Anantabotla Vamsi Mohan, Antony Hiasindh Ashmi, Parija Subhash Chandra, Rajkumari Nonika, Kini Jyoti R, Manipura Radhakrishna, Nag Vijaya Lakshmi, Gadepalli R, Chayani Nirupama, Patro Somi
Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
Department of Microbiology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
Parasitol Int. 2019 Jun;70:92-97. doi: 10.1016/j.parint.2019.03.001. Epub 2019 Mar 2.
Malaria is a sterning public health concern in India and contribute to a major part of malaria burden in Southeast Asia. Being more populated and diverse geographic conditions makes more suitable place for sustaining malaria parasite in India. Anti-malarial resistance is a major concern in the battle against malaria, and the identified molecular markers will aid us to monitor the drug resistance in endemic areas. The aim of the current study is to determine the genotype of drug resistance associated genes pvmdr-1 and pvcrt-o from four different regions of India. Especially from Puducherry and Jodhpur, there were no prior studies focused on screening of drug resistance genes in P. vivax parasite. A total of 240 positive P. vivax infected patient samples were collected from four tertiary care hospitals from four different regions of India, namely, Puducherry (PDY), Mangaluru (MAQ), Cuttack (CTC), Jodhpur (JDH). All samples were screened by microscopy, RDT, QBC, and further DNA was extracted and vivax mono-infection was confirmed by nested PCR. Randomly selected amplicons were further subjected to nucleotide sequencing. The prevalence of K10 insertion in pvcrt-o gene was detected with 18.8% in PDY, 12.5% in MAQ and 6.3% in CTC P. vivax isolates, whereas no change in nucleotide was identified in P. vivax isolates collected from JDH region. Based on the F1076L mutation in pvmdr-1 gene, resistant P. vivax isolates was highly predominant in both the regions, JDH and CTC, with 100%, followed by MAQ with 93.3% and PDY with 73.3%. This study showed less frequency of pvcrt-o and high frequency of pvmdr-1 gene variants associated with CQ resistance, which act as an indicator and the onset of P. vivax drug resistance trend in four different regions of India. Due to the poor phenotypic studies available for P. vivax parasite, the present study data for CQ resistance based on pvcrt-o and pvmdr-1 markers should assist by providing base-line data for future monitoring of drug resistance.
疟疾是印度严峻的公共卫生问题，也是东南亚疟疾负担的主要组成部分。印度人口众多且地理条件多样，为疟原虫的生存提供了更适宜的环境。抗疟耐药性是抗击疟疾的主要问题，已鉴定出的分子标记将有助于我们监测流行地区的耐药情况。本研究的目的是确定来自印度四个不同地区，尤其是本地治里和焦特布尔的间日疟原虫耐药相关基因pvmdr - 1和pvcrt - o的基因型。此前尚无针对本地治里和焦特布尔地区间日疟原虫耐药基因筛查的研究。从印度四个不同地区的四家三级护理医院收集了总共240份间日疟原虫感染阳性患者样本，分别来自本地治里（PDY）、芒格洛尔（MAQ）、库塔克（CTC）、焦特布尔（JDH）。所有样本均通过显微镜检查、快速诊断试验、定量 Buffy 层分析法进行筛查，进一步提取DNA，并通过巢式PCR确认间日疟原虫单感染。对随机选择的扩增子进行核苷酸测序。在本地治里的间日疟原虫分离株中，pvcrt - o基因K10插入的发生率为18.8%，芒格洛尔为12.5%，库塔克为6.3%，而从焦特布尔地区收集的间日疟原虫分离株未发现核苷酸变化。基于pvmdr - 1基因的F1076L突变，耐药的间日疟原虫分离株在焦特布尔和库塔克地区占主导地位，均为100%，其次是芒格洛尔，为93.3%，本地治里为73.3%。本研究显示，与氯喹耐药相关的pvcrt - o基因频率较低，pvmdr - 1基因变异频率较高，这可作为印度四个不同地区间日疟原虫耐药趋势的指标和开端。由于间日疟原虫的表型研究较少，本研究基于pvcrt - o和pvmdr - 1标记的氯喹耐药数据应为未来耐药监测提供基线数据提供帮助。
