Genomic characterization of a novel Hepatovirus identified in Maranhão state, Brazil

Bats are efficient reservoirs of a number of viruses with zoonotic potential, and are involved directly in the transmission cycle of many zoonoses. In the present study, which is part of a larger project that is documenting the viromes of the bat species found in the Mid-North states of Maranhão and Piauí, we analyzed 16 pooled samples obtained from four species of bat of the genus Artibeus-Artibeus obscurus, Artibeus cinereus, Artibeus lituratus and Artibeus planirostris. We describe and identify a Hepatovirus, denominated Hepatovirus H isolate sotense, which was found in a pool of internal organs (liver and lungs) extracted from a specimen of A. planirostris, a frugivorous bat, collected in the Cerrado biome of Maranhão state. This material was analyzed using new generation sequencing, which produced a contig of 7390 nucleotides and presented a degree of identity with a number of existing Hepatovirus sequences available for bats (amino acid identity of 61.5% with Bat hepatovirus C of Miniopterus cf. manavi, 66.6% with Bat hepatovirus G of Coleura afra, 67.4% with Hepatovirus G2 of Rhinolophus landeri, and 75.3% with Hepatovirus H2 of Rhinolophus landeri). The analysis of the functional domains of this contig confirmed a pattern consistent with the characteristics of the genus Hepatovirus (Picornaviridae). In the phylogenetic tree with several other Hepatovirus species, this genome also grouped in a monophyletic clade with Hepatovirus H (HepV-H1; HepV-H2, and HepV-H3) albeit on an external branch, which suggests that it may be a distinct genotype within this species. This is the first isolate of Hepatovirus H identified in bats from South America, and represents an important discovery, given that most studies of viruses associated with bats in the state of Maranhão have focused on the family Rhabdoviridae.

A novel hantavirus identified in bats (Carollia perspicillata) in Brazil

Bats play an essential role in maintaining ecosystems. Their unique characteristics increase the likelihood of interactions with various species, making them a potential source for the emergence and spread of infectious diseases. Hantaviruses are continuously expanding their range of hosts. This study presents the identification of a partial genome associated with Hantavirus in samples collected from neotropical bats. We conducted a metagenomic study using samples from Carollia perspicillata in Maranhão, Brazil. Tissue fragments were used for RNA extraction and subsequent sequencing. The resulting data was subjected to bioinformatic analysis. A sequence showing an identity of 72.86% with the L gene in the reference genome was obtained. The phylogenetic analysis revealed the study sequence, denoted as Buritiense, clustering within the Mobatvirus clade. The intragroup analysis showed a broader dispersion and were markedly asymmetric. This observation suggests the possibility that Buritiense could potentially represent a new species within the bat-borne hantaviruses, but further analyses are needed to provide additional insights if bats plays a role as reservoirs and the potential for transmission to human populations.

Molossusmelini Montani et al. 2021 (Chiroptera, Molossidae) in Brazil: new insights for distribuition, morphology and genetics

Background

The species M.melini has been observed in both the Pampa and Spinal ecoregions of Argentina. Researchers have underscored that distinguishing M.melini from other species within the same genus relies primarily on craniometric and molecular analyses. Morphological measurements alone do not offer a clear differentiation between M.melini and other members of this genus.This study aims to document the presence of M.melini within the Brazilian ecoregion, focusing on its morphological, morphometric and genetic characteristics. By undertaking a comprehensive examination, we seek to contribute valuable insights into the distribution and differentiation of M.melini in this region.

New information

Molossusmelini specimens exhibited a forearm length ranging from 39.9 to 40.08 mm. The average intraspecific divergence was 1.2%, with specimens from the Argentine Pampas clustering in the same clade with a 98% bootstrap support and a posterior probability of: Regarding dorsal colouration, the specimens displayed fur with two bands-a Snow White base colour and apex colours ranging from Olive Brown, Broccoli Brown, Wood Brown to Yellowish-Brown. This marks the first record of M.melini in Brazil, expanding its distribution 1,300 km northeastwards into the Curitiba, Paraná, Atlantic Forest Ecoregion. The findings contribute valuable information on the distribution, morphology, morphometrics and genetics of this species.

