Mecanismos de expressão de resistência aos antibióticos e saúde pública / Mechanisms of expression of resistance to antibiotics and public health / Mecanismos de expresión de la resistencia a los antibióticos y salud pública

Com o avanço da medicina e o aumento do uso de antimicrobianos, a resistência microbiana vem se tornando um problema sério na saúde pública. Para que uma bactéria se torne resistente, são necessários vários fatores, entre eles, o uso indiscriminado e prolongado de antimicrobianos e as resistências intrínsecas e adquiridas. Nesse contexto, o objetivo do trabalho foi explorar os mecanismos de ação dos antimicrobianos, de resistência e a sua importância na saúde pública. Foram utilizadas para a presente pesquisa, as bases de dados Pubmed, Google acadêmico e Scielo. Segundo a Organização Mundial da Saúde define-se resistência ao antibiótico quando o mesmo não produz mais efeito. A inserção cada vez mais frequente de antimicrobianos favorece a resistência, onde provocam uma pressão seletiva sobre os microrganismos, tornando-os resistentes a diversas drogas. O uso indiscriminado de antimicrobianos é o principal fator de resistência microbiana, assim como o uso de antimicrobianos sem exame de cultura e teste de sensibilidade. Neste sentido, conclui-se que é de suma importância a atualização de protocolos que contenham os mecanismos de resistência bacteriana a fim de minimizar o uso indiscriminado de antimicrobianos, assim como capacitar os profissionais da saúde para este problema na saúde pública.

With the advance of medicine and the increase in the use of antimicrobials, microbial resistance has become a serious problem in public health. For a bacterium to become resistant, several factors are necessary, among them, the indiscriminate and prolonged use of antimicrobials and the intrinsic and acquired resistance. In this context, the objective of the work was to explore the mechanisms of action of antimicrobials, resistance and their importance in public health. Pubmed, Google academic and Scielo databases were used for this research. According to the World Health Organization, resistance to antibiotics is defined when it no longer has an effect. The increasingly frequent insertion of antimicrobials favors resistance, where they put selective pressure on microorganisms, making them resistant to various drugs. The indiscriminate use of antimicrobials is the main factor of microbial resistance, as well as the use of antimicrobials without culture examination and sensitivity test. In this sense, it is concluded that it is extremely important to update protocols that contain the mechanisms of bacterial resistance in order to minimize the indiscriminate use of antimicrobials, as well as to train health professionals for this problem in public health.

Con los avances de la medicina y el mayor uso de antimicrobianos, la resistencia microbiana se ha convertido en un grave problema de salud pública. Para que una bacteria se vuelva resistente son necesarios varios factores, entre ellos, el uso indiscriminado y prolongado de antimicrobianos y la resistencia intrínseca y adquirida. En este contexto, el objetivo de este trabajo fue explorar los mecanismos de acción de los antimicrobianos, la resistencia y su importancia en la salud pública. Para esta investigación se utilizaron las bases de datos Pubmed, Google Scholar y Scielo. Según la Organización Mundial de la Salud, la resistencia a un antibiótico se define cuando deja de producir efecto. El uso cada vez más frecuente de antimicrobianos favorece la resistencia, ya que provocan una presión selectiva sobre los microorganismos, haciéndolos resistentes a varios fármacos. El uso indiscriminado de antimicrobianos es el principal factor de resistencia microbiana, así como el uso de antimicrobianos sin pruebas de cultivo y sensibilidad. En este sentido, se concluye que es de suma importancia actualizar los protocolos que contienen los mecanismos de resistencia bacteriana para minimizar el uso indiscriminado de antimicrobianos, así como capacitar a los profesionales de la salud para este problema en la salud pública.

Comparação da pressão arterial mensurada pelos métodos oscilométrico ou invasivo em ovinos e caprinos / Comparison of blood pressure measured by oscillometric or invasive methods in sheep and goats / Comparación de la presión arterial medida por métodos oscilométricos o invasivos en ovinos y caprinos

Resumo A pressão arterial é um parâmetro indispensável na monitorização anestésica. A mensuração da pressão artéria invasiva (iPA) mediante cateterização arterial periférica é confiável, mas requer experiência e pode desencadear complicações. A técnica oscilométrica não é invasiva (NiPA), só requer um manguito sobre uma artéria periférica e a mensuração é automatizada. Não obstante a acurácia da NiPA tem sido pouco explorada e, por tal motivo, este estudo objetivou comparar esta técnica com a iPA em ovelhas e cabras. Foram utilizadas 20 ovelhas e 20 cabras que seriam submetidas a laparoscopia sob anestesia geral. Uma vez em plano anestésico, foi cateterizada a artéria auricular caudal e conectada a um transdutor eletrônico de pressão acoplado a monitor multiparamétrico para mensuração da iPA, sistólica (S), diastólica (D) e média (M). Ao mesmo tempo um manguito de tamanho apropriado foi posicionado sobre a artéria radial e conectado ao mesmo monitor. A cada 5 minutos foram registradas as pressões arteriais por ambos os métodos, posteriormente, comparadas pelo teste Student, correlacionados pelo Pearson e avaliada a concordância pelo Bland-Altman. Nas ovelhas, a PAD foi semelhante e correlacionada entre NiPA e iPA (P=0,69; r=0,65; viés 0,7 ± 13,1 mmHg), já a PAS e PAM foram superestimadas pela NiPA. Em Cabras, a PAM resultou semelhante e correlacionada entre NiPA e iPA (P=0,566; r=0,57; viés 2,4 ± 20,2 mmHg), enquanto PAS foi superestimada e PAD subestimada. Conclui-se que, em ovelhas apenas a PAD e em cabras a PAM, mensuradas pelo método oscilométrico, são alternativas acuradas, factíveis e confiáveis para a monitoração anestésica da pressão arterial.

