Molecular typing revealed the emergence of pvl-positive sequence type 22 methicillin-susceptible Staphylococcus aureus in Urumqi, Northwestern China

Figures & data

Table 1 Molecular characteristics of 605 Staphylococcus aureus isolates from Urumqi, Northwestern China

	ST (No. of isolates,%)	spa types (No. of isolates)	SCCmec types (No. of isolates)	No. of pvl-positive isolates*
MRSA (271)	ST239 (203,74.9%)	t030 (198), t233 (5)	III (203)	0
	ST59 (34,12.5%)	t437 (32), t441 (1), t3523 (1)	IV (34)	5
	ST22 (6,2.2%)	t309 (6)	IV (6)	0
	ST398 (4,1.5%)	t034 (2), t693 (2)	V (4)	1
	ST72 (4,1.5%)	t324 (2), t664 (2)	IV (4)	0
	Other STs (20,7.4%)	t8918 (3), et al	II (2), III (11), IV (5), V (2)	2
MSSA (334)	ST22 (99,29.6%)	t309 (87), t790 (2), t1977 (2), t5335 (1), t625 (1), t8221 (1), t8934 (1), t12442 (1), t12481 (1), t13828 (1), t15234 (1)		80
	ST121 (34,10.2%)	t435 (16), t284 (5), t1425 (3), t2091 (2), t159 (1), t162 (1), t1994 (1), t2086 (1), t2092 (1), t287 (1), t308 (1), t645 (1)		18
	ST398 (33,9.9%)	t571 (12), t034 (8), t1451 (4), t011 (3), t2530 (1), t2582 (2), t3085 (1), t11483 (1), t12280 (1)		6
	ST5 (28,8.4%)	t002 (9), t502 (7), t045 (2), t062 (2), t688 (2), t954 (2), t242 (1), t5353 (1), t548 (1), t895 (1)		2
	ST7 (22,6.6%)	t796 (16), t091 (4), t2119 (1), t2883 (1)		0
	ST188 (18,5.4%)	t189 (17), t1858 (1)		0
	ST15 (14,4.2%)	t084 (9), t491 (2), t094 (1), t1034 (1), t793 (1)		1
	Other STs (86,25.7%)	t078 (8), et al		8

Note: *The percentage of isolates with the pvl gene was significantly greater for MSSA than MRSA (34.4% vs 3.0%, Student’s t-test: p<0.05).

Abbreviations: MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus; ST, sequence type.

Table 2 Typing results for 605 Staphylococcus aureus isolated from Urumqi, Northwestern China

	ST	Cases(%)	p-Value
MRSA(271)	ST239	74.9%	<0.05
	ST59	12.5%
MSSA(334)	ST22	29.6%	<0.05
	ST121	10.2%
	ST398	9.9%
	ST5	8.4%
	ST7	6.6%

Abbreviations: MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus; ST, sequence type.

Figure 1 Prevalence of Staphylococcus aureus STs among different clinical specimens. (A) Proportions of the two predominant MRSA sequence types, ST239 and ST59, among all S. aureus isolates. (B) Proportions of the predominant MSSA sequence types, ST22, ST398, ST121, ST5, ST7, ST188, and ST15, among all S. aureus isolates. (C) Distribution of STs in abscess/wound specimens. (D) Distribution of STs in blood specimens. (E) Distribution of STs in sputum specimens. (F) Distribution of STs in specimens of other fluids. (C–F: black bars indicate MRSA and grey bars indicate MSSA.).

Abbreviations: MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus; ST, sequence type.

Table 3 Antibiotic profiles of 605 Staphylococcus aureus isolated from Urumqi, Northwestern China

Agents	ST239		ST59	ST22	ST121	ST398	ST5	ST7	MRSA	MSSA	P-value
n=45	n=158	n=34	n=99	n=34	n=33	n=28	n=22	n=271	n=334	MRSA VS.MSSA
PEN	100	100	100	97	88.2	81.8	96.4	100	100	91.6	<0.05
FOX	100	100	100	0	0	0	0	0	100	0	-
GEN	100	100	0	0	0	15.2	25	68.2	78.6	9.3	<0.05
LEV	100	100	0	0	0	6.1	7.1	0	79.3	1.2	<0.05
CIP	100	100	0	0	0	9.1	14.3	0	79.7	3.9	<0.05
MXF	100	100	0	0	0	0	0	0	78.2	0	<0.05
RIF	100	100	0	0	0	0	0	0	77.5	0	<0.05
TET	100	100	70.6	0	0	0	17.9	18.2	87.1	5.7	<0.05
ERY	0	100	94.1	57.6	52.9	39.4	82.1	77.3	79.3	50.9	<0.05
CLI	0	100	85.3	15.2	14.7	18.2	39.3	68.2	74.2	20.1	<0.05
SXT	0	0	0	0	11.8	15.2	28.6	59.1	1.1	12.9	<0.05

Abbreviations: PEN, penicillin; FOX, cefoxitin; GEN, gentamicin; LEV, levofloxacin; CIP, ciprofloxacin; MXF, moxifloxacin; RIF, rifampicin; TET, tetracycline; ERY, erythromycin; CLI, clindamycin; SXT, trimethoprim/sulfamethoxazole; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus; ST, sequence type.