Resumo
Abstract Application of different fertilizers to check the efficiency of expression of Bt (Bacillus thuringiensis) gene in one of the leading commercialized crops (cotton) against Lepidopteran species is of great concern. The expression of Cry protein level can be controlled by the improvement of nutrients levels. Therefore, the myth of response of Cry toxin to different combinations of NP fertilizers was explored in three Bt cotton cultivars. Combinations include three levels of nitrogen and three levels of phosphorus fertilizers. Immunostrips and Cry gene(s) specific primer based PCR (Polymerase Chain Reaction) analysis were used for the presence of Bt gene that unveiled the presence of Cry1Ac gene only. Further, the ELISA (enzyme-linked immunosorbent assay) kit was used to quantify the expression of Cry1Ac protein. Under various NP fertilizers rates, the level of toxin protein exhibited highly significant differences. The highest toxin level mean was found to be 2.3740 and 2.1732 µg/g under the treatment of N150P75 kg ha-1 combination while the lowest toxin level mean was found to be 0.9158 and 0.7641 µg/g at the N50P25 kg ha-1 level at 80 and 120 DAS (Days After Sowing), respectively. It was concluded from the research that the usage of NP fertilizers has a positive relation with the expression of Cry1Ac toxin in Bt cotton. We recommend using the N150P50 kg ha-1 level as the most economical and practicable fertilizer instead of the standard dose N100P50 kg ha-1 to get the desired level of Cry1Ac level for long lasting plant resistance (<1.5). The revised dose of fertilizer may help farmers to avoid the cross-resistance development in contradiction of insect pests.
Resumo A aplicação de diferentes fertilizantes para verificar a eficiência da expressão do gene Bt (Bacillus thuringiensis) em uma das principais culturas comercializadas (algodão) contra espécies de lepidópteros é uma grande preocupação. A expressão do nível de proteína Cry pode ser controlada pela melhoria dos níveis de nutrientes. Portanto, o mito da resposta da toxina Cry a diferentes combinações de fertilizantes NP foi explorado em três cultivares de algodão Bt. As combinações incluem três níveis de nitrogênio e três níveis de fertilizantes de fósforo. A análise de PCR (reação em cadeia da polimerase) específica para o gene (s) Immunostrips e Cry (s) foi usada para a presença do gene Bt que revelou a presença do gene Cry1Ac apenas. Além disso, o kit ELISA (ensaio de imunoabsorção enzimática) foi usado para quantificar a expressão da proteína Cry1Ac. Sob várias taxas de fertilizantes NP, o nível de proteína de toxina exibiu diferenças altamente significativas. A média do nível mais alto de toxina foi de 2,3740 e 2,1732 µg / g sob o tratamento da combinação N150P75 kg ha-1, enquanto a média do nível mais baixo de toxina foi de 0,9158 e 0,7641 µg / g no nível de N50P25 kg ha-1 em 80 e 120 DAS (dias após a semeadura), respectivamente. Concluiu-se com a pesquisa que o uso de fertilizantes NP tem relação positiva com a expressão da toxina Cry1Ac no algodão Bt. Recomendamos o uso do nível de N150P50 kg ha-1 como o fertilizante mais econômico e praticável em vez da dose padrão N100P50 kg ha-1 para obter o nível desejado de nível de Cry1Ac para resistência de planta de longa duração (<1,5). A dose revisada de fertilizante pode ajudar os agricultores a evitar o desenvolvimento de resistência cruzada em contradição com as pragas de insetos.
Assuntos
Animais , Proteínas Hemolisinas/genética , Mariposas , Fósforo , Proteínas de Bactérias/genética , Resistência a Inseticidas , Plantas Geneticamente Modificadas/genética , Endotoxinas/genética , Fertilizantes , Toxinas de Bacillus thuringiensis , Larva , NitrogênioResumo
Purpose: To explore the potential immunomodulatory effects of total extract and different polar parts from Blaps rynchopetera Fairmaire. Methods: Phagocytic activity was evaluated by neutral red assay, and the effect of the immune function was investigated by normal and immunocompromised mice models. Results: In vitro, total extract, as well as chloroform, ethyl acetate, n-butanol and water fractions could individually enhance the phagocytic ability of mouse peritoneal macrophages; in addition, chloroform and ethyl acetate fractions had an increasing tendency when combined stimulation with lipopolysaccharide (LPS). In vivo, ethyl acetate fraction (EAF) could enhance the immune organ index, increase the serum hemolysin level and peripheral blood immune cells of immunocompromised mice, while for normal mice, the effect was inconspicuous. Conclusions: Blaps rynchopetera extracts had noteworthy immunomodulatory effect, especially for individuals with immune disorders.
Assuntos
Animais , Camundongos , Besouros/química , Hospedeiro Imunocomprometido , Fatores Imunológicos/análise , Medicina Tradicional Chinesa/métodos , MacrófagosResumo
This study aimed to identify potentially pathogenic microorganisms (Listeria innocua, L. seeligeri, L. ivanovii, L. monocytogenes, Staphylococcus aureus, and several virulence genes) in unpasteurized cheese production in the northeastern region of the state of São Paulo, Brazil. Listeria species were detected in 68 (64.14%) out of 106 samples of bovine feces, swabs from milkers' and cheese handlers' hands, milking buckets, raw milk, whey, water, cheese processing surface,s and utensils. All the samples collected at one farm were contaminated with Listeria spp. L. innocua, L. seeligeri, L. ivanovii, or L. monocytogenes were not detected in the samples collected in this study. A set of 391 Staphylococcus spp. isolates were obtained in these samples, from which 60 (15.31%) were identified as S. aureus using PCR (Polymerase Chain Reaction). S. aureus carrying virulence genes (eta, hlg, seg, seh, sei) were detected in milk, in swabs from cheese handler's hands, whey, milk, sieves, buckets, and cheese. The hlg gene (encodes gamma hemolysin) was detected in all the S. aureus isolates. These findings show that poor hygienic practice is associated with a higher risk of pathogenic bacteria in milk or cheese, providing useful information for public health authorities to increase food safety surveillance and prevent the dissemination of pathogens.
O objetivo desse estudo foi identificar microrganismos potencialmente patogênicos (Listeria innocua, L. seeligeri, L. ivanovii, L. monocytogenes, Staphylococcus aureus e diversos genes de virulência) na produção de queijos de leite cru na região noroeste do Estado de São Paulo, Brasil. Listeria foram detectadas em 68 (64,14%) das 106 amostras obtidas de fezes bovinas, suabes das mãos de ordenhadores e queijeiros, baldes, leite cru, soro, água, superfícies e utensílios da produção de queijos. Todas as amostras coletadas em uma fazenda estavam contaminadas com Listeria spp. L. innocua, L. seeligeri, L. ivanovii, e L. monocytogenes não foram detectadas nas amostras coletadas nesse estudo. Um conjunto de 391 isolados de Staphylococcus spp. foram obtidos das amostras, e desses 60 (15,31%) foram identificados como S. aureus pela PCR (Polymerase Chain Reaction). S. aureus contendo genes de virulência (eta, hlg, seg, seh, sei) foram detectados em leite, mãos dos ordenhadores, soro, utensílios e queijos. O gene hlg (gama-hemolisina)foi detectado em todos os isolados de S. aureus.Esses resultados demonstram que práticas inadequadas de higiene estão associadas com um maior risco da presença de bactérias patogênicas no leite e queijos crus, fornecendo informações para as autoridades de saúde pública para incrementarem a vigilância e prevenirem a disseminação de patógenos.
