Prevalence of Chromosomally Located bla _CTX-M-55 in Salmonella Typhimurium ST34 Isolates Recovered from a Tertiary Hospital in Guangzhou, China

Abstract

ESCs are the first choice for treating NTS infections. However, ESBLs and AmpC β-lactamases are the most typical cause for ESCs resistance.

Nasal carriage of CTX-M-55-producing Escherichia coli ST8369 in a healthy cohort in the city of Yangzhou, China

“…Therefore, the clinical importance of nasal carriage of CTX-M-producing E. coli might be underestimated. Although horizontal transfer is the main reason for bla CTX-M dissemination, clonal spread of bla CTX-M -harbouring strains, such as E. coli ST8369 in this study, CTX-M-15-producing E. coli ST949 in water surfaces, E. coli ST2179 encoding CTX-M-65 in retail meat, and bla CTX-M-55 -carrying Salmonella Typhimurium ST34 in patients ( Bevan et al., 2017 ; Falgenhauer et al., 2021 ; Leão et al., 2021 ; Zeng et al., 2022 ) is another important route for bla CTX-M transmission.…”

“…As a variant of bla CTX-M-15 , bla CTX-M-55 was first reported in clinical E. coli and K. pneumoniae isolates in Thailand in 2007 ( Kiratisin et al., 2007 ). Recently, bla CTX-M-55 has become the predominant CTX-M genotype in E. coli and Salmonella from food animals, food products, and patients in China ( Rao et al., 2014 ; Zhang et al., 2014 ; Fu et al., 2020 ; Huang et al., 2020 ; Liu et al., 2022 ; Zeng et al., 2022 ). One novel bla CTX-M variant bla CTX-M-252 was identified in this study.…”

“…Although we were not able to determine the location of bla CTX-M in some E. coli isolates in this study due to incomplete assembly, sequence analysis indicates that IS Ecp1 plays an important role in bla CTX-M dissemination among E. coli isolates and facilitates the horizontal transfer of bla CTX-M from plasmids to chromosomes in distinct integration sites. The chromosomal integration of bla CTX-M is increasingly reported in E. coli , K. pneumoniae , Salmonella , Proteus mirabilis and some other species of Enterobacteriaceae with the help of mobile elements ( Huang et al., 2017 ; He et al., 2017 ; Zeng et al., 2022 ; Yoon et al., 2022 ). Chromosomal integration of bla CTX-M seems to be an adaptive evolution in response to antimicrobial pressure ( Yoon et al., 2022 ).…”

“…-carrying Salmonella Typhimurium ST34 in patients(Bevan et al, 2017; Falgenhauer et al, 2021;Leão et al, 2021;Zeng et al, 2022) is another important route for bla CTX-M transmission.Horizontal transfer mediated by plasmids and mobile elements is responsible for the global spread of bla CTX-M(Bevan et al, 2017;Partridge et al, 2018). For example, IncI, IncFII, and IncHI2 plasmids facilitate the horizontal…”

Plugging the leaks: antibiotic resistance at human–animal interfaces in low‐resource settings

“…2021; Zeng et al . 2022). This suggests that Tn CTX‐M/qnrS has been mobilized by diverse mobile resistance elements and is likely under high selection pressure.…”