The Potential of Wood Vinegar to Replace Antimicrobials Used in Animal Husbandry-A Review.

The indiscriminate use of antimicrobials in animal husbandry can result in various types of environmental contamination. Part of the dose of these products is excreted, still active, in the animals' feces and urine. These excreta are widely used as organic fertilizers, which results in contamination with antimicrobial molecules. The impacts can occur in several compartments, such as soil, groundwater, and surface watercourses. Also, contamination by antimicrobials fed or administrated to pigs, chickens, and cattle can reach the meat, milk, and other animal products, which calls into question the sustainability of using these products as part of eco-friendly practices. Therefore, a search for alternative natural products is required to replace the conventional antimicrobials currently used in animal husbandry, aiming to mitigate environmental contamination. We thus carried out a review addressing this issue, highlighting wood vinegar (WV), also known as pyroligneous acid, as an alternative antimicrobial with good potential to replace conventional products. In this regard, many studies have demonstrated that WV is a promising product. WV is a nontoxic additive widely employed in the food industry to impart a smoked flavor to foods. Studies have shown that, depending on the WV concentration, good results can be achieved using it as an antimicrobial against pathogenic bacteria and fungi and a valuable growth promoter for poultry and pigs.

Enhancing Titanium Disk Performance through In-Pack Cold Atmospheric Plasma Treatment.

While titanium dental implants have already been clinically established, ongoing research is continuously being conducted to advance the fields of osseointegration and bacterial resistance, seeking further improvements in these areas. In this study, we introduce an innovative method for treating titanium surfaces within tightly sealed packaging. Specifically, titanium discs, enclosed in surgical-grade packaging, underwent treatment using cold atmospheric plasma (CAP). The surfaces were thoroughly characterized in terms of wettability, crystalline structure, and chemical composition. Hemocompatibility analyses were conducted using blood diluted in sodium citrate (1:9) exposed to titanium discs for 30 min inside a CO2 incubator at 37 °C. Subsequently, various blood parameters were evaluated, including prothrombin time (PT), activated partial thromboplastin time (APTT), and platelet adhesion. Microbiological analyses were also performed using Pseudomonas aeruginosa (ATCC 27853) for 4 h at 37 °C. The treatment with CAP Jet resulted in a reduction in contact angle without causing any changes in the crystalline structure. No statistically significant differences were observed in the blood parameters. The plasma-treated samples exhibited lower PT and APTT values compared to those of the control group. The surfaces treated with CAP Jet showed increased platelet activation, platelet density, and thrombus formation when compared with the untreated samples. Moreover, the treated surfaces demonstrated lower bacterial colony formation compared with other surfaces.

Antimicrobial activity and chemical profile of wood vinegar from eucalyptus (Eucalyptus urophylla x Eucalyptus grandis - clone I144) and bamboo (Bambusa vulgaris).

Microbial resistance to drugs is a public health problem; therefore, there is a search for alternatives to replace conventional products with natural agents. One of the potential antimicrobial agents is wood vinegar derived from the carbonization of lignocellulosic raw materials. The objectives of the present work were to evaluate the antibacterial and antifungal action of two kinds of wood vinegar (WV), one of Eucalyptus urograndis wood and another of Bambusa vulgaris biomass, and determine their chemical profile. The antimicrobial effect was assessed against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enteritidis, Escherichia coli, Streptococcus agalactiae, and Candida albicans. The minimum inhibitory concentration and the minimum bactericidal and fungicidal concentrations were determined. Micrographs of the microorganisms before and after exposure to both kinds of wood vinegar were obtained by scanning electron microscopy. The chemical profile of the eucalyptus and bamboo vinegar was carried out by gas chromatography and mass spectrometry (GC/MS). Both types of WV presented significant antimicrobial activity, with the bamboo one having a higher efficiency. Both studied pyroligneous extracts seem promising for developing natural antimicrobials due to their efficiency against pathogens. GC/MS analyses demonstrated that the chemical profiles of both kinds of WV were similar but with some significant differences. The major component of the eucalyptus vinegar was furfural (17.2%), while the bamboo WV was phenol (15.3%). Several compounds in both WVs have proven antimicrobial activity, such as acetic acid, furfural, phenol, cresols, guaiacol, and xylenols. Together, they are the major in the chemical composition of the organic fraction of both WVs. Bamboo vinegar had a more expressive content of organic acids. Micrographs of microorganisms taken after exposure to both kinds of wood vinegar displayed several cell modifications. The potential of both types of wood vinegar as a basis for natural antimicrobial products seems feasible due to their proven effect on inhibiting the microorganisms' growth assessed in this experiment.

