Genetic diversity of emerging Panton-Valentine leukocidine/arginine catabolic mobile element (ACME)-positive ST8 SCCmec-IVa meticillin-resistant Staphylococcus aureus (MRSA) strains and ACME-positive CC5 (ST5/ST764) MRSA strains in Northern Japan.
Panton-Valentine leukocidine (PVL) is a distinctive virulence factor of community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA), and arginine catabolic mobile element (ACME) is a staphylococcal genomic island that enhances fitness and the ability of bacterial cells to colonize on skin and mucous membranes. ACME is characteristically found in USA300, which is a predominant CA-MRSA clone [sequence type (ST) 8] in the USA and is spreading globally, and has also been detected in non-ST8 MRSA at low frequency. In Japan, spread of MRSA with PVL and/or ACME and their genetic traits have not yet been well characterized. In the present study, the prevalence and genetic diversity of PVL(+)/ACME(+) MRSA were investigated for 422 MRSA clinical isolates collected from outpatients in northern Japan over a period of 1 year. All the isolates were genotyped for the staphylococcal cassette chromosome mec (SCCmec) and coagulase genes (coa), and screened for PVL and ACME genes. The PVL(+)/ACME(+) isolates were studied further by genetic analysis, including single-nucleotide polymorphism (SNP) analysis based on PVL genes (lukS-PV-lukF-PV), ACME (arc and opp3 clusters) and the sarU promoter region. Among all the isolates examined, PVL genes and ACME were detected in eight (SCCmec-II, n = 1; SCCmec-IV, n = 6; SCCmec-V, n = 1) and 20 (SCCmec-II, n = 14; SCCmec-IV, n = 5; SCCmec-V, n = 1) isolates, respectively. Five isolates were found to have both PVL genes and ACME (type I), and were classified into ST8/spa-t008/agr-I/coa-IIIa, which is the same genetic traits as USA300. Fifteen PVL(-)/ACME(+) isolates had type ΔII-ACME, belonging to either ST5 or ST764 [clonal complex (CC) 5], and spa-t001, -t002 or -t3557. All the ST8 PVL(+)/ACME-I(+) MRSA had identical sequences of PVL genes (haplotype R) and ACME arc/opp3 clusters as those of USA300. In contrast, in the CC5 PVL(-)/ACME-ΔII(+) MRSA, SNPs in the arc cluster were detected in 11 sites (four haplotypes), with some different profiles of virulence/resistance factors. These results indicated single clonality of ST8 PVL(+)/ACME-I(+) MRSA and heterogeneity of CC5 PVL(-)/ACME-ΔII(+) MRSA, and suggest their potential spread in northern Japan.
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
Mitsuyo
M
Kawaguchiya
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
Noriko
N
Urushibara
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
Souvik
S
Ghosh
Sapporo Clinical Laboratory Inc., Sapporo 060-0005, Japan.
Osamu
O
Kuwahara
Sapporo Clinical Laboratory Inc., Sapporo 060-0005, Japan.
Shigeo
S
Morimoto
Sapporo Clinical Laboratory Inc., Sapporo 060-0005, Japan.
Masahiko
M
Ito
Sapporo Clinical Laboratory Inc., Sapporo 060-0005, Japan.
Kenji
K
Kudo
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan.
Nobumichi
N
Kobayashi
D001120:Arginine / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D005098:Exotoxins / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics*; D044404:Genomic Islands / Q000235:genetics; D005838:Genotype; D020071:Interspersed Repetitive Sequences / Q000235:genetics*; D007564:Japan; D007956:Leukocidins / Q000235:genetics*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics*; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000235:genetics* / Q000382:microbiology; D037521:Virulence Factors / Q000235:genetics
D001427:Bacterial Toxins; D004269:DNA, Bacterial; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D037521:Virulence Factors; D001120:Arginine