Selection for antimicrobial resistance by plant protection products - analysis of established experimental field sites

Lead Research Organisation: University of Exeter
Department Name: Institute of Biomed & Clinical Science


BBSRC : Laura May Murray : BB/T508330/1

Antibiotics are used to treat infections caused by bacteria. However, bacteria can become resistant to antibiotics, meaning they are still able to grow in the presence of antibiotics. For this reason, infections caused by antibiotic resistant bacteria are becoming more difficult to treat. Infections caused by antibiotic resistant bacteria are also extremely costly, for example, due to increased length of stay in hospital.

Overuse and misuse of antibiotics is driving the evolution of antibiotic resistant bacteria, and it has been predicted that by 2050, someone will die every three seconds from an antibiotic resistant infection. However, there is also evidence that other antimicrobial compounds can result in the evolution of antibiotic resistance. Antimicrobials are chemicals or compounds that kill bacteria, but cannot be used for treatment of infections in humans or animals because they are too toxic. Furthermore, there is new research indicating that other chemicals, which are not used as antimicrobials (for example, human medicines) may also lead to the development of antibiotic resistance. How mixtures of antibiotics, antimicrobials and other chemicals may interact and drive the evolution of antibiotic resistance is poorly understood.

Antibiotics are not just used to treat and prevent infections in humans and animals; they are also applied to agricultural soils as plant protection products (PPPs). PPPs are used globally to increase crop yields. There are many types of PPPs currently in use, such as herbicides (used to prevent growth of unwanted plants) or insecticides (used to kill pest insects). No research to date has investigated if non-antibiotic PPPs can drive evolution of antibiotic resistance.

This research placement will complement work being undertaken in the BBSRC/AstraZeneca iCASE PhD studentship entitled "Investigating selection and co-selection for antimicrobial resistance by non-antibiotic drugs and plant protection products". Laboratory experiments and a variety of culture based and molecular microbiology methods will be used to determine if exposing soil bacterial communities to non-antibiotic PPPs results in increased levels of antibiotic resistance. This placement provides a unique opportunity to study exposure to PPPs in well-established experiment field plots, which are treated with PPPs annually. This will aid interpretation of laboratory experiments and provide an environmentally realistic aspect to the PhD research.

The findings from this novel research may be useful for influencing regulation of PPPs, food safety policy and human health risk assessment of exposure to antibiotic resistant bacteria from environmental sources.


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