Use of a product based on wood vinegar of Eucalyptus clone I144 used in the control of bovine mastitis.

Bovine mastitis is one of the most frequent diseases in dairy cattle worldwide. The use of antiseptics in milking, if properly used, can lead to a reduction in potentially pathogenic microorganisms and their transmission between herds. Several medicinal plants have antiseptic potential, including eucalyptus (Eucalyptus spp.). Therefore, the objective of this study was to evaluate the effectiveness of wood vinegar from Eucalyptus urograndis clone GG I144 (EU) as an antiseptic in vitro and in vivo; in addition, to its cytotoxicity and antimicrobial resistance. Fifteen bovines were used, lactating females 3-6 years of age and divided into three groups of five animals each. The wood vinegar was placed in the teats of the animal for 28 days and collections of cellular debris were performed every 7 days. At the Veterinary Microbiology Laboratory (LAMIV) of UFERSA, the samples were processed and serial dilution was performed in Petri plates with plate count agar (PCA) at 37 °C. Cytotoxicity was verified based on morphological alterations and metabolic activity. Morphological changes were not observed in all cells incubated with 1 % pyroligneous extract. The in vitro data demonstrated antimicrobial activity against S. aureus, S. agalactiae, Salmonella, E. coli and P. aeruginosa. The bacteria of the genus Staphylococcus and Corynebacterium were resistant to penicillin (PEN), rifampicin (RIF), nitrofurantoin (NIT), erythromycin (ERI), and ciprofloxacin (CIP). The extract was used in vivo in the post-dipping of dairy cows, which reduced the microbiological load present in the mammary glands from 4.74 to 2.54 CFU, indicating its future use as an antiseptic.

Efficiency of Pyroligneous Extract from Jurema Preta (Mimosa tenuiflora [Willd.] Poiret) as an Antiseptic in Cats (Felis catus) Subjected to Ovariosalpingohysterectomy.

Pyroligneous extract of Jurema preta (Mimosa tenuiflora [Willd.] Poiret) was evaluated for its efficacy as a cutaneous antiseptic in cats (Felis catus) that were subjected to ovariosalpingohysterectomy. For this purpose, 30 cats without a defined breed were sterilized and divided into two groups. The first group was the positive control, treated with 0.5% chlorhexidine-alcohol solution, and the second group was treated with 20% pyroligneous extract of M. tenuiflora. Regardless of age and sex, all animals had visible healing at similar times. A significant reduction in bacterial growth was observed in animals treated with the extract, and no cytotoxicity was observed in the feline epithelial cells. In addition, surgical wounds of cats treated with M. tenuiflora extract exhibited improved healing. On agar plates, treatment with both chlorhexidine and M. tenuiflora extract resulted in the inhibition zones for all bacterial strains isolated from surgical wounds. Therefore, M. tenuiflora extract is demonstrated to have antiseptic effects on the surgical wounds of cats undergoing ovariosalpingohysterectomy.

Influence of antibiotics on bacterial load and sperm parameters during short-term preservation of collared peccary semen.

Studies on semen and sperm cells are critical to develop assisted reproductive technologies for the conservation of the collared peccary. The objective of the study was to compare the effect of different antibiotics on the bacterial load and sperm quality during short-term storage of peccary semen. Fresh semen samples from 10 males were extended in Tris-egg yolk or Tris-Aloe vera supplemented with streptomycin-penicillin (SP; 1 mg/mL - 1000 IU/mL or 2 mg/mL - 2000 IU/mL) or gentamicin (30 µg/mL or 70 µg/mL) before storage at 5°C. Bacterial load and sperm motility, membrane integrity and function, mitochondrial activity, and morphology, were evaluated at different time points for 36 h. The SP and gentamicin treatments concentration inhibited (p < 0.05) bacterial growth for 36 h regardless of the extender. Compared to the other treatments, Tris-egg yolk plus 70 µg/mL gentamicin maintained the sperm parameters for longer, including total motility (41.9 ± 6.1%) at 24 h, and membrane integrity (58.3 ± 2.1%) at 36 h. In contrast, the highest SP concentration in both extenders impaired sperm membrane integrity at 36 h (p < 0.05). For the liquid storage of collared peccary semen, it therefore is recommended to use Tris extender supplemented with egg yolk and gentamicin (70 µg/mL).

