Listeria monocytogenes em produtos de origem animal: investigação in silico sobre resistência antimicrobiana

Abstract

Listeriosis is a disease of great impact on public health, caused by the bacterium Listeria monocytogenes due to the consumption of contaminated food, especially those from products of animal origin. The administration of antibiotics in animal production as growth promoters can trigger antimicrobial resistance, and this resistance is transferred to products of animal origin. The objective of this work was to verify if the antimicrobial resistance profiles present in Listeria monocytogenes bacteria isolated from foods of animal origin are similar to those present among strains of different origins, such as: plant, environmental and clinical foods, regardless of their region of origin. For this, the metadata of 30,148 strains of L. monocytogenes via NCBI were used. Metadata information was kept for statistical analysis. Then, the genomes were divided into six groups based on source of isolation and location among Products of Animal Origin (POA), Products of Plant Origin (POV), Animal Environments (AA), Plant Environments (AV), Animal Clinical Infections (ICA) and Human Clinical Infections (ICH). Prevalence was calculated as the ratio between each antimicrobial resistance gene and the total number of genomes evaluated in each group. These data were used to build the prevalence heat map. 45 resistance genes were identified, 15 from Clinical Animal, 24 from Clinical Human, 7 from Animal Environment, 19 from Plant Environment, 11 from Animal Products and 34 from Plant Origin. The tetM and fosX resistance genes had a common prevalence in all regions. The prevalence map generated two distinct clusters of genomic sequences obtained according to the resistance profile, in which bacteria that were associated with the animal and plant food chain, including food and the environment, were grouped in Cluster 1, while those from clinical sources animals and humans were grouped into Cluster 2. The main resistance characteristics observed were the high frequency of InuG in the genomes of L. monocytogenes from Animal Environment, Plant Environment and Products of Plant Origin, the high frequencies of mefA and aph(3' ) – Illa in genomic sequences of plant origin (environment and food, respectively), and the high frequencies of tetM and tetL in L. monocytogenes of animal origin. Resistance of human clinical isolates was characterized by high frequencies of tetS and fexA genes, while animal clinical isolates showed high abundance of vgaA and aadD1. Thus, the antimicrobial resistance genes of the bacterium L. monocytogenes isolated from products of animal origin were similar to those found in strains of other origins, making it necessary to support an epidemiological surveillance plan in the country regarding the occurrence of this bacterium.