Amitav Mohanty

Publications (5)11.2 Total impact

• Article: Molecular identification and phylogeny of Myzomyia and Neocellia series of Anopheles subgenus Cellia (Diptera: Culicidae).

  Sunita Swain, Amitav Mohanty, H K Tripathy, Namita Mahapatra, Santanu K Kar, Rupenangshu K Hazra
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  ABSTRACT: Any biological study is only meaningful if the concerned organism is accurately identified; this is particularly important in vector-borne disease studies where correct and precise identification of the target species has medical and practical implications, such as in vector control. The Myzomyia series is divided into four groups including the Funestus group, which consists of five subgroups, i.e. Aconitus, Culicifacies, Funestus, Minimus, Rivulorum, and the Neocellia series, which is divided into three groups Annularis, Jamesii and Maculatus. Members of the Funestus group of Myzomyia and the Annularis group of the Neocellia series are difficult to identify because of the morphological overlap that exists within the groups. Therefore a multiplex polymerase chain reaction (PCR) assay was developed based on the sequence of the D3 region of 28S rDNA to distinguish between four members (An. fluviatilis, An. culicifacies, An. varuna and An. aconitus) of three subgroups (Minimus, Aconitus, Culicifacies) of the Funestus group of Myzomyia and three members (An. annularis, An. pallidus and An. philippinensis) of the Annularis group of the Neocellia series of the Anopheles subgenus Cellia, prevalent in Orissa, India. Polymorphism present on the D3 region of rDNA allowed the development of a species-specific primer that when combined with two universal primers lead to a simple and sensitive multiplex allele-specific polymerase chain reaction (AS-PCR) assay. This assay can be applied as an unbiased confirmatory method for the identification of morphological variants, imperfectly preserved specimens and life stages for which taxonomic keys do not allow a definitive species determination. Finally, phylogenetic relationships between the members of the two series were determined using D3 sequence data. The phylogenetic relationships inferred from maximum parsimony and the neighbour joining analysis separated two distinct monophyletic clades, one consisting of species of Myzomyia and other of species of the Neocellia series. The molecular phylogeny obtained in this work matches with that of the classical morphological taxonomy reasonably well, with proper species arrangements.
  Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 10/2010; 10(7):931-9. · 3.22 Impact Factor
• Article: A unique methodology for detecting the spread of chloroquine-resistant strains of Plasmodium falciparum, in previously unreported areas, by analyzing anophelines of malaria endemic zones of Orissa, India.

  Amitav Mohanty, Sunita Swain, Durg V Singh, Namita Mahapatra, Santanu K Kar, Rupenangshu K Hazra
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  ABSTRACT: Generally, clinical data is referred to study drug-resistance patterns of Plasmodium falciparum in an area. This is only possible after a clear manifestation of drug-resistance parasites inside the human host, and thereafter detection by healthcare persons. The detection of spread of drug-resistant P. falciparum in a population, before any pathological symptoms detected in humans is possible by analyzing the anopheline vectors, transmitting malaria. In the present study we implemented a new strategy to detect the spread of chloroquine-resistant (CQR) strains of P. falciparum by the major malaria vectors prevalent in selected endemic regions of Orissa, India. We screened P. falciparum positive vectors by using polymerase chain reaction (PCR)-based assay and thereafter detected K76T mutation in the Pfcrt gene, the chloroquine-resistance marker, of parasites present within the vectors. This study showed higher transmission rate of chloroquine-resistant P. falciparum parasites by Anopheles culicifacies and Anopheles fluviatilis. This study will help in assigning chloroquine-resistant P. falciparum sporozoite transmission potential of malaria vectors and suggest that by adopting the mentioned methodologies, we can detect the spreading of the drug-resistant P. falciparum in its transmission. This approach of studying the anophelines during regular vector collection and epidemiological analysis will give the knowledge of chloroquine-resistance pattern of P. falciparum of an area and help in devising effective malaria control strategy.
  Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 08/2009; 9(4):462-7. · 3.22 Impact Factor
• Article: The development and evaluation of a single step multiplex PCR for simultaneous detection of Anopheles annularis group mosquitoes, human host preference and Plasmodium falciparum sporozoite presence.

