Identification of novel FosX family determinants from diverse environmental samples.

Objectives: This study aimed to identify novel fosfomycin resistance genes across diverse environmental samples, ranging in levels of anthropogenic pollution. We focused on fosfomycin resistance, and given its increasing clinical importance, explored the prevalence of these genes within different environmental contexts.

Methods: Metagenomic DNA was extracted from wastewater and sediment samples collected from sites in India, Sweden, and Antarctica.

Hidden dissemination of carbapenem-susceptible OXA-48-producing Proteus mirabilis.

Objectives: To detect a potential hidden dissemination of the blaOXA-48 gene among Proteus mirabilis isolates obtained from a single centre.

Methods: P. mirabilis from diverse clinical samples presenting an ESBL phenotype or obtained from blood cultured from 2017 to 2019 were evaluated.

The expression of aminoglycoside resistance genes in integron cassettes is not controlled by riboswitches.

Regulation of gene expression is a key factor influencing the success of antimicrobial resistance determinants. A variety of determinants conferring resistance against aminoglycosides (Ag) are commonly found in clinically relevant bacteria, but whether their expression is regulated or not is controversial. The expression of several Ag resistance genes has been reported to be controlled by a riboswitch mechanism encoded in a conserved sequence.

Evidence for Pseudoxanthomonas mexicana as the recent origin of the bla carbapenemase gene.

Objectives: Elucidating the recent evolutionary history of clinically important antibiotic resistance genes may inform measures to delay the future emergence of additional resistance genes in clinics. This study investigated the recent origin of bla, a metallo-β-lactamase gene found in Pseudomonas aeruginosa, and the possible role of ISCR15 in its mobilisation and transfer into clinical species.

Methods: Comparative genomics were used to identify the recent origin of bla.