Discovery of Antibiofilm Activity of Elasnin against Marine Biofilms and Its Application in the Marine Antifouling Coatings

Biofilms are surface-attached multicellular communities that play critical roles in inducing biofouling and biocorrosion in the marine environment. Given the serious economic losses and problems caused by biofouling and biocorrosion, effective biofilm control strategies are highly sought after. In a screening program of antibiofilm compounds against marine biofilms, we discovered the potent biofilm inhibitory activity of elasnin. Elasnin effectively inhibited the biofilm formation of seven strains of bacteria isolated from marine biofilms. With high productivity, elasnin-based coatings were prepared in an easy and cost-effective way, which exhibited great performance in inhibiting the formation of multi-species biofilms and the attachment of large biofouling organisms in the marine environment. The 16S amplicon analysis and anti-larvae assay revealed that elasnin could prevent biofouling by the indirect impact of changed microbial composition of biofilms and direct inhibitory effect on larval settlement with low toxic effects. These findings indicated the potential application of elasnin in biofilm and biofouling control in the marine environment.

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Strategies for anti-coccidial prophylaxis

Parasitology ◽

10.1017/s0031182014000195 ◽

2014 ◽

Vol 141 (11) ◽

pp. 1379-1389 ◽

Cited By ~ 36

Author(s):

DAVID M. WITCOMBE ◽

NICHOLAS C. SMITH

Keyword(s):

Control Strategies ◽

Cost Effective ◽

Oral Route ◽

Current Control ◽

Economic Losses ◽

Parasite Life Cycle ◽

Prophylactic Drugs ◽

Protective Antibodies ◽

Egg Yolks ◽

Serious Disease

SUMMARYCoccidiosis, a serious disease resulting from infection with parasitic protozoa of the genusEimeria, causes significant economic losses to the poultry industry, where intensive rearing facilitates transmission of infectious oocysts via the fecal/oral route. Current control relies primarily on prophylactic drugs in feed but, whilst cost effective, the rise of drug resistance and public demands for residue-free meat has encouraged development of alternative control strategies. Chickens that recover from infection withEimeriadevelop solid immunity that is directed against the early asexual stages of the parasite life cycle. This has allowed development of a number of vaccines that utilize deliberate infection with controlled doses of virulent oocysts or reproductively attenuated lines ofEimeria.The latter are immunogenic but non-pathogenic. The realization that both prophylactic drugs and attenuated vaccines control but do not eradicate infection withEimeriaencouraged development of a vaccine based upon maternal immunity. Laying hens exposed toEimeriaare able to transfer protective antibodies to hatchlings via egg yolks and these antibodies have been used to identify parasite proteins that are conserved across the genus. When delivered maternally, these provide an economical means of preventing coccidiosis, offering immediate protection to newly hatched chicks.

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Experimental Assessment of a Conducting Polymer (PEDOT) and Microbial Biofilms as Deterrents and Facilitators of Macro-Biofouling: Larval Settlement of the Barnacle Notobalanus flosculus (Darwin, 1854) from Central Chile

Journal of Marine Science and Engineering ◽

10.3390/jmse9010082 ◽

2021 ◽

Vol 9 (1) ◽

pp. 82

Author(s):

Simone Baldanzi ◽

Ignacio T. Vargas ◽

Francisco Armijo ◽

Miriam Fernández ◽

Sergio A. Navarrete

Keyword(s):

Control Strategies ◽

Low Cost ◽

Larval Settlement ◽

Cost Effective ◽

Negative Consequences ◽

Marine Biofouling ◽

Microbial Biofilms ◽

Southeastern Pacific ◽

Potential Applications ◽

Coated Surfaces

Maritime enterprises have long sought solutions to reduce the negative consequences of the settlement and growth of marine biofouling (micro- and macro-organisms) on virtually all surfaces and materials deployed at sea. The development of biofouling control strategies requires solutions that are cost-effective and environmentally friendly. Polymer-based coatings, such as the poly (3,4-ethylenedioxythiophene) (PEDOT) and its potential applications, have blossomed over the last decade thanks to their low cost, nontoxicity, and high versatility. Here, using multiple-choice larval settlement experiments, we assessed the efficacy of PEDOT against the balanoid barnacle Notobalanus flosculus one of the most common biofouling species in Southeastern Pacific shores, and compared results against a commercially available antifouling (AF) coating, and biofilms at different stages of succession (1, 2, 4 and 8 weeks). We show that larval settlement on PEDOT-coated surfaces was similar to the settlement on AF-coated surfaces, while larvae settled abundantly on roughened acrylic and on early-to-intermediate stages of biofilm (one to four weeks old). These results are promising and suggest that PEDOT is a good candidate for fouling-resistant coating for specific applications at sea. Further studies to improve our understanding of the mechanisms of barnacle larval deterrence, as well as exposure to field conditions, are encouraged.

