Volume 17, Number 6—June 2011
Research
Methicillin-Resistant Staphylococcus aureus, Samoa, 2007–2008
, Helen Heffernan, Tracy Camp, Alice Richardson, Peter Herbison, and Pauline Norris
Table 2
Strains identified among the MRSA isolates, Samoa, summer 2007–2008*
| No. (%) isolates | Strain† | MLST type | No. (%) PVL-positive isolates | spa type (% of strain) | Antimicrobial drug susceptibility (% of strain) |
|---|---|---|---|---|---|
| 10 (29) | USA300 | ST8 | 9 (90) | t008 (100) | Resistant to ciprofloxacin and erythromycin (80); resistant to ciprofloxacin (20) |
| 9 (26) | Queensland clone | ST93 | 9 (100) | t3949 (56), t202 (44)‡ | Resistant only to β-lactams (100) |
| 9§ (26) | – | ST1 | 0 | t1853 (78), t6080 (11)¶ | Resistant only to β-lactams (89); resistant to erythromycin** (11) |
| 4 (12) | Southwest Pacific/ WSPP/Oceania clone | ST30 | 4 (100) | t019 (100) | Resistant only to β-lactams (100) |
| 2 (6) | AK3 | ST5 | 0 | t002 (50), t1265 (50)# | Resistant to erythromycin** (50); resistant only to β-lactams (50) |
*MRSA, methicillin-resistant S. aureus; MLST, multilocus sequence typing; PVL, Panton-Valentine leukocidin; WSPP, Western Samoa Phage Pattern.
†International MRSA strain designations, except for AK3, which is a New Zealand designation for a community-associated MRSA strain common in New Zealand.
‡spa type t3949 (11–17–23–17–17–17–16–16–25) is a single-repeat variant of t202 (11–17–23–17–17–16–16–25). The extra repeat is shown in boldface.
§Only 8/9 ST1 MRSA isolates were available for PVL PCR, spa typing, and pulsed-field gel electrophoresis (PFGE) typing. Seven of the 8 isolates had indistinguishable PFGE profiles, and the eighth shared 87% homology.
¶spa type t6080 (07–23–21–17–13–13–34–16–13–33–13) is a single-repeat variant of t1853 (07–23–21–17–13–34–16–13–33–13). The extra repeat is shown in boldface.
#spa type t1265 (26–23–17–34–17–20–17–12–12–12–16) is a variant of t002 (26–23–17–34–17–20–17–12–17–16). The differing repeats are shown in boldface.
**This isolate also had inducible clindamycin resistance.