First record of Eumops glaucinus (Wager, 1843) (Chiroptera, Molossidae) to the Brazilian state of Maranhão

The study provides the first record of Eumops glaucinus in the Maranhão state, located in the northern region of Brazil. The collected specimen was a non-lactating adult female, with grayish pelage, broad ears, smooth face, a well-developed and squarish tragus, and elongated snout. The combined analysis of the morphological and molecular data (COI, Cyt b, and rRNA 16S genes) confirmed the occurrence of E. glaucinus in the state of Maranhão. This record extends the known species range area by 660 km easternward from the closest locality, Belém, Pará.

Occurrence of Sturnira tildae De La Torre, 1959 (Chiroptera: Phyllostomidae) in the state of Maranhão, Brazil

The bat genus Sturnira is widely distributed in the Neotropical region, from northwestern Mexico to northern Argentina, and four species occur in Brazil: Sturnira lilium, Sturnira giannae, Sturnira magna, and Sturnira tildae. The present study is the first to record Sturnira tildae in the state of Maranhão, Brazil, based on morphological and molecular diagnoses. The specimen was identified based on its cranial and morphometric traits. The diagnostic traits include discreetly bilobed inner upper incisors with a broad base, lower first and second molars with lingual cusps separated by shallow grooves, and forearm longer than 45 mm. The molecular sequences of Cytochrome C Oxidase Subunit 1 (COI) and 16S rRNA genes confirmed the morphological identification and thus the occurrence of Sturnira tildae in the Amazon biome of Maranhão. This record represents an eastward extension of the known distribution of the species in the Amazonia, to Cândido Mendes, Maranhão, within an area dominated by dense rainforest and influenced by tides.

First record of Cynomops planirostris (Peters, 1865) (Chiroptera, Molossidae) from Maranhão state, Brazil, based on morphological and molecular data

Based on morphological and molecular data, we present the first record of Cynomops planirostris for the State of Maranhão. The specimen was collected in the Inhamum Municipal Environmental Protection Area in Maranhão, Brazil and characterized morphologically as an adult male with scrotal testicles, dorsal pelage reddish chestnut, with ventral pelage slightly lighter in color, forearm length 34.70-34.80mm dental formula i:1/1, c:1/1, pm:1/2, m:3/3 = 26. The sequence of the Cytochrome Oxidase I subunit (COI) molecular marker confirmed the morphological diagnosis of the specimen as C. planirostris with significant similarities. The combined analysis of both morphological and molecular confirmed the occurrence of C. planirostris in the Brazilian state of Maranhão, in the Cerrado biome and records extends the known geographic distribution of the species by 411.30 km.

Comparative analysis of absorbance calculations for integrated optical waveguide configurations by use of the ray optics model and the electromagnetic wave theory

Focusing on the use of planar waveguides as platforms for highly sensitive attenuated total reflection spectroscopy of organic thin films, we extend the ray optics model to provide absorbance expressions for the case of dichroic layers immobilized on the waveguide surface. Straightforward expressions are derived for the limiting case of weakly absorbing, anisotropically oriented molecules in the waveguide-cladding region. The second major focus is on the accuracy of the ray optics model. This model assumes that the introduction of absorbing species, either in the bulk cladding or as an adlayer on the waveguide surface, only causes a small perturbation to the original waveguide-mode profile. We investigate the accuracy of this assumption and the conditions under which it is valid. A comparison to an exact calculation by use of the electromagnetic wave theory is implemented, and the discrepancy of the ray optics model is determined for various waveguide configurations. We find that in typical situations in which waveguide-absorbance measurements are used to study organic thin films (k(l)/n(l) <or= (-1), h/lambda approximately (-2)) the discrepancy between the ray optics and the exact calculations is only a few percent (2-3%).

