Repellent effects of andiroba and copaiba oils against Musca domestica (common house fly) and ecotoxicological effects on the environment

Background: The main challenge in raising cattle in Brazil is related to ectoparasites, that cause negative effects on milk and meat production, and in severe cases, animal death. Sheds known as crèches attracts large number insects mainly due to milk residues in the environment. The housefly is a major problem due to act as vectors of many other diseases, and so there is the possibility of control of infestations with natural products. Andiroba and copaiba oils may act as natural biocides, there are only a few studies on their effect on biological soil parameters. Therefore, this study aimed to evaluate the repellent effect of andiroba and copaiba oils against flies and on biological soil parameters. Materials, Methods & Results: The repellency effect of oils of andiroba and copaiba was tested at a concentration of 5% in lambs shed maternity, containing 64 bays (1.8 m2 ). It was sprayed 30 mL per pen, where they were housed five lambs each. Pre-treatment counts were taken before the treatment (mean 46 per pen after Musca domestica), and post-treatment count was made on 2, 24 and 48 h. The data collected at 2 and 24 h was evaluated and the number of flies was reduced significantly (P < 0.001) in the pens treated with oil of copaiba and andiroba compared to control (untreated) pen. After 48 h, no difference was observed between treatments in relation to fly numbers [...]

Repellent effects of andiroba and copaiba oils against Musca domestica (common house fly) and ecotoxicological effects on the environment

Background: The main challenge in raising cattle in Brazil is related to ectoparasites, that cause negative effects on milk and meat production, and in severe cases, animal death. Sheds known as crèches attracts large number insects mainly due to milk residues in the environment. The housefly is a major problem due to act as vectors of many other diseases, and so there is the possibility of control of infestations with natural products. Andiroba and copaiba oils may act as natural biocides, there are only a few studies on their effect on biological soil parameters. Therefore, this study aimed to evaluate the repellent effect of andiroba and copaiba oils against flies and on biological soil parameters. Materials, Methods & Results: The repellency effect of oils of andiroba and copaiba was tested at a concentration of 5% in lambs shed maternity, containing 64 bays (1.8 m2 ). It was sprayed 30 mL per pen, where they were housed five lambs each. Pre-treatment counts were taken before the treatment (mean 46 per pen after Musca domestica), and post-treatment count was made on 2, 24 and 48 h. The data collected at 2 and 24 h was evaluated and the number of flies was reduced significantly (P < 0.001) in the pens treated with oil of copaiba and andiroba compared to control (untreated) pen. After 48 h, no difference was observed between treatments in relation to fly numbers [...](AU)

Evaluation of the in vitro cytotoxicity of the antimicrobial peptide P34.

The in vitro cytotoxicity of the antimicrobial peptide P34 was evaluated in different eukaryotic cells. The food-grade bacteriocin nisin was also analysed for comparison. Vero cells were treated with different concentrations (0.02-2.5 microg x ml(-1)) of antimicrobial peptide P34 and nisin. Cell viability and plasma membrane integrity were checked by MTT [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide], NRU (Neutral Red dye uptake) and LDH (lactate dehydrogenase) assays. The EC50 values of the peptide P34 in MTT and NRU assays were 0.60 and 1.25 microg x ml(-1) respectively, while values of nisin found were 0.50 and 1.04 microg x ml(-1). In the LDH assay, the EC50 values were 0.65 and 0.62 microg x ml(-1) for P34 and nisin, respectively. The peptide P34 revealed similar haemolytic activity on human erythrocytes (5.8%) when compared with nisin (4.9%). The effects on viability, motility and acrosomal exocytosis of human sperm were also evaluated. Nisin and P34 showed similar effects on sperm parameters. The evaluation of cytotoxicity of antimicrobial peptides is a critical step to guarantee their safe use.

Detection of Paenibacillus larvae by Real-Time PCR

Background: Paenibacillus larvae is the agent of the American Foulbrood disease (AFB), which may determine the death of the hive. The detection strategy for its diagnosis is based on clinical signs of disease, isolation and identification of P. larvae, which usually employs microbiological and biochemical methods. Recently, molecular methods based on analysis of 16S rDNA by conventional PCR have been adopted, providing greater security and analytical speed. The rapid diagnosis is important to minimize economic losses and assess routes of spread of the pathogen. Despite the strong existing sanitary control, P. larvae was recently identified in the Brazilian states of Rio Grande do Sul and Paraná. After that, outbreaks have been reported in neighboring countries. This investigation was conducted to develop a protocol for detection of P. larvae by real-time PCR, allowing the reduction in the time of diagnosis, without loss of robustness found in the conventional PCR methods. Materials, Methods & Results: Twenty-nine (29) P. larvae strains were evaluated by real-time PCR using SYBR Green. The primers Pltr-F/R were designed according to the sequence X60619 of 16S rDNA gene published in GenBank, to amplify a fragment of 74 base pairs. The target gene is highly conserved and specific to P. larvae. The amplification conditions consisted of 1 cycle of 50°C for 2 min and 1 cycle of 95°C for 10 min, followed by 40 cycles of 95°C for 15 s and 60°C for 1 min. The fluorescence was monitored during the annealing at 60°C. The reactions were conducted in a 7500 Real Time PCR System equipment, using SYBRGreen PCR master mix (both Applied Biosystems), containing 2X Platinum SYBRGreen qPCR Supermix-UDG. The concentrations of primers were 1, 10 and 100 mM, and different concentrations of MgCl2 (0,0 mM de MgCl2, 1.0 mM de MgCl2, 2.0 mM de MgCl2 and 3.0 mM de MgCl2) were tested, with a final volume of 50 mL; 25 mL and 15 mL, containing a 5 mL sample.(...)

Detection of Paenibacillus larvae by Real-Time PCR

Background: Paenibacillus larvae is the agent of the American Foulbrood disease (AFB), which may determine the death of the hive. The detection strategy for its diagnosis is based on clinical signs of disease, isolation and identification of P. larvae, which usually employs microbiological and biochemical methods. Recently, molecular methods based on analysis of 16S rDNA by conventional PCR have been adopted, providing greater security and analytical speed. The rapid diagnosis is important to minimize economic losses and assess routes of spread of the pathogen. Despite the strong existing sanitary control, P. larvae was recently identified in the Brazilian states of Rio Grande do Sul and Paraná. After that, outbreaks have been reported in neighboring countries. This investigation was conducted to develop a protocol for detection of P. larvae by real-time PCR, allowing the reduction in the time of diagnosis, without loss of robustness found in the conventional PCR methods. Materials, Methods & Results: Twenty-nine (29) P. larvae strains were evaluated by real-time PCR using SYBR Green. The primers Pltr-F/R were designed according to the sequence X60619 of 16S rDNA gene published in GenBank, to amplify a fragment of 74 base pairs. The target gene is highly conserved and specific to P. larvae. The amplification conditions consisted of 1 cycle of 50°C for 2 min and 1 cycle of 95°C for 10 min, followed by 40 cycles of 95°C for 15 s and 60°C for 1 min. The fluorescence was monitored during the annealing at 60°C. The reactions were conducted in a 7500 Real Time PCR System equipment, using SYBRGreen PCR master mix (both Applied Biosystems), containing 2X Platinum SYBRGreen qPCR Supermix-UDG. The concentrations of primers were 1, 10 and 100 mM, and different concentrations of MgCl2 (0,0 mM de MgCl2, 1.0 mM de MgCl2, 2.0 mM de MgCl2 and 3.0 mM de MgCl2) were tested, with a final volume of 50 mL; 25 mL and 15 mL, containing a 5 mL sample.(...)(AU)