  Sunita Swain, Amitav Mohanty, Namita Mahapatra, S K Parida, N S Marai, H K Tripathy, Santanu K Kar, Rupenangshu K Hazra
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  ABSTRACT: The Anopheles annularis group mosquitoes, subgenus Cellia Theobald (Diptera: Culicidae), includes five recognized species: An. annularis Van der Wulp, An. nivipes Theobald, An. pallidus Theobald, An. philippinensis Ludlow and An. schueffneri Stanton. From these five, the three most common species found in Orissa were considered for this study because of their remarkable vectorial and behavioral variation and the important role they play in malaria transmission. To identify and understand their role in malaria transmission we developed a single multiplex PCR-based assay. This assay included the detection of human blood feeding habit and Plasmodium falciparum sporozoite presence. Of the 186 An. annularis mosquitoes collected, morphological character-based identification showed that 94 were An. annularis, 54 were An. philippinensis and 38 were An. pallidus. However, the multiplex PCR assay confirmed that 91 were An. annularis, 56 were An. philippinensis and 39 were An. pallidus individuals after adjustments were made for misidentified specimens in the morphological method. Anopheles annularis and An. philippinensis were found positive for human blood, and two samples of An. annularis species were positive for P. falciparum sporozoites. This one-step PCR-based method constitutes a very powerful tool in large surveys of anopheline populations.
  Transactions of the Royal Society of Tropical Medicine and Hygiene 05/2009; 103(11):1146-52. · 2.16 Impact Factor
• Article: Multiplex PCR assay for the detection of Anopheles fluviatilis species complex, human host preference, and Plasmodium falciparum sporozoite presence, using a unique mosquito processing method.

  Amitav Mohanty, Priyanka Kar, Kirti Mishra, Durg V Singh, Namita Mohapatra, Santanu K Kar, Aditya P Dash, Rupenangshu K Hazra
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  ABSTRACT: A multiplex PCR assay has been developed for detection of Anopheles fluviatilis cryptic species, their human host preference, and Plasmodium falciparum presence in the mosquito. PCR conditions were optimized using primer sets specific for A. fluviatilis cryptic species, Homo sapiens, and P. falciparum and evaluated with field-collected mosquitoes. A unique mosquito processing method was used for screening P. falciparum carrying capacity and human host preference of A. fluviatilis mosquitoes in first-round multiplex PCR. The vectorial status of the mosquito for P. falciparum parasite was confirmed in second-round PCR. Of the 121 collected mosquitoes, 92 were of S type, 26 of T type, and 3 were of other types. Human host preference was dominant in S type, of which 4% were P. falciparum sporozoite positive. This assay and processing method can also be used to evaluate vector competence of other anophelines.
  The American journal of tropical medicine and hygiene 06/2007; 76(5):837-43. · 2.59 Impact Factor
• Article: Analysis of the phylogenetic relationship of Anopheles species, subgenus Cellia (Diptera: Culicidae) and using it to define the relationship of morphologically similar species

  Amitav Mohanty, Sunita Swain, Santanu K. Kar, Rupenangshu K. Hazra
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  ABSTRACT: Studies on the relationship of various vectors and non-vectors of malaria from the evolutionary point of view are important. Use of molecular methods to define phylogeny helps to understand the interrelationship among the members of the anophelines and elucidate the ambiguity that has arisen from improper classification. It could also help to design molecular markers for species differentiation, particularly in those which pose difficulty when classified, based on morphological features. In the present study, the phylogenetic relationships among the species of the anophelines of subgenus Cellia are inferred from the mitochondrial genes COI and COII, the ribosomal RNA gene, in particular the D3 region, and Internal Transcribed Spacer 2 (ITS2) region. The molecular phylogeny obtained in this work matches with that of the classical morphological taxonomy reasonably well, and was useful in properly defining species positions and resolving the ambiguity that normally arises due to morphological taxonomy. The correct arrangement of the various anopheline taxa as per the traditional morphological character-based classification of anophelines was there when we considered the D3 region of 28S rRNA gene and ITS2 region of rDNA. However, the arrangement of the taxa did not match with that of the morphological classification in some aspects, when we considered the COI and COII region of mitochondrial DNA. It may have been due to the variable degree of the rate of evolution of the different genes within the organism. Thus, a proper selection of those particular genes that evolve at the rate that is reflected at the species differentiation level, could help to construct the correct phylogenetic relationship among the anophelines and could be used to correlate with the grouping pattern done from the morphological perspective.
  Infection, Genetics and Evolution.