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author:("Sehgal, rakes")
1.  Genetic Diversity and Population Genetic Structure Analysis of Echinococcus granulosus sensu stricto Complex Based on Mitochondrial DNA Signature 
PLoS ONE  2013;8(12):e82904.
The genetic diversity and population genetics of the Echinococcus granulosus sensu stricto complex were investigated based on sequencing of mitochondrial DNA (mtDNA). Total 81 isolates of hydatid cyst collected from ungulate animals from different geographical areas of North India were identified by sequencing of cytochrome c oxidase subunit1 (coxi) gene. Three genotypes belonging to E. granulosus sensu stricto complex were identified (G1, G2 and G3 genotypes). Further the nucleotide sequences (retrieved from GenBank) for the coxi gene from seven populations of E. granulosus sensu stricto complex covering 6 continents, were compared with sequences of isolates analysed in this study. Molecular diversity indices represent overall high mitochondrial DNA diversity for these populations, but low nucleotide diversity between haplotypes. The neutrality tests were used to analyze signatures of historical demographic events. The Tajima’s D test and Fu’s FS test showed negative value, indicating deviations from neutrality and both suggested recent population expansion for the populations. Pairwise fixation index was significant for pairwise comparison of different populations (except between South America and East Asia, Middle East and Europe, South America and Europe, Africa and Australia), indicating genetic differentiation among populations. Based on the findings of the present study and those from earlier studies, we hypothesize that demographic expansion occurred in E. granulosus after the introduction of founder haplotype particular by anthropogenic movements.
doi:10.1371/journal.pone.0082904
PMCID: PMC3857302  PMID: 24349394
2.  Neurocysticercosis: A disease of neglect 
Tropical Parasitology  2013;3(2):106-113.
Neurocysticercosis (NCC) is a neglected tropical disease caused by larval forms of the parasite Taenia solium lodging in central nervous system (CNS). There is a huge morbidity and debilitation due to CNS manifestations of NCC in developing and underdeveloped regions of the globe, mainly Asian, African and Latin American countries. It is the cause of epilepsy in about 1% of the population of endemic countries and is the underlying etiology in about 15-50% persons with epilepsy, depending upon the geographical region. There is no perfect diagnostic method and the diagnosis relies on a combination of clinical, radio-imaging, immunologic and epidemiologic data. Treatment includes anti-parasitic treatment by cysticidal drugs and management of associated symptoms and complications. The disease is eradicable and control depends on an integrated and coordinated involvement of international bodies like the World Health Organization along with scientific institutions and political and administrative strata of the endemic countries to provide the essential tools such as adequate sanitation, live-stock management, health education and improved socio-economic conditions.
doi:10.4103/2229-5070.122111
PMCID: PMC3889086  PMID: 24470993
Neglected tropical disease; neurocysticercosis; Taenia solium
3.  Molecular Characterization of Echinococcus granulosus Cysts in North Indian Patients: Identification of G1, G3, G5 and G6 Genotypes 
Background
Cystic echinococcosis (CE) caused by the Echinococcus granulosus, is a major public health problem worldwide, including India. The different genotypes of E. granulosus responsible for human hydatidosis have been reported from endemic areas throughout the world. However, the genetic characterization of E. granulosus infecting the human population in India is lacking. The aim of study was to ascertain the genotype(s) of the parasite responsible for human hydatidosis in North India.
Methodology/Principal Findings
To study the transmission patterns of E. granulosus, genotypic analysis was performed on hydatid cysts obtained from 32 cystic echinococcosis (CE) patients residing in 7 different states of North India. Mitochondrial cytochrome c oxidase subunit1 (cox1) sequencing was done for molecular identification of the isolates. Most of the CE patients (30/32) were found to be infected with hydatid cyst of either G3 (53.1%) or G1 (40.62%) genotype and one each of G5 (cattle strain) and G6 (camel strain) genotype.
