO 2118 is a nondairy lactic acid bacterium, a xylose fermenter, and a gamma-aminobutyric acid (GABA) producer isolated from frozen peas. Here, we report the complete genome sequence of L. lactis NCDO 2118, a strain with probiotic potential activity.
RESUMO
Corynebacterium pseudotuberculosis is a facultative intracellular pathogen and the causative agent of several infectious and contagious chronic diseases, including caseous lymphadenitis, ulcerative lymphangitis, mastitis, and edematous skin disease, in a broad spectrum of hosts. In addition, Corynebacterium pseudotuberculosis infections pose a rising worldwide economic problem in ruminants. The complete genome sequences of 15 C. pseudotuberculosis strains isolated from different hosts and countries were comparatively analyzed using a pan-genomic strategy. Phylogenomic, pan-genomic, core genomic, and singleton analyses revealed close relationships among pathogenic corynebacteria, the clonal-like behavior of C. pseudotuberculosis and slow increases in the sizes of pan-genomes. According to extrapolations based on the pan-genomes, core genomes and singletons, the C. pseudotuberculosis biovar ovis shows a more clonal-like behavior than the C. pseudotuberculosis biovar equi. Most of the variable genes of the biovar ovis strains were acquired in a block through horizontal gene transfer and are highly conserved, whereas the biovar equi strains contain great variability, both intra- and inter-biovar, in the 16 detected pathogenicity islands (PAIs). With respect to the gene content of the PAIs, the most interesting finding is the high similarity of the pilus genes in the biovar ovis strains compared with the great variability of these genes in the biovar equi strains. Concluding, the polymerization of complete pilus structures in biovar ovis could be responsible for a remarkable ability of these strains to spread throughout host tissues and penetrate cells to live intracellularly, in contrast with the biovar equi, which rarely attacks visceral organs. Intracellularly, the biovar ovis strains are expected to have less contact with other organisms than the biovar equi strains, thereby explaining the significant clonal-like behavior of the biovar ovis strains.
Assuntos
Corynebacterium/genética , Genoma Bacteriano/genética , Animais , Deleção de Genes , Genes Bacterianos/genética , Variação Genética , Ilhas Genômicas/genética , Família Multigênica/genética , Especificidade da Espécie , Fatores de Virulência/genéticaRESUMO
Since the first successful attempt at sequencing the Corynebacterium pseudotuberculosis genome, large amounts of genomic, transcriptomic and proteomic data have been generated. C. pseudotuberculosis is an interesting bacterium due to its great zoonotic potential and because it causes considerable economic losses worldwide. Furthermore, different strains of C. pseudotuberculosis are capable of causing various diseases in different hosts. Currently, we seek information about the phylogenetic relationships between different strains of C. pseudotuberculosis isolates from different hosts across the world and to employ these data to develop tools to diagnose and eradicate the diseases these strains cause. In this review, we present the latest findings on C. pseudotuberculosis that have been obtained with the most advanced techniques for sequencing and genomic organization. We also discuss the development of in silico tools for processing these data to prompt a better understanding of this pathogen.
RESUMO
BACKGROUND: Corynebacterium pseudotuberculosis, a gram-positive, facultative intracellular pathogen, is the etiologic agent of the disease known as caseous lymphadenitis (CL). CL mainly affects small ruminants, such as goats and sheep; it also causes infections in humans, though rarely. This species is distributed worldwide, but it has the most serious economic impact in Oceania, Africa and South America. Although C. pseudotuberculosis causes major health and productivity problems for livestock, little is known about the molecular basis of its pathogenicity. METHODOLOGY AND FINDINGS: We characterized two C. pseudotuberculosis genomes (Cp1002, isolated from goats; and CpC231, isolated from sheep). Analysis of the predicted genomes showed high similarity in genomic architecture, gene content and genetic order. When C. pseudotuberculosis was compared with other Corynebacterium species, it became evident that this pathogenic species has lost numerous genes, resulting in one of the smallest genomes in the genus. Other differences that could be part of the adaptation to pathogenicity include a lower GC content, of about 52%, and a reduced gene repertoire. The C. pseudotuberculosis genome also includes seven putative pathogenicity islands, which contain several classical virulence factors, including genes for fimbrial subunits, adhesion factors, iron uptake and secreted toxins. Additionally, all of the virulence factors in the islands have characteristics that indicate horizontal transfer. CONCLUSIONS: These particular genome characteristics of C. pseudotuberculosis, as well as its acquired virulence factors in pathogenicity islands, provide evidence of its lifestyle and of the pathogenicity pathways used by this pathogen in the infection process. All genomes cited in this study are available in the NCBI Genbank database (http://www.ncbi.nlm.nih.gov/genbank/) under accession numbers CP001809 and CP001829.
Assuntos
Corynebacterium pseudotuberculosis/patogenicidade , Evolução Molecular , Genoma Bacteriano , Virulência/genética , Corynebacterium pseudotuberculosis/genéticaRESUMO
This work reports the completion and annotation of the genome sequence of Corynebacterium pseudotuberculosis I19, isolated from an Israeli dairy cow with severe clinical mastitis. To present the whole-genome sequence, a de novo assembly approach using 33 million short (25-bp) mate-paired SOLiD reads only was applied. Furthermore, the automatic, functional, and manual annotations were attained with the use of several algorithms in a multistep process.