scholarly journals A Global Screening Assay to Select for Maize Phenotypes with a High Tolerance or Resistance to Fusarium verticillioides (Sacc.) Nirenberg Rots

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1990
Author(s):  
Shamir Gabriel Román ◽  
Jesús Quiroz-Chávez ◽  
Miguel Villalobos ◽  
Vianey Urías-Gutiérrez ◽  
Eusebio Nava-Pérez ◽  
...  
Keyword(s):  
Life Cycle ◽  
Fusarium Species ◽  
Fusarium Verticillioides ◽  
Health Concern ◽  
Maize Breeding ◽  
Screening Assay ◽  
Screening Assays ◽  
Maize Stalks ◽  
Resistant Genotypes ◽  
Significant Health

Fusarium verticillioides (Sacc.) Nirenberg (Fv) causes rots in maize around the world and produces mycotoxins that contaminate grains, making this species a significant health concern for both animals and humans. One of the best approaches to address rots is to identify highly tolerant or resistant genotypes that can be used for genetic improvement. The aim of the study was to evaluate dose-response assays to tolerance or resistance for Fv rots throughout the maize life cycle. These tests assessed the effects of Fv during post-germination development and the seedling (V2) stage by seed infection, the plantlet (V4) stage by substrate infection, and in the reproductive phase in maize stalks (R2 stage) and ears (R6 stage) by R1 stage inoculation. In all assays, the doses were effective at distinguishing contrasting phenotypes. Severity, root fresh weight, and aerial length were the most informative parameters at the V2 and V4 stages. Evaluation of the stalk necrosis area between and within the internodes of susceptible genotypes revealed significant differences among doses, and a positive correlation between necrosis and conidia concentration was observed in internodes. Injecting eight million conidia in the ear was sufficient for selecting different phenotypes. A total of 85% of the genotypes conserved their same capacity to respond to Fv infection throughout the maize life cycle, so that screening at the early vegetative stage (e.g., V2) could be useful for distinguishing contrasting phenotypes in the reproductive stage. Implementing these screening assays in a maize breeding program could be valuable for classifying the degrees of resilience of maize germplasms to Fv rots. This global screening has the potential to be employed to select against other Fusarium species.

scholarly journals Potential Application of Lactic Acid Bacteria to Reduce Aflatoxin B1 and Fumonisin B1 Occurrence on Corn Kernels and Corn Ears

Toxins ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 21 ◽  
Author(s):  
Tiago de Melo Nazareth ◽  
Carlos Luz ◽  
Raquel Torrijos ◽  
Juan Manuel Quiles ◽  
Fernando Bittencourt Luciano ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Fusarium Verticillioides ◽  
Fumonisin B1 ◽  
Health Concern ◽  
Economic Losses ◽  
Antifungal Effect ◽  
Minimum Fungicidal Concentration ◽  
Sensory Defects ◽  
Corn Kernels

Fungal spoilage is an important issue for the food industry, leading to food sensory defects, food waste, economic losses and public health concern through the production of mycotoxins. Concomitantly, the search for safer natural products has gained importance since consumers began to look for less processed and chemically treated foods. In this context, the aim of this study was to evaluate the antifungal and antimycotoxigenic effect of seven strains of Lactobacillus plantarum. Lactic acid bacteria (LAB) were grown on Man Rogosa Sharpe (MRS) broth at 37 °C in anaerobic conditions. After that, the cell-free supernatant (CFS) were recovered to determine its antifungal activity by halo diffusion agar test. In addition, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) was determined for each L. plantarum CFS by 96-well microplates method. Additionally, CFS was used as a natural biocontrol agent on corn kernels and corn ears contaminated with Aspergillus flavus and Fusarium verticillioides, respectively. The L. plantarum CECT 749 CFS showed the highest antifungal effect against all essayed strains. Moreover, the employment of this CFS in food reduced the mycotoxin production at a percentage ranging from 73.7 to 99.7%. These results suggest that the L. plantarum CECT 749 CFS could be promising for the biocontrol of corn.

scholarly journals Hepatitis C Virus p7 and NS2 Proteins Are Essential for Production of Infectious Virus

2007 ◽  
Vol 81 (16) ◽  
pp. 8374-8383 ◽  
Author(s):  
Christopher T. Jones ◽  
Catherine L. Murray ◽  
Dawnnica K. Eastman ◽  
Jodie Tassello ◽  
Charles M. Rice
Keyword(s):  
Life Cycle ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Infectious Virus ◽  
Early Stage ◽  
Virus Production ◽  
Health Concern ◽  
Cell Culture Systems ◽  
Catalytic Active Site

