Incidence of Tetracycline and Erythromycin Resistance in Meat-Associated Bacteria: Impact of Different Livestock Management Strategies.

Cecilia Fontana,Vania Patrone,Lorenzo Morelli,Annalisa Rebecchi,Constanza Maria Lopez

doi:10.3390/microorganisms9102111

Cecilia Fontana, Vania Patrone + Show 3 more

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https://doi.org/10.3390/microorganisms9102111

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Abstract

The extensive use of antibiotics as growth promoters, or their continued abusive misuse to cure or prevent the onset of bacterial infections as occurs in the intensive farming, may have played a pivotal role in the spread of reservoirs of antibiotic resistance (AR) among food-associated bacteria including pathogens representing risks to human health. The present study compares the incidence of tetracycline and erythromycin resistances in lactic acid bacteria (LAB) and coagulase negative staphylococci (CNS) from fermented products manufacturing using meat from intensive animal husbandry (industrialized manufacturing Italian salami) and from extensive farms (artisanal sausages facilities pork and llama Argentinean sausages). A higher incidence of tetracycline resistance (TET-R) compared to erythromycin resistance (ERY-R) was observed among the 205 isolates. Unlike CNS strains, the LAB showed a significant correlation between the TET-R and the ERY-R phenotypes. Genotypic assessment shows a high correlation with tetK and tetM for the TET-R strains and with ermB and ermC for the ERY-R strains. Multiple correspondence analyses have highlighted the association between AR phenotypes and CNS species isolated from Italian salami, while the susceptible phenotypes were associated with the LAB species from Argentinean sausages. Since antibiotic resistance in meat-associated bacteria is a very complex phenomenon, the assessment of bacterial resistance in different environmental contexts with diverse farming practices and food production technologies will help in monitoring the factors influencing AR emergence and spread in animal production.

Highlights

Introduction iationsIntrinsic and acquired resistance to antibiotics have been described among bacteria; the former has minimal potential for horizontal spread
Phenotypic and genotypic evaluations of tetracycline and erythromycin resistance were performed in lactic acid bacteria (LAB) and coagulase negative staphylococci (CNS) species
205 strains belonging to the LAB and CNS groups isolated from

Summary

Introduction

Intrinsic and acquired resistance to antibiotics have been described among bacteria; the former has minimal potential for horizontal spread. As a consequence of the acquisition of genetic material, such as a plasmid or a transposon coding for antibiotic-resistant genes, is potentially transferable, which represents a risk of spreading from one bacterium to another through several mechanisms [1]. Many studies have reported acquired resistance to erythromycin and tetracycline among lactic acid bacteria (LAB) and coagulase negative staphylococci (CNS), and their corresponding genetic determinants are considered an important potential cause of the horizontal spread of antibiotic-resistant (AR) genes between different bacterial species [2,3]. The improper use of antimicrobial drugs in animal husbandry—mainly tetracycline and erythromycin—has contribute to an increase in AR bacteria in animal food.

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