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On the Optimal Dynamic Control Strategy of Disruptive Computer Virus

Discrete Dynamics in Nature and Society ◽

10.1155/2017/8390784 ◽

2017 ◽

Vol 2017 ◽

pp. 1-14 ◽

Cited By ~ 7

Author(s):

Jichao Bi ◽

Xiaofan Yang ◽

Yingbo Wu ◽

Qingyu Xiong ◽

Junhao Wen ◽

...

Keyword(s):

Optimal Control ◽

Control Strategy ◽

Control Strategies ◽

Dynamic Control ◽

Cost Effective ◽

Computer Virus ◽

Economic Losses ◽

Computer Viruses ◽

Effective Dynamic ◽

Optimal Dynamic

Disruptive computer viruses have inflicted huge economic losses. This paper addresses the development of a cost-effective dynamic control strategy of disruptive viruses. First, the development problem is modeled as an optimal control problem. Second, a criterion for the existence of an optimal control is given. Third, the optimality system is derived. Next, some examples of the optimal dynamic control strategy are presented. Finally, the performance of actual dynamic control strategies is evaluated.

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Microbiota identified from preserved Anopheles

Malaria Journal ◽

10.1186/s12936-021-03754-7 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Bianca E Silva ◽

Zvifadzo Matsena Zingoni ◽

Lizette L. Koekemoer ◽

Yael L. Dahan-Moss

Keyword(s):

Microbial Diversity ◽

Vector Competence ◽

Mosquito Species ◽

Anopheles Funestus ◽

Cost Effective ◽

Diversity Indices ◽

Malaria Vectors ◽

Microbial Composition ◽

Culture Independent ◽

Culture Dependent

Abstract Background Mosquito species from the Anopheles gambiae complex and the Anopheles funestus group are dominant African malaria vectors. Mosquito microbiota play vital roles in physiology and vector competence. Recent research has focused on investigating the mosquito microbiota, especially in wild populations. Wild mosquitoes are preserved and transported to a laboratory for analyses. Thus far, microbial characterization post-preservation has been investigated in only Aedes vexans and Culex pipiens. Investigating the efficacy of cost-effective preservatives has also been limited to AllProtect reagent, ethanol and nucleic acid preservation buffer. This study characterized the microbiota of African Anopheles vectors: Anopheles arabiensis (member of the An. gambiae complex) and An. funestus (member of the An. funestus group), preserved on silica desiccant and RNAlater® solution. Methods Microbial composition and diversity were characterized using culture-dependent (midgut dissections, culturomics, MALDI-TOF MS) and culture-independent techniques (abdominal dissections, DNA extraction, next-generation sequencing) from laboratory (colonized) and field-collected mosquitoes. Colonized mosquitoes were either fresh (non-preserved) or preserved for 4 and 12 weeks on silica or in RNAlater®. Microbiota were also characterized from field-collected An. arabiensis preserved on silica for 8, 12 and 16 weeks. Results Elizabethkingia anophelis and Serratia oryzae were common between both vector species, while Enterobacter cloacae and Staphylococcus epidermidis were specific to females and males, respectively. Microbial diversity was not influenced by sex, condition (fresh or preserved), preservative, or preservation time-period; however, the type of bacterial identification technique affected all microbial diversity indices. Conclusions This study broadly characterized the microbiota of An. arabiensis and An. funestus. Silica- and RNAlater®-preservation were appropriate when paired with culture-dependent and culture-independent techniques, respectively. These results broaden the selection of cost-effective methods available for handling vector samples for downstream microbial analyses.

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CRISPR/Cas9-based generation of a recombinant double-reporter pseudorabies virus and its characterization in vitro and in vivo

Veterinary Research ◽

10.1186/s13567-021-00964-4 ◽

2021 ◽

Vol 52 (1) ◽

Author(s):

Peng-Fei Fu ◽

Xuan Cheng ◽

Bing-Qian Su ◽

Li-Fang Duan ◽

Cong-Rong Wang ◽

...

