One Health Spread of 16S Ribosomal RNA Methyltransferase-Harboring Gram-Negative Bacterial Genomes: An Overview of the Americas

Abstract

Aminoglycoside antimicrobials remain valuable therapeutic options, but their effectiveness has been threatened by the production of bacterial 16S ribosomal RNA methyltransferases (16S-RMTases). In this study, we evaluated the genomic epidemiology of 16S-RMTase genes among Gram-negative bacteria circulating in the American continent. A total of 4877 16S-RMTase sequences were identified mainly in Enterobacterales and nonfermenting Gram-negative bacilli isolated from humans, animals, foods, and the environment during 1931-2023. Most of the sequences identified were found in the United States, Brazil, Canada, and Mexico, and the prevalence of 16S-RMTase genes have increased in the last five years (2018-2022). The three species most frequently carrying 16S-RMTase genes were Acinetobacter baummannii, Klebsiella pneumoniae, and Escherichia coli. The armA gene was the most prevalent, but other 16S-RMTase genes (e.g., rmtB, rmtE, and rmtF) could be emerging backstage. More than 90% of 16S-RMTase sequences in the Americas were found in North American countries, and although the 16S-RMTase genes were less prevalent in Central and South American countries, these findings may be underestimations due to limited genomic data. Therefore, whole-genome sequence-based studies focusing on aminoglycoside resistance using a One Health approach in low- and middle-income countries should be encouraged.

Keywords: 16S-RMTase; Acinetobacter baumannii; Enterobacterales; One Health; Pseudomonas aeruginosa; aminoglycoside resistance; armA; rmtB; rmtF.

Figure 1

Temporal distribution of 16S-RMTase genes during 2000–2022 in the Americas.

Figure 2

Geographical distribution of 16S-RMTase-harboring bacterial genomes from 1931 to June 2023 in the Americas. Colored countries show quantity of 16S-RMTase-harboring bacterial genomes found. Circle charts show the presence of the 16S-RMTase types present in each country. Sources of origins were grouped into human, animal, food, or environmental samples.