RESUMO
Antimicrobial resistance (AMR) mechanisms, especially those conferring resistance to critically important antibiotics, are a great concern for public health. 16S rRNA methyltransferases (16S-RMTases) abolish the effectiveness of most clinically used aminoglycosides, but some of them are considered sporadic, such as RmtE. The main goals of this work were the genomic analysis of bacteria producing 16S-RMTases from a 'One Health' perspective in Venezuela, and the study of the epidemiological and evolutionary scenario of RmtE variants and their related mobile genetic elements (MGEs) worldwide. A total of 21 samples were collected in 2014 from different animal and environmental sources in the Cumaná region (Venezuela). Highly aminoglycoside-resistant Enterobacteriaceae isolates were selected, identified and screened for 16S-RMTase genes. Illumina and Nanopore whole-genome sequencing data were combined to obtain hybrid assemblies and analyse their sequence type, resistome, plasmidome and pan-genome. Genomic collections of rmtE variants and their associated MGEs were generated to perform epidemiological and phylogenetic analyses. A single 16S-RMTase, the novel RmtE4, was identified in five Klebsiella isolates from wastewater samples of Cumaná. This variant possessed three amino acid modifications with respect to RmtE1-3 (Asn152Asp, Val216Ile and Lys267Ile), representing the most genetic distant among all known and novel variants described in this work, and the second most prevalent. rmtE variants were globally spread, and their geographical distribution was determined by the associated MGEs and the carrying bacterial species. Thus, rmtE4 was found to be confined to Klebsiella isolates from South America, where it was closely related to ISVsa3 and an uncommon IncL plasmid related with hospital environments. This work uncovered the global scenario of RmtE and the existence of RmtE4, which could potentially emerge from South America. Surveillance and control measures should be developed based on these findings in order to prevent the dissemination of this AMR mechanism and preserve public health worldwide.
Assuntos
Klebsiella , Aminoglicosídeos/farmacologia , Plasmídeos/genética , Hospitais , Animais , Venezuela , Klebsiella/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , FilogeniaRESUMO
Microplastic pollution represents a serious threat to coastal marine systems. We evaluated the presence of microplastics (MPs) in 168 specimens of six commercially exploited bivalve species in the Golfo de Nicoya, Costa Rica. MPs were present in 100â¯% of the specimens of Leukoma asperrima and L. ecuadoriana, 74â¯% of Mytella strigata, 82â¯% of M. guyanensis, 84â¯% of Asthenometis asthenodon, and 82â¯% of Tagelus affinis. When considering all specimens, we found on average 4.8⯱â¯8.0 pieces per individual and 2.1⯱â¯3.3 items g-1 of wet tissue. There were significant differences between species with L. asperrima and L. ecuadoriana containing the highest number of pieces. Fibers and particles comprised 92â¯% and 8â¯%, respectively. This is the first study from the Central America's Pacific region showing the presence of MPs in bivalve species.