Deleterious Effects of Polypropylene Microplastic Ingestion in Nile Tilapia (Oreochromis niloticus).

The effect of daily ingestion of polypropylene microplastic on the health of tilapia, Oreochromis niloticus, was evaluated. 60 fish (± 200 g) were placed in 6 aquariums (n = 10, 100 L each), constituting the following treatments: Control (without the addition of polymer), fed with 100 and 500 µg of polypropylene/kg of body weight (b.w.), respectively. After 30 days of feeding, the animals were submitted to blood collection for hemogram and biochemical study and later euthanized for gut microbiological analysis, somatic index of liver, spleen, heart, kidney, stomach, and intestine. In the serum biochemical study, an increase in cholesterol and serum Aspartate Aminotransferase (AST) activity levels was observed in animals treated with 500 µg of polypropylene. Tilapia-fed polypropylene in the diet showed an increase in thrombocyte and total leukocyte counts, marked by a significant increase in the number of circulating lymphocytes. The results of the somatic study revealed a significant increase in the stomach, liver, and heart of tilapia fed with the polymer. Increase in the number of Gram-negative microorganisms and decrease in mesophilic aerobic microorganisms were observed in the gut of fish exposed to the polymer, including a dose-response effect was observed for these analyses. Therefore, tilapias fed daily with diets containing polypropylene for 30 consecutive days showed deleterious effects, resulting in systemic inflammatory disturbs by altering liver functions, leukocyte profile, and organ morphometry, as well as changes in the intestinal microbiota. Such results demonstrate the impairment of fish health, highlighting the need for further studies that evaluate the impact of microplastics on aquatic organisms.

Use of photodynamic therapy in the treatment of bovine subclinical mastitis.

BACKGROUND: Bovine mastitis is a disease that causes a severe drawback in dairy production. Conventional treatments with antibiotic could leave antibiotic residues in the milk. The aim of this study was to evaluate the effect of photodynamic therapy in the treatment of bovine subclinical mastitis to develop an in vivo therapeutic protocol that could be used in routine farm practice, favoring the early return to production. METHODS: Forty cows with subclinical mastitis (n = 40) were divided into 4 groups (control, photodynamic therapy - PDT, light irradiation - LED, and photosensitizer - PS). Control group received no treatment, PDT group received application of 1.0 mL of 2.5% toluidine blue photosensitizer followed by LED irradiation at λ = 635 nm, the LED group was treated with LED irradiation alone, and the PS group received only 2.5% toluidine blue dye. LED irradiation was applied to the mammary gland by means of an acrylic light guide coupled to the LED equipment. The PDT and LED groups were irradiated with 200 J/cm2 at three different positions inside the mammary gland. Milk samples were collected at 0 h, 12 h, 24 h after treatment for microbial identification and total bacterial count. RESULTS: The treatment of the PDT group showed significant difference p < 0.05, characterizing the efficiency of this technique with the reduction of the microorganisms Streptococcus dysgalactiae and coagulase-negative Staphylococcus. CONCLUSION: Photodynamic therapy was effective when applied in vivo for subclinical bovine mastitis. There was no need to separate the animal from production.

Ação antimicrobiana in vitro de extratos de plantas medicinais na inibição de Streptococcus mutans / In vitro antimicrobial activity of medicinal plant extracts in the inhibition of Streptococcus mutans

Visando futuras matérias primas para diversos produtos/materiais dentários restauradores, o objetivo deste estudo foi avaliar a atividade antimicrobiana in vitro de extratos etanólicos de plantas medicinais contra Streptococcus mutans. Foram empregados extratos etanólicos de Cimbopongum nardus ( Citronela), Azadirachta indica A. Juss. ( Nim), Ruta graveolens L. ( Arruda) e Pterodon pubescens Benth. ( Sucupira). A linhagem bacteriana foi cultivada em meio SB20 sólido, incubada a 37ºC por 24 horas em microaerofilia. A atividade antibacteriana foi avaliada pelo método de difusão em ágar em meio sólido para a determinação da menor diluição, capaz de inibir o crescimento bacteriano, Concentração Inibitória Mínima (CIM) e, o número de colônias por placa foi calculado, a fim de determinar qual a menor concentração de cada extrato que apresentou 0,01% de bactérias viáveis, Concentração Mínima Bactericida (CMB). Foram confeccionados sete poços no meio SB20, com 6 mm de diâmetro cada. Nos poços foram colocados volumes crescentes dos extratos. As placas foram incubadas em estufa bacteriológica a 37°C em microaerofilia, por um período de 24 horas. Verificou-se a presença de atividade antibacteriana através do aparecimento de halos de inibição, mesurados com régua milimetrada. Os extratos etanólicos deCimbopongum nardus, Azadirachta indica A. Juss., Ruta graveolens L. ePterodon pubescens Benth. apresentaram CIM nas concentrações 25 µl para a primeira e 12,5 µl, para as restantes e, CMB nas concentrações de 50 µl, 12,5 µl, 12,5 µl, 25 µl, respectivamente. A ação antimicrobiana desses extratos sugere a possibilidade da sua utilização como meio alternativo na terapêutica odontológica

Aiming at future raw materials for various products/dental restorative materials, the objective of this study was to evaluate the in vitro antimicrobial activity of ethanol extracts from medicinal plants against Streptococcus mutans. Were used ethanol extracts of Cimbopongum nardus (Citronella), Azadirachta indica A. Juss. (Nim), Ruta graveolens L. (Rue), and P. pubescens Benth. (Sucupira). The bacterial strain was grown in solid SB20, incubated at 37 °C for 24 hours in microaerophilic. Antibacterial activity was evaluated by agar diffusion method on solid medium to determine the lowest dilution capable of inhibiting bacterial growth, minimal inhibitory concentration (MIC), and the number of colonies per plate was calculated, in order to determine which was the lowest concentration of each extract presenting 0.01% of viable bacteria, Minimum Bactericidal Concentration ( MBC). Seven wells were made through SB20, 6 mm in diameter each. Increasing volumes of the extracts were placed inside the wells. The plates were incubated in a bacteriological incubator at 37 ° C in microaerophilic conditions for a 24 hours period. Was verified the presence of antibacterial activity through the appearance of inhibition zones, measured with a millimeter ruler. The ethanol extracts of Cimbopongum nardus, Azadirachta indica A. Juss., Ruta graveolens L., and P. pubescens Benth. MIC concentrations were 25 µl for the former and 12.5 µl, to the other, and CMB at concentrations of 50µ l, 12.5 µl, 12.5 µl, 25 µl, respectively. The antimicrobial action of these extracts suggests the possibility of its use as an alternative mean on dental therapy