Abstract Blood pressure is an indispensable parameter in anesthetic monitoring. The measurement of invasive artery pressure (IBP) using peripheral arterial catheterization is reliable but requires experience and can lead to complications. The oscillometric technique is non-invasive (NIBP), it only requires a cuff over a peripheral artery and the measurement is automated. However, the accuracy of PANI has been little explored and, for this reason, this study aimed to compare this technique with PAI in sheep and goats. 20 sheep and 20 goats needed laparoscopy were used under general anesthesia. Once in anesthetic plane, the caudal auricular artery was catheterized and connected to an electronic pressure transducer, coupled to a multiparameter monitor to measure IBP, systolic (S), diastolic (D) and mean (M). At the same time, an appropriately sized cuff was placed over radial artery and connected to the same monitor. Every 5 minutes, blood pressures were recorded by both methods, subsequently compared by the Student test, correlated by Pearson and agreement assessed by the Bland-Altman. In sheep, DBP was similar and correlated between NIBP and IBP (P=0.69; r=0.65; bias 0.7 ± 13.1 mmHg), whereas SBP and MBP were overestimated by NIBP. In goats, MAP was similar and correlated between NIBP and IBP (P=0.566; r=0.57; bias 2.4 ± 20.2 mmHg), while SBP was overestimated and DBP underestimated. It is concluded that, in sheep only DBP and in goats, MBP, measured by the oscillometric method, are accurate, feasible and reliable alternatives for anesthetic monitoring of blood pressure.

Resumen La presión arterial es un parámetro indispensable en la monitorización anestésica. La medición de la presión arterial invasiva (PAI) mediante cateterismo arterial periférico es fiable, requiere experiencia y puede dar complicaciones. La técnica oscilométrica no es invasiva (PANI), requiere un manguito sobre una arteria periférica y medición automatizada. No obstante, la precisión de PANI ha sido poco explorada, por esta razón, este estudio tuvo por objetivo comparar esta técnica con la PAI en ovinos y caprinos. Se utilizaron 20 ovejas y 20 cabras que requerían laparoscopia bajo anestesia general. Una vez en plano anestésico, se cateterizó la arteria auricular caudal y se conectó a transductor de presión electrónico acoplado a monitor multiparamétrico para medir la PAI, sistólica (S), diastólica (D) y media (M). Al mismo tiempo, se colocó un manguito de tamaño adecuado sobre la arteria radial y se conectó al mismo monitor. Cada 5 minutos se registraron las presiones por ambos métodos, posteriormente se compraron por test de Student, correlacionaron por Pearson y se evaluó concordancia por Bland-Altman. En ovejas, la PAD fue similar y se correlacionó entre PANI y PAI (P=0,69; r=0,65; sesgo 0,7 ± 13,1 mmHg), mientras que PAS y MAP fueron sobreestimadas por PANI. En Cabras, la PAM fue similar y se correlacionó entre PANI y PAI (P=0,566; r=0,57; sesgo 2,4 ± 20,2 mmHg), mientras PAS se sobreestimó y PAD se subestimó. Se concluye que, en ovinos solo PAD y en caprinos PAM, medidas por el método oscilométrico son alternativas precisas, factibles y confiables para el monitoreo anestésico de la presión arterial.

Production and use of immunoglobulin Y in the diagnosis of haemorrhagic septicemia caused by Aeromonas hydrophila in Piaractus mesopotamicus

Aeromonas hydrophila is an opportunistic pathogen frequently isolated from outbreaks with higher mortality rates in tropical farms, causing disease in pacus Piaractus mesopotamicus. The objective of this study was to obtain a purified polyclonal immunoglobulin Y (IgY) by immunizing laying White Leghorn hens with A. hydrophila. Antibodies anti-A. hydrophila derived from the yolks and serum of hens showed antibody titres increased at 60 days and remained detectable until 90 days after immunization. Pacus were challenged intraperitoneally with A. hydrophila and the capacity of antibodies to detect A. hydrophila was tested by immunohistochemistry using tissues from pacus. The results observed in this study demonstrated the utility of IgY for the diagnosis of A. hydrophila within the phagosomes of phagocytes and extracellular bacteria colonizing host tissues in pacus.