Libidibia ferrea antimicrobial and disinfectant activity

Microorganisms are becoming resistant to the commonly used chemical disinfectants. Thereby, these chemical products should now be replaced by natural ones. In this context, this research aimed to evaluate the disinfectant activity of the extract and decoction of Libidibia ferrea leaves in different surfaces. Thus, two forms of jucá leaf extraction (decoction and hydroalcoholic extraction) were tested through the diffusion disk technique from Kirby and Bauer, growth curve, acceptability test with the population, and surface test. Results showed sensibility to decoction of S. aureus and E. faecalis strains; however, for the extract, the strains that demonstrated sensibility were S. aureus, P. aeruginosa, Micrococcus spp. Corynebacterium spp., and S. Typhimurium in the diffusion disk test. A reduction of the bacterial charge throughout the growth curve was seen through the absorbance values after 24 hours to the strains of E. coli, E. feacalis, Micrococcus spp. and K. pneumoniae in the concentration of 100 mg/mL of the decoction and extract. Regarding the surfaces test, there was a reduction in the bacterial charge in all tested strains. Therefore, the L. ferrea may be used as an effective alternative disinfectant measure.

Spondias mombin L. decoction utilization as antiseptic in cats submitted to castration / Uso de decocto de Spondias mombin L. como antisséptico em felinos submetidos à castração

This survey evaluated mombin leaves (Spondias mombin L.) decoction efficiency as an antiseptic during post-surgery period on cats submitted to orchiectomy and ovariosalpingohisterectomy. For this purpose, 45 castrated mongrels cats were divided into three groups, the first group as a positive control using 0.5% chlorhexidine-alcohol solution, the second a negative control group using sterile distilled water and, finally, the test group using mombin leaves decocted with a concentration of 100 mg/mL. All animals, independent of age and sex, had visibly healed in most cases in a similar time. Animals treated with mombin leaves decoction presented a significant reduction of bacterial growth. In addition, the animals treated in the test group had better surgical wound healing. All isolated bacterial strains presented inhibition halo for chlorhexidine and for Spondias mombin L. Thus, the decoction of Spondias mombin L. leaves proved antiseptic efficacy in the surgical wounds of cats submitted to orchiectomy and ovariosalpingohisterectomy.(AU)

Foi avaliada a eficiência do decocto das folhas de cajá (Spondias mombin L.) como antisséptico no pós-cirúrgico de gatos submetidos à orquiectomia e ovariosalpingohisterectomia. Para tal, foram submetidos à castração 45 gatos sem raça definida, divididos em três grupos. O primeiro grupo como controle positivo com Solução Alcoólica de Clorexidine a 0,5%; segundo grupo controle negativo com água destilada estéril; e o grupo teste com o decocto de cajá à concentração de 100 mg/mL. Todos os animais, independentemente da idade e sexo, tiveram cicatrização visível em tempo similar. Animais tratados com o decocto apresentaram uma redução significativa do crescimento bacteriano. Além disso, observou-se uma melhor cicatrização das feridas cirúrgicas dos animais tratados no grupo teste. Todas as estirpes bacterianas isoladas apresentaram halo de inibição para clorexidine e para Spondias mombin L. Portanto, o decocto das folhas da Spondias mombin L. apresentou eficácia antisséptica nas feridas cirúrgicas de gatos submetidos à orquiectomia e ovariosalpingohisterectomia.(AU)

Knowledge of the population about visceral leishmaniasis transmission in endemic areas near the banks of the Mossoró River in northeastern Brazil.

