Distribution of Biocide Resistance Genes and Association with Clonal Complex Genotypes in Staphylococcus aureus Isolated from School-Age Children in Guangzhou

Figures & data

Table 1 Sequences of Primers for PCR of Biocide Resistance Genes

Gene	Annealing Temperature (℃)	Primer	Sequence (5’-3’)	Size (bp)	References
qacA/B	53.725	F	ATGCCTTATATTTATTTAATAATAGCC	321	20
		R	ATGCGATGTTCCGAAAATGTTTAAC
mupA	54.215	F	TATATTATGCGATGGAAGGTTGG	458	13
		R	AATAAAATCAGCTGGAAAGTGTTG
mupB	53.985	F	CTAGAAGTCGATTTTGGAGTAG	674	53
		R	AGTGTCTAAAATGATAAGACGATC
mepA	53.985	F	ATGTTGCTGCTGCTCTGTTC	718	20
		R	TCAACTGTCAAACGATCACG
sepA	53.875	F	GCAGTCGAGCATTTAATGGA	103	20
		R	ACGTTGTTGCAACTGTGTAAGA
smr	51.86	F	ATAAGTACTGAAGTTATTGGAAGT	285	20
		R	TTCCGAAAATGTTTAACGAAACTA
norA	52.325	F	TTCACCAAGCCATCAAAAAG	620	20
		R	CTTGCCTTTCTCCAGCAATA
qacG	49.625	F	CAACAGAAATAATCGGAACT	321	44
		R	TACATTTAAGAGCACTACA
lmrS	59.43	F	GCAAGCTTATGGCTAAAGTTGAATTAACAAC	1441	20
		R	GCGGATCCTTAAAATTTCCTTCTATTACTTT

Figure 1 The distribution of biocide resistance genes in different groups. (A) MRSA and MSSA, (B) educational ages, and (C) four main clonal complex (CC) genotypes among 722 S. aureus isolates from school-age students in Guangzhou. The data shown above the column are percentages in that population. “*” indicates statistics which were significantly different (P<0.05).

Table 2 Association Between ten Biocide Resistance Genes and Conventional Antibiotic Resistance Among 722 Staphylococcus Aureus Isolates