Immunogenicity in Oreochromis niloticus vaccinated with sonicated antigens against streptococcosis.

Streptococcosis causes great economic losses in intensive culture of tilapia. Vaccination is the most effective and safest way to tackle infectious diseases. Thus, this study sought the more effective and safer antigenic fraction after sonication of Streptococcus agalactiae to elaborate a vaccine against streptococcosis in Nile tilapia. For this, twenty-one days after vaccination with different fractions (soluble and insoluble) of S. agalactiae, the fish were challenged with the homologous strain (LD50). Then, samples were taken at zero, 14, 28, 60 and 90 days post-vaccination (DPV, n = 7). Blood and organs (cranial kidney, spleen and liver) were collected from vaccinated and unvaccinated fish. Finally, insoluble fraction vaccine presented the best effect, resulting in a 100% relative percent of survival (RPS) and without clinical manifestations. In view of the results, it was to evaluate the role of the insoluble fraction of the antigen in the protective immunity against streptococcosis. The results indicate that the spleen might be the main organ in the vaccine response in Nile tilapia due to the great morphological and immunological differences in vaccinated fish, evidenced by the greater of melanomacrophage centers (MMC) and IgM + lymphocytes in relation to the non-vaccinated fish. At 60 DPV, it was observed the peak of the protective immunity related to the maximum concentration of proteins, circulating leukocytes, antibody titers in the serum and tissue changes with greater expression of IgM + and MMC number in the spleen and kidney of Oreochromis niloticus. Vaccination with insoluble fraction of S. agalactiae was safe and provided effective protection against streptococcosis with maximum protective response at 60 DPV.

Pionefrose unilateral em cão - relato de caso / Unilateral pyonephrosis in a dog - case report / Pionefrosis unilateral en perro - relato de caso

A pionefrose consiste em uma hidronefrose contaminada, associada à destruição do parênquima renal. Tem como causas o bloqueio ureteral ou uretral por urólitos, inflamação crônica, neoplasia e ureter ectópico, seguidos de contaminação. O diagnóstico é realizado através de exames de imagem, principalmente a ultrassonografia e também através de urinálise e urocultura. Em casos avançados o tratamento preconizado é a nefrectomia. O presente trabalho tem como objetivo relatar um caso de um cão com suspeita inicial de hidronefrose. O paciente passou por nefrectomia, no pós-operatório observou-se melhora do seu quadro clínico, porém permanecendo a anemia. O diagnóstico definitivo, realizado por exame histopatológico, revelou pionefrose, entretanto sua causa não foi estabelecida.(AU)

Pyonephrosis consists of a contaminated hydronephrosis associated with the destruction of the renal parenchyma. Its causes include ureter or urethra blockage by uroliths, chronic inflammation, neoplasm, and ectopic ureter, followed by contamination. The diagnosis is made through image exams, mainly ultrasound, and also through urinalysis and uroculture. In advanced cases, nephrectomy is the recommended treatment. The objective of this study is to report a case of a dog with initial suspicion of hydronephrosis. The patient underwent nephrectomy, and during the postoperative period, an improvement in the clinical scenario was observed, despite the persistent anemia. The definitive diagnosis, carried out by histopathological examination, revealed pyonephrosis; however, its cause was not established.(AU)

La pionefrosis es una hidronefrosis contaminada, asociada con la destrucción del parénquima renal. Sus causas son el bloqueo ureteral o uretral por urolitos, inflamación crónica, neoplasia y uréter ectópico, seguido de contaminación. El diagnóstico se realiza mediante exámenes de imágenes, principalmente ultrasonografía y también mediante análisis de orina y urocultivo. En casos avanzados el tratamiento recomendado es la nefrectomía. Este artículo tiene como objetivo informar un caso de un perro con sospecha inicial de hidronefrosis. El paciente se sometió a nefrectomía; después de la operación, su estado clínico mejoró, pero la anemia permaneció. El diagnóstico definitivo realizado por el examen histopatológico reveló pionfrosis, sin embargo, su causa no se ha establecido.(AU)

Clinical features and corneal optical anisotropies in a rabbit model of limbal stem cell deficiency / Fenótipos clínicos e anisotropias ópticas da córnea em coelhos com deficiência de células tronco limbais