Assuntos
Staphylococcus aureus , Contaminação de Alimentos/análise , Higiene dos Alimentos , Queijo/análise , Reação em Cadeia da Polimerase , Inocuidade dos Alimentos/métodos , Microbiologia de Alimentos , ListeriaResumo
Genetically modified plants are one of the tactics used in integrated pest management - IPM. There is great concern about the impact of these plants on non-target organisms. On the other hand, there is little information in the literature on the effects of transgenics (Bacillus thuringiensis) Bt on populations of phytophagous mites, and the physiological responses that this attack promotes on plants. The objective of this work was to evaluate the biology of the T. ludeni mite in Bt cotton, expressing the Cry1F and Cry1Ac proteins. To evaluate the behavior of food and oviposition preference of the T. ludeni with Bt cotton and isohybrid. Verify if the physiological stress caused by T. ludeni's attack is differentiated in Bt cotton. The mites were reared in Bt cotton and isohybrid, in a total of 40 replicates in the completely randomized design and the biological cycle was evaluated. The food preference and oviposition analysis were done with 10 replicates, with choice. The physiological stress was evaluated through chlorophyll fluorescence, under greenhouse conditions. The data of the T. ludeni biology were analyzed by Student's t-test, for food and oviposition preference the chi-square test was performed. Regression models were fitted for the fluorescence parameters. The model identity test was used to evaluate the differences between Bt and isohybrid treatments. Cry1F and Cry1Ac proteins have not affected the biology of T. ludeni. The photosynthetic parameters in Bt cotton plants were less influenced by T. ludeni infestation.
O uso de plantas geneticamente modificadas é uma das táticas utilizadas no manejo integrado de pragas - MIP. Observa-se grande preocupação com o impacto dessas plantas sobre organismos não alvos. Por outro lado, existe pouca informação na literatura sobre efeitos dos transgênicos (Bacillus thuringiensis) Bt em populações de ácaros fitófagos, e as respostas fisiológicas que esse ataque promove nas plantas. Objetivou-se com esse trabalho avaliar a biologia do ácaro T. ludeni em algodoeiro Bt, expressando as proteínas Cry1F e Cry1Ac. Avaliar se há comportamento de preferência alimentar e postura de T. ludeni em relação ao algodoeiro Bt e seu iso-híbrido. E verificar se o estresse fisiológico causado pelo ataque de T. ludeni é diferenciado em algodoeiro Bt. Os ácaros foram criados em algodoeiro Bt e iso-híbrido, em um total de 40 repetições no delineamento inteiramente casualizado, onde foi avaliado o ciclo biológico. A análise de preferência alimentar e de posturas foi feita com 10 repetições, com escolha. O estresse fisiológico foi avaliando através da fluorescência da clorofila, em casa de vegetação. Os dados da biologia de T. ludeni foram analisados pelo teste t Student, para preferência alimentar e postura foi realizado o teste qui-quadrado. Para os parâmetros da fluorescência, foram ajustados modelos de regressão. Para testar as diferenças entre Bt e iso-híbrido foi utilizado o teste de identidade de modelos. As proteínas Cry1F e Cry1Ac não afetaram a biologia de T. ludeni. Os parâmetros fotossintéticos em plantas de algodoeiro Bt foram menos influenciados pela infestação de T. ludeni.
Assuntos
Animais , Feminino , Plantas Geneticamente Modificadas/genética , Tetranychidae/genética , Estresse Fisiológico , Proteínas de Bactérias/genética , Gossypium/genética , Endotoxinas , Toxinas de Bacillus thuringiensis , Proteínas Hemolisinas/genética , LarvaResumo
Staphylococcus aureus is one of the main agents isolated from bovine mastitis cases, characterized by lower cure rates compared to other pathogens causing this disease. This phenomenon is mainly explained by the multiresistance acquisition to antimicrobials and the ability of S. aureus to form biofilms on biotic and abiotic surfaces. In this work 15 samples of S. aureus isolated from the automated milking facility were analyzed regarding the resistance profile to antimicrobials, virulence factors (capsule production, hemolysin, and protease) and adhesion capacity under different temperatures (42±1°C, 36±1°C, 25±1°C, 9±1°C, and 3±1°C). All isolates showed methicillin-resistant (MRSA) characteristics and multidrug resistance profile to the antimicrobials tested (penicillin G, chloramphenicol, oxacillin, cephalexin, tetracycline, amoxicillin + clavulanic acid, sulfa + trimetropim, gentamicin, doxycycline, ceftiofur, neomycin, and vancomycin) with an IRMA index between 0.5 and 1.0. Five isolates were resistant to vancomycin (VRSA), two were resistant to all active principles, and the others to at least six of these drugs. Adhesion capacity and biofilm formation were found in 3 of the 5 evaluated temperatures, including the cooling conditions. Regarding the virulence factors, 86.7% of the isolates formed capsules, 60% revealed the presence of protease, 26.7% expressed the α-hemolysin factor, and 13.3% of them presented β-hemolysin. The fact that all isolates presented MRSA characteristics represents a potential risk to those exposed to this agent, and the formation of biofilm in liners even after the use of detergents and sanitization highlights the urgency of searching for alternatives for dispersion of the biofilm by S. aureusin the automated milking facility.
O Staphylococcus aureus é um dos principais agentes isolados de casos de mastite bovina, caracterizado por menores taxas de cura em comparação com outros patógenos desta enfermidade. Esse fenômeno é explicado principal-mente pela aquisição de resistência à antimicrobianos e a capacidade do S. aureus formar biofilmes em superficies bióti-cas e abióticas. Neste trabalho foram utilizadas 15 amostras de S. aureus isolados de ordenhadeira, analisados quanto ao perfil de resistência à antimicrobianos, fatores de virulência (produção de cápsula, hemolisina e protease) e capacidade de adesão sob diferentes temperaturas (42±1°C, 36±1°C, 25±1ºC, 9±1ºC e 3±1ºC). Todos os isolados apresentaram perfil de multirresistência aos antimicrobianos testados (penicilina G, cloranfenicol, oxacilina, cefalexina, tetraciclina, amoxicilina + ácido clavulônico, sulfa + trimetropim, gentamicina, doxiciclina, ceftiofur, neomicina e vancomicina) com índice IRMA entre 0,5 a 1,0. Duas cepas foram resistentes a todos os princípios ativos e as demais a pelo menos seis destes fármacos. Os isolados avaliados apresentaram característica de meticilina-resistentes (MRSA) e destes, 33,34% (5/15) foram resistentes à vancomicina (VRSA). Houve capacidade de adesão e formação de biofilmes em 3 das 5 tem-peraturas avaliadas, incluindo as temperaturas de refrigeração. Em relação aos fatores de virulência, 86,7% dos isolados formaram cápsula, 60% presença de protease, 26,7% expressaram o fator α-hemolisina e 13,3% β-hemolisina. O fato de todos isolados apresentarem característica MRSA representa um risco potencial aos expostos a esse agente. Já a for-mação de biofilmes em teteiras, mesmo após detergência e sanitização, destacam a urgência de alternativas de dispersão de biofilmes no ambiente de ordenha.
