Potential associations between hematogenous complications and bacterial genotype in Staphylococcus aureus infection.
BACKGROUND
The impact of bacterial clonality on infections caused by Staphylococcus aureus is unclear.


METHODS
Three hundred seventy-nine S. aureus isolates (125 methicillin-resistant S. aureus [MRSA] and 254 methicillin-susceptible S. aureus [MSSA]) were genotyped by spa typing and multilocus sequence typing. For MRSA isolates, the staphylococcal chromosomal cassette mec (SCCmec) element was also typed. Three clinical categories were identified: nasal carriage only (n=118), uncomplicated infection (n=104), and bacteremia with hematogenous complications (n=157).


RESULTS
By use of eBURST, 18 clonal complexes (CCs) were found in 371 isolates. Eight CCs accounted for 89% of isolates and occurred in all clinical categories. CC5 (P=.0025) and CC30 (P=.0308) exhibited a significant trend toward more frequent hematogenous complications. Isolates within spa types 2 and 16 showed the same significant trend and grouped within CC5 and CC30, respectively. SCCmec II isolates also showed the same significant trend compared with SCCmec IV; 96% were CC5 or CC30.


CONCLUSIONS
Although most S. aureus genotypes exhibited the capacity to cause invasive disease, strains within CC5 and CC30 exhibited a significant trend toward increasing levels of hematogenous complications. Isolates within these CCs were also implicated by use of spa and SCCmec typing. The genetic determinants underlying these findings remain to be demonstrated.
Fowler
Vance G
VG
Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA. vance.fowler@duke.edu
Nelson
Charlotte L
CL
McIntyre
Lauren M
LM
Kreiswirth
Barry N
BN
Monk
Alastair
A
Archer
Gordon L
GL
Federspiel
Jerome
J
Naidich
Steven
S
Remortel
Brian
B
Rude
Thomas
T
Brown
Pamela
P
Reller
L Barth
LB
Corey
G Ralph
GR
Gill
Steven R
SR
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000150:complications* / Q000453:epidemiology / Q000382:microbiology*; D002353:Carrier State / Q000382:microbiology; D002648:Child; D005838:Genotype; D006801:Humans; D016106:Methicillin Resistance; D008875:Middle Aged; D009666:Nose / Q000382:microbiology; D013203:Staphylococcal Infections / Q000150:complications* / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics*
D000900:Anti-Bacterial Agents