ABSTRACT Purposes: To investigate the intra-laboratory reproducibility of clinical features and to evaluate corneal optical anisotropies in a rabbit model of limbal stem cell deficiency. Methods: Limbal injury was induced in the right eye of 23 adult New Zealand White rabbits using a highly aggressive protocol that combined 360 degrees limbal peritomy, keratolimbectomy, alkaline chemical burn, and mechanical removal of the epithelium. Clinical evaluation of the injured eyes was performed for 28 days and included corneal impression cytology. Corneas with a severe clinical outcome set typical of limbal stem cell deficiency were then collected, subjected to a histopathological examination, and examined for optical anisotropies. Corneas from healthy rabbit eyes were used as controls. Differences in optical path due to stromal collagen birefringence, as well as linear dichroism related to the expression and spatial orientation of glycosaminoglycan chains from proteoglycans, were measured from cross-sections under a quantitative polarized light microscope. Results: One eye showed signs of hypopyon and was excluded. Signs of ocular inflammation were observed in all eyes studied (n=22). Corneal impression cytology did not detect goblet cells. Twelve of the 22 corneas presented a clinical outcome set typical of limbal stem cell deficiency, which is characterized by the presence of epithelial defects, inflammatory cells, moderate-to-severe opacity, and neovascularization. Microscopic studies under polarized light revealed that relative to controls, limbal stem cell deficiency caused a 24.4% increase in corneal optical path differences. Further, corneas with limbal stem cell deficiency were less dichroic than controls. Conclusions: These results suggest that rabbit models of limbal stem cell deficiency must be rigorously screened for use in preclinical studies to ensure experimental homogeneity because protocols used to create limbal stem cell deficiency could be not associated with good intra-laboratory reproducibility of clinical features. Limbal stem cell deficiency, as induced herein, altered the optical anisotropic properties of the corneal stroma. Such alterations are indicative of changes in collagen packing and the spatial orientation of glycosaminoglycan chains from proteoglycans. Knowledge of these changes is important to potentiate strategies aimed at restoring the morphofunctional integrity of the corneal stroma affected by limbal stem cell deficiency.

RESUMO Objetivos: Investigar a reprodutibilidade intra-la­boratorial dos fenótipos clínicos e avaliar anisotropias ópticas em córneas de coelhos com deficiência de células tronco limbais. Métodos: Lesões ao limbo foram feitas no olho direito de 23 coelhos adultos da Nova Zelândia Branco, usando um protocolo altamente agressivo, que envolveu peritomia limbal em 360 graus, ceratolimbectomia, cauterização por álcali, e remoção mecânica de epitélio remanescente. Os olhos foram clinicamente avaliados por 28 dias, inclusive por citologia de impressão corneal. As córneas que manifestaram um conjunto de alterações típicas de deficiência de células tronco limbais foram coletadas e submetidas à estudos em histopatologia e em anisotropias ópticas. Córneas saudáveis foram usadas como controles. Diferenças de caminho óptico de birrefringência relacionada à organização do colágeno estromal, e dicroísmo linear relacionado à expressão e à orientação das cadeias de glicosaminoglicanos dos proteoglicanos estromais, foram quantificados por microscopia de luz polarizada. Resultados: Um olho apresentou hipópio e foi excluído do estudo. Todos os olhos estudados (n=22) apresentaram sinais de inflamação ocular. A citologia de impressão não detectou células caliciformes na superfície corneal. Doze de 22 córneas manifestaram alterações clínicas típicas de deficiência de células tronco limbais, caracterizado por defeitos epiteliais, infiltrados inflamatórios, opacidade de moderada à severa, e neovascularização. Estudos por microscopia de luz polarizada mostraram que a deficiência de células tronco limbais aumentou a diferenças de caminho óptico corneal em 24,4% (versus controles). As cór­neas com deficiência de células tronco limbais foram menos dicroicas do que as córneas controle. Conclusões: Coelhos com deficiência de células tronco limbais, para aplicações em estudos pré-clínicos, devem ser rigorosamente selecionados para assegurar homogeneidade experimental, pois há evidências de que protocolos utilizados para indução de deficiência de células tronco limbais não estão associados com boa reprodutibilidade intra-laboratorial de fenótipos clínicos. A deficiência de células tronco limbais, como induzida aqui, alterou as propriedades ópticas anisotrópicas do estroma corneal. Tais alterações são indicativas de mudanças no empacotamento de colágeno e na orientação das cadeias de glicosaminoglicanos dos proteoglicanos. Conhecimentos nessas alterações são importantes para potencializar estratégias que visam a restabelecer a integridade morfofuncional do estromal corneal acometido pela deficiência de células tronco limbais.

Clinical features and corneal optical anisotropies in a rabbit model of limbal stem cell deficiency.

