Isolation and molecular identification of Mycobacterium bovis in tissue lesions of cattle slaughtered in slaughterhouses located in the State of Ceará / [Isolamento e identificação molecular de Mycobacterium bovis em lesões teciduais de bovinos abatidos em matadouros-frigoríficos localizados no estado do Ceará]

The objective of this research was to identify Mycobacterium bovis in lesions suggestive of tuberculosis in bovine carcasses in the State of Ceará, by means of bacteriological and molecular diagnostic tests. Between August 2017 and January 2019, the State inspection service (SIE) inspected 59,512 cattle, of which 7.4% (44 / 59,512) presented suggestive lesions. Of these animals, 68 samples were sent, of which 4.5% (31/68) located in the lung, 2.9% (20/68) in lymph nodes, 2.0% (14/68) in the liver, and 0.4% in the carcass (3/68). When performing bacteriological isolation, 15.9% (7/44) of bovines showed colony growth in the samples. The smears of the isolates were submitted to Zielh-Neelsen staining and all confirmed acid-fast bacilli. The polymerase chain reaction identified all isolates 100% (7/7) as M. bovis. The association of diagnostic techniques allowed to identify the presence of the agent in the State and the molecular analysis proved to be a beneficial technique in the monitoring of bovine tuberculosis and can be used as an auxiliary method in the bovine tuberculosis control and eradication program in the State of Ceará.

O objetivo do trabalho foi pesquisar Mycobacterium bovis em lesões sugestivas de tuberculose nas carcaças de bovinos no estado do Ceará, por meio dos testes de diagnóstico bacteriológico e molecular. Entre agosto de 2017 e janeiro de 2019, o Serviço de Inspeção Estadual (SIE) inspecionou 59.512 bovinos; destes, 7,4% (44/59.512) apesentaram lesões sugestivas. Desses animais foram enviadas 68 amostras, das quais 4,5% (31/68) estavam localizadas no pulmão, 2,9% (20/68) nos linfonodos, 2,0% (14/68) no fígado e 0,4% (3/68) na carcaça. Ao realizar o isolamento bacteriológico, 15,9% (7/44) dos bovinos evidenciaram crescimento de colônias nas amostras. Os esfregaços dos isolados foram submetidos à coloração de Zielh-Neelsen e todos eles confirmaram bacilo álcool-ácido resistente. A reação em cadeia da polimerase identificou todos os isolados, 100% (7/7), como M. bovis. A associação das técnicas de diagnóstico permitiu identificar a presença do agente no estado, e a análise molecular demonstrou ser uma técnica benéfica no monitoramento da tuberculose bovina, podendo ser utilizada como um método auxiliar no programa de controle e erradicação da tuberculose bovina no estado do Ceará.

X-ray powder diffraction and other analyses of cellulose nanocrystals obtained from corn straw by chemical treatments.

The extraction of nanocellulose from agro-industrial wastes is feasible due to a significant amount of cellulose contained in these natural fibers. The analysis of chemical treatments effects on the fibers to obtain the nanocellulose must be taken into consideration for the definition of an adequate and efficient methodology. In this study, two alkaline treatments were used (cleaning and bleaching), as well as an acid treatment for the extraction of nanocellulose from corn straw residues. The samples were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), dynamic light scattering (DLS) and atomic force microscopy (AFM) to verify the action and modifications caused in their chemical and physical structures. It was possible to verify the extraction of hemicellulose and lignin, the reduction of fiber sizes to the nanoscale, and the final sample presenting superior crystallinity for the bleached fiber.

Modulation of the consolidation and reconsolidation of fear memory by three different serotonin receptors in hippocampus.

