Jpn. J. Infect. Dis., 54, 2001

Laboratory and Epidemiology Commumications

EpidemiologlCal Analysis Of Methicillin‑Resistant Staphylococcus aureus
in a Community Hospital in Hiroshima
Rie Sasaki, Tomoko Fujinol , Junko Kawasaki, Tsutomu Furukawa,

Namiko Moril , Norikazu Shigeto and TeruO Kirikael *National Hataka Hospital,Hataka 2114‑1, Aki, Hiy10Shima 736‑0088 andJInternational Medical Center ofJapan,

Toyama ll23‑1, Shinjuku‑ku, Too,0 162‑8655
Communicated by Hiroshi Yoshikura(Accepted October 30, 2001)

Methicillin‑resistant Staphylococcus.aureus (MRSA) is aM

maj or nosocomial pathogen in hospitals, Including community

123456789Mhospitals with relatively small numbers of beds ( 1 ). Molecularanalysis Of MRSA isolates in a hospital, uslng restriction
丘agment length polymorphisms ofgenomic DNA using pulsed‑

field gel electrophoresis (PFGE), is essential for assessmentof hospital infection controls (2).

The present study was conducted in a hospital in Hiroshima

with two wards and loo beds. In September 2001, MRSA
was isolated from two patients'sputa and one patient's urine
in ward I and fわur patients'sputa, One patient's bile, and one

patient's nasal swab in ward II. MRSA was isolatedfrom thesputum offive patients and the pusofone in ward I, and thesputum of three patients in ward II in December 2000. Theisolates were tested for chromosomal DNA typing by uslng a
contour‑clamped homogeneous electric field system (CHEF

MapperTM: Bio‑Rad Laboratories, Hercules, Calif., USA),enterotoxin. serotyping (SET‑RPLA: Denka Seiken Col,Tokyo), toxic Shock syndrome toxin‑ 1 (TSSTl 1 ) production(TST‑RPLA : Denka Seiken), and coagulase serotyping (DenkaSeiken).

From nine MRSA isolates, seven different PFGE pattems‑ofSmaI DNA digests were detected (Fig. 1). isolate N0. 898
from ward I andNo. 903 from ward lI, and isolates Nos. 901
and 905from ward II had the same PFGE pattem, respectively.
All isolates except Nos. 899 and 900 produced enterotoxin

ng. 1. Pulsed‑field gel electrophoresis ofSmaI‑digested genomic DNA
from MRSA isolates. Lane I: MRSA isolate No. 898, lane 2: No.
899, lane 3: No. 900, lane4: No. 901, lane 5: No. 902, 1ane6: No.
903, Iane7: No. 904, lane 8: No. 905, lane 9: No. 907. M: Iowrange

type C, TSST‑1, and coagulase type II (Table 1). Isolate No.
899 produced TSSTJl and coagulase type II, but not entero‑

PFG Marker.

Table I. Phenotypic and genotypic characterization ofS. aureus isolates
WardIsolate
89No.
8Specimep

PFGE

pattern

sputumTSST‑1C899

unne

900

sputum90 1bile

A2

902

sputumAlュ

9sputum

AI03

Enterotoxin

A,C904sputum

A3905

spu山m

A2907

nasal cavityA7*Corres.ponding author: Fax: +8 1 ‑3‑3202‑7364, E‑mail: tkirikae@
ri.imq.goJp191

CCCCCC

Coagulase+lI+ⅠI+ⅠⅠ+ + +＼ゝ + +Jpn. J. Infect. Dis., 54, 2001

toxin. Isolate N0. 900 produced enterotoxin types A and C,

August 2000, nine of 13 isolates in December 2000, and eightof nine isolates in September 2001 were ofcluster type A.

TSST‑1, and coagulase type ll.

The PFGE pattems orthese MRSA isolates were comparedwith those ofMRSA isolates obtained in the same hospital inThree isolates from ward I in August, five from the sameward in December, and one from ward I (No. 898) and one
from ward II (No. 903) in September were of the same PFGE

August and December 2000 (2). From a total of3 1 isolates, 20

different PFGE pattems were detected (Fig. 2A). Band‑basedpattem (Al). One isolate from ward ll in August and two
isolates from ward lI (Nos. 90l and 905) in September werecluster analysis orthese pattems (Molecular AnalystTM: Bio‑Rad) revealed six clusters A to F (Fig. 2B) battems sharing asimilarity of70% Or higher were grouped into a cluster). ThePFGE pattern and the isolation term of all MRSA isolates
were summarized in Table 2, Six of nine MRSA isolates inMl234567

8of the same PFGE pattem. Other MRSA isolates were ofdifferent PFGE pattems &om those with pattems Al and A2,and from eachother(A3 toA12, B, Cl to C3, andEl andE2,and F). Collectively, the above observation indicates that the9 1011121314151617181920M

Fig. 2A. Pulsed‑field gel elcctrophoresis ofSmaI‑digested genomic DNA from MRSA isolates･ Lane 1 : MRSA isolate No･898 (pattemAl), lane 2: No. 901 (pattemA2), lane 3: No. 904 (pattemA3), lane4: No. 401 (1) (pattemA4), lane 5: No. 635(1) battemA5), lane 6: No, 900 (pattemA6), lane 7: No. 907 (pattemA7), lane 8: No. 636 (I) (pattemA8), lane 9: Not 396(1) (pattemA9), lane 10: No. 634 (1) (pattemAIO), lane ll: No. 629 (I) (pattemAll), lane 12: No. 902 (pattern A12), lane13: No. 623 (1) (pattern B), lane 14: No. 399 (1) (pattem Cl), lane 15: No･ 627 (1) (patternC2), Iane 16: Nol 899 (patternC3), lane 17: No. 630(1) (pattem D), lane 18: No. 398 (1) (pattem El), lane 19: No. 404 (1) (pattem E2), lane20: No･ 628(I) (pattem F). M: low range PFG Marker.

Table 2. PFGE pattem ofMRSA isolates
5060

70

$090100(%)

PFGEAug.

pattem

A2A lA3A2A4A3A5A4A62000

I

●●●●

A5A7A6ASA7A9A8A A A 1 1 1 0 l 'ムーA9AIOAllB

A12CIBC2ClC3DEIC2C3E2FDElFig. 2B. Cluster analysis ofMRSA isolates based on PFGE pattems ofSmaI‑digested genomic DNA.

192

:

●Dec.

Il:I

2000

:ⅠⅠSep.

;

I

●

●2001

Jpn. J. Infect. Dis., 54, 2001

Shigeto, N･ and Kirikae, T･ (200 1 ): Molecular epidem.i‑spread of a single MRSA strain (pattem Al) Occurred in ward
i in August and December 2000. The MRSA outbreak of aology of methicillin‑resistant Staphylococcus aureus lnslngle strain was being stamped out in ward I in Septembera communityhospital in Hiroshima. Jpn. J. Infect. Dis.,

200 1. Meanwhile, most other MRSAinfeCtionsinthis hospital

54, 117‑118.

2. Fujino, T., Mori, N., Kawana, A., Kawabata, H., Kuratsujl,
T., Kudo, K., Kobori, 0., Yazaki, Y. and Kirikae, T.

叩peared to occur sporadically, indicatlng that these MRSA

were mainly come from other healthcare facilities in the same(200 1 ): Molecular epidemiology of methicillin‑resistant

C Omm unlty･Staphylococcus aureus in a Tokyo hospital in 2000. Jpn.

J. Infect. Dis., 54, 91‑93.

REFERENCES

1. Kawasaki, J., Fujio, T., Naiki, Y., Mori, N., Sasaki, R.,

193