PURPOSES: To investigate the intra-laboratory reproducibility of clinical features and to evaluate corneal optical anisotropies in a rabbit model of limbal stem cell deficiency. METHODS: Limbal injury was induced in the right eye of 23 adult New Zealand White rabbits using a highly aggressive protocol that combined 360 degrees limbal peritomy, keratolimbectomy, alkaline chemical burn, and mechanical removal of the epithelium. Clinical evaluation of the injured eyes was performed for 28 days and included corneal impression cytology. Corneas with a severe clinical outcome set typical of limbal stem cell deficiency were then collected, subjected to a histopathological examination, and examined for optical anisotropies. Corneas from healthy rabbit eyes were used as controls. Differences in optical path due to stromal collagen birefringence, as well as linear dichroism related to the expression and spatial orientation of glycosaminoglycan chains from proteoglycans, were measured from cross-sections under a quantitative polarized light microscope. RESULTS: One eye showed signs of hypopyon and was excluded. Signs of ocular inflammation were observed in all eyes studied (n=22). Corneal impression cytology did not detect goblet cells. Twelve of the 22 corneas presented a clinical outcome set typical of limbal stem cell deficiency, which is characterized by the presence of epithelial defects, inflammatory cells, moderate-to-severe opacity, and neovascularization. Microscopic studies under polarized light revealed that relative to controls, limbal stem cell deficiency caused a 24.4% increase in corneal optical path differences. Further, corneas with limbal stem cell deficiency were less dichroic than controls. CONCLUSIONS: These results suggest that rabbit models of limbal stem cell deficiency must be rigorously screened for use in preclinical studies to ensure experimental homogeneity because protocols used to create limbal stem cell deficiency could be not associated with good intra-laboratory reproducibility of clinical features. Limbal stem cell deficiency, as induced herein, altered the optical anisotropic properties of the corneal stroma. Such alterations are indicative of changes in collagen packing and the spatial orientation of glycosaminoglycan chains from proteoglycans. Knowledge of these changes is important to potentiate strategies aimed at restoring the morphofunctional integrity of the corneal stroma affected by limbal stem cell deficiency.

Dietary camu camu, Myrciaria dubia, enhances immunological response in Nile tilapia.

Camu camu, Myrciaria dubia, is an Amazon plant that presents high levels of vitamin C in its composition. Several studies in animals and humans have demonstrated their efficiency in the prevention and treatment of various diseases. However, there are no reports of its properties in fish. The aim of this study was to evaluate the effect of the oral administration of the extract of this plant in the immune parameters in Nile tilapia, Oreochromis niloticus. 400 Nile tilapia (80 ± 5 g) were randomly distributed into 20 tanks with 1500 L capacity each (20 fish/tank). After a week of adaptation to environmental conditions, it was provided a diet for 5 weeks, using different levels of inclusion of camu camu extract: 0, 50, 100, 250, and 500 mg/kg of feed. Each treatment consisted of four replicates. It was obtained 40.5 mg of vitamin C/g of camu camu pulp powder by high-performance liquid chromatography. At the end of the trial period, fish were inoculated with Aeromonas hydrophila in the swim bladder. Samples were taken after 6; 24 and 48 h of the challenge. Results revealed that fish supplemented with this herb showed significant increase (P < 0.05) in white blood cells counts in blood and exudate, burst respiratory activity, lysozyme activity, serum bactericidal activity, direct agglutination, and melanomacrophage centers count. Red blood cells count, hemoglobin, hematocrit, and biochemical profile of fish supplemented with the herb presented no statistical differences compared to control group (P > 0.05). No histopathological lesions were observed in intestine, kidney, spleen, and gills. It can be concluded that the addition of Myrciaria dubia in tilapia feed improves the immune response and the growth after 5 weeks, especially, at a dose of 500 mg/kg.

Uncaria tomentosa increases growth and immune activity in Oreochromis niloticus challenged with Streptococcus agalactiae.

Cat's claw (Uncaria tomentosa) is an Amazon herb using in native cultures in Peru. In mammals, it has been described several effects of this herb. However, this is the first report of its use on the diet of fish. The aim of this study was to determinate the effect of this plant on the growth and immune activity in Oreochromis niloticus. Nile tilapia (81.3 ± 4.5 g) were distributed into 5 groups and supplemented with 0 (non-supplement fish), 75, 150, 300, and 450 mg of U. tomentosa.kg(-1) of diet for a period of 28 days. Fish were inoculated in the swim bladder with inactivated Streptococcus agalactiae and samples were taken at 6, 24, and 48 h post inoculation (HPI). Dose dependent increases were noted in some of the evaluated times of thrombocytes and white blood cells counts (WBC) in blood and exudate, burst respiratory activity, lysozyme activity, melanomacrophage centers count (MMCs), villi length, IgM by immunohistochemistry in splenic tissue, and unexpectedly on growth parameters. However, dietary supplementation of this herb did not affect red blood cells count (RBC), hemoglobin, and there were no observed histological lesions in gills, intestine, spleen, and liver. The current results demonstrate for the first time that U. tomentosa can stimulate fish immunity and improve growth performance in Nile tilapia.

Parasitic infections in ornamental cichlid fish in the Peruvian Amazon.

