Published in 2023

Artemisinin-based combination therapy successfully treated two hyperparasitaemic Plasmodium falciparum cases

Authors: Benudhar Mukhi, Himanshu Gupta, Kishore Punnath, Anupkumar R Anvikar, Bina Srivastava, Susanta Kumar Ghosh

Journal: The Journal of Infection in Developing Countries

Published in 2020

Plasmodium vivax liver stage assay platforms using Indian clinical isolates

Authors: Subramani PA, Vartak-Sharma N, Sreekumar S, Mathur P, Nayer B, Dakhore S, Basavanna SK, Kalappa DM, Krishnamurthy RV, Mukhi B, Mishra P

Journal: Malaria Journal

Description:

Background Vivax malaria is associated with significant morbidity and economic loss, and constitutes the bulk of malaria cases in large parts of Asia and South America as well as recent case reports in Africa. The widespread prevalence of vivax is a challenge to global malaria elimination programmes. Vivax malaria control is particularly challenged by existence of dormant liver stage forms that are difficult to treat and are responsible for multiple relapses, growing drug resistance to the asexual blood stages and host-genetic factors that preclude use of specific drugs like primaquine capable of targeting Plasmodium vivax liver stages. Despite an obligatory liver-stage in the Plasmodium life cycle, both the difficulty in obtaining P. vivax sporozoites and the limited availability of robust host cell models permissive to P. vivax infection are responsible for the limited knowledge of hypnozoite formation biology and relapse mechanisms, as well as the limited capability to do drug screening. Although India accounts for about half of vivax malaria cases world-wide, very little is known about the vivax liver stage forms in the context of Indian clinical isolates. Methods To address this, methods were established to obtain infective P. vivax sporozoites from an endemic region in India and multiple assay platforms set up to detect and characterize vivax liver stage forms. Different hepatoma cell lines, including the widely used HCO4 cells, primary human hepatocytes as well as hepatocytes obtained from iPSC’s generated from vivax patients and healthy donors were tested for infectivity with P. vivax sporozoites. Results Both large and small forms of vivax liver stage are detected in these assays, although the infectivity obtained in these platforms are low. Conclusions This study provides a proof of concept for detecting liver stage P. vivax and provide the first characterization of P. vivax liver stage forms from an endemic region in India.

Published in 2020

Haplotype of RNASE 3 polymorphisms is associated with severe malaria in an Indian population

Authors: Mukhi, B., Gupta, H., Wassmer, S.C., Anvikar, A.R. and Ghosh, S.K

Journal: Molecular Biology Reports

Description:

Severe malaria (SM) caused by Plasmodium falciparum (Pf) infection has been associated with life-threatening anemia, metabolic acidosis, cerebral malaria and multiorgan dysfunction. It may lead to death if not treated promptly. RNASE 3 has been linked to Pf growth inhibition and its polymorphisms found associated with SM and cerebral malaria in African populations. This study aimed to assess the association of RNASE 3 polymorphisms with SM in an Indian population. RNASE 3 gene and flanking regions were amplified followed by direct DNA sequencing in 151 Indian patients who visited Wenlock District Government Hospital, Mangalore, Karnataka, India. Allele, genotype and haplotype frequencies were compared between patients with SM (n = 47) and uncomplicated malaria (UM; n = 104). Homozygous mutant genotype was only found for rs2233860 (+ 499G > C) polymorphism (< 1% frequency). No significant genetic associations were found for RNASE 3 polymorphism genotypes and alleles in Indian SM patients using the Fisher's exact test. C-G-G haplotype of rs2233859 (− 38C > A), rs2073342 (+ 371C > G) and rs2233860 (+ 499G > C) polymorphisms was correlated significantly with SM patients (OR = 3.03; p = 0.008) after Bonferroni correction. A haplotype of RNASE 3 gene was found associated with an increased risk of SM and confirming that RNASE 3 gene plays a role in susceptibility to SM.

Published in 2019

Clinical features and haematological parameters among malaria patients in Mangaluru city area in the southwestern coastal region of India

Authors: Kishore Punnath, Kiran K. Dayanand, Valleesha N. Chandrashekar, Rajeshwara N. Achur, Srinivas B. Kakkilaya, Susanta K. Ghosh, Benudhar Mukhi, Vishal Midya, Suchetha N. Kumari, D. Channe Gowda

Journal: PARASITOLOGY RESEARCH

Published in 2018

Drug resistance genes: pvcrt-o and pvmdr-1 polymorphism in patients from malaria endemic South Western Coastal Region of India

Authors: Joy, S., Mukhi, B., Ghosh, S.K., Achur, R.N., Gowda, D.C. and Surolia, N.

Journal: Malaria Journal

Description:

Background: Malaria is highly prevalent in many parts of India and is mostly caused by the parasite species Plas modium vivax followed by Plasmodium falciparum. Chloroquine (CQ) is the frst-line treatment for blood stage P. vivax parasites, but cases of drug resistance to CQ have been reported from India. One of the surveillance strategies which is used to monitor CQ drug resistance, is the analysis of single nucleotide polymorphisms (SNPs) of the associated gene markers. Susceptibility to CQ can also be determined by copy number assessment of multidrug resistant gene (mdr-1). The current study has examined the prevalence of SNPs in P. vivax orthologs of P. falciparum chloroquine resistant and multi-drug resistant genes (pvcrt-o and pvmdr-1, respectively) and pvmdr-1 copy number variations in isolates from the highly endemic Mangaluru city near the South Western Coastal region of India. Methods: A total of 140 blood samples were collected from P. vivax infected patients attending Wenlock Hospital Mangaluru during July 2014 to January 2016. Out of these 140 samples, sequencing was carried out for 54 (38.5%) and 85 (60.7%) isolates for pvcrt-o and pvmdr-1, respectively. Single nucleotide polymorphisms (SNPs) in the pvcrt-o and pvmdr-1 genes were analysed by direct sequencing method, while copy number variations of 60 isolates (42. 8%) were determined by real time PCR. Results: Out of 54 clinical isolates analysed for pvcrt-o, three (5.6%) showed K10 insertion and the rest had wild type sequence. This is the frst report to show K10 insertion in P. vivax isolates from India. Further, out of 85 clinical isolates of P. vivax analysed for mutations in pvmdr-1 gene, only one isolate had wild type sequence (~ 1%) while the remain ing (99%) carried mutant alleles. Seven non-synonymous mutations with two novel mutations (I946V and Y1028C) were observed. Of all the observed mutations in pvmdr-1 gene, T958M was most highly prevalent (present in 90% of samples) followed by F1076L (76%), and Y976F (7%). Amplifcation of pvmdr-1 gene was observed in 31.6% of the isolates, out of 60 amplifed. Conclusion: The observed variations both in pvmdr-1 and pvcrt-o genes indicate a trend towards parasite acquiring CQ resistance in this endemic area.