Occurrence of the colistin resistance mcr‐1 gene in soils from intensive vegetable production and native vegetation

Abstract

Colistin, currently regarded as the last‐resort antibiotic for the treatment of infections caused by multidrug‐resistant bacteria, is used in poultry production to treat and prevent infection, and as a growth promoter. Poultry litter is commonly used as organic fertilizer; however, there are no reports on the effect of its application regarding colistin resistance in soils. Thus, the objective of the present study was to compare the abundance of the colistin resistance gene (mcr‐1) in soils from vegetable production areas that received non‐composted poultry litter as organic fertilizer and native vegetation areas. The mcr‐1 gene was detected in all soil samples from both areas. A significant difference (p < 0.05) was observed in the relative abundance of the mcr‐1 gene between soils pertaining to the vegetable production area and the native vegetation area in six of those 10 properties. This is the first report of the presence of the colistin resistance gene in soils from Brazil. The vast majority of antibiotic resistance genes acquired by human pathogens originated in natural environments. Thus, the presence of the mcr‐1 gene in soils treated with poultry litter and from native vegetation areas reinforces the need for studies that minimize potential risks of the development of colistin resistance. Highlights Poultry litter usually is employed as fertilizer; however, there are no reports of its impact in colistin resistance in soils. The mcr‐1 gene was detected in soils from both native vegetation and vegetable production. This is the first report of the presence of colistin resistance gene in soils from Brazil. The presence of mcr‐1 gene in soils can increase risks of the development and spread of colistin resistance.

Of Animal and Men: The Importance of Animal Environment to Antimicrobial Resistance: A One Health Approach

“…The enhancement of the concentration and diversity of antibiotic resistance determinants in soils treated with this organic fertilizer is of concern, even considering that untreated soil environments harbor a natural source of both antibiotics and antibiotic resistance genes [43][44][45][46]. The colistin resistance mcr-1 gene was detected in all soil samples from intensive vegetable production that received poultry litter as organic fertilizer but also in native vegetation areas that comprise a legal reserve at a mountain region of Rio de Janeiro, Brazil, confirming the previous statement that even natural soil environments act as a reservoir of resistance determinant [47].…”

Colistin-Resistant mcr-1-Positive Escherichia coli ST131-H22 Carrying blaCTX–M–15 and qnrB19 in Agricultural Soil

“…(Touati et al, 2020), respectively. In Brazil, mcr-type genes from soil samples have only been detected in total DNA or cultivable microbiota so far (Oliveira et al, 2019;Furlan et al, 2020b;Dos Santos et al, 2020). In this study, we report for the first time the presence of an mcr-1-positive E. coli isolated from the soil ecosystem in American countries, representing a potential risk of human exposure to antimicrobial-resistant bacteria.…”

Antimicrobial Resistance in Farm Animals in Brazil: An Update Overview

“…The occurrence of mcr-1 in birds not treated with polymyxin may be related to a previously undetected environmental presence of this gene [167]. For instance, a study developed with soils from a vegetable production area in Rio de Janeiro State (SE) where poultry litter is commonly used as organic fertilizer, indicated the presence of mcr-1 not only in the production area but also, at lower concentrations, in the surrounding native vegetation [168].…”