Assuntos
Anti-Infecciosos/análise , Biofilmes , Staphylococcus aureus/imunologia , Staphylococcus aureus/patogenicidade , Mastite BovinaResumo
Staphylococcus aureus is one of the main agents isolated from bovine mastitis cases, characterized by lower cure rates compared to other pathogens causing this disease. This phenomenon is mainly explained by the multiresistance acquisition to antimicrobials and the ability of S. aureus to form biofilms on biotic and abiotic surfaces. In this work 15 samples of S. aureus isolated from the automated milking facility were analyzed regarding the resistance profile to antimicrobials, virulence factors (capsule production, hemolysin, and protease) and adhesion capacity under different temperatures (42±1°C, 36±1°C, 25±1°C, 9±1°C, and 3±1°C). All isolates showed methicillin-resistant (MRSA) characteristics and multidrug resistance profile to the antimicrobials tested (penicillin G, chloramphenicol, oxacillin, cephalexin, tetracycline, amoxicillin + clavulanic acid, sulfa + trimetropim, gentamicin, doxycycline, ceftiofur, neomycin, and vancomycin) with an IRMA index between 0.5 and 1.0. Five isolates were resistant to vancomycin (VRSA), two were resistant to all active principles, and the others to at least six of these drugs. Adhesion capacity and biofilm formation were found in 3 of the 5 evaluated temperatures, including the cooling conditions. Regarding the virulence factors, 86.7% of the isolates formed capsules, 60% revealed the presence of protease, 26.7% expressed the α-hemolysin factor, and 13.3% of them presented β-hemolysin. The fact that all isolates presented MRSA characteristics represents a potential risk to those exposed to this agent, and the formation of biofilm in liners even after the use of detergents and sanitization highlights the urgency of searching for alternatives for dispersion of the biofilm by S. aureusin the automated milking facility.(AU)
O Staphylococcus aureus é um dos principais agentes isolados de casos de mastite bovina, caracterizado por menores taxas de cura em comparação com outros patógenos desta enfermidade. Esse fenômeno é explicado principal-mente pela aquisição de resistência à antimicrobianos e a capacidade do S. aureus formar biofilmes em superficies bióti-cas e abióticas. Neste trabalho foram utilizadas 15 amostras de S. aureus isolados de ordenhadeira, analisados quanto ao perfil de resistência à antimicrobianos, fatores de virulência (produção de cápsula, hemolisina e protease) e capacidade de adesão sob diferentes temperaturas (42±1°C, 36±1°C, 25±1ºC, 9±1ºC e 3±1ºC). Todos os isolados apresentaram perfil de multirresistência aos antimicrobianos testados (penicilina G, cloranfenicol, oxacilina, cefalexina, tetraciclina, amoxicilina + ácido clavulônico, sulfa + trimetropim, gentamicina, doxiciclina, ceftiofur, neomicina e vancomicina) com índice IRMA entre 0,5 a 1,0. Duas cepas foram resistentes a todos os princípios ativos e as demais a pelo menos seis destes fármacos. Os isolados avaliados apresentaram característica de meticilina-resistentes (MRSA) e destes, 33,34% (5/15) foram resistentes à vancomicina (VRSA). Houve capacidade de adesão e formação de biofilmes em 3 das 5 tem-peraturas avaliadas, incluindo as temperaturas de refrigeração. Em relação aos fatores de virulência, 86,7% dos isolados formaram cápsula, 60% presença de protease, 26,7% expressaram o fator α-hemolisina e 13,3% β-hemolisina. O fato de todos isolados apresentarem característica MRSA representa um risco potencial aos expostos a esse agente. Já a for-mação de biofilmes em teteiras, mesmo após detergência e sanitização, destacam a urgência de alternativas de dispersão de biofilmes no ambiente de ordenha.(AU)
Assuntos
Staphylococcus aureus/imunologia , Staphylococcus aureus/patogenicidade , Anti-Infecciosos/análise , Biofilmes , Mastite BovinaResumo
Feed is the main route of transmission of pathogenic microorganisms and is responsible for a large part of the cost of poultry production, so the inclusion of alternative foods in diets for monogastrics has been a constant. Among alternative foods most used in modern poultry farming are animal meal, however, when contaminated they constitute a route of transmission of several pathogenic agents, including Escherichia coli. In addition, there is a zoonotic potential, as poultry products are intended for human consumption. The objective of this research was to detect virulence genes, as well as to evaluate the resistance profile of Escherichia coli isolates from meat meal samples. A total of 40 Escherichia coli isolates were analyzed and the virulence genes surveyed iss, ompT, hlyF, iutA, and fimA identified by Polymerase Chain Reaction (PCR). The antimicrobial agents tested were: amoxycillin (30 µg), ceftiofur (30 µg), ciprofloxacin (5 µg), doxycycline (30 µg), florfenicol (30 µg), fosfomycin (200 µg), gentamicin (10 µg), norfloxacin (10 µg) and oxacillin (1 µg). It was possible to observe the occurrence of the iss resistance gene in 100% of Escherichia coli isolates, followed by hlyF (85%), fimA (75%), ompT (17.5%) and iutA (5%). Regarding the simultaneous detection for the genes, a greater association between the genes iss, hlyF and fimA (60%) was verified. All isolates showed resistance to oxacillin (100%), followed by doxycycline (25%), amoxicillin (22.5%), norfloxacin (17.5%), ceftiofur (15%), florfenicol (12.5%), fosfomycin (12.5%), ciprofloxacin (10%) and gentamycin (2.5%). In this study, a variation of the multiple antimicrobial resistance index (IRMA) was observed between 0.22 and 0.77. The indiscriminate use of of antimicrobials as performance enhancers in production animals, may have contributed to the increase in antimicrobial resistance, with the occurrence of multiresistant Escherichia coli carrying virulence genes. Virulence genes present in Escherichia coli isolates are studied to understand the degree of influence they exert in the establishment of the disease, one of the most researched genes is the iss gene, involved in the processes that promote serum resistance. In this study, iss (100%) was present in all the isolates analyzed, although it is not the only mechanism used by these bacteria to reach internal organs and trigger an infection, this gene encodes an important mechanism associated with high levels of virulence. The second highest prevalence found was of the hlyF gene (85%), the high prevalence of hlyF suggests virulence potential, involved with the production of hemolysin and improvement of outer membrane vesicles associated with the release of toxins. The fimA gene (75%) was detected in a slightly lower percentage when compared to iss and hlyF. With the second lowest prevalence, the ompT gene (17.5%), is involved in a process that includes the proteolytic degradation of antimicrobial peptides and with the lowest prevalence the iutA gene (5%). Certain combinations of virulence genes make the strains easier to survive, adhere to, colonize and even the ability to develop septicemic conditions. Multiresistant E. coli strains, is a fact of concern for both animal and human health, since the presence of multiresistant strains, originating from poultry, can be transmitted from chicken carcasses. In this sense, the importance of sanitary control of the inputs used in animal feed is emphasized, as well as the prudent use of antimicrobials in animal production, with a view to producing a safe food, minimizing not only the economic losses, but also the risks to human health.(AU)