The process of memory formation is complex and highly dynamic. During learning, the newly acquired information is found in a fragile and labile state. Through a process known as consolidation, which requires specific mechanisms such as protein synthesis, the memory trace is stored and stabilized. It is known that when a consolidated memory is recalled, it again becomes labile and sensitive to disruption. To be maintained, this memory must undergo an additional process of restabilization called reconsolidation, which requires another phase of protein synthesis. Memory consolidation has been studied for more than a century, while the molecular mechanisms underlying the memory reconsolidation are starting to be elucidated. For this, is essential compare the participation of important neurotransmitters and its receptors in both processes in brain regions that play a central role in the fear response learning. With focus on serotonin (5-HT), a well characterized neurotransmitter that has been strongly implicated in learning and memory, we investigated, in the CA1 region of the dorsal hippocampus, whether the latest discovered serotonergic receptors, 5-HT5A, 5-HT6 and 5-HT7, are involved in the consolidation and reconsolidation of contextual fear conditioning (CFC) memory. For this, male rats with cannulae implanted in the CA1 region received immediately after the training or reactivation session, or 3h post-reactivation of the CFC, infusions of agonists or antagonists of the 5-HT5A, 5-HT6 and 5-HT7 receptors. After 24h, animals were subjected to a 3-min retention test. The results indicated that in the CA1 region of the hippocampus the 5-HT5A, 5-HT6 and 5-HT7 serotonin receptors participate in the reconsolidation of the CFC memory 3h post-reactivation. Additionally, the results suggest that the 5-HT6 and 5-HT7 receptors also participate in the consolidation of the CFC memory.

New route for hollow materials.

Hollow micro/nano structures form an important family of functional materials. We have used the thermal oxidation process combined with the passage of electric current during a structural phase transition to disclose a colossal mass diffusion transfer of Ti ions. This combination points to a new route for fabrication of hollow materials. A structural phase transition at high temperature prepares the stage by giving mobility to Ti ions and releasing vacancies to the system. The electric current then drives an inward delocalization of vacancies, condensing into voids, and finally turning into a big hollow. This strong physical phenomenon leading to a colossal mass transfer through ionic diffusion is suggested to be driven by a combination of phase transition and electrical current followed by chemical reaction. We show this phenomenon for Ti leading to TiO2 microtube formation, but we believe that it can be used to other metals undergoing structural phase transition at high temperatures.

Multifunctional biosensors based on peptide-polyelectrolyte conjugates.

A novel enzymatic platform for the sensing of H2O2 and glucose that uses L,L-diphenylalanine micro/nanostructures (FF-MNSs) as an enzyme support is shown. This platform is obtained by the self-assembly of poly(allylamine hydrochloride) (PAH), FF-MNSs, and microperoxidase-11 (MP11) anchored onto the peptide matrix, in two different crystal structures of FF-MNSs: hexagonal (P61) and orthorhombic (P22121). The electroactive area of the electrodes increases in the presence of FF-MNSs. We also demonstrate via theoretical calculations that the valence band energy of the orthorhombic structure allows it to be doped, similarly to p-type semiconductors, where PAH acts as a doping agent for the orthorhombic peptide structure, decreasing the band-gap by around 1 eV, which results in a smaller charge transfer resistance. These results are consistent with electrochemical impedance spectroscopy measurements, which further elucidate the role of the band structure of the orthorhombic FF-MNSs in the conductivity and electron transfer rates of the hybrid material. An effective communication between the electrode and the active site of a glucose oxidase enzyme through MP11-protein complexes occurs, paving the way for FF-MNSs in the orthorhombic phase for the future development of bioelectronics sensing devices.

Unusual specific heat of almost dry L-cysteine and L-cystine amino acids.

A detailed quantitative analysis of the specific heat in the 0.5- to 200-K temperature range for almost dry L-cysteine and its dimer, L-cystine, amino acids is presented. We report the occurrence of a sharp first-order transition at ∼76 K for L-cysteine associated with the thiol group ordering which was successfully modeled with the two-dimensional Ising model. We demonstrated that quantum rotors, two-level systems (TLS), Einstein oscillators, and acoustic phonons (the Debye model) are essential ingredients to correctly describe the overall experimental data. Our analysis pointed out the absence of the TLS contribution to the low temperature specific heat of L-cysteine. This result was similar to that found in other noncrystalline amorphous materials, e.g., amorphous silicon, low density amorphous water, and ultrastable glasses. L-cystine presented an unusual nonlinear acoustic dispersion relation ω(q)=vq0.95 and a Maxwell-Boltzmann-type distribution of tunneling barriers. The presence of Einstein oscillators with ΘE∼70 K was common in both systems and adequately modeled the boson peak contributions.

Anharmonic transitions in nearly dry L-cysteine I.

