title: Detection and characterisation of SCCmec remnants in multiresistant methicillin-susceptible Staphylococcus aureus causing a clonal outbreak in a Swedish county.
abstract: The purpose of this study was to investigate if multiresistant methicillin-susceptible Staphylococcus aureus (MR-MSSA) causing a clonal outbreak in Östergötland County, Sweden, were derived from methicillin-resistant S. aureus (MRSA) by carrying remnants of SCCmec, and, if so, to characterise this element. A total of 54 MSSA isolates with concomitant resistance to erythromycin, clindamycin and tobramycin from 49 patients (91% clonally related, spa type t002) were investigated with the BD GeneOhm MRSA assay and real-time polymerase chain reaction (PCR) targeting the SCCmec integration site/SCCmec right extremity junction. DNA sequencing of one isolate representing the MR-MSSA outbreak clone was performed by massive parallel 454 pyrosequencing. All isolates that were part of the clonal outbreak carried SCCmec remnants. The DNA sequencing revealed the carriage of a pseudo-SCC element 12 kb in size, with a genomic organisation identical to an SCCmec type ΙΙ element, except for a 41-kb gap. This study demonstrates the presence of a pseudo-SCC element resembling SCCmec type II among MR-MSSA, suggesting possible derivation from MRSA. The presence of SCCmec remnants should always be considered when SCCmec typing is used for MRSA detection, and may not be suitable in locations with a high prevalence of MR-MSSA, since this might give a high number of false-positive results.
authors: Department of Infection Control, Linköping University Hospital, Linköping, Sweden. maria.m.lindqvist@lio.se
authors: M
authors: M
authors: Lindqvist
authors: B
authors: B
authors: Isaksson
authors: C
authors: C
authors: Grub
authors: T Ø
authors: TØ
authors: Jonassen
authors: A
authors: A
authors: Hällgren
references: Antimicrob Agents Chemother. 2008 Apr;52(4):1221-9
references: 18212094
references: J Antimicrob Chemother. 2005 Sep;56(3):455-62
references: 16046464
references: J Clin Microbiol. 2010 Oct;48(10):3525-31
references: 20668131
references: Scand J Infect Dis. 2009;41(5):324-33
references: 19294581
references: Antimicrob Agents Chemother. 2008 Dec;52(12):4407-19
references: 18852274
references: J Clin Microbiol. 2005 Aug;43(8):4191-3
references: 16081974
references: Antimicrob Agents Chemother. 2007 Dec;51(12):4342-50
references: 17709473
references: Lancet Infect Dis. 2002 Mar;2(3):180-9
references: 11944188
references: Antimicrob Agents Chemother. 2003 Dec;47(12):3926-34
references: 14638503
references: Antimicrob Agents Chemother. 2007 Jan;51(1):264-74
references: 17043114
references: J Clin Microbiol. 2002 Mar;40(3):1048-52
references: 11880436
references: Drug Resist Updat. 2003 Feb;6(1):41-52
references: 12654286
references: J Gen Microbiol. 1990 Nov;136(11):2231-9
references: 2079622
references: Clin Microbiol Infect. 2010 May;16(5):456-62
references: 19624504
references: Antimicrob Agents Chemother. 2009 Dec;53(12):4961-7
references: 19721075
references: Lancet. 1972 Dec 9;2(7789):1257
references: 4117751
references: J Antimicrob Chemother. 2000 Oct;46(4):617-20
references: 11020261
references: J Clin Microbiol. 2003 Nov;41(11):5113-20
references: 14605147
references: Antimicrob Agents Chemother. 2000 Jun;44(6):1549-55
references: 10817707
references: Clin Microbiol Infect. 2006 Mar;12 Suppl 1:9-15
references: 16445719
references: J Med Microbiol. 1991 Apr;34(4):193-201
references: 2020016
references: J Clin Microbiol. 2004 May;42(5):1875-84
references: 15131143
references: Lancet. 2002 May 25;359(9320):1819-27
references: 12044378
references: Trends Microbiol. 2001 Oct;9(10):486-93
references: 11597450
references: Antimicrob Agents Chemother. 2001 May;45(5):1323-36
references: 11302791
references: J Antimicrob Chemother. 2007 Mar;59(3):465-72
references: 17289763
references: Lancet. 2001 Apr 21;357(9264):1225-40
references: 11418146
references: J Clin Microbiol. 2006 Apr;44(4):1219-23
references: 16597841
references: Int J Med Microbiol. 2002 Jul;292(2):67-74
references: 12195737