Keyword(s):

Pseudorabies Virus ◽

Fluorescent Protein ◽

Antiviral Agents ◽

Firefly Luciferase ◽

Inhibitory Effect ◽

Economic Losses ◽

Green Fluorescent ◽

Swine Herds

AbstractPseudorabies, caused by pseudorabies virus (PRV) variants, has broken out among commercial PRV vaccine-immunized swine herds and resulted in major economic losses to the pig industry in China since late 2011. However, the mechanism of virulence enhancement of variant PRV is currently unclear. Here, a recombinant PRV (rPRV HN1201-EGFP-Luc) with stable expression of enhanced green fluorescent protein (EGFP) and firefly luciferase as a double reporter virus was constructed on the basis of the PRV variant HN1201 through CRISPR/Cas9 gene-editing technology coupled with two sgRNAs. The biological characteristics of the recombinant virus and its lethality to mice were similar to those of the parental strain and displayed a stable viral titre and luciferase activity through 20 passages. Moreover, bioluminescence signals were detected in mice at 12 h after rPRV HN1201-EGFP-Luc infection. Using the double reporter PRV, we also found that 25-hydroxycholesterol had a significant inhibitory effect on PRV both in vivo and in vitro. These results suggested that the double reporter PRV based on PRV variant HN1201 should be an excellent tool for basic virology studies and evaluating antiviral agents.

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Prevalence of mastitis in Nigerian livestock: a Review

Open Veterinary Science ◽

10.1515/ovs-2020-0101 ◽

2020 ◽

Vol 1 (1) ◽

pp. 20-29

Author(s):

Hussaini Ojagefu Adamu ◽

Rahimat Oshuwa Hussaini ◽

Cedric Obasuyi ◽

Linus Irefo Anagha ◽

Gabriel Oscy Okoduwa

Keyword(s):

Control Strategies ◽

Dairy Farms ◽

Livestock Production ◽

Sub Saharan Africa ◽

Economic Losses ◽

Ecological Development ◽

Management Plans ◽

Sub Saharan ◽

Control And Management ◽

The Impact

AbstractMastitis is a disease of livestock that directly impede livestock production and thus hindering the socio-ecological development of sub-Saharan Africa. Studies have estimated the prevalence of this disease in 30% of Africa countries, with Ethiopia having the highest prevalence. The coverage is low, despite the wide livestock and dairy farms distribution in Africa. Furthermore, estimated economic losses due to the impact of mastitis are lacking in Nigeria. The disease is endemic in Nigeria as indicated by the available data and there are no proposed management plans or control strategies. This review is thus presented to serve as a wakeup call to all parties involved to intensify efforts towards the diagnosis, control, and management of the disease in Nigeria.

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Molecular detection and genetic diversity of Leucocytozoon sabrazesi in chickens in Thailand

Scientific Reports ◽

10.1038/s41598-021-96241-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Runglawan Chawengkirttikul ◽

Witchuta Junsiri ◽

Amaya Watthanadirek ◽

Napassorn Poolsawat ◽

Sutthida Minsakorn ◽

...

Keyword(s):

Genetic Diversity ◽

Egg Production ◽

Control Strategies ◽

Amino Acid Sequences ◽

Economic Losses ◽

Nested Polymerase Chain Reaction ◽

Blood Samples ◽

Tropical Regions ◽

Vaccination Programs ◽

High Entropy

AbstractLeucocytozoon sabrazesi is the intracellular protozoa of leucocytozoonosis, which is transmitted by the insect vectors and affects chickens in most subtropical and tropical regions of the globe, except South America, and causing enormous economic losses due to decreasing meat yield and egg production. In this study, L. sabrazesi gametocytes have been observed in the blood smears, and molecular methods have been used to analyse the occurrence and genetic diversity of L. sabrazesi in blood samples from 313 chickens raised in northern, western and southern parts of Thailand. The nested polymerase chain reaction (nested PCR) assay based on the cytb gene revealed that 80.51% (252/313) chickens were positive of L. sabrazesi. The phylogenetic analysis indicated that L. sabrazesi cytb gene is conserved in Thailand, showed 2 clades and 2 subclades with similarity ranged from 89.5 to 100%. The diversity analysis showed 13 and 18 haplotypes of the sequences from Thailand and from other countries, respectively. The entropy analyses of nucleic acid sequences showed 26 high entropy peaks with values ranging from 0.24493 to 1.21056, while those of amino acid sequences exhibited 5 high entropy peaks with values ranging from 0.39267 to 0.97012. The results; therefore, indicate a high molecular occurrence of L. sabrazesi in chicken blood samples with the associated factors that is statistically significant (p < 0.05). Hence, our results could be used to improve the immunodiagnostic methods and to find appropriate preventive control strategies or vaccination programs against leucocytozoonosis in order to mitigate or eliminate the harmful impact of this infection on chicken industry.