Conclusions/Significance
These findings demonstrate the zoonotic potential of G1 (sheep strain) and G3 (buffalo strain) genotypes of E. granulosus as these emerged as predominant genotypes infecting the humans in India. In addition to this, the present study reports the first human CE case infected with G5 genotype (cattle strain) in an Asian country and presence of G6 genotype (camel strain) in India. The results may have important implications in the planning of control strategies for human hydatidosis.
Author Summary
Cystic echinococcosis caused by Echinococcus granulosus is a widespread zoonotic disease. This cestode parasite is a complex of genetic variants and to date, ten distinct genotypes (genotypes G1–G10) have been identified on the basis of mitochondrial DNA sequences. The strain variation in E. granulosus may influence life-cycle patterns, host range, antigenicity and transmission dynamics. The disease is endemic in different parts of India. Although the presence of G1, G2, G3 and G5 has been reported in animal isolates in India, the zoonotic potential of the different genotypes has not been evaluated. In the present study, a genotype analysis was carried out in hydatid cysts collected from 32 cystic echinococcosis patients residing in North India. Most of the CE patients (30/32) were found to be infected with hydatid cyst of either G3 (53.1%) or G1 (40.62%) genotype and one each of G5 (cattle strain) and G6 (camel strain) genotype.
doi:10.1371/journal.pntd.0002262
PMCID: PMC3681628  PMID: 23785531
4.  Reversible dementia as a presenting manifestation of racemose neurocysticercosis 
Racemose cysticercosis is a less frequent presentation of neurocysticercosis (NCC). It's presentation and management is quite different from cerebral parenchymal NCC. Diagnosis of racemose cysticercosis is based on the combination of clinical, epidemiologic, radiographic, and immunologic information. Compared with cysticercus cellulose, which most commonly presents as seizures, racemose NCC due to its extraaxial location presents with raised intracranial pressure and meningitis, and frequently requires neurosurgical intervention. Dementia as a sole presenting feature of NCC is rare. We report a case of racemose NCC with dementia as the presenting manifestation. The outcome of dementia patients with NCC seems favorable in most cases therefore a high index of suspicion for NCC should be kept especially in endemic areas.
doi:10.4103/0972-2327.107706
PMCID: PMC3644790  PMID: 23661971
Cisternal neurocysticercosis; intraventricular neurocysticercosis; neurocysticercosis; racemose neurocysticercosis; subarachnoid neurocysticercosis
5.  Trichomoniasis and Lactoferrin: Future Prospects 
Trichomonas vaginalis is a parasitic protozoan which infects the urogenital tract and requires iron as an essential nutrient. Iron is known to upregulate various adhesins required for cytoadherance and other factors involved in pathogenesis. At mucosal surfaces, iron is chelated by lactoferrin resulting in low levels of free iron. However, pathogens have evolved mechanisms for an increased uptake of iron. The present review highlights the role of iron in survival of Trichomonas during fluctuating concentrations of iron at mucosal surfaces during the menstrual cycle. Future prospects in terms of new drug and vaccine targets related to iron and its receptors have also been described.
doi:10.1155/2012/536037
PMCID: PMC3439953  PMID: 22988421
6.  Evaluation of dried blood spots collected on filter paper for serodiagnosis of human hydatidosis by enzyme-linked immunosorbent assay 
Tropical Parasitology  2012;2(2):119-123.
Background and Objectives:
Serological diagnosis of hydatidosis is usually performed by detecting the circulating antibodies in serum by ELISA. The present study was carried out to standardize and evaluate procedure of the ELISA using elute from dried blood spots (DBS) on filter paper and blood stored at different temperatures and at different durations for its further application under field conditions.
Materials and Methods:
Dried blood spots were collected from fifty study subjects and fifty control subjects and evaluated for the detection of IgG antibodies against hydatid. Samples were stored at room temperature and 4°C and tested by ELISA at 0, 15 and 30 days.
Results:
The present study shows that elute of DBS on filter paper can be stored at room temperature for a maximum of 30 days without a decrease in antibody titer as compared to serum samples tested by ELISA.
