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1.
Toxins (Basel) ; 13(1)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33477742

RESUMO

The Common Krait (Bungarus caeruleus) shares a distribution range with many other 'phenotypically-similar' kraits across the Indian subcontinent. Despite several reports of fatal envenomings by other Bungarus species, commercial Indian antivenoms are only manufactured against B. caeruleus. It is, therefore, imperative to understand the distribution of genetically distinct lineages of kraits, the compositional differences in their venoms, and the consequent impact of venom variation on the (pre)clinical effectiveness of antivenom therapy. To address this knowledge gap, we conducted phylogenetic and comparative venomics investigations of kraits in Southern and Western India. Phylogenetic reconstructions using mitochondrial markers revealed a new species of krait, Romulus' krait (Bungarus romulusi sp. nov.), in Southern India. Additionally, we found that kraits with 17 mid-body dorsal scale rows in Western India do not represent a subspecies of the Sind Krait (B. sindanus walli) as previously believed, but are genetically very similar to B. sindanus in Pakistan. Furthermore, venom proteomics and comparative transcriptomics revealed completely contrasting venom profiles. While the venom gland transcriptomes of all three species were highly similar, venom proteomes and toxicity profiles differed significantly, suggesting the prominent role of post-genomic regulatory mechanisms in shaping the venoms of these cryptic kraits. In vitro venom recognition and in vivo neutralisation experiments revealed a strong negative impact of venom variability on the preclinical performance of commercial antivenoms. While the venom of B. caeruleus was neutralised as per the manufacturer's claim, performance against the venoms of B. sindanus and B. romulusi was poor, highlighting the need for regionally-effective antivenoms in India.


Assuntos
Bungarotoxinas/química , Bungarus/genética , Bungarus/metabolismo , Proteoma , Animais , Antivenenos/química , Evolução Biológica , Bungarus/classificação , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Índia , Masculino , Camundongos , Mitocôndrias/genética , Tipagem Molecular , Paquistão , Filogenia , Proteômica , Especificidade da Espécie
2.
Zootaxa ; 4860(2): zootaxa.4860.2.8, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33056167

RESUMO

A new species of the natricine snake genus Smithophis Giri et al. 2019 is described based on three specimens collected from Arunachal Pradesh, India. An additional three referred specimens are documented. Smithophis arunachalensis sp. nov. differs from all known congeners by a combination of 4-5 (rarely 6) small scales around the eye (excluding labial scales), presence of temporal scales, and a distinctive colour pattern of a blackish dorsum and bright yellow venter that form a sharply-defined zigzag border. The new species is known only from ca. 100 km2 in Lower Dibang Valley and Changlang Districts in eastern Arunachal Pradesh. A revised key to the identification of the species of Smithophis is presented.


Assuntos
Colubridae , Animais , Cor , Meio Ambiente , Índia
3.
Zootaxa ; 4603(2): zootaxa.4603.2.2, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31717226

RESUMO

Based on the first molecular phylogenetic analyses of samples from northeast India, specimens referred to Rhabdops from this region are more closely related to the southeast and east Asian natricine genera Opisthotropis Günther, 1872 and Sinonatrix Rossman Eberle, 1977 (as well as to New World and western Palearctic natricines) than to peninsular Indian (true) Rhabdops. Morphologically, these northeast Indian populations differ from other natricines by having a single ('fused' or unpaired) internasal shield and a single prefrontal shield. Given the morphological and phylogenetic distinctiveness of these northeast Indian populations, we refer them to a new genus, Smithophis gen. nov., and transfer Rhabdops bicolor (Blyth, 1854) to Smithophis bicolor comb. nov. Based on morphological and molecular variation within our northeast Indian sample, we additionally describe Smithophis atemporalis sp. nov. from the state of Mizoram.


Assuntos
Colubridae , Animais , Índia , Filogenia
4.
Zootaxa ; 4085(4): 481-503, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-27394315

RESUMO

A new species of the uropeltid snake genus, Melanophidium Günther, 1864 is described based on a series of eight specimens. Melanophidium khairei sp. nov. is the fourth species described in the genus, and the first for 144 years. Superficially M. khairei sp. nov. resembles M. punctatum Beddome, 1871 in being piebald and punctate (and it was previously misidentified as M. punctatum), but in many scalation characters it more closely resembles M. wynaudense (Beddome, 1863). The new species occurs in southern Maharashtra, Goa, and northern Karnataka, in the Western Ghats region of peninsula India. It is the most northerly member of its genus. Lectotypes and paralectotypes are designated for M. wynaudense, M. bilineatum Beddome, 1870, and M. punctatum. A new key to the species of Melanophidium is presented. Aspects of the morphology, taxonomy and distribution of the three previously described species of Melanophidium are reviewed and revised.


Assuntos
Lagartos/anatomia & histologia , Lagartos/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Ecossistema , Feminino , Índia , Lagartos/crescimento & desenvolvimento , Masculino , Tamanho do Órgão
5.
Trop Med Health ; 40(3): 103-8, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23264729

RESUMO

We report a case of severe envenoming with unusual complications and two anecdotal cases of fatalities following proven 17-scale-row 'Sind krait' (Bungarus cf. sindanus) bites on people sleeping in temporary huts at construction sites in Pune District, Maharashtra, India. A 25-yr-old male developed progressive neuromuscular paralysis, abdominal pain and autonomic disturbances complicated by four prolonged episodes of pulseless ventricular tachycardia requiring defibrillation, and followed by pulmonary edema secondary to impaired left ventricular systolic function and hyperfusion. There was no response to antivenom; mechanical ventilation was required for six days. Only one other case of fatal envenoming likely caused by this species had been reported previously in India. The distribution of B. sindanus sensu lato from eastern Afghanistan to India overlaps with that of the superficially very similar common krait (Bungarus caeruleus). Thus, B. cf. sindanus envenoming may be common but routinely overlooked or misdiagnosed.

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