ABSTRACT Hepatitis C virus (HCV) infection is a global health concern affecting an estimated 3% of the world's population. Recently, cell culture systems have been established, allowing recapitulation of the complete virus life cycle for the first time. Since the HCV proteins p7 and NS2 are not predicted to be major components of the virion, nor are they required for RNA replication, we investigated whether they might have other roles in the viral life cycle. Here we utilize the recently described infectious J6/JFH chimera to establish that the p7 and NS2 proteins are essential for HCV infectivity. Furthermore, unprocessed forms of p7 and NS2 were not required for this activity. Mutation of two conserved basic residues, previously shown to be important for the ion channel activity of p7 in vitro, drastically impaired infectious virus production. The protease domain of NS2 was required for infectivity, whereas its catalytic active site was dispensable. We conclude that p7 and NS2 function at an early stage of virion morphogenesis, prior to the assembly of infectious virus.

scholarly journals Heterocyclic Compounds That Inhibit Rev-RRE Function and Human Immunodeficiency Virus Type 1 Replication

2008 ◽  
Vol 52 (9) ◽  
pp. 3169-3179 ◽  
Author(s):  
Deidra Shuck-Lee ◽  
Fei Fei Chen ◽  
Ryan Willard ◽  
Sharmila Raman ◽  
Roger Ptak ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Life Cycle ◽  
Cell Line ◽  
Particle Production ◽  
Screening Assay ◽  
Rev Response Element ◽  
Immunodeficiency Virus ◽  
A Cell ◽  
Viruslike Particles

ABSTRACT A cell-based screening assay was performed to identify compounds that inhibited the postintegration stage of the human immunodeficiency virus (HIV) life cycle. This assay utilized a cell line that contains the HIV gag and pol genes expressed in a Rev-dependent fashion. The cell line produces about 10 to 15 ng of p24 per milliliter of medium over a 24-h period in the form of viruslike particles. Any compound that inhibits a postintegration step in the HIV life cycle scores in this assay by decreasing particle production. Forty thousand compounds were screened, and 192 compounds were selected from the original screen because they showed more than 50% inhibition at a 10 μM concentration. The cumulative evidence presented in this study strongly suggests that 2 of the 192 compounds work as inhibitors of HIV Rev function. This was determined by a variety of cell-based assays, although the compounds do not interfere with Rev-RRE (Rev response element) binding in vitro. Both compounds inhibit replication of the lab isolate NL4-3 as well as an HIV primary isolate from Brazil (93BR021) and thus are promising leads as therapeutic candidates that target HIV replication through inhibition of Rev function.

scholarly journals Morpho-Molecular Identification, Pathogenicity Variation, Mating Biology, and Fumonisin Production of Fusarium Species in Zea mays L.

2018 ◽  
Vol 7 (1) ◽  
pp. 31-49
Author(s):  
Narges Atabaki ◽  
Vahid Rahjoo ◽  
Mohamed M. Hanafi ◽  
Rambod Abiri ◽  
Hamidreza Z. Zadeh ◽  
...  
Keyword(s):  
Zea Mays ◽  
Mating Type ◽  
Molecular Identification ◽  
Zea Mays L ◽  
Fusarium Species ◽  
Fusarium Verticillioides ◽  
Fusarium Proliferatum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Wide Range

Fusarium verticillioides and Fusarium proliferatum cause a wide range of maize diseases.  These fungi produce dangerous mycotoxins, such as fumonisin B1, which are important threats to humans and animals. Given this predicament, the present study aimed to identify the fungi both molecular-morphologically and also investigate the pathogenicity variation and mating type of 41 Fusarium strains in maize (Zea mays L.) samples with sifting their fumonisin contents.  Furthermore, species-specific primers for the molecular identification of distinct strains amplified 2 fragments of 578 and 800 bp in Fusarium verticillioides, while a single 585 bp band was amplified in Fusarium proliferatum.  Accordingly, 24 isolates out of 41 were identified as F. verticillioides, and 13 isolates were identified as F. proliferatum.  The fumonisin-producing and non-producing Fusarium strains were identified using the VERTF-1/VERTF-2 primers.  A total of 24 isolates of F. verticillioides were positively scored based on the amplification of a single 400 bp fragment.  The highest and lowest fumonisin content, as measured using an enzyme-linked immunosorbent assay (ELISA), belonged to strains MS1 and MG3, respectively, and ranged from 960-12673 and 4.07-23 ppm, respectively.  Additionally, the mating type test showed that the sexual form of the studied Fusarium species could possibly belong to the A and D mating populations.  In vivo and in vitro pathogenicity tests revealed a high susceptibility.