Assuntos
Animais , Aves Domésticas , Dieta/veterinária , Escherichia coli/genética , Escherichia coli/patogenicidade , Ração Animal/análise , Padrão de Identidade e Qualidade para Produtos e ServiçosResumo
Staphylococcus aureus is a gram-positive bacterium, commonly found colonizing the skin and mucous membranes of humans and animals. This report describes a case of fetal loss associated with S. aureus infection in a cow. A six-month old, crossbred male bovine fetus from a beef farm was submitted for necropsy. At gross examination fibrinous pleuropneumonia was observed. Histologically, lesions were restricted to the lungs and consisted of marked multifocal to coalescing areas of inflammatory infiltrate of neutrophils, abundant fibrin exudation, necrosis of bronchiolar epithelium and numerous aggregates of coccoid bacteria. Lung and abomasal fluid bacterial culture yielded pure culture of S. aureus, which was characterized as a multidrug resistant strain. Molecular analysis indicated that the studied strain presented several genes of virulence factors including toxic shock syndrome toxin-1 (tst), staphylococcal enterotoxin type A (sea), Panton-Valentine leukocidin (pvl), alpha-hemolysin (hla) and delta-hemolysin (hld). This report documents an infrequent case of fetal loss in cattle due to infection with a highly virulent S. aureus strain.(AU)
Staphylococcus aureus é uma bactéria gram-positiva, comumente encontrada colonizando a pele e as membranas mucosas de humanos e animais. O presente relato descreve um caso de aborto bovino associado à infecção por S. aureus. Um feto bovino, macho, cruzado, com seis meses de idade gestacional proveniente de uma fazenda de gado de corte foi submetido para a necropsia. Pleuropneumonia supurativa foi observada na avaliação macroscópica. Histologicamente as lesões encontravam-se restritas aos pulmões e eram representadas por infiltrado inflamatório acentuado, multifocal a coalescente de neutrófilos, acentuada exsudação de fibrina, necrose do epitélio bronquiolar e numerosos agregados bacterianos cocoides. A cultura bacteriana de fragmento de pulmão e líquido do abomaso revelou o crescimento puro de S. aureus, que foi caracterizado como uma cepa multirresistente a drogas. Análises moleculares indicaram que a cepa estudada apresentava vários fatores de virulência, incluindo toxina 1 da síndrome do choque tóxico (TSST-1), enterotoxina estafilocócica tipo A (sea), leucocidina Panton-Valentine (pvl), hemolisina alfa (hla) e hemolisina delta (hld). O presente relato documenta um caso infrequente de aborto bovino devido à infecção por uma cepa altamente virulenta de S. aureus.(AU)
Assuntos
Animais , Bovinos , Aborto Animal , Staphylococcus aureus/patogenicidade , Doenças dos BovinosResumo
This study aimed to identify serogroups of Escherichia coli important for human health in isolates from psittacine of illegal wildlife trade in Ceará State. In addition, hemolysis and production of Extended Spectrum Beta-Lactamases (ESBL) was assessed in the isolates. A total of 78 E. coli strains isolated from different Psittaciformes species from a wildlife rehabilitation center in Fortaleza, Brazil. The isolates used in this study were previously identified and stored. Serogroup identification was performed using polyvalent sera for EPEC (O55, O111, O119, O114, O125, O86, O126, O127, O128), EIEC (O136, O124) and EHEC (O157). ESBL detection was performed with double disk synergy method. For hemolysis detection, isolates were inoculated in blood agar base enriched with ovine blood. Only 31 (39.7%) isolates were seropositive and the most frequent were O127, O114, O128 and O111. There was no agglutination for serogroups O55, O124, O136 or O157. Considering both seropositive and seronegative isolates, 9 (11.5%) and 35 (44.9%) presented hemolysis and ESBL production, respectively. In conclusion, the investigated psittacine from illegal wildlife trade hosted ESBL-producing E. coli strains and some belong to important serogroups often linked to severe human infections.(AU)
Este trabalho teve como objetivo identificar sorogrupos de E. coli importantes para a saúde humana, oriundos de psitacídeos provenientes do tráfico no estado do Ceará, assim como detectar atividade hemolítica e produção de betalactamase de espectro estendido (ESBL). Foram testadas 78 cepas de Escherichia coli provenientes de psitaciformes do Centro de Triagem de Animais Silvestres, Fortaleza, CE. Para a identificação dos sorogrupos, utilizaram-se soros polivalentes EPEC (O55, O111, O119, O114, O125, O86, O126, O127, O128), EIEC (O136, O124) e EHEC (O157). Para detecção de ESBL, as cepas foram submetidas ao método de aproximação de disco e, para a detecção de hemolisina, foram plaqueadas em ágar sangue base enriquecido com sangue de carneiro. No geral, 31 (39,7%) das amostras foram soropositivas. Os sorogrupos mais frequentemente detectados foram O127, O114, O128 e O111. Não houve positividade para os sorogrupos O55, O124, O136 e O157. Considerando-se as amostras sororreagentes e não sororreagentes, observou-se que nove (11,5%) e 35 (44,9%) cepas de E. coli apresentaram produção de hemolisinas e de ESBL, respectivamente. Em conclusão, constatou-se que psitacídeos provenientes do tráfico de animais silvestres albergam cepas de E. coli produtoras de ESBL e providas de importantes sorogrupos implicados em graves infecções humanas.(AU)
Assuntos
Animais , beta-Lactamases , Escherichia coli/isolamento & purificação , Papagaios/microbiologia , Proteínas Hemolisinas/análise , SorogrupoResumo
