One Health Landscape of Antimicrobial Resistance in Bacteria Isolated from Virginia between 2007-2021

The emergence of antimicrobial-resistant (AMR) bacteria has become a critical global One Health issue, mainly attributed to the extensive use of antimicrobial agents in human and agricultural settings. Regional and local AMR surveillance data is essential for implementing awareness and mitigation strategies. This article assesses AMR frequency in 1604 bacterial isolates consisting of Escherichia coli (E. coli) and Salmonella spp. isolated from diverse sources in Virginia, including farm animals, wildlife, environment, and food samples from 2007 to 2021. The results are based on the Kirby-Bauer disc diffusion assessment method of susceptibility to select antimicrobial agents, spanning nine distinct categories approved by the US Food and Drug Administration for clinical use. Streptomycin (STR) and tetracycline (TCY) exhibited the highest frequency of resistance in E. coli (39.1%) and Salmonella (25.2%), respectively. Multidrug resistance (MDR) was evident in 6.6% of E. coli and 10.9% of Salmonella isolates. Notably, 51% of E. coli and 36% of Salmonella isolates demonstrated resistance to more than one antimicrobial. None of the tested antimicrobials guaranteed effectiveness against the bacteria isolated from the surveyed sources and regions. The study found heightened MDR and distinct AMR patterns in bacteria isolated from food products compared to other sampled sources. These findings are vital for comprehending the current AMR landscape, prompting the development of strategies to mitigate the emergence of AMR bacteria, and advocating prudent antimicrobial use from a One Health perspective.

Hypervirulent clonal complex (CC) of Listeria monocytogenes in fresh produce from urban communities

Introduction

This study aimed to determine the prevalence and virulome of Listeria in fresh produce distributed in urban communities.

Methods

A total of 432 fresh produce samples were collected from farmer's markets in Michigan and West Virginia, USA, resulting in 109 pooled samples. Listeria spp. were isolated and L. monocytogenes was subjected to genoserogrouping by PCR and genotyping by pulsed-field gel electrophoresis (PFGE). Multi-locus sequence typing (MLST) and core-genome multi-locus sequence typing (cgMLST) were conducted for clonal identification.

Results

Forty-eight of 109 samples (44.0%) were contaminated with Listeria spp. L. monocytogenes serotype 1/2a and 4b were recovered from radishes, potatoes, and romaine lettuce. Four clonal complexes (CC) were identified and included hypervirulent CC1 (ST1) and CC4 (ST219) of lineage I as well as CC7 (ST7) and CC11 (ST451) of lineage II. Clones CC4 and CC7 were present in the same romaine lettuce sample. CC1 carried Listeria pathogenicity island LIPI-1 and LIPI-3 whereas CC4 contained LIPI-1, LIPI-3, and LIPI-4. CC7 and CC11 had LIPI-1 only.

Discussion

Due to previous implication in outbreaks, L. monocytogenes hypervirulent clones in fresh produce pose a public health concern in urban communities.

Food Safety in Local Farming of Fruits and Vegetables

The world’s population will be around 9 billion people by 2050. Humans need to feed in order to survive and thus the high demographic growth may impact the sustainability of our food systems. Sustainable food production practices such as local farming have been explored. Consumption of vegetables and fruits has been increasing due to their health benefits, but this increase is also related to a significant number of foodborne outbreaks. Foodborne outbreaks pose a threat to public health and the economy on a local and national scale. Food safety begins on the farm and proceeds over the supply chain. Thus, to provide safe products, food producers must follow specific procedures to avoid food hazards along the supply chain. This work aimed to present the importance of food safety in vegetables and fruits in local farming, as this form of production and consumption has increased in several countries of the northern hemisphere and as these are considered a form of providing more sustainable food products.