Static tester for characterization of phase-change, dye-polymer, and magneto-optical media for optical data storage

We have designed and built a static tester around a commercially available polarized light microscope. This device employs two semiconductor laser diodes (at 643- and 680-nm wavelengths) for the purpose of recording small marks on various media for optical data storage and for the simultaneous monitoring of the recording process. We use one of the lasers in the single-pulse mode to write a mark on the sample and operate the other laser in the cw mode to monitor the recording process. The two laser beams are brought to coincident focus on the sample through the objective lens of the microscope. The reflected beams are sent through a polarizing beam splitter and thus divided into two branches, depending on whether they are p or s polarized. In each branch the beam is further divided into two according to the wavelength. The four beams thus produced are sent to four high-speed photodetectors, and the resulting signals are used to monitor the reflectance as well as the polarization state of the beam on reflection from the sample. We provide a comprehensive description of the tester's design and operating principles. We also report preliminary results of measurements of phase-change, dye-polymer, and magneto-optical samples, which are currently of interest in the areas of writable and rewritable optical data storage.

Integrated optical biosensor for detection of multivalent proteins

We have developed a simple, highly sensitive and specific optical waveguide sensor for the detection of multivalent proteins. The optical biosensor is based on optically tagged glycolipid receptors embedded within a fluid phospholipid bilayer membrane formed upon the surface of a planar optical waveguide. Binding of multivalent cholera toxin triggers a fluorescence resonance energy transfer that results in a two-color optical change that is monitored by measurement of emitted luminescence above the waveguide surface. The sensor approach is highly sensitive and specific and requires no additional reagents and washing steps. Demonstration of protein-receptor recognition by use of planar optical waveguides provides a path forward for the development of fieldable miniaturized biosensor arrays.

On probing molecular monolayers: a spectroscopic optical waveguide approach of ultra-sensitivity

A broadband, multichannel, single-mode, planar waveguide based spectrometer was developed for probing molecular monolayers. A protein sub-monolayer (thickness h @ 3 nm, imaginary part of refractive index kl oe 0.01) immobilized on the waveguide surface was characterized by the waveguide attenuated total reflection (ATR) spectrometer. A sensitivity enhancement of 4 orders of magnitude, compared to conventional transmission measurements, has been experimentally achieved in the characterization of ultra-thin films. In addition, polarized spectroscopic measurements at the TE and TM waveguide modes were implemented to determine the average orientation angle of the adsorbed molecules. The work developed here is a new research tool for the investigation of some fundamental aspects of molecular films and a novel platform to develop new technological devices of high sensitivity and selectivity such as biosensors.

70-nm-bandwidth achromatic waveguide coupler

We report a general approach to the design of broadband waveguide couplers. A double-parallel grating assembly is used to cancel the first chromatic order, and a proper choice of prism glass and base angle is made to compensate for the second chromatic order. The technique was applied to a Corning glass 7059 waveguide, and a spectral bandwidth of 70 nm was measured by the use of two complementary procedures.

Envelope and waveguide methods: a comparative study of PbF(2) and CeO(2) birefringent films

We have characterized low-birefringence, PbF(2) coatings to permit, first, agreement between envelope and prism-coupler waveguide methods under the standard isotropic assumption. In essentially the same measurement conditions, for obliquely deposited (58.3°) CeO(2) coatings the isotropic model becomes unsustainable. Explicit consideration of the film microstructure is then required for good correlation between thickness results from TE (503 ± 9 nm) and TM (504 ± 10 nm) modes in the waveguide experiment as well as between refractive-index results from envelope (n(2) = 1.78 ± 0.03) and waveguide (n(2) = 1.794 ± 0.002) techniques. We considered uniaxial and biaxial models to achieve consistency, and the refractive indices along the principal axes of symmetry were determined.