This study aimed to identify serogroups of Escherichia coli important for human health in isolates from psittacine of illegal wildlife trade in Ceará State. In addition, hemolysis and production of Extended Spectrum Beta-Lactamases (ESBL) was assessed in the isolates. A total of 78 E. coli strains isolated from different Psittaciformes species from a wildlife rehabilitation center in Fortaleza, Brazil. The isolates used in this study were previously identified and stored. Serogroup identification was performed using polyvalent sera for EPEC (O55, O111, O119, O114, O125, O86, O126, O127, O128), EIEC (O136, O124) and EHEC (O157). ESBL detection was performed with double disk synergy method. For hemolysis detection, isolates were inoculated in blood agar base enriched with ovine blood. Only 31 (39.7%) isolates were seropositive and the most frequent were O127, O114, O128 and O111. There was no agglutination for serogroups O55, O124, O136 or O157. Considering both seropositive and seronegative isolates, 9 (11.5%) and 35 (44.9%) presented hemolysis and ESBL production, respectively. In conclusion, the investigated psittacine from illegal wildlife trade hosted ESBL-producing E. coli strains and some belong to important serogroups often linked to severe human infections.(AU)
Este trabalho teve como objetivo identificar sorogrupos de E. coli importantes para a saúde humana, oriundos de psitacídeos provenientes do tráfico no estado do Ceará, assim como detectar atividade hemolítica e produção de betalactamase de espectro estendido (ESBL). Foram testadas 78 cepas de Escherichia coli provenientes de psitaciformes do Centro de Triagem de Animais Silvestres, Fortaleza, CE. Para a identificação dos sorogrupos, utilizaram-se soros polivalentes EPEC (O55, O111, O119, O114, O125, O86, O126, O127, O128), EIEC (O136, O124) e EHEC (O157). Para detecção de ESBL, as cepas foram submetidas ao método de aproximação de disco e, para a detecção de hemolisina, foram plaqueadas em ágar sangue base enriquecido com sangue de carneiro. No geral, 31 (39,7%) das amostras foram soropositivas. Os sorogrupos mais frequentemente detectados foram O127, O114, O128 e O111. Não houve positividade para os sorogrupos O55, O124, O136 e O157. Considerando-se as amostras sororreagentes e não sororreagentes, observou-se que nove (11,5%) e 35 (44,9%) cepas de E. coli apresentaram produção de hemolisinas e de ESBL, respectivamente. Em conclusão, constatou-se que psitacídeos provenientes do tráfico de animais silvestres albergam cepas de E. coli produtoras de ESBL e providas de importantes sorogrupos implicados em graves infecções humanas.(AU)
Assuntos
Animais , beta-Lactamases , Escherichia coli/isolamento & purificação , Papagaios/microbiologia , Proteínas Hemolisinas/análise , SorogrupoResumo
Nine Legionella pneumophila strains isolated from cooling towers and a standard strain (L. pneumophila serogroup 1, ATCC 33152, Philadelphia 1) were analyzed and compared in terms of motility, flagella structure, ability to form biofilms, enzymatic activities (hemolysin, nucleases, protease, phospholipase A, phospholipase C, acid phosphatase, alkaline phosphatase and lipase), hemagglutination capabilities, and pathogenicity in various host cells (Acanthamoeba castellanii ATCC 30234, mouse peritoneal macrophages and human peripheral monocytes). All the isolates of bacteria appeared to be motile and polar-flagellated and possessed the type-IV fimbria. Upon the evaluation of virulence factors, isolate 4 was found to be the most pathogenic strain, while 6 out of the 9 isolates (the isolates 1, 2, 3, 4, 5, and 7) were more virulent than the ATCC 33152 strain. The different bacterial strains exhibited differences in properties such as adhesion, penetration and reproduction in the hosts, and preferred host type. To our knowledge, this is the first study to compare the virulence of environmental L. pneumophila strains isolated in Turkey, and it provides important information relevant for understanding the epidemiology of L. pneumophila.(AU)
Assuntos
Legionella pneumophila/patogenicidade , Virulência , Estudos Epidemiológicos , TurquiaResumo
Por sua característica zoonótica, a dermatofitose tem grande importância para a saúde pública. Particularmente, os dermatófitos geofílicos são insuficientemente estudados por serem considerados estritamente oportunistas; entretanto, Nannizzia gypsea (sin. Microsporum gypseum), que é geofílica, tem sido isolada por todo o mundo causando infecções no homem e animais, confirmando o potencial patogênico que os fungos geofílicos apresentam. O sucesso no estabelecimento da infecção pelos dermatófitos depende de varias proteínas e enzimas fúngicas, que são a chave na invasão e utilização do estrato córneo do hospedeiro; portanto, o estudo dos fatores de virulência envolvidos na patogenicidade desses fungos auxiliará na compreensão da epidemiologia das dermatofitoses. Objetivo: O objetivo do presente estudo foi pesquisar a secreção de hemolisinas e das enzimas proteinase, fosfolipase, lipase e gelatinase em cepas de N. gypsea. Métodos: Foram testadas 21 cepas de N. gypsea isoladas do solo de 21 parques do município de São Paulo pela técnica de Vanbreuseghem. A produção das enzimas fosfolipase, proteinase e lipase foi verificada empregando-se placas de Petri com meio sólido contendo o respectivo substrato a ser degradado, respectivamente, gema de ovo, albumina sérica bovina e Tween 20. O teste foi considerado positivo quando ocorreu uma zona clara de degradação ao redor da colônia. Para a verificação da produção da enzima gelatinase foi empregado meio contendo gelatina, o qual foi distribuído em tubos; a semeadura ocorreu em picada e antes da leitura final, os tubos foram refrigerados a 4° C por 30 minutos. O teste foi considerado positivo quando houve liquefação do meio. Na prova da produção de hemolisinas empregou-se base de ágar sangue suplementada com 5% de sangue de carneiro desfibrinado; nesta prova, após a leitura de 14 dias, as placas foram incubadas a 32° C. Em cada um dos testes, após a semeadura, as placas foram incubadas por 14 dias a 25° C, realizando-se leituras aos 5, 7, 10 e 14 dias. Resultados: Todas as 21 cepas de N. gypsea produziram fosfolipase aos 14 dias, gelatinase, a partir de 10 dias, proteinase e lipase, a partir de 7 dias de incubação. Em relação à fosofolipase, a maioria das reações foi fortemente positiva para a produção da enzima. Aos 14 dias a 32° C, se verificou hemólise em 81,0% (17/21) das cepas, sendo 82,4% (14/17) de -hemólise (hemólises parciais) e 17,6% (3/17) de -hemólise (hemólise total). Todas as cepas de N. gypsea testadas produziram enzimas e/ou hemolisinas, consideradas fatores de virulência, revelando seu potencial de patogenicidade. Os intervalos de leitura ideais para a produção das enzimas fosfolipase, proteinase, lipase e gelatinase foram, respectivamente, 14, 7, 7 e 10 dias; em relação à atividade hemolítica sugere-se 14 dias com temperatura de 32° C. Conclusão: A presença de N. gypsea, com a produção de fatores de virulência em solos de parques do município de São Paulo, pode representar potencial risco de infecção aos humanos e animais que usufruem desses espaços dedicados ao lazer.