The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57%) was the most parasitized, followed by Aequidens diadema (26.32%), Pterophyllum scalare (22.69%), Cichlasoma sp. (9.52%), Apistogramma sp. (3.88%) and Symphysodon aequifasciatus (3.66%). Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

Influence of temperature on streptococcus agalactiae infection in Nile tilapia / Influência da temperatura na infecção de tilápias do Nilo por Streptococcus agalactiae

Environmental changes affect fish homeostasis, turning them more susceptible to diseases. In Brazil, outbreaks of Streptococcus agalactiae infection have been reported in Nile tilapia when they are outside of their thermal comfort zone. This investigation evaluated mortality rate and which were the most infected organs at temperatures that naturally occurred in southern of Brazil. Forty Nile tilapia (Oreochromis niloticus) were infected with S. agalactiae and distributed in four groups (n=10) and each group was exposed to a different temperature: G1: 24°C, G2: 26°C, G3: 28°C, and G4: 32°C. Fish were monitored for 10 days. In this period, fish that presented irreversible clinical signs were sacrificed and samples of brain, liver, and kidney were collected for bacteriological and molecular analysis. Signs compatible with a streptococcal infection were observed in all groups. Highest mortality rates occurred at 24°C and 32°C. The brain was the most affected organ with the highest percentage of isolation of S. agalactiae by both methods of diagnosis. The results suggest that, as in mammals, temperatures that are further away from the comfort zone influence fish homeostasis, increasing susceptibility to bacterial infections.

Mudanças ambientais afetam a homeostase dos peixes, tornando-os mais suscetíveis a doenças. No Brasil, têm sido relatados surtos de infecção por Streptococcus agalactiae em tilápia do Nilo, principalmente quando se encontram fora da zona de conforto térmico. No presente trabalho, foi avaliada a taxa de mortalidade e determinado quais foram os órgãos mais afetados por essa bactéria em temperaturas que ocorrem naturalmente no Sul do Brasil. Quarenta tilápias-do-nilo (Oreochromis niloticus) foram infectadas por Streptococcus agalactiae e distribuídas em quatro grupos (n = 10), cada um deles submetidos a diferentes temperaturas: G1: 24°C, G2: 26°C, G3: 28°C e G4: 32°C. Os peixes foram monitorados durante 10 dias. Os peixes com sinais clínicos irreversíveis foram sacrificados e coletadas amostras de cérebro, fígado e rins para análise bacteriológica e molecular. Foram observados sinais compatíveis com infecção estreptocócica em todos os grupos. A taxa de mortalidade mais elevada ocorreu nos grupos mantidos nas temperaturas de 24°C e 32°C. O cérebro foi o órgão mais afetado, com a maior percentagem de isolamento de S. agalactiae pelos dois métodos de diagnóstico. Os resultados sugerem que, tal como nos mamíferos, temperaturas que estão mais afastadas da zona de conforto afetam significativamente a homeostase dos peixes, aumentando a sua susceptibilidade para infecções bacterianas.

Isolamento de Streptococcus agalactiae em diferentes órgãos de tilápias do nilo (Oreochromis niloticus) criadas em tanques-rede / Isolation of Streptococcus agalactiae in different organs of nile tilapia (Oreochromis niloticus) reared in net cages

A estreptococose é uma das principais causas de mortalidade na criação de tilápias no Brasil, causando grandes perdas econômicas. Assim, o estudo objetivou determinar a frequência de isolamento e identificação por PCR de Streptococcus agalactiae em diferentes órgãos de tilápias do Nilo (Oreochromis niloticus) naturalmente infectadas, oriundas de oito pisciculturas da região norte do estado do Paraná que apresentavam sinais clínicos característicos de infecção estreptocócica. Para tanto, coletaram-se amostras de sangue e fragmentos de rim, fígado, baço, coração e encéfalo. Essas foram semeadas em meio ágar infusão de cérebro e coração (BHI) adicionado 5% de sangue de ovino e incubados à 29ºC, durante 7 dias em aerofília. Após o crescimento bacteriano e a partir das características macro e microscópicas, foram selecionadas colônias compatíveis com as do gênero Streptococcus sp.. As espécies foram identificadas através de PCR e confirmadas por meio do sequenciamento do gene 16S rDNA. Os resultados demonstraram que em tilápias do Nilo infectadas com S. agalactiae, o isolamento é mais frequente em encéfalo, rim e fígado em ordem decrescente.

Streptococcosis is one of the major causes of mortality in tilapia's creation in Brazil, inducing great economic losses. As soon, the study objectived to determinate the frequency of isolation and identification the Streptococcus agalactiae in organs different of Oreochromis niloticus naturally infected, derived from eight fish farms in the northern region of the state of Paraná, that presented clinical signs characteristics of streptococcal disease. However, blood samples and fragments (kidney, liver, spleen, heart and brain) were collected. These all samples were plated on solid medium of brain and heart infusion (BHI) added 5% ovine blood and incubated at 29ºC for 7 days in aerophilic conditions. Behind, the bacterial growth and from the macro and microscopic features, colonies compatibles with Streptococcus sp. gender, were selected. The species were identified by PCR reaction and confirmed by sequencing of 16S rDNA gene. The results exhibited that in tilapia of Nile infected with S. agalactiae the isolation is more common in brain, kidney and liver in descending order.

