The role of pathogen diversity on the evolution of resistance in an insect

2016 ◽  
Author(s):  
Leon Yu Zheng Li
Keyword(s):  
Pathogen Diversity ◽  
Evolution Of Resistance

scholarly journals Parallel adaptation of rabbit populations to myxoma virus

Science ◽  
2019 ◽  
Vol 363 (6433) ◽  
pp. 1319-1326 ◽  
Author(s):  
Joel M. Alves ◽  
Miguel Carneiro ◽  
Jade Y. Cheng ◽  
Ana Lemos de Matos ◽  
Masmudur M. Rahman ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Parallel Evolution ◽  
Rapid Evolution ◽  
Antiviral Effect ◽  
Myxoma Virus ◽  
European Rabbit ◽  
The United Kingdom ◽  
Before And After ◽  
Evolution Of Resistance

In the 1950s the myxoma virus was released into European rabbit populations in Australia and Europe, decimating populations and resulting in the rapid evolution of resistance. We investigated the genetic basis of resistance by comparing the exomes of rabbits collected before and after the pandemic. We found a strong pattern of parallel evolution, with selection on standing genetic variation favoring the same alleles in Australia, France, and the United Kingdom. Many of these changes occurred in immunity-related genes, supporting a polygenic basis of resistance. We experimentally validated the role of several genes in viral replication and showed that selection acting on an interferon protein has increased the protein’s antiviral effect.

scholarly journals Regulation of GSTu1-mediated insecticide resistance in Plutella xylostella by miRNA and lncRNA

PLoS Genetics ◽  
2021 ◽  
Vol 17 (10) ◽  
pp. e1009888
Author(s):  
Bin Zhu ◽  
Linhong Li ◽  
Rui Wei ◽  
Pei Liang ◽  
Xiwu Gao
Keyword(s):  
Drug Resistance ◽  
Insecticide Resistance ◽  
Plutella Xylostella ◽  
Mrna Stability ◽  
Noncoding Rna ◽  
Antisense Transcript ◽  
Regulatory Mechanisms ◽  
Detoxifying Enzymes ◽  
Evolution Of Resistance

The evolution of resistance to insecticides is well known to be closely associated with the overexpression of detoxifying enzymes. Although the role of glutathione S-transferase (GST) genes in insecticide resistance has been widely reported, the underlying regulatory mechanisms are poorly understood. Here, one GST gene (GSTu1) and its antisense transcript (lnc-GSTu1-AS) were identified and cloned, and both of them were upregulated in several chlorantraniliprole-resistant Plutella xylostella populations. GSTu1 was confirmed to be involved in chlorantraniliprole resistance by direct degradation of this insecticide. Furthermore, we demonstrated that lnc-GSTu1-AS interacted with GSTu1 by forming an RNA duplex, which masked the binding site of miR-8525-5p at the GSTu1-3′UTR. In summary, we revealed that lnc-GSTu1-AS maintained the mRNA stability of GSTu1 by preventing its degradation that could have been induced by miR-8525-5p and thus increased the resistance of P. xylostella to chlorantraniliprole. Our findings reveal a new noncoding RNA-mediated pathway that regulates the expression of detoxifying enzymes in insecticide-resistant insects and offer opportunities for the further understanding of the mechanisms of insecticide and drug resistance.

scholarly journals Antimicrobial resistance among GLASS priority pathogens from Pakistan: 2006–2018

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dania Khalid Saeed ◽  
Joveria Farooqi ◽  
Sadia Shakoor ◽  
Rumina Hasan
Keyword(s):  
Antimicrobial Resistance ◽  
Potential Role ◽  
Carbapenem Resistance ◽  
Steady Increase ◽  
Published Data ◽  
Situational Analysis ◽  
Antimicrobial Surveillance ◽  
Evolution Of Resistance ◽  
Resistance Rates

Abstract Background In 2018 Pakistan initiated its national antimicrobial resistance (AMR) surveillance aligned with Global Antimicrobial Surveillance System (GLASS). To complement this surveillance, we conducted a situational analysis of AMR rates among GLASS organisms in the country. Data from published studies and from antibiograms was compared and role of antibiograms as potential contributors to national AMR surveillance explored. Methods AMR rates for GLASS specified pathogen/antimicrobials combination from Pakistan were reviewed. Data sources included published studies (2006–2018) providing AMR rates from Pakistan (n = 54) as well as antibiograms (2011–2018) available on the Pakistan Antimicrobial Resistance Network (PARN) website. Resistance rates were categorized as follows: Very low: 0–10%, Low: 11–30%, Moderate: 30–50% and High: > 50%. Results Published data from hospital and community/laboratory-based studies report resistance rates of > 50% and 30–50% respectively to 3rd generation cephalosporins, fluoroquinolones and cotrimoxazole amongst Klebsiella pneumoniae and Escherichia coli. Carbapenem resistance rates amongst these organisms remained below 30%. High (> 50%) resistance was reported in Acinetobacter species to aminoglycosides and carbapenems among hospitalized patients. The evolution of ceftriaxone resistant Salmonella Typhi and Shigella species is reported. The data showed > 50% to fluoroquinolones amongst Neisseria gonorrhoeae and the spread of methicillin resistant Staphylococcus aureus (< 30%; 2008) to (> 50%; 2010) in hospital settings. Resistance reported in published studies aligned well with antibiogram data. The latter also captured a clear picture of evolution of resistance over the study period. Conclusion Both published studies as well antibiograms suggest high rates of AMR in Pakistan. Antibiogram data demonstrating steady increase in AMR highlight its potential role towards supplementing national AMR surveillance efforts particularly in settings where reach of national surveillance may be limited.