Visceral leishmaniasis (VL) is an anthropozoonosis with high prevalence and incidence in the Northeastern region of Brazil. This study aimed to determine whether people living near the Mossoró River in the city of Mossoró, Rio Grande do Norte, have knowledge of VL and to characterize the environmental properties of this region. Questionnaires were administered to 478 residents in three neighborhoods near the Mossoró River, addressing the population's knowledge about VL and environmental characteristics. Most survey participants were female, with ages between 18 and 40 years, 53.8% had completed primary education, and 61.5% owned pet dogs (p<0.05). The majority (95.9%) showed little knowledge about the characteristics inherent to sandflies, and 85.3% were unaware of the environments preferred by this vector (p<0.05). Sewage from the homes of respondents was mainly dumped into the river (44.6%), and 76.6% of the respondents complained about the accumulation of garbage in the streets (p<0.05). The association between education and knowledge about the transmission of VL and preferred vector locations was statistically significant (p<0.05). The lack of knowledge in the population about VL and the residential environment indicates a risk of maintaining sand fly habitats and hence disease transmission.

Isolamento de Alcaligenes faecalis em peixe Betta splendens Regan, 1910 no Brasil / Isolation of Alcaligenes faecalis in fish Betta splendens Regan, 1910 in Brazil

Descreve-se um caso de infecção por Alcaligenes faecalis em peixe ornamental Betta splendens, incluindo avaliação clínica, patológica e bacteriológica. Um peixe fêmea, com peso de 16 g, inicialmente demonstrou discreta lesão escoriativa no tegumento, inapetência, emagrecimento progressivo, letargia, dispneia e aumento de volume na região lateral esquerda. Constataram-se em necropsia a presença de exoftalmia bilateral, opacidade de córnea, ascite e abscesso no subcutâneo provocando distensão da cavidade celomática. As alterações histológicas da pele se caracterizaram por abscesso, necrose, hemorragia e infiltrado inflamatório constituído principalmente de heterófilos. No exame microbiológico com exsudato e sangue venoso isolou-se exclusivamente A. faecalis.(AU)

This paper aimed to describe one case of infection by Alcaligenes faecalis in an ornamental fish Betta splendens, including clinical, pathological, and bacteriological evaluation. A female fish weighing 16 g initially showed discrete ulcerative lesions in the integument, inappetence, progressive weight loss, lethargy, dyspnea, and increased volume in the left lateral region. Necropsy revealed bilateral exophthalmia, corneal opacity, ascites, and subcutaneous abscess causing distension of the celomatic cavity. Histological changes of the skin were characterized by abscess, necrosis, hemorrhage, and inflammatory infiltrate consisting mainly of heterophils. Microbiological assays using the exudates and venous blood isolated exclusively A. faecalis.(AU)

Rhinocerebral and rhinopharyngeal conidiobolomycosis in sheep / Conidiobolomicose rinocerebral e rinofaríngea em ovinos

The present study aimed to report the occurrence as well as the clinical, laboratorial, pathological and mycological findings of three outbreaks of rhinocerebral and rhinopharyngeal conidiobolomycosis in sheep from Rio Grande do Norte state, Brazil. A total of six sheep with clinical signs of conidiobolomycosis were evaluated, and information on history was obtained from ranchers. Clinical signs included depression, progressive emaciation, sero-sanguinolent nasal discharge, tachycardia, dyspnea, miosis and unilateral exophthalmia with increased ocular globe volume, corneal ulceration and nervous system signs. The main hematological alteration was neutrophilia. Serum biochemical evaluation revealed increased values for AST, GGT, creatinine, urea, and glucose, and decreased total proteins and albumin levels. Cerebrospinal fluid analysis showed the presence of fibrin reticules and pleocytosis. Upon necropsy, longitudinal sections of the head revealed the presence of a nodular mass with a friable consistency and a white-yellowish coloration. Microscopic findings included meningitis, cortex necrosis and encephalitis with the presence of eosinophilic Splendore-Hoeppli substance. Histopathology of the lungs revealed a Splendore-Hoeppli-like material and hyperplasia of alveolar and bronchiolar epithelium. Renal lesions were suggestive of amyloidosis.