Antimicrobial Agents	Susceptibility	qacA/B		smr		mupA		mupB		mepA		sepA		lmrS		norA
		Positive (%)	P value	Positive (%)	P value	Positive (%)	P value	Positive (%)	P value	Positive (%)	P value	Positive (%)	P value	Positive (%)	P value	Positive (%)	P value
PEN	R (n=618)	64(10.4)	0.7257	9(1.5)	>0.9999	17(2.8)	0.1523	3(0.5)	>0.9999	596(96.4)	0.0163*	353(57.1)	0.1971	470(76.1)	0.1655	475(76.9)	0.0011*
	S (n=104)	9(8.7)		1(1.0)		0(0)		0(0)		94(90.4)		67(64.4)		86(82.7)		94(90.4)
CLI	R (n=295)	44(15.0)	0.0006*	5(1.7)	0.7478	12(4.1)	0.0216*	3(1.0)	0.0678	292(99.0)	0.0001*	105(35.6)	<0.0001*	227(77.0)	>0.9999	212(71.9)	0.0002*
	S (n=427)	29(6.8)		5(1.2)		5(1.2)		0(0)		398(93.2)		315(73.8)		329(77.0)		357(83.6)
ERY	R (n=311)	46(14.7)	0.0004*	5(1.6)	0.7524	12(3.9)	0.0253*	3(1.0)	0.0795	301(96.8)	0.2023	121(38.9)	<0.0001*	241(77.5)	0.8583	227(73.0)	0.0012*
	S (n=411)	27(6.6)		5(1.2)		5(1.2)		0(0)		389(94.6)		299(72.7)		315(76.6)		342(83.2)
TCY	R (n=60)	6(10)	>0.9999	2(3.3)	0.1992	3(5)	0.1616	0(0)	>0.9999	55(91.7)	0.17	51(85.0)	<0.0001*	42(70.0)	0.1982	47(78.3)	0.8698
	S (n=662)	67(10.1)		8(1.2)		14(2.1)		3(0.1)		635(95.9)		369(55.7)		514(77.6)		522(78.9)
SXT	R (n=24)	1(4.2)	0.499	0(0)	>0.9999	1(4.2)	0.4413	0(0)	>0.9999	24(100)	0.6191	21(87.5)	0.0026*	18(75)	0.8064	20(83.3)	0.7999
	S (n=698)	72(10.3)		10(1.4)		16(2.3)		3(0)		666(95.4)		399(57.2)		538(77.1)		549(78.7)
RIF	R (n=12)	0(0)	0.6219	0(0)	>0.9999	0(0)	>0.9999	0(0)	>0.9999	11(91.7)	0.4221	4(33.3)	0.1367	9(75)	0.743	10(83.3)	>0.9999
	S (n=710)	73(10.3)		10(1.4)		17(2.4)		3(0)		679(96.6)		416(58.6)		547(77.0)		559(78.7)
CIP	R (n=7)	0(0)	>0.9999	0(0)	>0.9999	0(0)	>0.9999	0(0)	>0.9999	7(100)	>0.9999	7(100)	0.0455*	6(85.7)	>0.9999	5(71.4)	0.6366
	S (n=715)	73(10.2)		10(1.4)		17(2.4)		3(0)		690(96.5)		420(58.7)		556(77.8)		564(78.9)
LVX	R (n=7)	0(0)	>0.9999	0(0)	>0.9999	0(0)	>0.9999	0(0)	>0.9999	7(100)	>0.9999	7(100)	0.0455*	6(85.7)	>0.9999	5(71.4)	0.6366
	S (n=715)	73(10.2)		10(1.4)		17(2.4)		3(0)		690(96.5)		420(58.7)		556(77.8)		564(78.9)
MFX	R (n=5)	0(0)	>0.9999	0(0)	>0.9999	0(0)	>0.9999	0(0)	>0.9999	5(100)	>0.9999	5(100)	0.0785	5(100)	0.5945	4(80)	>0.9999
	S (n=717)	73(10.2)		10(1.4)		17(2.4)		3(0)		685(95.5)		415(57.9)		551(76.8)		555(77.4)
GEN	R (n=4)	1(25)	0.3477	0()	>0.9999	1(25)	0.0911	0(0)	>0.9999	4(100)	>0.9999	4(100)	0.1441	3(75)	>0.9999	3(75)	>0.9999
	S (n=718)	72(10.0)		10(1.4)		16(2.2)		3(0)		686(95.5)		416(57.9)		566(78.8)		566(78.8)

Note: *In bold indicates statistics were significantly different (P<0.05).

Abbreviations: R, resistant; S, susceptible.

Table 3 The Susceptibility to CHG & Mupirocin and Biofilm Formation Ability of qacA/B and mupA Genes Positive Isolates

Categories	Degree	qacA/B+ (n=68) (%)	mupA+ (n=12) (%)	qacA/B+mupA+(n=5) (%)
CHG susceptibility	S	5(5.9)	–	1(20)
	R	68(94.1)		4(80)
Mupirocin susceptibility	S	–	0(0)	0(0)
	L		7(58.3)	0(0)
	H		5(41.7)	5(100)

Abbreviations: qacA/B+, S. aureus isolates carried qacA/B gene but no mupA gene; mupA+, S. aureus isolates carried mupA gene but no qacA/B gene; qacA/B+mupA+, S. aureus isolates carried qacA/B and mupA genes simultaneously; S, susceptible; R, resistant; L, low-level resistance; H, high-level resistance.

Figure 2 CC genotype distribution of (A) CHG and (B) mupirocin resistance isolates. “Others” represent CC8, CC25, CC121, CC944 and CC1610 genotypes; each includes only one isolate.

Table 4 Relationship Between CHG & Mupirocin Susceptibility and Biofilm Formation Ability Among qacA/B & mupA Positive Isolates

Isolates	Antimicrobial Agents	Susceptibility	Biofilm Formation Ability				P value
			+ (%)		++ (%)
			Weak	Non	Moderate	Strong
qacA/B gene positive (n=73)	CHG	S (n=5)	1(20)	4(80)	0(0)	0(0)	0.0134*
		R (n=68)	0(0)	27(39.7)	34(50)	7(10.3)
mupA gene positive (n=17)	Mupirocin	L (n=7)	0(0)	6(85.7)	1(14.3)	0(0)	0.0498*
		H (n=10)	0(0)	3(30)	7(70)	0(0)

Note: *In bold indicates statistics were significantly different (P<0.05).

Abbreviations: S, susceptible; R, resistant; L, low-level resistance; H, high-level resistance; +, non and weak biofilm producers; ++, moderate and strong biofilm producers.