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Controlling the Spatial Spread of a Xylella Epidemic

Bulletin of Mathematical Biology ◽

10.1007/s11538-021-00861-z ◽

2021 ◽

Vol 83 (4) ◽

Author(s):

Sebastian Aniţa ◽

Vincenzo Capasso ◽

Simone Scacchi

Keyword(s):

Spatial Structure ◽

Numerical Simulations ◽

Control Strategies ◽

Xylella Fastidiosa ◽

Cost Effective ◽

Olive Tree ◽

Control Measures ◽

Weed Biomass ◽

Spatial Spread ◽

Olive Trees

AbstractIn a recent paper by one of the authors and collaborators, motivated by the Olive Quick Decline Syndrome (OQDS) outbreak, which has been ongoing in Southern Italy since 2013, a simple epidemiological model describing this epidemic was presented. Beside the bacterium Xylella fastidiosa, the main players considered in the model are its insect vectors, Philaenus spumarius, and the host plants (olive trees and weeds) of the insects and of the bacterium. The model was based on a system of ordinary differential equations, the analysis of which provided interesting results about possible equilibria of the epidemic system and guidelines for its numerical simulations. Although the model presented there was mathematically rather simplified, its analysis has highlighted threshold parameters that could be the target of control strategies within an integrated pest management framework, not requiring the removal of the productive resource represented by the olive trees. Indeed, numerical simulations support the outcomes of the mathematical analysis, according to which the removal of a suitable amount of weed biomass (reservoir of Xylella fastidiosa) from olive orchards and surrounding areas resulted in the most efficient strategy to control the spread of the OQDS. In addition, as expected, the adoption of more resistant olive tree cultivars has been shown to be a good strategy, though less cost-effective, in controlling the pathogen. In this paper for a more realistic description and a clearer interpretation of the proposed control measures, a spatial structure of the epidemic system has been included, but, in order to keep mathematical technicalities to a minimum, only two players have been described in a dynamical way, trees and insects, while the weed biomass is taken to be a given quantity. The control measures have been introduced only on a subregion of the whole habitat, in order to contain costs of intervention. We show that such a practice can lead to the eradication of an epidemic outbreak. Numerical simulations confirm both the results of the previous paper and the theoretical results of the model with a spatial structure, though subject to regional control only.

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Novel combination of CRISPR-based gene drives eliminates resistance and localises spread

Scientific Reports ◽

10.1038/s41598-021-83239-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nicky R. Faber ◽

Gus R. McFarlane ◽

R. Chris Gaynor ◽

Ivan Pocrnic ◽

C. Bruce A. Whitelaw ◽

...

Keyword(s):

Driving Forces ◽

Spatial Models ◽

Cost Effective ◽

Biodiversity Loss ◽

Invasive Pest ◽

Economic Losses ◽

Sciurus Carolinensis ◽

Gene Drive ◽

Grey Squirrel ◽

Gene Drives

AbstractInvasive species are among the major driving forces behind biodiversity loss. Gene drive technology may offer a humane, efficient and cost-effective method of control. For safe and effective deployment it is vital that a gene drive is both self-limiting and can overcome evolutionary resistance. We present HD-ClvR in this modelling study, a novel combination of CRISPR-based gene drives that eliminates resistance and localises spread. As a case study, we model HD-ClvR in the grey squirrel (Sciurus carolinensis), which is an invasive pest in the UK and responsible for both biodiversity and economic losses. HD-ClvR combats resistance allele formation by combining a homing gene drive with a cleave-and-rescue gene drive. The inclusion of a self-limiting daisyfield gene drive allows for controllable localisation based on animal supplementation. We use both randomly mating and spatial models to simulate this strategy. Our findings show that HD-ClvR could effectively control a targeted grey squirrel population, with little risk to other populations. HD-ClvR offers an efficient, self-limiting and controllable gene drive for managing invasive pests.

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