O presente estudo objetivou relatar a ocorrência e os achados clínicos, laboratoriais, patológicos e micológicos de três surtos de conidiobolomicose rinocerebral e rinofaríngea em ovinos do estado do Rio Grande do Norte, Brasil. Um total de seis ovinos com sinais clínicos de conidiobolomicose foi avaliado, e informações sobre o histórico foram obtidas dos proprietários. Os sinais clínicos incluíram depressão, emaciação progressiva, descarga nasal serossanguinolenta, taquicardia, dispneia, miosite e exoftalmia unilateral com aumento do volume do globo ocular, ulceração da córnea e sinais nervosos. A principal alteração hematológica foi neutrofilia. A avaliação bioquímica sérica revelou aumento nos valores de AST, GGT, creatinina, ureia e glicose, e redução nos níveis de proteínas totais e albumina. A análise do fluido cerebrospinal revelou presença de retículos de fibrina e pleocitose. À necropsia, secções longitudinais da cabeça revelaram presença de uma massa nodular com consistência friável e coloração branco-amarelada. Os achados microscópicos incluíram meningite, necrose do córtex e encefalite com presença da substância eosinofílica de Splendore-Hoeppli. A histopatologia dos pulmões revelou uma substância similar à de Splendore-Hoeppli e hiperplasia do epitélio alveolar e bronquiolar. As lesões renais foram sugestivas de amiloidose.

Sandflies (Psychodidae: Phlebotominae) survey in an urban transmission area of visceral leishmaniasis, Northeastern Brazil.

Visceral leishmaniasis (VL) is a major public health challenge in Brazil, especially in states where it is endemic. The aim of this study was to investigate the relationship of sand fly population density with environmental variables (temperature, rainfall and relative humidity) in urban areas of the city of Mossoró, Rio Grande do Norte, Northeastern Brazil. Sand flies were captured with Center Disease Control (CDC) traps installed monthly in the intra and peridomicile of three houses. Data analysis was based on the chi-square test and linear regression. A total of 7,347 sand flies were captured, being 93.85% Lutzomyia longipalpis and 6.15% Lutzomyia evandroi. Sand flies were more commonly found in the peridomicile and there was no difference between the number of males and females. The variables rainy season as well as relative humidity and rainfall, alone or together, did not have an effect on sand fly population density. However, high temperatures had a negative effect. The study of the behavior of sand flies in specific units of endemic areas can provide input to public health authorities for planning appropriate VL vector control measures.

Sandflies (Psychodidae: Phlebotominae) survey in an urban transmission area of visceral leishmaniasis, Northeastern Brazil / Pesquisa de flebotomíneos (Psychodidae: Phlebotominae) em área urbana de transmissão de leishmaniose visceral no Nordeste do Brasil

Visceral leishmaniasis (VL) is a major public health challenge in Brazil, especially in states where it is endemic. The aim of this study was to investigate the relationship of sand fly population density with environmental variables (temperature, rainfall and relative humidity) in urban areas of the city of Mossoró, Rio Grande do Norte, Northeastern Brazil. Sand flies were captured with Center Disease Control (CDC) traps installed monthly in the intra and peridomicile of three houses. Data analysis was based on the chi-square test and linear regression. A total of 7,347 sand flies were captured, being 93.85 percent Lutzomyia longipalpis and 6.15 percent Lutzomyia evandroi. Sand flies were more commonly found in the peridomicile and there was no difference between the number of males and females. The variables rainy season as well as relative humidity and rainfall, alone or together, did not have an effect on sand fly population density. However, high temperatures had a negative effect. The study of the behavior of sand flies in specific units of endemic areas can provide input to public health authorities for planning appropriate VL vector control measures.

A leishmaniose visceral (LV) é um grande desafio para a saúde pública no Brasil, particularmente nos estados onde é endêmica. O objetivo deste estudo foi verificar a relação da densidade populacional de flebotomíneos com as variáveis ambientais (temperatura, precipitação de chuva e umidade relativa do ar) em bairros urbanos de Mossoró, Rio Grande do Norte. Os flebotomíneos foram capturados com armadilhas CDC instaladas mensalmente no intra e peridomicílio de três casas. A análise dos dados foi baseada no teste Qui-quadrado e na regressão linear. Foram capturados 7.347 flebotomíneos, sendo 93,85 por cento Lutzomyia longipalpis e 6,15 por cento Lutzomyia evandroi. Os flebotomíneos foram encontrados mais comumente no peridomicílio e nenhuma diferença significativa entre o número de machos e fêmeas foi observada. As variáveis estação chuvosa, bem como a umidade relativa e precipitação de chuva, associadas ou isoladas, não influenciou a densidade populacional dos flebotomíneos. No entanto, a alta temperatura afetou essa densidade de forma negativa. Portanto, este estudo específico em áreas endêmicas é importante, porque as agências de Saúde Pública podem usar essas informações para um planejamento adequado das medidas de controle de vetores LV.

