Nano-emulsions are promising carriers for antigen delivery. Here, we evaluated the efficacy of a water-oil nano-emulsion containing concentrated, inactivated Clostridium novyi (C. novyi) type B supernatant culture (nano-iCnB) in protecting Swiss mice against a lethal dose of alpha toxin concentrated extract. Proteins were confirmed in the nano-iCnB and their stabilities were determined according physical parameters such as Zeta Potential (ZP). Biochemical, hematological parameters and morphological appearance of liver, spleen and thigh muscle alterations were examined to determine the safety of the compound. Partial protection against lethal doses was achieved in immunized mice despite low IgG titers. These data suggest that our nano-emulsion is a simple and efficient method of promoting antigen delivery for toxin-related diseases.

The fungus Fusarium verticillioides produces fumonisins (FB1 and FB2), characterized by being the most frequently produced molecular forms and with greater toxicity. Fumonisin contamination is responsible for substantial losses during the meat production chain, so the safe levels of these compounds must be determined. The study was directed to establish safe levels of FB1 in poultry production; for this purpose, were used COBB 500® birds on experimental lots of infected corn during the 2015/2016 season in Brazil. The experimental group included 160 animals, divided into two groups: The T1 without fumonisin in the diet (control); and the T2 group in which corn was contaminated with 2.78 μg/g of fumonisin FB1. Histopathological effects of liver, heart, and small intestine, and zootechnical parameters were measured in birds treated. We found that there were no significant differences between the birds treated and untreated after 21 days of exposure to each treatment; F-values > P-values (P<0,05) for feed intake and weekly weight gain. Taken together, our data showed that the concentration evaluated is safe in poultry and will contribute to the design of future clinical studies.

Acinetobacter baumannii is a Gram-negative, immobile, aerobic nosocomial opportunistic coccobacillus that causes pneumonia, septicemia, and urinary tract infections in immunosuppressed patients. There are no commercially available alternative antimicrobials, and multi-drug resistance is an urgent concern that requires emergency measures and new therapeutic strategies. This study evaluated a multi-drug-resistant A. baumannii whole-cell vaccine, inactivated and adsorbed on an aluminum hydroxide–chitosan (mAhC) matrix, in an A. baumannii sepsis model in immunosuppressed mice by cyclophosphamide (CY). CY-treated mice were divided into immunized, non-immunized, and adjuvant-inoculated groups. Three vaccine doses were given at 0D, 14D, and 28D, followed by a lethal dose of 4.0 × 108 CFU/mL of A. baumannii. Immunized CY-treated mice underwent a significant humoral response, with the highest IgG levels and a higher survival rate (85%); this differed from the non-immunized CY-treated mice, none of whom survived (p < 0.001), and from the adjuvant group, with 45% survival (p < 0.05). Histological data revealed the evident expansion of white spleen pulp from immunized CY-treated mice, whereas, in non-immunized and adjuvanted CY-treated mice, there was more significant organ tissue damage. Our results confirmed the proof-of-concept of the immune response and vaccine protection in a sepsis model in CY-treated mice, contributing to the advancement of new alternatives for protection against A. baumannii infections.

Bacteria responsible for causing infections are common in hospital environments, water, soil, and food products. The infection risk is intensified by the absence of public sanitation, poor quality of life, and food scarcity. These external factors promote the dissemination of pathogens by direct contamination or biofilm formation. In this work, we identified bacterial isolates obtained from intensive care units in the southern region of Tocantins, Brazil. We compared matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques and 16S ribosomal ribonucleic acid (rRNA) molecular analysis; we also performed phenotypic characterization. Fifty-six isolates characterized using morphotinctorial tests were classified as gram-positive (80.4%; n = 45) and gram-negative (19.6%; n = 11) and were resistant to several antibiotic classes; notably, we identified the blaOXA-23 resistance gene in the ILH10 isolate. Microbial identification using MALDI-TOF MS resulted in the identification of Sphingomonas paucimobilis and Bacillus circulans. 16S rRNA sequencing revealed four isolates belonging to the genera Bacillus and Acinetobacter. The similarity was superior to 99% for Acinetobacter schindleri in the Basic Local Alignment Search Tool (BLAST), grouped in the clade superior to 90%. Several strains isolated from intensive care units (ICU) were resistant to various antibiotic classes. These techniques allowed for the identification of several microorganisms of importance in public health, enabling improvements in human infection control and proving the quality of inputs, food, and water.

Prospecting of new isolates producers of pectinolitic enzymes were performed with cultivation of substrates of rice, soybean and corn bran. Pectinolitic enzymes were observed in cultures of the isolates NFC 1, NFC 2, NFC 4, NFC 5 and NFC 6 identified as belonging to the genus Aspergillus sp. Isolates NFR 1, NFR 2 and NFS1 were identified as belonging to the genus Rhizopus and NFC 3 belonging to the genus Cladosporium; however, pectinolitic enzymes production was not observed. The polygalacturonase (PG) production in submerged fermentation of Aspergillus NFC 2 in culture medium proposed (SM) at 28 and 37°C was quantified by agar diffusion and spectrophotometric methods. The highest PG production was obtained at 28°C by greater formation of halo degradation pectin and the activity measured by spectrophotometric methods. The activity of PG obtained was 7 U.mL -1 with volumetric productivity greater in the first 24 h of fermentation both at 28 and 37°C. A decrease in PG synthesis occurred after 48 to 120 h. The study allowed, by means of rapid microbiological tests, the selection of new isolates fungi for PG production and the definition of crucial stages for cultivation in liquid medium.