Clonal diversity of methicillin-resistant Staphylococcus aureus (MRSA) from bloodstream infections in northern Japan: Identification of spermidine N-acetyltransferase gene (speG) in staphylococcal cassette chromosomes (SCCs) associated with type II and IV SCCmec

Meiji Soe Aung; Noriko Urushibara; Mitsuyo Kawaguchiya; Mina Hirose; Masahiko Ito; Satoshi Habadera; Nobumichi Kobayashi

doi:10.1016/j.jgar.2020.12.008

Clonal diversity of methicillin-resistant Staphylococcus aureus (MRSA) from bloodstream infections in northern Japan: Identification of spermidine N-acetyltransferase gene (speG) in staphylococcal cassette chromosomes (SCCs) associated with type II and IV SCCmec

J Glob Antimicrob Resist. 2021 Mar:24:207-214. doi: 10.1016/j.jgar.2020.12.008. Epub 2020 Dec 26.

Authors

Meiji Soe Aung¹, Noriko Urushibara², Mitsuyo Kawaguchiya², Mina Hirose³, Masahiko Ito⁴, Satoshi Habadera⁴, Nobumichi Kobayashi²

Affiliations

¹ Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo, Japan. Electronic address: meijisoeaung@sapmed.ac.jp.
² Department of Hygiene, Sapporo Medical University School of Medicine, Hokkaido, Sapporo, Japan.
³ Division of Pediatric Dentistry, Department of Oral Growth and Development, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Japan.
⁴ Sapporo Clinical Laboratory, Hokkaido, Sapporo, Japan.

PMID: 33373735
DOI: 10.1016/j.jgar.2020.12.008

Abstract

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of bloodstream infections (BSIs). We aimed to study molecular epidemiological characteristics of MRSA isolates from BSIs in northern Japan to elucidate the recent trend of their clonal diversity.

Methods: MRSA isolates (n = 277) were collected from blood samples of patients who attended healthcare facilities in Hokkaido, the northern main island of Japan, for a two-year period from August 2017. Genotypes, virulence factors/drug-resistance determinants, and structure of SCCmec complex were analysed by PCR and sequencing analysis.

Results: SCCmec-IIa (n = 171, 61.7%) with coagulase genotype (coa-) II, ST5/ST764/ST2389 was the most common genetic trait, followed by SCCmec-IVa (n = 78, 28.2%), and IVl (n = 10, 3.6%). Among the MRSA-IVa, 14 isolates (5.1% of all the isolates) had genetic features identical to USA300 clone (ST8/coa-IIIa/spa-t008 having ΦSa2USA and ACME-I), while PVL/ACME-negative MRSA-IVa isolates (n = 64) were classified into coa-IIa/IIIa/VIIa/VIIb, with coa-VIIa/spa-t1784/ST1 being dominant. Other minor clones included ST8-SCCmec-I, and ST30/ST45/ST81/ST121/ST1232-SCCmec-V, among which the ST1232 isolate harboured PVL genes. Spermidine N-acetyltransferase gene (speG), which is typically present in ACME-I of USA300 clone, was also identified in two isolates, ACME-II'-positive ST764-MRSA-IIa and ACME-negative ST1-MRSA-IVa, showing resistance to spermine. speG of these isolates was located in additional SCCs adjacent to SCCmec.

Conclusions: Our present study revealed clonal diversity of MRSA from BSIs in Japan, with increased prevalence of ST8-USA300. Distinct types of speG-carrying SCCs associated with SCCmec-II or IV were identified.

Keywords: ACME; Bloodstream infection; Clonal diversity; Japan; MRSA; speG.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acetyltransferases / genetics
Bacterial Toxins*
Chromosomes
DNA, Bacterial
Humans
Japan / epidemiology
Leukocidins / genetics
Methicillin-Resistant Staphylococcus aureus* / genetics
Sepsis*
Spermidine
Staphylococcal Infections* / epidemiology

Substances

Bacterial Toxins
DNA, Bacterial
Leukocidins
Acetyltransferases
Spermidine