scholarly journals Short Communication: Genetic diversity of fumonisin producing Fusarium isolates from rice using PCR-RFLP of IGS-rDNA region

2018 ◽  
Vol 19 (2) ◽  
pp. 571-576
Author(s):  
SHUBHRANSU NAYAK ◽  
URMILA DHUA ◽  
APURBA CHHOTARAY ◽  
SOMA SAMANTA ◽  
CHANDAN SENGUPTA
Keyword(s):  
Genetic Diversity ◽  
Short Communication ◽  
Fusarium Species ◽  
Fusarium Verticillioides ◽  
Rice Varieties ◽  
Separate Branch ◽  
Pcr Rflp ◽  
Pcr Products ◽  
Silver Nitrate Staining ◽  
High Degree

Nayak S, Dhua U, Chhotaray A, Samanta S, Sengupta C. 2018. Short Communication: Genetic diversity of fumonisin producing Fusarium isolates from rice using PCR-RFLP of IGS-rDNA region. Biodiversitas 19: 571-576. Fusarium verticillioides (Sacc.) and related species produce carcinogenic mycotoxin known as Fumonisins in several agricultural crops including rice. However, this principal food crop has been infected by genetically diverse Fusarium species. Odisha belongs to the coastal part of India and many popular rice varieties are in the food chain in this region. Many Fusarium species producing fumonisins have been found to be associated with these rice varieties. Hence, the genetic diversity of twenty eight Fumonisin producers and non producers of Fusarium pathogens in this region was carried out in the current study. The IGS regions of 28 Fusarium isolates (both fumonisin producing and non producing) were amplified and the PCR products were restriction digested with ECoRI and HhaI. The digested products were separated on PAGE and bands were visualized by Silver Nitrate Staining. The 28 isolates could be separated into 14 IGS haplotypes. The lowest similarity was detected to be of 33% between F40 and F47. A group containing 14 isolates represented the biggest haplotypes. The isolates in which the FUM gene had not been detected (fumonisin non producer) were in a separate group having 90% similarity with each other and placed consistently in separate branch from others. Presence of unique band for this group was observed at 1650bp where as absence of specific bands was observed at 380bp and 300bp. The result of this study indicated a high degree of genetic variation among 28 Fusarium isolates. PCR RFLP of IGS region was also found to be useful for diversity study in Fusarium.

scholarly journals The spread of chloramphenicol-resistant Neisseria meningitidis in Southeast Asia

2019 ◽  
Author(s):  
Elizabeth M. Batty ◽  
Tomas-Paul Cusack ◽  
Janjira Thaipadungpanit ◽  
Wanitda Watthanaworawit ◽  
Verena Carrara ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Neisseria Meningitidis ◽  
Democratic Republic ◽  
Invasive Disease ◽  
Health Concern ◽  
Chloramphenicol Resistance ◽  
Ciprofloxacin Resistance ◽  
Diagnostic Microbiology ◽  
Susceptibility Patterns ◽  
Significant Health

AbstractInvasive disease caused by Neisseria meningitidis is a significant health concern globally, but our knowledge of the prevailing serogroups, antimicrobial susceptibility patterns, and genetics of N. meningitidis in Southeast Asia is limited. Chloramphenicol resistance in N. meningitidis has rarely been reported, but was first described in isolates from Vietnam in 1998. Using whole-genome sequencing of meningococcal isolates from 18 patients collected between 2007 and 2018 from diagnostic microbiology laboratories in Cambodia, Thailand and the Lao People’s Democratic Republic (Laos), of which eight were non-susceptible to chloramphenicol, we report the spread of this chloramphenicol-resistant lineage of N. meningitidis across Southeast Asia. Strains resistant to penicillin, tetracycline, and ciprofloxacin were also observed, including a chloramphenicol-resistant strain from the previously-described lineage which has acquired penicillin and ciprofloxacin resistance, and most isolates were of serogroup B. This study suggests that chloramphenicol-resistant N. meningitidis is more widespread than previously thought.

scholarly journals A seven-year surveillance of epidemiology of malaria reveals travel and gender are the key drivers of dispersion of drug resistant genotypes in Kenya