Conclusions:
The collection of blood sample on filter paper may serve useful purpose in resource limited countries for carrying out sero-epidemiological surveys at a cost effective level.
doi:10.4103/2229-5070.105177
PMCID: PMC3680872  PMID: 23767019
Dried blood spots; enzyme-linked immunosorbent assay; hydatidosis
7.  Evaluation of Nephroprotective and Immunomodulatory Activities of Antioxidants in Combination with Cisplatin against Murine Visceral Leishmaniasis 
Background
Most available drugs against visceral leishmaniasis are toxic, and growing limitations in available chemotherapeutic strategies due to emerging resistant strains and lack of an effective vaccine against visceral leishmaniasis deepens the crisis. Antineoplastic drugs like miltefosine have in the past been effective against the parasitic infections. An antineoplastic drug, cisplatin (cis-diamminedichloroplatinum II; CDDP), is recognized as a DNA-damaging drug which also induces alteration of cell-cycle in both promastigotes and amastigotes leading to cell death. First in vivo reports from our laboratory revealed the leishmanicidal potential of cisplatin. However, high doses of cisplatin produce impairment of kidney, which can be reduced by the administration of antioxidants.
Methodology/Principal Findings
The present study was designed to evaluate the antileishmanial effect of cisplatin at higher doses (5 mg and 2.5 mg/kg body weight) and its combination with different antioxidants (vitamin C, vitamin E and silibinin) so as to eliminate the parasite completely and reduce the toxicity. In addition, various immunological, hematological and biochemical changes induced by it in uninfected and Leishmania donovani infected BALB/c mice were investigated.
Conclusion/Significance
A significant reduction in parasite load, higher IgG2a and lower IgG1 levels, enhanced DTH responses, and greater concentration of Th1 cytokines (IFN-γ, IL-2) with a concomitant down regulation of IL-10 and IL-4 pointed towards the generation of the protective Th1 type of immune response. A combination of cisplatin with antioxidants resulted in successful reduction of nephrotoxicity by normalizing the enzymatic levels of various liver and kidney function tests. Reduction in parasite load, increase in Th1 type of immune responses, and normalization of various biochemical parameters occurred in animals treated with cisplatin in combination with various antioxidants as compared to those treated with the drug only. The above results are promising as antioxidants reduced the potential toxicity of high doses of cisplatin, making the combination a potential anti-leishmanial therapy, especially in resistant cases.
Author Summary
Leishmaniasis, a neglected tropical disease (NTD) caused by Leishmania, has been put on the World Health Organization agenda for eradication as a part of their Special Programme for Tropical Diseases Research. Visceral leishmaniasis (VL) is a life-threatening disease when no treatment is given. Most of the drugs still used to treat VL are often expensive, difficult to administer, have serious side effects, and several are becoming ineffective because of increasing parasite resistance. Cisplatin is a first-generation platinum-containing drug, used in the treatment of various solid tumors. We have for the first time characterized the in vivo effect of cisplatin in murine experimental visceral leishmaniasis, but at higher doses it is nephrotoxic. Considering the above findings, the present study was designed to evaluate the protective efficacy of the drug in combination with various antioxidants to reduce or prevent cisplatin-induced nephrotoxicity. Drug treatment induces a higher secretion of Th1 cytokines, diminution in parasite burden, and the supplementation of antioxidants which are antagonists of the toxicity helps in reducing the nephrotoxicity.
doi:10.1371/journal.pntd.0001629
PMCID: PMC3341342  PMID: 22563510
8.  Microarray in parasitic infections 
Tropical Parasitology  2012;2(1):6-12.
