Publikationsdatenbank

Origin and evolution of ST9 MRSA of swine origin in China (2019)

Art

Poster

Autoren

Jiang, Nansong

Feßler, Andrea T. (WE 7)

Krüger, Henrike (WE 7)

Wang, Yang

Schwarz, Stefan (WE 7)

Wu, Congming

Kongress

8th Symposium on Antimicrobial Resistance in Animals and the Environment

Tours Val de Loire - France, 01. – 03.07.2019

Quelle

8th Symposium on Antimicrobial Resistance in Animals and the Environment : Abstracts book : 1-3 July 2019 — UMR 1282 Infectiologie et Santé Publique Institut National de la Recherche Agronomique (Hrsg.)

France: INRA Science & Impact, 2019 — S. 105

Sprache

Englisch

Verweise

URL (Volltext): https://symposium.inrae.fr/arae2019/Abstract-Book

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

Aim:
To study the origin and the dynamic process of evolution genetic evolution of ST9 Methicillin-Resistant S. aureus(MRSA) in China.

Method:
A total of 105 pig-associated ST9 MRSA collected from eight Chinese provinces during 2009-2016 were sequenced using illumina X and Pac Bio platforms. Paired-end reads were mapped onto the reference sequence using the Burrows-Wheeler Aligner (BWA) [1]. To estimate the time of most recent common ancestor (TMRCA), all of the 105 isolates were used to reconstruct the phylogenetic trees. Bayesian ancestor reconstruction analysis was performed with the BEAST v1.8.4 package [2]. We compared the results of different models. A strict, exponential-uncorrelated relaxed clock and lognormal-uncorrelated relaxed clock with constant size coalescent was used respectively.

Result:
The phylogenetic tree showed significant differences in the core genome. MRSA isolates in different regions have evolved from the same ancestor and developed before 2009. We have determined a time frame for the emergence and expansion of CC9 pandemics based on Bayesian analysis, and the TMRCA for the MRSA ST9 was estimated to be 1989. The mean nucleotide substitution within CC9 was 2.4×10-6 per site per year (5.4 nucleotides per year per genome), which varied negligibly depending on the clock model (Fig. 1).

Discussion:
The MRSA ST9 isolates likely persisted in the pigs in China, accruing nucleotide diversity over time within this isolate population. It is possible that a mixed population of ST9 strains, which could have originated from one or more pigs, may have been introduced to China at 1989. This conclusion is of significant for exploring the genesis of the predominant clone of LA-MRSA in China.