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8082
Author(s):  
Moureen Maraka ◽  
Hoseah M. Akala ◽  
Asito S. Amolo ◽  
Dennis Juma ◽  
Duke Omariba ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Reference Group ◽  
Multivariate Model ◽  
Chloroquine Resistance ◽  
Health Concern ◽  
Univariate Model ◽  
And Gender ◽  
Resistant Genotypes

Malaria drug resistance is a global public health concern. Though parasite mutations have been associated with resistance, other factors could influence the resistance. A robust surveillance system is required to monitor and help contain the resistance. This study established the role of travel and gender in dispersion of chloroquine resistant genotypes in malaria epidemic zones in Kenya. A total of 1,776 individuals presenting with uncomplicated malaria at hospitals selected from four malaria transmission zones in Kenya between 2008 and 2014 were enrolled in a prospective surveillance study assessing the epidemiology of malaria drug resistance patterns. Demographic and clinical information per individual was obtained using a structured questionnaire. Further, 2 mL of blood was collected for malaria diagnosis, parasitemia quantification and molecular analysis. DNA extracted from dried blood spots collected from each of the individuals was genotyped for polymorphisms in Plasmodium falciparum chloroquine transporter gene (Pfcrt 76), Plasmodium falciparum multidrug resistant gene 1 (Pfmdr1 86 and Pfmdr1 184) regions that are putative drug resistance genes using both conventional polymerase chain reaction (PCR) and real-time PCR. The molecular and demographic data was analyzed using Stata version 13 (College Station, TX: StataCorp LP) while mapping of cases at the selected geographic zones was done in QGIS version 2.18. Chloroquine resistant (CQR) genotypes across gender revealed an association with chloroquine resistance by both univariate model (p = 0.027) and by multivariate model (p = 0.025), female as reference group in both models. Prior treatment with antimalarial drugs within the last 6 weeks before enrollment was associated with carriage of CQR genotype by multivariate model (p = 0.034). Further, a significant relationship was observed between travel and CQR carriage both by univariate model (p = 0.001) and multivariate model (p = 0.002). These findings suggest that gender and travel are significantly associated with chloroquine resistance. From a gender perspective, males are more likely to harbor resistant strains than females hence involved in strain dispersion. On the other hand, travel underscores the role of transport network in introducing spread of resistant genotypes, bringing in to focus the need to monitor gene flow and establish strategies to minimize the introduction of resistance strains by controlling malaria among frequent transporters.

scholarly journals Fusarium Species and Mycotoxins Contaminating Veterinary Diets for Dogs and Cats

2019 ◽  
Vol 7 (1) ◽  
pp. 26 ◽  
Author(s):  
Natalia Witaszak ◽  
Łukasz Stępień ◽  
Jan Bocianowski ◽  
Agnieszka Waśkiewicz
Keyword(s):  
Animal Feed ◽  
Fusarium Species ◽  
Fusarium Verticillioides ◽  
Animal Health ◽  
Companion Animals ◽  
Fumonisin B1 ◽  
Additional Risk ◽  
Two Samples ◽  
The Mean ◽  
The Eu

Veterinary diets are intended for diseased animals and may contain cereal grains, mainly maize and/or wheat. These, in turn, are often infected with pathogens of the Fusarium genus, which are able to produce numerous harmful mycotoxins. Forty-two samples of veterinary diets for dogs and cats were analyzed for the presence of Fusarium species and mycotoxins. Species were identified using molecular methods and the ergosterol and mycotoxins (fumonisin B1, deoxynivalenol, nivalenol and zearalenone) were quantified using HPLC methods. Two Fusarium species were identified: Fusarium proliferatum and Fusarium verticillioides. The highest concentrations of fumonisin B1, deoxynivalenol, nivalenol and zearalenone were 74.83, 2318.05, 190.90, and 45.84 ng/g, respectively. Only 9.5% of the samples were free from Fusarium mycotoxins. The acceptable limits of mycotoxin content in animal feed, specified by the EU regulations, were not exceeded in any of the samples tested. The mean mycotoxin content in veterinary diets for cats was lower than for dogs. Thus, it is recommended that veterinary diets are examined, since the mycotoxin contamination pose additional risk to animal health. The knowledge on Fusarium occurrence in veterinary diets is scarce and as far as we are aware this is the first report concerning the occurrence of Fusarium spp. and their important secondary metabolites—mycotoxins—in different types of veterinary diets for companion animals in Poland.

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