scholarly journals When resistance gene pyramids are not durable-the role of pathogen diversity

2018 ◽  
Vol 19 (3) ◽  
pp. 521-524 ◽  
Author(s):  
Remco Stam ◽  
Bruce A. McDonald
Keyword(s):  
Resistance Gene ◽  
Pathogen Diversity

scholarly journals Reduced Expression of a Novel Midgut Trypsin Gene Involved in Protoxin Activation Correlates with Cry1Ac Resistance in a Laboratory-Selected Strain of Plutella xylostella (L.)

Toxins ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 76 ◽  
Author(s):  
Lijun Gong ◽  
Shi Kang ◽  
Junlei Zhou ◽  
Dan Sun ◽  
Le Guo ◽  
...  
Keyword(s):  
Plutella Xylostella ◽  
Insect Pests ◽  
Sustainable Use ◽  
High Dose ◽  
Protease Gene ◽  
Rna Seq ◽  
Down Regulation ◽  
Bt Toxins ◽  
Evolution Of Resistance

Bacillus thuringiensis (Bt) produce diverse insecticidal proteins to kill insect pests. Nevertheless, evolution of resistance to Bt toxins hampers the sustainable use of this technology. Previously, we identified down-regulation of a trypsin-like serine protease gene PxTryp_SPc1 in the midgut transcriptome and RNA-Seq data of a laboratory-selected Cry1Ac-resistant Plutella xylostella strain, SZ-R. We show here that reduced PxTryp_SPc1 expression significantly reduced caseinolytic and trypsin protease activities affecting Cry1Ac protoxin activation, thereby conferring higher resistance to Cry1Ac protoxin than activated toxin in SZ-R strain. Herein, the full-length cDNA sequence of PxTryp_SPc1 gene was cloned, and we found that it was mainly expressed in midgut tissue in all larval instars. Subsequently, we confirmed that the PxTryp_SPc1 gene was significantly decreased in SZ-R larval midgut and was further reduced when selected with high dose of Cry1Ac protoxin. Moreover, down-regulation of the PxTryp_SPc1 gene was genetically linked to resistance to Cry1Ac in the SZ-R strain. Finally, RNAi-mediated silencing of PxTryp_SPc1 gene expression decreased larval susceptibility to Cry1Ac protoxin in the susceptible DBM1Ac-S strain, supporting that low expression of PxTryp_SPc1 gene is involved in Cry1Ac resistance in P. xylostella. These findings contribute to understanding the role of midgut proteases in the mechanisms underlying insect resistance to Bt toxins.

Evolution of resistance to diclofop-methyl in ryegrass (Lolium multiflorum): investigation of the role of introgression with related species

1997 ◽  
Vol 51 (3) ◽  
pp. 305-308 ◽  
Author(s):  
María A. Martínez-Ghersa ◽  
Claudio M. Ghersa ◽  
Martín M. Vila-Aiub ◽  
Emilio H. Satorre ◽  
Steve R. Radosevich
Keyword(s):  
Related Species ◽  
Lolium Multiflorum ◽  
Evolution Of Resistance

Marine pathogen diversity and disease outcomes

2020 ◽  
pp. 3-44
Author(s):  
Kelly S. Bateman ◽  
Stephen W. Feist ◽  
John P. Bignell ◽  
David Bass ◽  
Grant D. Stentiford
Keyword(s):  
Cell System ◽  
Emerging Diseases ◽  
Presumptive Diagnosis ◽  
Pathogen Diversity ◽  
Disease Outcomes ◽  
Secondary Infections ◽  
Specific Pathogen ◽  
Tissue Changes ◽  
The Individual

This chapter provides an introduction to important marine pathogens, providing an overview of the diversity of pathogen types and how they affect different hosts in the marine environment. The chapter focuses on wild and cultured species and highlights that single infections are relatively rare, with co- and secondary infections being commonplace. The authors highlight the importance of understanding “normal” host tissue structure prior to interpreting pathological changes and outline the role of histology to assess pathogenicity of emerging diseases, linking presence of individual pathogens and co-infections with degree of host response. Fact sheets focus on the pathology (i.e., interaction of a specific pathogen group with the host cell/system) with high-quality histology and TEM images, emphasizing tissue changes caused by pathogens, and point the reader to presumptive diagnosis via histology while highlighting the need for confirmatory testing via other means. The pathobiome concept is introduced and explained, and the utility for predicting outcomes at the individual and population levels discussed.

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