Parasitic infections in ornamental cichlid fish in the Peruvian Amazon / Infestação parasitária em ciclídeos ornamentais da Amazônia de Peru

The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57%) was the most parasitized, followed by Aequidens diadema (26.32%), Pterophyllum scalare (22.69%), Cichlasoma sp. (9.52%), Apistogramma sp. (3.88%) and Symphysodon aequifasciatus (3.66%). Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

O objetivo deste estudo foi avaliar a prevalência e distribuição sazonal das principais espécies de parasitas em ciclídeos ornamentais amazônicos que afetam seu comércio. O estudo foi realizado entre agosto de 2007 e setembro de 2009. Foram amostrados 3042 espécimes de 9 espécies diferentes, das quais 9,47% tinham pelo menos um tipo de parasita externo. Na estação seca, ocorreram 81,25% dos casos. Crenicichla anthurus (28,57%) foi o mais parasitado, seguido por Aequidens diadema (26,32%), Pterophyllum scalare (22,69%), Cichlasoma sp. (9,52%), Apistogramma sp. (3,88%), e Symphysodon aequifasciatus (3,66%). Monogenea foi o grupo mais abundante de parasitas, ocorrendo em 66,67% dos casos. Na estação seca, ocorreram 96,88% deles. Este parasita infestou 95,68% dos casos em Pterophyllum scalare, 76,67% em Apistogramma sp., 33,33% em Cichlasoma sp. e 23,81% em Symphysodon aequifasciatus. Ichthyophthirius multifiliis infestou 100% dos casos em Aequidens diadema, 76,19% em Symphysodon aequifasciatus, 66,67% em Cichlasoma sp., 41,67% em Crenicichla anthurus e 23,33% em Apistogramma sp.; Myxosporidia infestou 58,33% dos casos em Crenicichla anthurus; Trichodina infestou 4,32% dos casos em Pterophyllum scalare. A prevalência desses parasitas está relacionada com a época do ano, hábitat preferido, comportamento dos peixes, suscetibilidade individual e manejo dos animais durante o transporte pelos pescadores.

Acute Toxicity and Determination of the Active Constituents of Aqueous Extract of Uncaria tomentosa Bark in Hyphessobrycon eques.

Uncaria tomentosa is a medicinal plant used in folk medicine by Amazon tribes. In this study the constituents of aqueous extract of U. tomentosa bark were quantified by chromatographic technique and its lethal concentration 50 (48 h) in Hyphessobrycon eques was determined. The chromatography showed high levels of oxindole alkaloids, quinovic acid glycosides, and low molecular weight polyphenols. The CL50 48 h was 1816 mg/L. Fish showed behavior changes at concentrations above 2000 mg/L, accompanied by a significant decrease of dissolved oxygen. At the highest concentration 100% mortality was observed attributed to oxygen reduction by the amount of oxindole alkaloids, polyphenols accumulation of the extract in the gills, and the interaction of these compounds with dopamine. In conclusion, the aqueous extract of U. tomentosa did not alter the chemical components and it was shown that U. tomentosa has low toxicity to H. eques; therefore, it can be used safely in this species.

Influence of glyceryl guaiacolate ether on anesthetics in tilapia compared to benzocaine and eugenol / Influencia del eter gliceril guayacolato sobre la anestesia en tilapias comparado con benzocaina y eugenol

Objective. The study aimed to investigate the effectiveness of glyceryl guaiacolate ether (GGE) and compare the times of induction, recovery, hematological changes, total protein and glycaemia among anesthetics in Nile tilapia, Oreochromis niloticus. Materials and methods. A total of 60 tilapia distributed in 3 aquariums (N=20) were used, which formed the group benzocaine (100 mg/L), eugenol (50 mg/L) and guaiacol glyceryl ether (9.000 mg/L). After the induction of anesthesia fish blood samples were collected to determine the complete hemogram and glycemia. Then the animals were placed in aquariums with running water for assessing the anesthesia recovery. Results. It was verified that GGE showed longer induction and recovery times as well a significant increase (p<0.05) of glycemia, when compared with the other groups (p<0.05). The concentration of total protein did not differ between groups (p>0.05). An increase in the number of monocytes in the group treated with benzocaine (p <0.05) was observed in the analysis of the hematological parameters with no difference between groups for other variables. Conclusions. Eugenol and benzocaine allow rapid induction and recovery in Nile tilapia, without evidence of stress during handling and GGE showed high induction and recovery times, being inadequate for anesthetic use in Nile tilapia.

Objetivo. El trabajo tuvo como objetivo investigar la eficacia del eter gliceril guayacolato (EGG) y comparar los tiempos de inducción, recuperación, alteraciones hematológicas, de proteínas totales y glicemia entre los anestésicos en tilapias del Nilo, Oreochromis niloticus. Materiales y métodos. Fueron utilizadas 60 tilapias distribuidas en 3 acuarios (n=20), que formaron los grupos benzocaína (100 mg/L), eugenol (50 mg/L) y éter gliceril guayacolato (9.000 mg/L). Después de la inducción anestésica se procedió a colectar la sangre para determinar el hemograma y glicemia. A seguir, los animales fueron colocados en acuarios con agua corriente para la evaluación de la recuperación anestésica. Resultados. Se verificó que el EGG presentó mayor tiempo de inducción y recuperación, así como aumento significativo (p<0.05) de la glicemia, cuando fue comparado con los otros grupos (p<0.05). La concentración de las proteínas totales no fueron diferentes entre los grupos (p>0.05). En el análisis de los parámetros hematológicos fue observado aumento del número de monocitos en el grupo tratado con benzocaína (p<0.05) sin diferencia ente los grupos para las otras variables. Conclusiones. El eugenol y la benzocaína permiten rápidas inducciones y recuperación en tilapias del Nilo, sin evidencias de estrés durante la manipulación y el EGG presenta tiempos elevados de inducción y recuperación, no siendo este adecuado para el uso en tilapias del Nilo.

