Spectroscopic characterization and investigation of the dynamic of charge compensation process of supramolecular films derived from tetra-2-pyridyl-1,4-pyrazine ligand

This work describes the infrared spectroscopy characterization and the charge compensation dynamics in supramolecular film FeTPPZFeCN derived from tetra-2-pyridyl-1,4-pyrazine (TPPZ) with hexacyanoferrate, as well as the hybrid film formed by FeTPPZFeCN and polypyrrole (PPy). For supramolecular film, it was found that anion flux is greater in a K+ containing solution than in Li+ solution, which seems to be due to the larger crystalline ionic radius of K+. The electroneutralization process is discussed in terms of electrostatic interactions between cations and metallic centers in the hosting matrix. The nature of the charge compensation process differs from others modified electrodes based on Prussian blue films, where only cations such as K+ participate in the electroneutralization process. In the case of FeTPPZFeCN/PPy hybrid film, the magnitude of the anions’s flux is also dependent on the identity of the anion of the supporting electrolyte.

ISOLATION OF Rickettsia bellii FROM Amblyomma ovale AND Amblyomma incisum TICKS FROM SOUTHERN BRAZIL

Objective. To isolate and characterize rickettsiae from the ticks Amblyomma ovale and Amblyomma incisum collected in the state of Sao Paulo. Materials and methods. Adult, free-living A. ovale and A. incisum were collected in an Atlantic rainforest area in the state of Sao Paulo, Brazil. Each tick was tested using the hemolymph assay; samples from positive ticks were placed in shell vials in order to isolate rickettsiae and subsequently grown in Vero cells. Amplification of three rickettsial genes ( gltA, htrA and ompA) was attempted using polymerase chain reaction (PCR) for each isolate obtained. Amplicons were subsequently sequenced. Results. A total of 388 A. incisum and 50 A. ovale were collected. Only one A. incisum and one A. ovale were hemolymph-test positive. Rickettsiae were successfully isolated from these ticks; however establishment in Vero cell culture was successful only for the isolate from A. ovale. Bacterial contamination in the first cell passage of the A. incisum isolate precluded successful isolation of the organism. PCR products were obtained with the gltA and htrA primers for the two isolates, but no product was obtained with the ompA primers. By BLAST analysis, partial gltA and htrA sequences of isolates from A. ovale and A. incisum were similar to the corresponding sequences of R. bellii. Conclusions. This is the first report of R. bellii infecting A. incisum and the first successful isolation from A. ovale.