The number of
copies of the resistance gene varies among cultivars; a new method, developed by University of Illinois researchers, is able to efficiently quantify this variation for the first time.
No doctor wants to ignore an opportunity to save a patient from infectious disease, yet much of what is prescribed is probably unnecessary — and all of it feeds the spread
of resistance genes in hospitals and apparently throughout the environment.
Using high - throughput sequencing of DNA from river sediment up and downstream from the Indian treatment plant [11] we identified a high prevalence
of resistance genes from multiple classes of antibiotics.
The researchers also called for more monitoring of VRE and the
presence of resistance genes outside of the hospital setting where they are more commonly found.
«Wastewater contains a great many intestinal bacteria that have been described in detail, so we were surprised to find that the vast
majority of the resistance genes we identified in the wastewater treatment plants were unknown,» relates Christian Munck from DTU.
«Over the course of the river, we saw the
concentration of resistance genes increase by several orders of magnitude,» Pruden says, «far more than could ever be accounted for by chance alone.»
By combining
understanding of resistance genes with knowledge of the pathogen, they hope to develop Desiree and Maris Piper varieties that can completely thwart attacks from late blight.
Trolling the waters and sediments of the Cache la Poudre, Storteboom and Pruden are collecting solid evidence to support suspicions that both livestock operations and human sewage are major players in the dramatic
rise of resistance genes in our environment and our bodies.
Lastly, the injected DNA can act as «gluing DNA» and mediate the
uptake of resistance gene back to the pathogens through a phenomenon called natural transformation.
The researchers then observed how the
frequency of resistance genes changed over six generations of mosquitoes — a process, biologists refer to as «microevolution.»
«Antibiotics don't promote
swapping of resistance genes: Bacterial resistance spreads through population dynamics, not an increase in gene transfers.»
But what our studies suggest is that there is a whole new universe where you can now screen for other functions, like the ability to block conjugation or to induce the
loss of resistance genes.
If the chicken coops of subsistence farmers are hot
spots of resistance gene transfer, he speculated that bacteria present in industrial farming operations — where chickens regularly receive antibiotics — would see even more pressure to share resistance genes.
Rapid Avr 9 - and Cf - 9 Dependent Activation of MAP Kinases in Tobacco Cell Cultures and Leaves:
Convergence of Resistance Gene, Elicitor, Wound, and Salicylate Responses
Integrons capture and disseminate gene - cassettes; short circular pieces of DNA that may contain resistance genes [35], and integrons associated with class 1 integrases are known to transfer many
forms of resistance genes [36].
There are two general
types of resistance genes found in wheat: Race - specific genes confer a high - level of resistance to specific strains of leaf rust but can be easily overcome by genetic mutation in pathogen populations, while slow rusting (APR) resistance provides partial resistance to a broad spectrum of races, but is typically effective only at the adult stage of plant growth.
«The factors we found to favor sustained efficacy of Bt crops are in line with what we would expect based on evolutionary theory,» said Carrière, explaining that conditions are most favorable if resistance genes are initially rare in pest populations; inheritance of resistance is recessive — meaning insects survive on Bt plants only if have two
copies of a resistance gene, one from each parent — and abundant refuges are present.
«We anticipate that the
combination of resistance genes we will test this time will be even more difficult for late blight to overcome than the single gene we previously field tested, but the proof of the pudding is in the planting.»
White is helping with that by chairing the World - Wide Anti-Malarial Resistance Network — a global community of scientists who are rapidly collecting data on how quickly patients respond to drugs, the
presence of resistance genes, the numbers of fake drugs, and more.
«This indicates that the
majority of the resistance genes we identify in wastewater treatment plants are to be found in the special microorganisms that are able to survive in the extraordinary conditions of these treatment plants,» continues Professor Per Halkær Nielsen.
As millions of tons of fishmeal are used every year with much of it sinking uneaten to the ocean floor, Jing Wang and colleagues wanted to see what its impact could be on the mariculture «resistome,» or collection
of resistance genes.
Others might be engineered to include nutrients like beta carotene, iron, and vitamin A. Instead of one gene to fight off insects or disease, crops will be engineered with «stacks»
of resistance genes to prevent pests from evolving resistance to a single approach.
Then the team let loose a special strain of diamondback moth pupa, some of which carried at least one copy
of a resistance gene to the Bt toxin.
The team collected and counted the larvae that grew on the crops and tracked whether the insects had inherited one or two copies
of the resistance genes.