Dermatophytosis is of significant importance for public health because of its zoonotic characteristic. In particular, geophilic dermatophytes have been insufficiently studied because they are considered strictly opportunistic. However, cases of infections due to Nannizzia gypsea (syn. Microsporum gypseum), a geophilic dermatophyte, in both humans and animals have been found globally, confirming the pathogenic potential of geophilic fungi. Dermatophytoses caused by these fungi is attributed to several proteins and enzymes produced by them and also the use of the hosts stratum corneum by the fungi. Therefore, the study of virulence factors of these fungi will be helpful in understanding the epidemiology of dermatophytoses. The aim of this study was to investigate the secretion of hemolysins, proteinase, phospholipase, lipase, and gelatinase enzymes by N. gypsea strains. Twenty-one strains of N. gypsea isolated using the Vanbreuseghem technique from the soil samples of 21 parks in São Paulo, Brazil, were tested. The production of phospholipase, proteinase, and lipase was verified by culturing these strains in Petri dishes containing a solid culture medium. This medium contained the respective substrate for degradation such as egg yolk, bovine serum albumin, and Tween 20. The test was considered positive when there was a clear area of degradation around the colony. To check the production of gelatinase, a medium containing gelatin was used that was distributed in tubes and punctiform inoculation was performed. Before the final reading, the tubes were refrigerated at 4° C for 30 min. The test was considered positive when there was a liquefaction of the medium. In the hemolysin production test, blood agar base supplemented with 5% defibrinated sheep blood was used. In this test, after reading for 14 days, the plates were incubated at 32° C. In each of these tests, after inoculation, the plates were incubated for 14 days at 25° C, with readings taken at 5, 7, 10, and 14 days. All the 21 strains of N. gypsea produced phospholipase at 14 days, gelatinase from 10 days, and proteinase and lipase from 7 days of incubation. Most of the reactions were strongly positive for the production of phospholipase. At 14 days at 32° C, hemolysis was observed in 81.0% (17/21) of the strains, with -hemolysis (partial hemolysis) in 82.4% (14/17) of the strains and -hemolysis (complete hemolysis) in 17.6% (3/17) of the strains. One of the strains produced both - and -hemolysis. All the strains of N. gypsea produced enzymes and/or hemolysins, which are considered virulence factors, thus revealing their pathogenic potential. The ideal reading intervals for detecting the production of phospholipase, proteinase, lipase, and gelatinase were 14, 7, 7, and 10 days respectively. For detecting hemolytic activity, 14 days at a temperature of 32° C is recommended. The presence of virulent strains of N. gypsea in the soils of parks in São Paulo may represent a potential risk of infection to humans and animals that enjoy these spaces for leisure.
Resumo
Background: Motile aeromonads are considered to be one of the most important food-borne pathogens because of potential human health significance. Aerolysin and hemolysin are virulence factors playing a significant role in the pathogenesis of infections. Antimicrobial resistance is an important problem limiting therapeutic options. The main objective of the present study was to isolate motile Aeromonas species from cow and Anatolian buffalo quarter milk samples and determine the antimicrobial resistance and hemolysin (hlyA) and aerolysin (aerA) virulence genes of isolated species by PCR.Material, Methods & Results: The present study was carried out on apparently healthy 200 dairy cows and 103 Anatolian water buffaloes in different stages of lactation, hand-milked twice a day, held in private farms located in Afyonkarahisar province of Western Turkey. Before milking, 771 and 399 quarter milk samples were collected from cows and Anatolian buffaloes, respectively. For the isolation, APW, SAA and blood agar were used. The certain identification of isolates was made using API 20NE system. The strains were tested for susceptibility to 21 different antibiotics by disc diffusion test. Bacterial DNAs were extracted from all strains using a genomic DNA extraction kit and strains were screened for the presence of hlyA and aerA genes by PCR. While A. hydrophila was isolated from 22 (1.9%) of 1170 quarter milk samples, A. caviae and A. sobria were not detected in the examined milk samples. The isolation rate of A. hydrophila from cow and buffalo milk samples was 2.1% (n = 16) and 1.5% (n = 6), respectively. The highest resistance rate in strains was against ampicillin (100%), followed by ampicillin-sulbactam (95.5%), methicillin (95.5%) and cephazoline (81.8%). The most of strains were also resistant at least to one of the antibiotics.[...](AU)
Assuntos
Animais , Feminino , Bovinos , Aeromonas hydrophila , Resistência Microbiana a Medicamentos , Proteínas Hemolisinas , Búfalos , Leite/microbiologia , Reação em Cadeia da Polimerase/veterinária , TurquiaResumo
Background: Motile aeromonads are considered to be one of the most important food-borne pathogens because of potential human health significance. Aerolysin and hemolysin are virulence factors playing a significant role in the pathogenesis of infections. Antimicrobial resistance is an important problem limiting therapeutic options. The main objective of the present study was to isolate motile Aeromonas species from cow and Anatolian buffalo quarter milk samples and determine the antimicrobial resistance and hemolysin (hlyA) and aerolysin (aerA) virulence genes of isolated species by PCR.Material, Methods & Results: The present study was carried out on apparently healthy 200 dairy cows and 103 Anatolian water buffaloes in different stages of lactation, hand-milked twice a day, held in private farms located in Afyonkarahisar province of Western Turkey. Before milking, 771 and 399 quarter milk samples were collected from cows and Anatolian buffaloes, respectively. For the isolation, APW, SAA and blood agar were used. The certain identification of isolates was made using API 20NE system. The strains were tested for susceptibility to 21 different antibiotics by disc diffusion test. Bacterial DNAs were extracted from all strains using a genomic DNA extraction kit and strains were screened for the presence of hlyA and aerA genes by PCR. While A. hydrophila was isolated from 22 (1.9%) of 1170 quarter milk samples, A. caviae and A. sobria were not detected in the examined milk samples. The isolation rate of A. hydrophila from cow and buffalo milk samples was 2.1% (n = 16) and 1.5% (n = 6), respectively. The highest resistance rate in strains was against ampicillin (100%), followed by ampicillin-sulbactam (95.5%), methicillin (95.5%) and cephazoline (81.8%). The most of strains were also resistant at least to one of the antibiotics.[...]