Two special dynamical transitions of universal character have recently been observed in macromolecules (lysozyme, myoglobin, bacteriorhodopsin, DNA and RNA) at T* ~100-150 K and T(D) ~180-220 K. The underlying mechanisms governing these transitions have been the subject of debate. In the present work, a survey is reported on the temperature dependence of structural, vibrational and thermodynamical properties of a nearly anhydrous amino acid (orthorhombic polymorph of the amino acid l-cysteine at a hydration level of 3.5%). The temperature dependence of x-ray powder diffraction patterns, Raman spectra and specific heat revealed these two transitions at T* = 70 K and T(D) = 230 K for this sample. The data were analyzed considering amino acid-amino acid, amino acid-water, water-water phonon-phonon interactions and molecular rotor activation. Our results indicated that the two referred temperatures define the triggering of very simple and particular events that govern all the interactions of the biomolecular: activation of CH(2) rigid rotors (T < T* ), phonon-phonon interactions between specific amino acid and water dimer vibrational modes (T* < T < T(D)), and water rotational barriers surpassing (T > T(D)).

Characterization of wax as a potential diffraction intensity standard for macromolecular crystallography beamlines.

A number of commercially available waxes in the form of thin disc samples have been investigated as possible diffraction intensity standards for macromolecular crystallography synchrotron beamlines. Synchrotron X-ray powder diffraction measurements show that beeswax offers the best performance of these waxes owing to its polycrystallinity. Crystallographic lattice parameters and diffraction intensities were examined between 281 and 309 K, and show stable and predictable thermal behaviour. Using an X-ray beam of known incident flux at lambda = 1 A, the diffraction power of two strong Bragg reflections for beeswax were quantified as a function of sample thickness and normalized to 10(10) photons s(-1). To demonstrate its feasibility as a diffraction intensity standard, test measurements were then performed on a new third-generation macromolecular crystallography synchrotron beamline.

Environmental dissemination of group A rotavirus: P-type, G-type and subgroup characterization.

Rotaviruses A (RV-A) infection is the most common cause of acute diarrheal diseases in infants and the dissemination of these viruses in the environment represents a public health hazard. The present study aims to evaluate reverse transcription-polymerase chain reaction (RT-PCR) based protocols for the detection of RV-A genes in different types of environmental samples. RV-A were concentrated by the adsorption-elution method using negatively charged membranes associated with a Centriprep Concentrator 50. The RV-A VP4, VP7 and VP6 genes were detected using RT-PCR in river water from the Amazon Hydrographic basin (Northern region) and from wastewater in a sewage treatment plant in Rio de Janeiro (Southeast region), Brazil. RV-A were successfully detected in water environmental samples by the methods used. The detection of the VP6 gene by RT-PCR was the most sensitive for detecting RV-A in environmental samples (44.0%), when compared to the detection of the VP4 (33.3%) and VP7 (25.3%) genes. Based on nucleotide sequence and phylogenetic analysis of the partial VP6 gene, 22 environmental samples were determined to be subgroup II (Wa-like). These results indicate that analysis of environmental samples could possibly make a valuable contribution to studies on the epidemiology of RV-A.

Molecular detection of hepatitis A virus in urban sewage in Rio de Janeiro, Brazil.

AIMS: A one-year survey was conducted to examine hepatitis A virus (HAV) prevalence, distribution of genotypes and their relationship to bacterial indicators in raw and treated sewage samples. METHODS AND RESULTS: Fifty sewage samples (raw = 25 and treated = 25) were collected twice monthly from one sewage treatment plant in Rio de Janeiro. Virus concentration was performed by adsorption to an electronegative membrane followed by ultrafiltration. Viral RNA was detected by nested reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR and positive products were directly sequenced. Total and faecal coliform concentrations were also determined. By nested RT-PCR, HAV RNA was detected in 16/50 (32%) and eight (16%) of them were found in treated sewage samples. By real-time PCR, HAV RNA was detected in 46/50 (92%) samples and 24 were from treated sewage. Phylogenetic analyses classified nine isolates (56%) as subgenotype IA and seven (44%) as IB. CONCLUSIONS: Real-time PCR was more sensitive than nested RT-PCR; the presence of subgenotypes IA and IB was described and bacterial indicators cannot be used to predict HAV presence in sewage. SIGNIFICANCE AND IMPACT OF THE STUDY: These results demonstrated that HAV still remains in the environment after sewage treatment and could play an important role in maintaining the endemicity of HAV infection.