Monitoring of Lutzomyia longipalpis Lutz & Neiva, 1912 in an area of intense transmission of visceral leishmaniasis in Rio Grande do Norte, Northeast Brazil.

Urban increase of visceral leishmaniasis (VL) in Brazil is associated with the adaptation of its vector, Lutzomyia longipalpis, to environments modified by humans. The present study reports the results of an entomological monitoring of L. longipalpis and the effect of environmental variables on its population density. Sandflies were captured in the municipality of Mossoró, State of Rio Grande do Norte, Northeastern Brazil, from January 2005 to December 2006. Two CDC light traps were placed monthly for four consecutive nights in the peridomicile of selected households. Data analysis was based on the chi-square test and linear regression. A total of 2,087 sandflies were captured, 99.86% of which were L. longipalpis. A higher proportion of females were captured (p < 0.05). Monthly analysis of the variables temperature, relative humidity and rainfall did not show a significant influence on population density. However, there were seasonal differences: approximately 70% of sand flies were captured during the rainy season (p < 0.05). The predominant species, L. longipalpis, is present in substantial number, representing a public health risk. Therefore, because of higher prevalence during the rainy season, we recommend intensified VL control measures before and during this season to reduce the risk of disease transmission.

Monitoring of Lutzomyia longipalpis Lutz & Neiva, 1912 in an area of intense transmission of visceral leishmaniasis in Rio Grande do Norte, Northeast Brazil / Monitoramento de Lutzomyia longipalpis Lutz & Neiva, 1912 em área de transmissão intensa de leishmaniose visceral no Rio Grande do Norte, Nordeste do Brasil

Urban increase of visceral leishmaniasis (VL) in Brazil is associated with the adaptation of its vector, Lutzomyia longipalpis, to environments modified by humans. The present study reports the results of an entomological monitoring of L. longipalpis and the effect of environmental variables on its population density. Sandflies were captured in the municipality of Mossoró, State of Rio Grande do Norte, Northeastern Brazil, from January 2005 to December 2006. Two CDC light traps were placed monthly for four consecutive nights in the peridomicile of selected households. Data analysis was based on the chi-square test and linear regression. A total of 2,087 sandflies were captured, 99.86 percent of which were L. longipalpis. A higher proportion of females were captured (p < 0.05). Monthly analysis of the variables temperature, relative humidity and rainfall did not show a significant influence on population density. However, there were seasonal differences: approximately 70 percent of sand flies were captured during the rainy season (p < 0.05). The predominant species, L. longipalpis, is present in substantial number, representing a public health risk. Therefore, because of higher prevalence during the rainy season, we recommend intensified VL control measures before and during this season to reduce the risk of disease transmission.

No Brasil, o crescimento urbano da leishmaniose visceral (LV) está associado com a adaptação do seu vetor, Lutzomyia longipalpis, aos ambientes modificados pelo homem. Este estudo relata a vigilância entomológica de L. longipalpis e os efeitos das variáveis ambientais sobre a sua densidade populacional. Os flebotomíneos foram capturados no município de Mossoró, Rio Grande do Norte, no Nordeste do Brasil, a partir de janeiro de 2005 a dezembro de 2006. Duas armadilhas tipo CDC foram colocadas mensalmente durante quatro noites consecutivas no peridomicílio das casas escolhidas. A análise dos dados foi baseada no teste Qui-quadrado e regressão linear. Um total de 2.087 flebotomíneos foram capturados, dos quais 99,86 por cento foram L. longipalpis. Mais fêmeas do que machos foram capturados (p < 0,05). Na análise mensal das variáveis ambientais a temperatura, umidade relativa e a chuva não tiveram impacto significativo sobre a densidade populacional de L. longipalpis. No entanto, houve diferenças sazonais: aproximadamente 70 por cento dos flebotomíneos foram capturados durante a estação chuvosa (p < 0,05). Assim, L. longipalpis, a espécie predominante, representa um risco à saúde pública. Portanto, devido à maior prevalência no período chuvoso, recomendamos intensificar as medidas de controle da LV antes e durante este período para reduzir o risco de transmissão da doença.