Assuntos
Feminino , Animais , Bovinos , Aeromonas hydrophila , Búfalos , Leite/microbiologia , Proteínas Hemolisinas , Resistência Microbiana a Medicamentos , Reação em Cadeia da Polimerase/veterinária , TurquiaResumo
Background: Modified embryo in vitro culture (IVC) systems have been devised for the culture of individual embryos, suchas in microdroplets, capillary tubes, or co-cultures systems. However, the development of the Well-of-the-Well (WOW)system takes advantage of both the individual and the grouped culture systems, as embryos are cultured into microwellsdisposed into a larger well. The aim of this study was to evaluate the in vitro and in vivo developmental potential of handmade cloning (HMC)-derived cloned bovine embryos after the IVC in three microwell (WOW) systems.Material, Methods & Results: Adipose tissue-derived mesenchymal stem cells (MSCs) isolated after subcutaneous biopsy from a Nellore adult female were used as nucleus donor cells for cloning. Collected adipose tissue was incubated in0.075% collagenase for 60 min at 39oC. After digestion, cell suspension was centrifuged at 80 g for 10 min, supernatantwas discarded, and 2 mL of Red Blood Cells Lysis Buffer (RBC) was added to the pellet, remaining for 2 min. The RBCbuffer was diluted with 20 mL PBS, with cell suspension spun at 80 g for 5 min. Supernatant was discarded and the pelletre-suspended in DMEM culture medium + 10% fetal calf serum (FCS). Following cell counting, 5 x 105 cells were seededin 25-cm² bottles containing 6 mL DMEM + 10% FCS, and cultured at 38.3°C, 5% CO2 in air and saturated humidity.After IVM, oocytes were denuded and incubated in demecolcine, followed by zona pellucida removal, oocyte bisection,embryo reconstruction, electrofusion and chemical activation. Cloned embryos were allocated to one of three IVC groups:cWOW: conventional microwells (250 µm, round); mWOW: modified microwells (130 µm, conical); and WOW-PDMS:microwells in polydimethylsiloxane chips (170 µm, cylindrical, with interconnecting microchannels); IVF embryos wereused as controls. Cleavage (D2), blastocyst (D7) and pregnancy (D30) rates were analyzed by the χ2 test, for P < 0.05...(AU)
Assuntos
Animais , Feminino , Bovinos , Leite/química , Leite/microbiologia , Farmacorresistência Bacteriana , Búfalos , Aeromonas hydrophila , Turquia , Proteínas HemolisinasResumo
Background: Modified embryo in vitro culture (IVC) systems have been devised for the culture of individual embryos, suchas in microdroplets, capillary tubes, or co-cultures systems. However, the development of the Well-of-the-Well (WOW)system takes advantage of both the individual and the grouped culture systems, as embryos are cultured into microwellsdisposed into a larger well. The aim of this study was to evaluate the in vitro and in vivo developmental potential of handmade cloning (HMC)-derived cloned bovine embryos after the IVC in three microwell (WOW) systems.Material, Methods & Results: Adipose tissue-derived mesenchymal stem cells (MSCs) isolated after subcutaneous biopsy from a Nellore adult female were used as nucleus donor cells for cloning. Collected adipose tissue was incubated in0.075% collagenase for 60 min at 39oC. After digestion, cell suspension was centrifuged at 80 g for 10 min, supernatantwas discarded, and 2 mL of Red Blood Cells Lysis Buffer (RBC) was added to the pellet, remaining for 2 min. The RBCbuffer was diluted with 20 mL PBS, with cell suspension spun at 80 g for 5 min. Supernatant was discarded and the pelletre-suspended in DMEM culture medium + 10% fetal calf serum (FCS). Following cell counting, 5 x 105 cells were seededin 25-cm² bottles containing 6 mL DMEM + 10% FCS, and cultured at 38.3°C, 5% CO2 in air and saturated humidity.After IVM, oocytes were denuded and incubated in demecolcine, followed by zona pellucida removal, oocyte bisection,embryo reconstruction, electrofusion and chemical activation. Cloned embryos were allocated to one of three IVC groups:cWOW: conventional microwells (250 µm, round); mWOW: modified microwells (130 µm, conical); and WOW-PDMS:microwells in polydimethylsiloxane chips (170 µm, cylindrical, with interconnecting microchannels); IVF embryos wereused as controls. Cleavage (D2), blastocyst (D7) and pregnancy (D30) rates were analyzed by the χ2 test, for P < 0.05...
Assuntos
Feminino , Animais , Bovinos , Búfalos , Farmacorresistência Bacteriana , Leite/microbiologia , Leite/química , Aeromonas hydrophila , Proteínas Hemolisinas , TurquiaResumo
Membros termofílicos do gênero Campylobacter são reconhecidos como importantes enteropatógenos para o ser humano e animais. A grande diversidade ecológica destes micro-organismos em diferentes habitats tais como água, animais e alimentos predispõem ao aparecimento de novos fatores de virulência. Este trabalho teve por objetivo detectar os genes codificantes da Toxina Distensiva Citoletal (CDT) por meio da técnica de PCR, pesquisar a atividade de hemolisinas e a influência de soluções quelantes e de íons nesta atividade. Foram utilizadas 45 amostras de Campylobacter jejuni de origem avícola para pesquisa de atividade hemolítica, cultivadas em Caldo Triptona de Soja (TSB). Após o crescimento bacteriano, as amostras foram semeadas em Ágar tríptico de soja (TSA) contendo 5% de sangue de ovino. Para verificar a influência de agentes quelantes e solução de íons na atividade hemolítica, as amostras de C. jejuni foram cultivadas em TSB contendo separadamente os quelantes EDTA, ácido acético, soluções de íons CaCl2, MgCl2 e FeCl3, em atmosfera de microaerofilia. Quanto à atividade de hemolisina de C. jejuni em placas de TSA - sangue ovino foi possível observar que houve hemólise em 40% das amostras analisadas apenas com caldo TSB. Somente o ácido acético apresentou ação quelante sobre a atividade de hemolisinas em amostras de C. jejuni semeadas em placas de TSA - sangue ovino. Para detecção dos genes cdtA, cdtB e cdtC através da técnica da Reação em Cadeia da Polimerase (PCR) foram utilizadas 119 amostras de C. jejuni de origem avícola. Foi possível observar que 37,8% possuíam o perfil de genes cdtABC. Os resultados demonstraram em amostras avícolas a presença de cepas de C. jejuni com potencial virulento, devido à presença dos genes da toxina CDT e potencial hemolítico, que apresentou ação reduzida in vitro com ácido acético.(AU)
Thermophilic members of the Campylobacter genus are recognized as important enteropathogenics for humans and animals. The great variety of ecological habitats, such as water, food and milk, may promote new virulence factors. To detect the encoding genes distending cytolethal toxin (CDT) by PCR and study the hemolytic activity with influence of chelation solutions and ions, 45 Campylobacter jejuni samples from poultry production origin were used to perform the hemolytic research. To check the influence of chelation agents and solution of ions in the hemolytic activity, samples of C. jejuni strains were grown in tryptone soy broth TSB containing chelation agents separately EDTA, acetic acid, CaCl2, MgCl2 and FeCl3 ions solutions in microaerophilic atmosphere and then streaked on 5% sheep blood tryptic soy agar (TSA). To perform the detection of cdtA, cdtB and cdtC genes the technique of Polymerase Chain Reaction (PCR) was used in 119 samples of C. jejuni from poultry production origin. We found 40% of samples showing hemolysis after growing with TSB. Only the acetic acid showed reduction in hemolysis. The prevalent gene profile was cdtABC in 37.8 % of the samples. It was observed that the results showed the presence of C. jejuni strains with virulent potential, due to presence of the CDT toxin genes and the hemolytic activity, which showed in vitro reduced when acetic acid was added.(AU)
Assuntos
Animais , Aves Domésticas/microbiologia , Campylobacter jejuni/patogenicidade , Campylobacter jejuni/isolamento & purificação , Hemolíticos/metabolismo , Fatores de Virulência/classificação , Reação em Cadeia da Polimerase/veterinária , Toxinas Bacterianas/isolamento & purificação , Ácido Acético/uso terapêuticoResumo
