Manuel Varela, PhD Eastern New Mexico University manuel.varela@enmu.edu Phone:(505) 562-2464 Personal Website

Title: Bacterial Antibiotic Resistance in Agriculture

Project Description:

Bacterial antibiotic resistance is an emerging problem and poses a severe clinical public health concern due to compromised effectiveness of chemotherapy for infectious diseases. In order to help circumvent the problem of bacterial antibiotic resistance, it is first necessary to know the extent of the problem. Yet, is it not understood how widespread antibiotic resistant bacteria are in agriculture. The lack of surveillance data is especially evident in dairy farms. It is also unknown to what extent various modulators, such as salycilate, a component of aspirin and known model modulator of multiple aantibiotic resistance (mar) genes, influence multidrug resistance in bacterial isolates. Other modulators include organic solvents, oxidative stress agents and household disinfectants.

The long term goal is to comprehend fully the severity of the problem of bacterial antibiotic resistance from both surveillance and phylogenetic standpoints, in order to eliminate the reservoir of resistant microorganisms in agriculture and to find better means of treatment. The objective of is application is to determine which areas within dairy farms harbor intrinsic or inducible antibiotic resistance and to determine phylogenetic relationships for modulated resistance determinants. The central hypothesis is that dairy farms already harbor multidrug resistant bacteria or that known relevant modulators induce multidrug resistance. The rationale for the hypothesis is that once it is known how widespread intrinsic and inducible bacterial multidrug resistances are present phylogenetically in agriculture, such as dairy farms, it will be possible to invoke measures to reduce the problem of the limited efficacy of antibiotics.

Specific Aims:
AIM 1: Identify the occurrence of intrinsic versus inducible antibiotic resistant bacteria in dairy farm soil.
AIM 2: Establish whether water sources and milk from dairy farms harbor bacteria resistant to clinically relevant antibiotics.
AIM 3: Establish the extent of bacterial resistance to clinically relevant antibiotics in bacterial isolates from dairy milking stations.

It is anticipated that the proposed experiments will enhance our understanding of the extent and nature of the bacterial antibiotic resistance problem in agricultural settings, such as dairy farms. This is the first study that proposes to examine bacterial antibiotic resistance in dairy soil from a bioinformatics standpoint. The systematic study of various dairy farm environments (soil, water and facilities) and the analyses of intrinsic versus inducible resistance make this study innovative, as the potential exists for helping to reduce infections transmitted from farm animals to humans.