Lectinhistoquímica del granuloma inducido por el bacilo de Calmette Guérin en Piaractus mesopotamicus / Lectinhistochemical staining of granuloma induced by bacillus Calmette-Guerin in Piaractus mesopotamicus

Objetive. This study was conducted to evaluate, by means of lectinhistochemistry (LHC), the expression of carbohydrates in granulomas induced by the bacillus Calmette-Guerin (BCG) in muscle tissue of Piaractus mesopotamicus after 33 days. Material and methods. Histological sections with 3 μm thick were incubated with the following lectins :WGA (Wheat germ agglutinin), DBA (Dolichos biflorus agglutinin) and HPA (Helix pomatia agglutinin), and the results were evaluated by light microscopy. Results. Acid fast bacilli were stained by Ziehl Neelsen (ZN) and strong labeled by WGA in the cytoplasm of macrophages. Labeling with DBA was intense in fibroblasts and weak in macrophages. On the other hand, HPA binding was stronger in macrophages, especially in those that were in close contact with epithelioid cells, without evidence of binding to fibroblasts. The epithelioid cells were not labeled by the used lectins, but they were identified by Hematoxilin-Eosin (HE). The lectins labeled specific type saccharides in glycoproteins, as N-acetylglucosamine present in bacilli and macrophages, as well as N-acetyl-galactosamine in macrophages. The control group showed no inflammation or lectin binding. Conclusions. This technique may be useful in identifying receptors for WGA, DBA and the HPA lectins in epithelioid granuloma induced by BCG in P. mesopotamicus.

El presente estudio fue realizado para evaluar por medio de lectinhistoquímica (LHC), la expresión de carbohidratos en granulomas inducidos por el bacilo de Calmette-Guérin (BCG) en músculo de Piaractus mesopotamicus después de 33 días. Materiales y métodos. Cortes histológicos de 3 µm de grosor fueron incubados con las siguientes lectinas: WGA (Wheat germ aglutinin), DBA (Dolichos biflorus agglutin) y HPA (Helix pomatia agglutinin), y los resultados evaluados por medio de microscopia de luz. Resultados. Bacilos ácido resistentes fueron identificados por la tinción de Ziehl Neelsen(ZN). Se observó un marcaje intenso con WGA en el citoplasma de macrófagos. El marcaje con DBA fue intenso en fibroblastos y débil en macrófagos. Con la lectina HPA el marcaje fue intenso en macrófagos, principalmente en los que estaban en estrecho contacto con las células epitelióides, externamente se observó marcaje débil en fibroblastos. Las células epitelióides no fueron marcadas por las lectinas, pero fueron identificadas con la tinción de Hematoxilina-Eosina (HE). Las lectinas tuvieron un tipo de marcaje específico en algunos monosacáridos, como N-acetilglucosamina presente en los bacilos y en macrófagos, y N-acetilgalactosamina en macrófagos. En el grupo control no fue observada inflamación así como tampoco marcaje con las lectinas. Conclusiones. Esta técnica resultó eficiente en la identificación de receptores para las lectinas WGA, DBA y HPA en el granuloma epitelióide inducido por BCG en P. mesopotamicus.

Acute aerocystitis in Piaractus mesopotamicus: participation of eicosanoids and pro-inflammatory cytokines.

A total of 360 pacus (Piaractus mesopotamicus) were used to study vascular permeability (VP) and inflammatory cell component (CC) in induced aerocystitis in P. mesopotamicus through inoculation of inactivated Aeromonas hydrophila, and the effect of steroidal and nonsteroidal anti-inflammatory drugs. It was observed that after inoculation of A. hydrophila, the maximum VP occurred 180 min post-stimulus (MPS). Pretreatment with anti-inflammatory drugs inhibited VP, and the inhibitory effect of dexamethasone was seen earlier than the effects caused by meloxicam and indomethacin. Inoculation of the bacterium caused a gradual increase in the accumulation of cells, which reached a maximum 24 h post-stimulus (HPS). Pretreatment with dexamethasone, indomethacin and meloxicam reduced the accumulation of lymphocytes, thrombocytes, granulocytes and macrophages. There was no significant difference between the different doses of the drugs tested. The results suggest that eicosanoids and pro-inflammatory cytokines participate in chemical mediation in acute inflammation in pacus.