Background Millepora complanata is a plate-like fire coral common throughout the Caribbean. Contact with this species usually provokes burning pain, erythema and urticariform lesions. Our previous study suggested that the aqueous extract of M. complanata contains non-protein hemolysins that are soluble in water and ethanol. In general, the local damage induced by cnidarian venoms has been associated with hemolysins. The characterization of the effects of these components is important for the understanding of the defense mechanisms of fire corals. In addition, this information could lead to better care for victims of envenomation accidents.Methods An ethanolic extract from the lyophilized aqueous extract was prepared and its hemolytic activity was compared with the hemolysis induced by the denatured aqueous extract. Based on the finding that ethanol failed to induce nematocyst discharge, ethanolic extracts were prepared from artificially bleached and normal M. complanata fragments and their hemolytic activity was tested in order to obtain information about the source of the heat-stable hemolysins.Results Rodent erythrocytes were more susceptible to the aqueous extract than chicken and human erythrocytes. Hemolytic activity started at ten minutes of incubation and was relatively stable within the range of 28-50°C. When the aqueous extract was preincubated at temperatures over 60°C, hemolytic activity was significantly reduced. The denatured extract induced a slow hemolytic activity (HU50= 1,050.00 ± 45.85 g/mL), detectable four hours after incubation, which was similar to that induced by the ethanolic extract prepared from the aqueous extract (HU50= 1,167.00 ± 54.95 g/mL). No significant differences were observed between hemolysis induced by ethanolic extracts from bleached and normal fragments, although both activities were more potent than hemolysis induced by the denatured extract...(AU)
Assuntos
Animais , Venenos de Cnidários , Proteínas Hemolisinas , Citotoxinas/análise , HidrozoáriosResumo
Background Millepora complanata is a plate-like fire coral common throughout the Caribbean. Contact with this species usually provokes burning pain, erythema and urticariform lesions. Our previous study suggested that the aqueous extract of M. complanata contains non-protein hemolysins that are soluble in water and ethanol. In general, the local damage induced by cnidarian venoms has been associated with hemolysins. The characterization of the effects of these components is important for the understanding of the defense mechanisms of fire corals. In addition, this information could lead to better care for victims of envenomation accidents.Methods An ethanolic extract from the lyophilized aqueous extract was prepared and its hemolytic activity was compared with the hemolysis induced by the denatured aqueous extract. Based on the finding that ethanol failed to induce nematocyst discharge, ethanolic extracts were prepared from artificially bleached and normal M. complanata fragments and their hemolytic activity was tested in order to obtain information about the source of the heat-stable hemolysins.Results Rodent erythrocytes were more susceptible to the aqueous extract than chicken and human erythrocytes. Hemolytic activity started at ten minutes of incubation and was relatively stable within the range of 28-50°C. When the aqueous extract was preincubated at temperatures over 60°C, hemolytic activity was significantly reduced. The denatured extract induced a slow hemolytic activity (HU50= 1,050.00 ± 45.85 g/mL), detectable four hours after incubation, which was similar to that induced by the ethanolic extract prepared from the aqueous extract (HU50= 1,167.00 ± 54.95 g/mL). No significant differences were observed between hemolysis induced by ethanolic extracts from bleached and normal fragments, although both activities were more potent than hemolysis induced by the denatured extract...
Assuntos
Animais , Citotoxinas/análise , Hidrozoários , Proteínas Hemolisinas , Venenos de CnidáriosResumo
Staphylococcus aureus pode expressar diferentes fatores de virulência e resistência a vários agentes antimicrobianos em casos de mastite bovina. O presente estudo teve como objetivo avaliar os fatores de virulência e os mecanismos genéticos de resistência à drogas em 400 isolados de S. aureus de mastite bovina no Brasil, bem como verificar a associação entre essas características, ano de isolamento e origem geográfico. A identificação dos genes de virulência e resistência foi realizada por PCR singleplex e multiplex. A identificação fenotípica de formação de exopolissacarídeos (biofilme) foi realizado no caldo Triptona de Soja com Vermelho Congo e sacarose e incubados a 37 °C por 48 horas. Como resultado, 83,5% dos isolados foram produtores de biofilme. Os genes de resistência icaAD foram detectados em 98,5% isolados. Os genes luk (leucocidina Panton-Valentine), seb (enterotoxina estafilocócica B), sec (enterotoxina estafilocócica C), sed (enterotoxina estafilocócica D), tst (toxina 1 da síndrome do choque tóxico) foram observados em 3,5%, 0,5%, 1%, 0,25% e 0,74% dos isolados, respectivamente. Os genes das hemolisinas foram observados em 82,85% (hla + hlb +), 16,5% (hla +), 0,75% (hlb +). O gene blaZ, associado à resistência à penicilina, foi detectado em 82,03% dos isolados, enquanto os genes tetK de resistência à tetraciclina e aac(6) -Ieaph(2)-Ia de resistência à aminoglicosídeos foi exibido em 33,87% e 45.15% dos isolados, respectivamente. O gene mepA associado a resistência a fluoroquinolonas foi detectado pela primeira vez em todos os isolados. Os genes de resistência identificados com menor frequência foram tetM (3,22%), tetL (1,61%), ermA (14,29%), ermB (14,29%), ermC (33,3%), ermT (9,52%), ermY (4,76%), msrA (9,52). %), mphC (9,52%). Concluí-se que houve uma alta frequência de S. aureus carregando genes de virulência para biofilme e hemolisina. Além disso, foi encontrada uma grande variedade de genes de resistência que conferem resistência a todas as classes de antimicrobianos utilizados em animais e população humana. Esses resultados mostram o potencial patogênico de S. aureus isolados de mastite bovina para causar doenças tanto em humanos quanto em animais.
Staphylococcus aureus can present many mechanisms in order to remain in mammary gland. The present study aimed to evaluate virulence factors and genetic mechanisms of drug resistance in 400 S. aureus strains isolated from bovine mastitis in Brazil, as well as to assess the association between these characteristics, year of isolation and geographic origin of the strains. Singleplex and multiplex PCR was used to identify virulence factors and drug resistance encoding genes. Detection of biofilm-forming was carried out using Congo red Tryptic Soy Broth assay. As a result, 83.5% isolates were biofilm-forming and 98.5% strains exhibited the biofilm gene icaAD. Virulence genes luk (PantonValentine Leukocidin), seb (Staphylococcal Enterotoxin B), sec (Staphylococcal Enterotoxin C), sed (Staphylococcal Enterotoxin D), tst (Toxic shock syndrome toxin 1) were observed in 3.5%, 0.5%, 1%, 0.25% and 0.74% of the strains, respectively. Hemolysin genes were observed in 82.85% (hla+ hlb+ ), 16.5% (hla+ ) and 0.75% (hlb+ ) isolates. The gene blaZ, associated with penicillin resistance, was detected in 82.03% isolates, whereas tetracycline resistance gene tetK and aminoglycoside gene aac(6)-Ieaph(2)-Ia were observed in 33.87% and 45.15%, respectively. Fluoroquinolone resistance gene mepA was detected for the first time in all fluoroquinolone resistance S. aureus isolates. Resistance genes tetM (3.22%), tetL (1.61%), ermA (14.29%), ermB (14.29%), ermC (33.3%), ermT (9.52%), ermY (4.76%), msrA (9.52%) and mphC (9.52%) were detected in low frequency among the isolates. Our results showed a high frequency of S. aureus carrying mainly biofilm and hemolysin genes. Moreover, a wide variety of antimicrobial resistance genes that confers resistance to all classes of antimicrobial agents used in animals and human population were observed. These results highlight the pathogenic potential of S. aureus from cattle to cause severe disease in both humans and animals. K