Preliminary Evaluation of Wound Healing Potential of Leonurus japonicus Houtt. Extracts.

Leonurus japonicus Houtt. is a medicinal plant popular in Brazil as "rubim", used in local folk medicine for several applications as an anti-inflammatory, antioxidant, analgesic, and antimicrobial phytomedicine. The traditional use for wound healing is related; however, few studies have evaluated the wound healing activity. Thus, this study aimed to analyse the popular indication of the hydroalcoholic and aqueous extracts of L. japonicus aerial parts in a rat wound healing model. The initial chemical characterization was performed using flavonoid quantification and complemented with mass spectroscopy/chemometrics analysis. The wound's lesion contraction and tissue regeneration (histological study stained with hematoxylin-eosin and picrosirius) were determined. Hydroalcoholic and aqueous extracts presented high flavonoid content, and mass spectrometry analysis of the extracts demonstrated the presence of compounds with a mass between 100-650, reinforcing the presence of polyphenolic constituents. The extracts of L. japonicus improve various wound healing phases, like inflammatory modulation, wound contraction, and collagen synthesis, resulting in faster healing in rats. These effects could be related to the extracts' polyphenolic compounds.

Norovirus and rotavirus in surface, malacoculture, and human consumption water in Santa Catarina State, Brazil.

This study evaluated the results recorded at the Central Public Health Laboratory of Santa Catarina state (Brazil) concerning the investigation of Rotavirus (RVA) and Norovirus (NoVs) - genogroups GI and GII. Samples were taken from seawater, river water, estuary water, lagoon water, and treated water samples, from 2018 to 2021. The aim was to correlate them with each other and evaluate their association with the type of water, presence of shellfish farming, population density, and sewage treatment. The most prevalent enteric virus was RVA, followed by NoV GI and NoV GII. There was a strong correlation between the presence/absence of RVA and the presence/absence of at least one NoV genogroup, mainly in samples collected in rivers. No correlation was observed between the presence of any virus and the presence of shellfish farming. When evaluating the binomial sewage treatment vs. population density, the correlation coefficients between population density and the presence of the virus in a sample were higher than the coefficients between the percentage of treated sewage and the presence of the virus. Sources of human-origin pollution impair the quality of treated and surface waters, and therefore the results of this work can help develop viral-monitoring programs in these places.

Optimization of a propidium monoazide-qPCR method for Escherichia coli quantification in raw seafood.

The present study compared different concentrations of propidium monoazide (PMA), time of exposure to light and different light intensities to determine the optimal conditions for the quantification of viable Escherichia coli in cell suspension and in food matrix. The influence of cell density and the effectiveness of PMA in viable but non-culturable (VBNC) E. coli cells were evaluated and also applied in food matrix. For that purpose, different concentrations of PMA (20 µM, 40 µM, 50 µM, 60 µM and 80 µM) under different times of exposure (5 min, 10 min, 15 min, 20 min and 30 min) to lights of different intensities (500 W and 650 W) were evaluated. After determining the optimal conditions, the PMA-qPCR methods were applied to different compositions of live and heat-killed E. coli suspensions (v:v; 0:1; 1:0; 1:1) in concentrations ranging from 3 Log to 7 Log CFU/mL. The same dilutions were prepared with E. coli in VBNC state and applied in food matrix. The results obtained from qPCR, PMA-qPCR and plate counts were compared. The results suggested that a PMA treatment of 50 µM PMA for 15 min under 650 W light intensity was optimal under our conditions. For E. coli cell suspensions, the amplification of heat-killed cells was inhibited greatly by PMA when concentrations were ≤ 5 Log CFU/mL. For the samples of oyster inoculated with heat-killed cells, E. coli was not detected by PMA-qPCR in concentrations ≤4 Log CFU/g. Regarding the results with VBNC state, we considered the PMA-qPCR method to be applicable for enumerating E. coli VBNC cells in oyster samples. Based on our findings, we further recommend the use of PMA-qPCR with the aim of reducing the amplification of dead cells for improving its performance, since false-positives could still occur depending on the level of E. coli in the sample. The application of the PMA-qPCR for quantification of bacteria, compared to the use of culture-dependent methods, is quite promising. However, further studies are recommended, especially using different food matrices.

Genotypic and phenotypic characterization of Escherichia coli isolated from mollusks in Brazil and the United States.

The aim of this study was to determine the serogroups, antimicrobial resistance and genetic diversity of Escherichia coli isolates from samples of bivalve mollusks collected along Santa Catarina coast, Brazil, and from the Chesapeake Bay, Maryland, USA. One hundred forty-one E. coli isolates were characterized for serogroups with 181 specific O antisera and antimicrobial susceptibility using the disk diffusion method. The genetic diversity was assessed using pulsed-field gel electrophoresis (PFGE). The results showed that among the isolates, 19.9% were classified as multi-drug resistant (MDR) and resistance was most frequently observed to cephalothin, nitrofurantoin, and ampicillin. The predominant serogroups were O6, O8, and O38. Some serogroups were recognized as pathogenic E. coli. PFGE dendrograms indicated extensive genetic diversity among the isolates. Although characteristics of the E. coli isolates were highly variable, it is important to note that E. coli belonging to pathogenic serogroups and MDR isolates are present in mollusks of both study areas. This is the first report on the phenotypic and genotypic characterization of E. coli from mollusks from Santa Catarina and the Chesapeake Bay that should encourage studies focusing on comparison of isolates across countries.