Analysis on the copy number variation of multidrug resistance-1 gene in 122 imported cases of falciparum malaria in Changsha

doi:10.12140/j.issn.1000-7423.2022.01.021

Abstract

Abstract:

To understand the copy number variation (CNV)of Plasmodium falciparum multidrug resistence-1 (Pfmdr1) gene among imported Plasmodium falciparum, real-time fluorescence quantitative PCR was used to detect Pfmdr1 and β-tubulin (Pftub) gene from dried blood samples on filter paper collected from imported falciparum malaria cases in Changsha City from 2016 to 2019, with Pftub as the reference gene, for calculating the Pfmdr1 CNV in the samples examined. SPSS 23.0 statistic software was used to analyze the detection results and individuals’ clinical treatment information. The gene detection indicated that among 122 samples, 18 (14.8%) had Pfmdr1 CNV, with the variation rate 14.8% (18/122). The average of Pfmdr1 CNV in the samples collected from 2016 to 2019 was 1.020 ± 0.076, 1.136 ± 0.403, 1.387 ± 0.657 and 1.142 ± 0.349, respectively. The blood samples with CNV of the falciparum malaria cases were imported from Equatorial Guinea, Angola, Benin, Sierra Leone, Democratic Republic of Congo, Nigeria, Cameroon, Ghana and The Republic of Congo. The average Pfmdr1 CNV of the blood samples of the cases imported from East, West and Central Africa were 0.999 ± 0.073, 1.150 ± 0.368 and 1.249 ± 0.448, respectively, with significant difference between the regions (t = 2.663, 3.995, P < 0.05). The average medication duration for the cases with Pfmdr1 varied CNV was (5.93 ± 0.94) d, which was longer than that from non-varied CNV [(3.21 ± 1.23) d] (t = 8.930, P < 0.01). One month after medication, recrudescence occurred in two cases with varied CNV Pfmdr1, but in one case with non-varied CNV (likelyhood ratio χ ² = 3.831, P < 0.05). One year after treatment ended, recrudescence occurred in two cases with varied CNV, whereas in one case with non-varied CNV （likelyhood ratio χ ² = 5.372,P < 0.05). Gametocytes were detected in the blood smears of 5 cases with varies CNV, while in 3 cases with non-varied CNV （likelyhood ratio χ² = 10.599, P < 0.01). Pfmdr1 gene CNV was found in the imported P. falciparum parasite in Changsha, and the variation may result in longer treatment duration for the patients and unable to completely clear up the parasites.

Key words: Malaria, Plasmodium falciparum, Multidrug resistance-1 gene, Copy number variations, Resistant strain

CLC Number:

R383.3

TIAN Bin, LIAO Yu, WEN Lan, XIAO Fang, ZHANG Bin, SHEN Xiao-jun. Analysis on the copy number variation of multidrug resistance-1 gene in 122 imported cases of falciparum malaria in Changsha[J]. CHINESE JOURNAL OF PARASITOLOGY AND PARASITIC DISEASES, 2022, 40(1): 127-131.

Figures/Tables 3

References 24

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基因	序列	产物大小/bp
Pfmdr1	F: 5′-TGCATCTATAAAACGATCAGACAAA-3′	87
	R: 5′-TCGTGTGTTCCATGTGACTGT-3′
	FAM: 5′-TTTAATAACCCTGATCGAAATGG-AACCTTTG-3′ TAMRA
Pftub	F: 5′-TGATGTGCGCAAGTGATCC-3′	79
	R: 5′-TCCTTTGTGGACATTCTTCCTC-3′
	JOE: 5′-TAGCACATGCCGTTAAATATCTTC-CATGTCT-3′ TAMRA

区域	国别	患者数		$\bar{x}±s$	t 值	P值
区域	国别	CNV ≤ 1.5	CNV > 1.5	$\bar{x}±s$	t 值	P值
东非	坦桑尼亚	1	0	1.218 ± 0.023	1.674	> 0.05
	埃塞俄比亚	4	0	1.040 ± 0.125	3.094	< 0.05
	马维拉	1	0	1.002 ± 0.012	7.017	< 0.01
	肯尼亚	1	0	0.812 ± 0.028	12.706	< 0.01
	莫桑比克	2	0	0.950 ± 0.074	5.839	< 0.01
	乌干达	4	0	0.941 ± 0.258	2.972	< 0.05
	马达加斯加	2	0	1.067 ± 0.126	1.876	> 0.05
	布隆迪	1	0	1.002 ± 0.024	6.295	< 0.01
	小计	16	0	0.999 ± 0.073	3.919	< 0.01
西非	尼日利亚	13	2	1.083 ± 0.323	1.682	> 0.05
	加纳	8	1	1.043 ± 0.357	1.476	> 0.05
	贝宁	1	1	1.976 ± 0.348	4.376	< 0.01
	塞拉利昂	6	2	1.415 ± 0.595	1.957	> 0.05
	利比里亚	2	0	0.922 ± 0.046	8.373	< 0.01
	科特迪瓦	5	0	1.128 ± 0.116	1.185	> 0.05
	布基纳法索	1	0	0.867 ± 0.023	1.184	> 0.05
	马里	5	0	0.962 ± 0.072	7.067	< 0.01
	小计	41	6	1.150 ± 0.368	0.314	> 0.05
中非	刚果共和国	13	1	1.066 ± 0.357	1.497	> 0.05
	几内亚	2	0	0.960 ± 0.025	8.354	< 0.01
	刚果民主共和国	14	4	1.228 ± 0.384	0.858	> 0.05
	喀麦隆	7	1	1.111 ± 0.547	1.498	> 0.05
	赤道几内亚	2	3	1.747 ± 0.507	4.849	< 0.01
	安哥拉	3	3	1.600 ± 0.703	2.552	< 0.05
	加蓬	3	0	1.260 ± 0.176	1.378	> 0.05
	小计	44	12	1.249 ± 0.448	1.239	> 0.05
亚洲	巴基斯坦	2	0	0.986 ± 0.030	7.089	< 0.01
大洋洲	巴布亚新几内亚	1	0	1.114 ± 0.023	2.195	< 0.05

分组	用药方案	用药平均时长/d	治疗结束后1月病原学检查结果/份		治疗结束后1年病原学检查结果/份
分组	用药方案	用药平均时长/d	阳性	阴性	阳性	阴性
CNV > 1.5 （n = 18）	ACT口服药或注射剂（n = 7）	4.86 ± 0.98	1	7	2	4
	ACT口服药 + 注射剂（n = 10）	6.97 ± 1.76	0	9	0	4
	其他（n = 1）	3.00 ± 0.00	1	0	0	0
小计		5.93 ± 0.94	2	16	2	8
CNV ≤ 1.5 （n = 104）	ACT口服药或注射剂（n = 93）	3.11 ± 1.07	0	84	0	72
	ACT口服药 + 注射剂（n = 7）	4.65 ± 2.29	0	2	0	2
	其他（n = 4）	3.10 ± 0.64	1	2	1	1
小计		3.21 ± 1.23	1	88	1	75