Non-multiresistant methicillin-resistant Staphylococcus aureus bacteraemia in Sydney, Australia: emergence of EMRSA-15, Oceania, Queensland and Western Australian MRSA strains.
OBJECTIVE
To describe clinical features and molecular epidemiology of non-multiresistant methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia.


METHODS
Patients with non-multiresistant MRSA isolated from blood at South Western Area Pathology Service from 1 January 1999 to 31 December 2001 were enrolled. Pulsed field gel electrophoresis, phage typing, and (selected instances) multilocus sequence and staphylococcal cassette chromosome typing was performed. PCR was used to detect Panton-Valentine leukocidin (PVL), toxic shock syndrome toxin-1 (TSST-1), and enterotoxin genes.


RESULTS
Sixteen patients were detected: eight with UK EMRSA-15 (ST22-MRSA-IV), three with Oceania (South-West Pacific/Western Samoan phage pattern) (ST30-MRSA-IV), two with WA MRSA-5 (ST8-MRSA-IV), and one each with WA MRSA-1 (ST1-MRSA-IV), Queensland strain (ST93-MRSA-IV), and WA MRSA-15 (ST59-MRSA-IV). Prior hospital admissions occurred with six of the eight patients with UK EMRSA-15, none of the three with Oceania, and three of the five with other strains. Thirteen of 16 patients had underlying disease. Three of the three patients with Oceania strain bacteraemia were Polynesians; 11 of 13 of the others were Caucasians. PVL genes were detected in four of 16 isolates (all Oceania and Queensland strains). entC was detected in two EMRSA-15 strains; entA in one Oceania, two WA MRSA-5 and the WA MRSA-1 strain, with entA and entB in the WA MRSA-15 strain. tst was not detected.


CONCLUSIONS
Multiple epidemic strains cause non-multiresistant MRSA bacteraemia. Most patients had risk factors. Oceania and Queensland strains possess the PVL gene.
Gosbell
Iain B
IB
SWAPS Staphylococcal Reference Facility, South Western Area Pathology Service, Liverpool, Australia. i.gosbell@unsw.edu.au
Barbagiannakos
Thelma
T
Neville
Stephen A
SA
Mercer
Joanne L
JL
Vickery
Alison M
AM
O'Brien
Frances G
FG
Coombs
Geoffrey W
GW
Malkowski
Mary J
MJ
Pearson
Julie C
JC
D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D016470:Bacteremia / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D001427:Bacterial Toxins / Q000235:genetics; D017714:Community-Acquired Infections; D004196:Disease Outbreaks; D006801:Humans; D008712:Methicillin / Q000494:pharmacology* / Q000627:therapeutic use; D016106:Methicillin Resistance / Q000235:genetics; D017720:Molecular Epidemiology; D011114:Polynesia / Q000208:ethnology; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D044465:White People / Q000208:ethnology
D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D008712:Methicillin