Modern biology and genomic sciences are rooted in parasitic disease research. Genome sequencing efforts have provided a wealth of new biological information that promises to have a major impact on our understanding of parasites. Microarrays provide one of the major high-throughput platforms by which this information can be exploited in the laboratory. Many excellent reviews and technique articles have recently been published on applying microarrays to organisms for which fully annotated genomes are at hand. However, many parasitologists work on organisms whose genomes have been only partially sequenced. This review is mainly focused on how to use microarray in these situations.
doi:10.4103/2229-5070.97232
PMCID: PMC3593500  PMID: 23508469
Genome sequencing; microarray; parasitic infections
9.  Transfusion-transmitted parasitic infections 
The transmission of parasitic organisms through transfusion is relatively rare. Of the major transfusion-transmitted diseases, malaria is a major cause of TTIP in tropical countries whereas babesiosis and Chagas’ disease pose the greatest threat to donors in the USA In both cases, this is due to the increased number of potentially infected donors. There are no reliable serologic tests available to screen donors for any of these organisms and the focus for prevention remains on adherence to donor screening guidelines that address travel history and previous infection with the etiologic agent. One goal is the development of tests that are able to screen for and identify donors potentially infectious for parasitic infections without causing the deferral of a large number of non-infectious donors or significantly increasing costs. Ideally, methods to inactivate the infectious organism will provide an element of added safety to the blood supply.
doi:10.4103/0973-6247.67018
PMCID: PMC2937300  PMID: 20859503
Parasites; transfusion; transmitted
10.  Role of cholesterol in parasitic infections 
The requirement of cholesterol for internalization of eukaryotic pathogens like protozoa (Leishmaniasis, Malaria and Toxoplasmosis) and the exchange of cholesterol along with other metabolites during reproduction in Schistosomes (helminths) under variable circumstances are poorly understood. In patients infected with some other helminthes, alterations in the lipid profile have been observed. Also, the mechanisms involved in lipid changes especially in membrane proteins related to parasite infections remain uncertain. Present review of literature shows that parasites induce significant changes in lipid parameters, as has been shown in the in vitro study where substitution of serum by lipid/cholesterol in medium and in experimental models (in vivo). Thus changes in lipid profile occur in patients having active infections with most of the parasites. Membrane proteins are probably involved in such reactions. All parasites may be metabolising cholesterol, but the exact relationship with pathogenic mechanism is not clear. So far, studies suggest that there may be some factors or enzymes, which allow the parasite to breakup and consume lipid/cholesterol. Further studies are needed for better understanding of the mechanisms involved in vivo. The present review analysis the various studies till date and the role of cholesterol in pathogenesis of different parasitic infections.
doi:10.1186/1476-511X-4-10
PMCID: PMC1142336  PMID: 15882457
Protozoa; Helminths; Pathogenesis; Lipids/Cholesterol
11.  In vitro activity of antiamoebic drugs against clinical isolates of Entamoeba histolytica and Entamoeba dispar 
Background
Amoebiasis is a major public health problem in tropical and subtropical countries. Although a number of antiamoebic agents are used for its treatment, yet the susceptibility data on clinical isolates of Entamoeba histolytica and Entamoeba dispar are not available. Therefore, the present study was aimed to assess the in vitro susceptibility of clinical isolates of E. histolytica and E. dispar to metronidazole, chloroquine, emetine and tinidazole.
Methods
A total of 45 clinical isolates (15 E. histolytica and 30 E. dispar) were maintained in polyxenic cultures followed by monoxenic cultures. In vitro drug sensitivity (IC50) of clinical isolates and standard reference strain of E. histolytica (HM1: IMSS) was assessed by nitro blue tetrazolium (NBT) reduction assay after exposure to various concentrations of each drug.
Results
The results showed that all clinical isolates had a higher IC50 compared to reference strain to all the four drugs. E. histolytica isolates appeared to be more susceptible [IC50 (μm) 13.2,26.3,31.2 and 12.4] compared to E. dispar isolates [IC50(μm) 15.6,28.9,32.8 and 13.2] and the reference strain of E. histolytica [IC50 (μm) 9.5, 15.5, 29.9 and 10.2] to the metronidazole, chloroquine, emetine and tinidazole respectively.
Conclusions
The results indicate that till date, Entamoeba isolates in India do not seem to be resistant to the commonly used antiamoebic drugs.
doi:10.1186/1476-0711-3-27
PMCID: PMC544836  PMID: 15610563

Results 1-11 (11)