resistance Flashcards
Mechanistic bases for costs of resistance
Metabolic
impaired enzyme function (but not complete loss of function)
disruption of cellular and intercellular transport
Energetic
increased allocation of resources to defence cf. growth
changes in patterns of resource allocation between plant organs
Ecological
increased susceptibility to competition
increased susceptibility to pathogens
Pharmaceuticals and Personal Care Products (PPCPs) as Pollutants
Products used for personal healthcare or cosmetic reasons
Products used by agribusiness to enhance growth or health of livestock
PPCPs Enter The EnvironmentThrough Use and Disposal
PPCPs have probably been present in the environment for as long as humans have been using them. Individuals add PPCPs to the environment through:
Excretion
Bathing
Disposal of medications to sewers and trash.
Unused/unwanted quantities as much as 50% of many prescriptions - 80% for antibiotics and 15% other pharmaceutical compounds.
Common/historical recommendation was to flush; “crush & flush” is still widely practiced method
Pharmaceuticals and Personal Care Products as Pollutants
From World Health Organisation- Pharmaceuticals in drinking water:
The drugs that we take may be excreted in a biologically active form into wastewater and ultimately released into lakes and rivers.
Advances in technology have improved our ability to detect and quantify these chemicals.
Their effect on the environment is now recognized as an important area of research.
Rapid Increase of Pharmaceutical Sales
Sales of medical products have increased dramatically over the last two decades
Most products are small molecules that target neurological activity
Some Pharmaceuticals areEndocrine Disrupting Chemicals
A group of chemicals, known as endocrine disruptor chemicals (EDCs), has been identified as having the potential to cause adverse health effects in humans and wildlife.
Among this group DDT, PCBs, endosulfan, methoxychlor, diethylphthalate, diethylhexylphthalate, and bisphenol A may occur in drinking water.
Diclofenac and Vultures
Cheap, effective treatment of inflammation, pain and fever in livestock, used throughout SE Asia but also EU
Dramatic declines (95%) in 3 species of vultures in India as well as Pakistan, Nepal, and others since 1990s. Critically endangered.
Necropsies revealed acute gout
Suspected disease, pesticides
Birds with gout had high concentrations of NSAID (nonsteroid anti-inflammatory drug) diclofenac in kidneys
Sewage effluent and hermaphrodism in fish
First Observed in Roach in the UK
Now found in Germany, UK, US, Denmark, The Netherlands, Canada, South Africa, Spain and others
Roach, white sucker, flounder, bass, sunfish, catfish, carp, salmon, perch, etc.
0-100% incidence intersex, often ~15-35%
Gross-Sorokin, M. Y., Roast, S. D., & Brighty, G. C. (2006). Assessment of Feminization of Male Fish in English Rivers by the Environment Agency of England and Wales. Environmental Health Perspectives, 114: 147–151
Triclosan and Thyroid Hormone-associated amphibian development
Antibacterial agent in PCP (Pneumocystis pneumonia), food handling, clothing, surgical supplies
Detected in human breast milk, fish, shellfish
Similar structure to TH and non-steroidal estrogens- may be weakly androgenic
Overt toxic effects in native anurans and fish
Adaptation genomics: the next generation
Next-generation sequencing (NGS) offers many opportunities for determining the underlying genetic basis of contemporary adaptation
QTL mapping
Genome-wide association studies
Population genomics
To address some of our fundamental questions:
How many genes?
Standing or novel variation?
Regulatory or structural genes?
key findings
Heavy metal detoxification by bacterial siderophores is a cooperative behaviour, that selects for rapid evolution of social ‘cheats’
In toxic copper soil, cheat fitness is increased in the presence of the community, but in monoculture conditions only.
Cheats cannot ‘invade’ populations of cooperators in soil as they can in synthetic media.
