Metadata Analysis of mcr-1-Bearing Plasmids Inspired by the Sequencing Evidence for Horizontal Transfer of Antibiotic Resistance Genes Between Polluted River and Wild Birds

Abstract

We sequenced the whole genomes of three mcr-1-positive multidrug-resistant E. coli strains, which were previously isolated from the environment of egret habitat (polluted river) and egret feces. The results exhibit high correlation between antibiotic-resistant phenotype and genotype among the three strains. Most of the mobilized antibiotic resistance genes (ARGs) are distributed on plasmids in the forms of transposons or integrons. Multidrug-resistant (MDR) regions of high homology are detected on plasmids of different E. coli isolates. Therefore, horizontal transfer of resistance genes has facilitated the transmission of antibiotic resistance between the environmental and avian bacteria, and the transfer of ARGs have involved multiple embedded genetic levels (transposons, integrons, plasmids, and bacterial lineages). Inspired by this, systematic metadata analysis was performed for the available sequences of mcr-1-bearing plasmids. Among these plasmids, IncHI2 plasmids carry the most additional ARGs. The composition of these additional ARGs varies according to their geographical distribution. The phylogenetic reconstruction of IncI2 and IncX4 plasmids provides the evidence for their multiregional evolution. Phylogenetic analysis at the level of mobile genetic element (plasmid) provides important epidemiological information for the global dissemination of mcr-1 gene. Highly homologous mcr-1-bearing IncI2 plasmids have been isolated from different regions along the East Asian-Australasian Flyway, suggesting that migratory birds may mediate the intercontinental transportation of ARGs.

Colistin-Resistant Enterobacteriaceae Isolated From Process Waters and Wastewater From German Poultry and Pig Slaughterhouses

“…Escherichia coli isolates carrying mcr-1 on transferable IncHI2 plasmids were detected in on-site preflooder downstream the discharge point of mWWTP. Possible entry sources could be run-offs from the fields fertilized with contaminated manure (Guenther et al, 2017) and feces of wild animals (birds) (Lin et al, 2020). Previously, (Zurfluh et al, 2016) and (Falgenhauer et al, 2019) detected mcr-1 harboring E. coli in surface water and rivers in Switzerland and Germany, respectively.…”

Comparative Genome Analysis of Livestock and Human Colistin-Resistant Escherichia coli Isolates from the Same Household

“…Since the discovery of mcr on plasmids, many studies have been conducted on mcr -carrying plasmids of COR bacteria isolated from various sources. 7 , 8 , 18 , 19 Outcomes of a metadata analysis revealed that the mcr -carrying plasmids are diverse. 19 Among these mcr -carrying plasmids, IncI2, IncX4, and IncHI2 plasmids are found most frequently, even in livestock isolates.…”

“… 7 , 8 , 18 , 19 Outcomes of a metadata analysis revealed that the mcr -carrying plasmids are diverse. 19 Among these mcr -carrying plasmids, IncI2, IncX4, and IncHI2 plasmids are found most frequently, even in livestock isolates. The outcomes of the present study regarding mcr-1 -harboring plasmid IncHI2 of the livestock COR isolate are consistent with those of previous studies.…”

Migratory birds-one major source of environmental antibiotic resistance around Qinghai Lake, China

“…The role of migratory birds in facilitating the transfer of antibioticresistant bacteria and resistance genes has been gradually recognized (Guenther et al, 2012;Atterby et al, 2016;Ramey et al, 2018;Marcelino et al, 2019). The potential of intercontinental transportation of antibiotic-resistant bacteria and resistance genes via avian migration was also proposed (Liakopoulos et al, 2016;Mohsin et al, 2016;Lin et al, 2020).…”

“…However, N150,000 migratory birds use this lake as breeding or stopover ground annually (Zheng et al, 2018). In our previous work, we reported the transportation of bacterial antibiotic resistance from a polluted urban river (Jin River, Chengdu, China) to surrounding environment (Wangjianglou Park) mediated by the wild birds (the egrets) (Wu et al, 2018;Lin et al, 2020). In the similar manner, the migratory birds may transport antibiotic-resistant bacteria or resistance genes from other places along the migration route to the environment around Qinghai Lake.…”