Seroepidemiology Study of Porcine Epidemic Diarrhea Virus in Mexico by Indirect Enzyme-Linked Immunosorbent Assay Based on a Recombinant Fragment of N-Terminus Domain Spike Protein.

Porcine epidemic diarrhea (PED) is an intestinal disease caused by the porcine epidemic diarrhea virus (PEDV) and affects Mexico's swine industry. Despite the disease initially being described in Mexico in 2013, there has been no research into the virus's seroepidemiology carried out in Mexico. Thus, the goal of this study was to develop an indirect ELISA (iELISA) based on a recombinant N-terminal domain truncated spike (S) protein (rNTD-S) of PEDV to evaluate serum obtained from different pig-producing states in Mexico. A total of 1054 sera were collected from pig farms, slaughterhouses, and backyard production in the states of Aguascalientes, Guanajuato, Hidalgo, Jalisco, Morelos, Queretaro, Sinaloa, and Veracruz between 2019 and 2021. The rNTD-S protein was expressed in E. coli BL21 (DE3) cells. Negative and positive serum samples used in the iELISA were previously tested by Western blot. According to our findings, 61.66% of the serum samples (650/1054) were positive, with Jalisco having the highest percentage of positive samples, at a rate of 21.44% (226/1054). This is the first seroepidemiology study of PEDV carried out in Mexico, revealing that the virus is still circulating since the initial outbreak; furthermore, it provides an overview of PEDV's spread and high level of persistence across the country's key swine-producing states.

Comparability of a three-dimensional structure in biopharmaceuticals using spectroscopic methods.

Protein structure depends on weak interactions and covalent bonds, like disulfide bridges, established according to the environmental conditions. Here, we present the validation of two spectroscopic methodologies for the measurement of free and unoxidized thiols, as an attribute of structural integrity, using 5,5'-dithionitrobenzoic acid (DTNB) and DyLight Maleimide (DLM) as derivatizing agents. These methods were used to compare Rituximab and Etanercept products from different manufacturers. Physicochemical comparability was demonstrated for Rituximab products as DTNB showed no statistical differences under native, denaturing, and denaturing-reducing conditions, with Student's t-test P values of 0.6233, 0.4022, and 0.1475, respectively. While for Etanercept products no statistical differences were observed under native (P = 0.0758) and denaturing conditions (P = 0.2450), denaturing-reducing conditions revealed cysteine contents of 98% and 101%, towards the theoretical value of 58, for the evaluated products from different Etanercept manufacturers. DLM supported equality between Rituximab products under native (P = 0.7499) and denaturing conditions (P = 0.8027), but showed statistical differences among Etanercept products under native conditions (P < 0.001). DLM suggested that Infinitam has fewer exposed thiols than Enbrel, although DTNB method, circular dichroism (CD), fluorescence (TCSPC), and activity (TNF α neutralization) showed no differences. Overall, this data revealed the capabilities and drawbacks of each thiol quantification technique and their correlation with protein structure.

Antimutagenic and antioxidant activities of quebracho phenolics (Schinopsis balansae) recovered from tannery wastewaters.

Quebracho extracts are used in tannery due to their high concentration of phenolics. The Mexican tannery industry uses around 450 kg/m(3) of which, 150 kg/m(3) remains in wastewaters and are discharged in drain pipe systems or rivers. The quebracho phenolics recovered from tannery wastewater (QPTW) was characterized by HPLC. The antimutagenic and antioxidant activities as well as the microbiological quality were evaluated. Total phenolic content of QPTW was 621mg catechin equivalent/g sample. Gallic and protocatechuic acids were the major components characterized by HPLC. QPTW showed an inhibition range on aflatoxin B(1) mutagenicity from 16 to 60% and was dose-dependent. Antioxidant activity (defined as beta-carotene bleaching) of QPTW (64.4%) at a dose of 12.3mg/mL was similar to that of BHT (68.7%) at a dose of 0.33 mg/mL, but lower than Trolox (90.8% at a dose of 2.5mg/mL); meanwhile antiradical activity (measured as reduction of DPPH) (60.8%) was higher than that of BHT (50.8%) and Trolox (34.2%). Quebracho residues were demonstrated to be an outstanding source of phenolic acids and for research and industrial uses.