Comportamentos espontâneos e induzidos em ratos com dor neuropática por constrição crônica do nervo ciático / Spontaneous and induced behaviors in rats with neuropathic pain by chronic sciatic nerve constriction

JUSTIFICATIVA E OBJETIVOS: A dor neuropática é uma condição frequente e desafiadora no que concerne ao tratamento, necessitando assim do uso de modelos experimentais para a melhor compreensão de seus mecanismos. O objetivo deste estudo foi reproduzir cirurgicamente o modelo de constrição crônica do nervo ciático e quantificar os comportamentos auto-dirigidos sugestivos de dor neuropática crônica experimental durante quatro semanas.MÉTODO: Foram utilizados 21 ratos Wistar divididos em três grupos: normal (n = 7), pseudo-cirúrgico (n = 7) e cirúrgico (n = 7). No grupo pseudo-cirúrgico, procedeu-se apenas a exposição bilateral do nervo ciático, sem lesioná-los. No grupo cirúrgico procedeu-se a exposição do nervo ciático à direita e então constrição com fio mononylon 4.0 em quatro locais, separados por 2 mm de distância. No membro esquerdo, fez-se apenas exposição do nervo ciático, sem lesioná-lo. RESULTADOS: A análise dos comportamentos revelou um aumento significativo (p < 0,05) de coçar-se e morder-se nos membros posteriores direito e esquerdo (em espelho), com predomínio à direita. Além disso, houve diminuição significativa de empinar-se e exploratórios como correr, andar, farejar, e aumento significativo de descansar/dormir e congelar-se. A análise dos testes térmicos revelou presença de alodínia (40º C) e hiperalgesia (46º C) nos membros posteriores direito e esquerdo.CONCLUSÃO: O modelo induziu mononeuropatia ciática dolorosa expressa por comportamentos espontâneos sugestivos de dor crônica, além de alodínia e hiperalgesia.

BACKGROUND AND OBJECTIVES: Neuropathic pain is a frequent and challenging condition in terms of management, thus requiring the use of experimental models to better understand its mechanisms. This study aimed at surgically reproducing chronic sciatic nerve constriction model and at quantifying self-directed behaviors suggestive of experimental chronic neuropathic pain during four weeks.METHOD: Twenty-one Wistar rats were divided in three groups: normal (n = 7), pseudo-surgical (n = 7) and surgical (n = 7). The pseudo-surgical group was submitted to bilateral sciatic nerve exposure without injury. The surgical group was submitted to right sciatic nerve exposure and constriction with mononylon thread 4.0 in four sites 2 mm apart from each other. Left sciatic nerve was exposed without injury. RESULTS: Behavioral analysis has shown significant increase (p < 0.05) in scratching and biting right and left hind limbs (in mirror), predominantly to the right. In addition there has been significant decrease in rearing up and exploratory behaviors such as running, walking and sniffing, and significant increase in resting / sleeping and freezing. Thermal tests analysis has shown allodynia (40º C) and hyperalgesia (46º C) in right and left hind limbs. CONCLUSION: The model has induced painful sciatic single neuropathy expressed by spontaneous behaviors suggestive of chronic pain, in addition to allodynia and hyperalgesia

The effects of the fungus Metarhizium anisopliae var. acridum on different stages of Lutzomyia longipalpis (Diptera: Psychodidae).

The control of Visceral Leishmaniasis (VL) vector is often based on the application of chemical residual insecticide. However, this strategy has not been effective. The continuing search for an appropriate vector control may include the use of biological control. This study evaluates the effects of the fungus Metarhizium anisopliae var. acridum on Lutzomyia longipalpis. Five concentrations of the fungus were utilized, 1 x 10(4) to 1 x 10(8) conidia/ml, accompanied by controls. The unhatched eggs, larvae and dead adults previously exposed to fungi were sown to reisolate the fungi and analysis of parameters of growth. The fungus was subsequently identified by PCR and DNA sequencing. M. anisopliae var. acridum reduced egg hatching by 40%. The mortality of infected larvae was significant. The longevity of infected adults was lower than that of negative controls. The effects of fungal infection on the hatching of eggs laid by infected females were also significant. With respect to fungal growth parameters post-infection, only vegetative growth was not significantly higher than that of the fungi before infection. The revalidation of the identification of the reisolated fungus was confirmed post-passage only from adult insects. In terms of larvae mortality and the fecundity of infected females, the results were significant, proving that the main vector species of VL is susceptible to infection by this entomopathogenic fungus in the adult stage.