Understanding the diffusion and persistence of extended-spectrum β-lactamase producing E. coli in dairy cattle farms.
Antimicrobial resistance (AMR) is a threat of global relevance, which impacts on public health and food security, as stated by the WHO.
Among the microorganisms that show antimicrobial resistance, 3GCRE (Third-Generation Cephalosporin Resistant Enterobacterales), especially Escherichia coli, are of particular interest.
These commensal enteric bacteria are ubiquitous in the environment and can acquire the ability to resist especially third- and fourth generation cephalosporins, by producing enzymes called extended spectrum β-lactamases (ESBL).
3GCRE are listed by the WHO among the “highest priority” critical pathogens, together with carbapenem-resistant Acinetobacter baumannii and carbapenem-resistant Enterobacterales.
ESBL-producing E. coli can be found also on dairy farms, where preliminary data has shown an extremely high prevalence especially among calves.
Even though antimicrobial use is crucial in the emergence of AMR, other risk factors should be taken into account, which seem to be especially linked to hygiene, management variables and biosecurity measures.
In particular, the dynamics of the transmission and maintenance among the environment and the animals in the farm (including cows, calves, companion animals, wild animals and pests such as flies or rodents) are still unclear.
This research project thus aims to evaluate the diffusion and persistence of ESBL-producing E. coli on dairy cattle farms, with the specific objectives of:
- Assessing the prevalence and the resistance characteristics of ESBL E. coli in the animals, including calves, cows, pests and pets and investigating on their transmission pathways and environmental dynamics by using phenotypic and genotypic characterisation techniques;
- Evaluating the correlations between the farm’s biosecurity level, hygiene and management variables, including antimicrobial use, and the distribution of ESBL E. coli;
- Establishing the associated risk factors and recommending the adequate intervention measures to control the spread and maintenance of the bacteria;
- Expanding the research also to Acinetobacter baumannii and Enterobacterales that show resistance to carbapenems.
I have a Master’s in Scienze e Tecnologie delle Produzioni Animali (STPA) at the University of Milan, which I obtained in 2023 with an evaluation of 110/110 cum laude, with a thesis on the use of a lime-based product to control the microbiological, chemical and physical properties of “green bedding” used in dairy farming.
I have a Bachelor’s in Allevamento e Benessere Animale (ABA), obtained at the University of Milan in 2021, with an evaluation of 110/110.
Publications: Orcid
Supervisor Prof. Maria Filippa Addis
Co-supervisor Prof. Guido Grilli
