Publikationsdatenbank

Identification of the novel Macrolide-Lincosamide-Streptogramin B resistance gene erm(54) in a porcine LA-MRSA ST398 (2023)

Art

Poster

Autoren

Krüger-Haker, Henrike (WE 7)

Ji, Xing

Hanke, Dennis (WE 7)

Schink, Anne-Kathrin (WE 7)

Fiedler, Stefan

Kaspar, Heike

Wang, Yang

Schwarz, Stefan (WE 7)

Wu, Congming

Feßler, Andrea T. (WE 7)

Kongress

ARAE 2023

Tours, Frankreich, 03. – 05.07.2023

Quelle

9th Symposium on Antimicrobial Resistance in Animals and the Environment : abstracts book

Tours, Frankreich, 2023 — S. 137

Sprache

Englisch

Verweise

URL (Volltext): https://arae2023.symposium.inrae.fr/content/download/770/8117?version=1

Kontakt

Institut für Mikrobiologie und Tierseuchen

Robert-von-Ostertag-Str. 7-13
14163 Berlin
+49 30 838 51843 / 66949
mikrobiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Background and objectives: Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) can represent a health risk for humans, specially for those having frequent contact to livestock. LA-MRSA are mainly associated with sequence type (ST) 398 in many parts of the world and often multiresistant to antimicrobial agents. Here, 178 porcine LA-MRSA isolated in Germany from 2007 - 2019 were investigated for new antimicrobial resistance genes.
Methodology: Whole-genome sequencing on Illumina MiSeq and PacBio Sequel II platforms was followed by hybrid assembly and sequence analysis. Plasmid pHKS3860 was transferred into S. aureus RN4220 via electrotransformation. Antimicrobial susceptibility testing via broth microdilution and agar disc diffusion was performed according to CLSI standards to confirm the functionality of erm(54). An erm(54)-specific PCR assay was developed and applied to 30 macrolide-resistant staphylococcal isolates, which harbored next-related erm genes.
Results: A novel Macrolide-Lincosamide-Streptogramin B (MLSB) resistance gene, erm(54), was detected on the non-conjugative plasmid HKS3860 of 36,929 bp in a porcine LA-MRSA ST398. The gene encoded a 23S rRNA methylase of 245 amino acids (aa) that was next-related to Erm(B) (72%). Moreover, erm(54) was expressed constitutively. A complex regulatory region composed of a small reading frame for a 30 aa protein and seven pairs of inverted repeats, which can form varying mRNA secondary structures, was detected upstream of erm(54). The transferred erm(54) caused a distinct increase in the minimal inhibitory concentrations of MLSB antibiotics in S. aureus RN4220. The new PCR assay detected erm(54) in the original strain and the transformants carrying pHKS3860, but none of the next-related erm genes available to us. Copper, mercury and cadmium resistance genes as well as an ica cluster for biofilm formation were also found on plasmid pHKS3860.
Conclusion: The new transferable and functionally active MLSB resistance gene erm(54) was identified in a porcine LA-MRSA ST398 isolate from Germany. The co-location of erm(54) on a plasmid with heavy metal resistance genes may increase the risk for co-selection under selection pressure imposed by heavy metals in animal feed or the environment. Due to this possibility of co-selection and the zoonotic potential, erm(54)-carrying isolates might pose a public health threat in the future.