Gram-negative bacterial diversity and evidence of international clones of multidrug-resistant strains in zoo animals

Antimicrobial resistance(AMR)is a growing phenomenon that poses a major public health challenge worldwide(Dhingra et al.2020;Antimicrobial Resistance Collaborators 2022).The selective pressure exerted in clinical settings has contributed to the longlasting successful dissemination of multidrug-resistant(MDR)Gram-negative bacteria in these environments(Chia et al.2020).

Presence of blaOXA-48-carrying IncF plasmid in an Escherichia fergusonii strain isolated from a sugarcane soil

Dear Editor,A large number of antimicrobial agents used for the treatment of humans and animals reach water sources and agricultural soils in different ways,including animal excreta.Therefore,antimicrobial-resistant bacteria,carrying important antimicrobial resistance genes(ARGs),circulate between humans,animals,and the environment,giving attention to the concept of One Health(Topp,2017;Tiedje et al.,2019).

Genomic characterization of multidrug-resistant extraintestinal pathogenic Escherichia coli isolated from grain culture soils

Multidrug-resistant(MDR)Escherichia coli,mainly extraintestinal pathogenic E.coli(ExPEC),has been widely reported in infections worldwide.In agricultural soils,manure is a hotspot for the dissemination of antimicrobial resistance genes(ARGs)and pathogenic bacteria;however,MDR bacteria have also been reported in soils with no history of manure use.In addition,cross-resistance and co-resistance have been described as responsible for the metal-driven selection of bacteria resistant to antimicrobials.Therefore,the aim of this study was to analyze three MDR E.coli isolates obtained from Brazilian grain culture soil samples with no history of manure use by whole-genome sequencing.The MDR E.coli isolates were recovered from soils from corn and coffee fields,and presented resistance toβ-lactams,quinolones,aminoglycosides,tetracyclines,sulphonamides,and dihydrofolate reductase inhibitor.Resistome analysis showed ARGs to several antimicrobials(i.e.,β-lactams,tetracyclines,aminoglycosides,sulphonamides,trimethoprim,phenicols,fosfomycin,and macrolides)as well as several metal resistance genes and antibacterial biocide resistance genes.In addition,known mutations in quinolone-resistance-determining regions of GyrA(Ser83Leu and Asp87Asn),ParE(Ser458Thr),and ParC(Ser80Ile)were also detected.Virulome analysis showed the presence of virulence genes(lpfA,mcmA,gad,mchF,iroN,cma,and iss)associated with ExPEC.Multidrug-resistant ExPEC isolates were assigned to phylogenetic group B1.The presence of MDR B1-ExPEC in soil samples shows the ability of these isolates to survive in soils.This study reports for the first time some sequence types(i.e.,ST345,ST448,and ST1146)of MDR E.coli in Brazilian soils.Therefore,these findings contribute to the monitoring of antimicrobial resistance and surveillance studies based on whole-genome sequencing worldwide.

Molecular characterization of an extensively drug-resistant Acinetobacter baumannii isolated from a corn culture soil

Dear Editor,Soil is the most biodiverse habitat on Earth and it has been estimated that one gram of soil can contain up to one billion bacterial cells(Fierer,2017).The microorganisms of soil produce a wide variety of secondary metabolites,including antibiotics.