RESUMO
Multiresistant and invasive hypervirulent Klebsiella pneumoniae strains have become one of the most urgent bacterial pathogen threats. Recent analyses revealed a high genomic plasticity of this species, harboring a variety of mobile genetic elements associated with virulent strains, encoding proteins of unknown function whose possible role in pathogenesis have not been addressed. K. pneumoniae virulence has been studied mainly in animal models such as mice and pigs, however, practical, financial, ethical and methodological issues limit the use of mammal hosts. Consequently, the development of simple and cost-effective experimental approaches with alternative host models is needed. In this work we described the use of both, the social amoeba and professional phagocyte Dictyostelium discoideum and the fish Danio rerio (zebrafish) as surrogate host models to study K. pneumoniae virulence. We compared three K. pneumoniae clinical isolates evaluating their resistance to phagocytosis, intracellular survival, lethality, intestinal colonization, and innate immune cells recruitment. Optical transparency of both host models permitted studying the infective process in vivo, following the Klebsiella-host interactions through live-cell imaging. We demonstrated that K. pneumoniae RYC492, but not the multiresistant strains 700603 and BAA-1705, is virulent to both host models and elicits a strong immune response. Moreover, this strain showed a high resistance to phagocytosis by D. discoideum, an increased ability to form biofilms and a more prominent and irregular capsule. Besides, the strain 700603 showed the unique ability to replicate inside amoeba cells. Genomic comparison of the K. pneumoniae strains showed that the RYC492 strain has a higher overall content of virulence factors although no specific genes could be linked to its phagocytosis resistance, nor to the intracellular survival observed for the 700603 strain. Our results indicate that both zebrafish and D. discoideum are advantageous host models to study different traits of K. pneumoniae that are associated with virulence.
Assuntos
Interações Hospedeiro-Patógeno , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/fisiologia , Animais , Carga Bacteriana , Comportamento Animal , Biofilmes , Dictyostelium , Resistência à Doença , Interações Hospedeiro-Patógeno/imunologia , Infecções por Klebsiella/imunologia , Klebsiella pneumoniae/patogenicidade , Viabilidade Microbiana , Neutrófilos/imunologia , Neutrófilos/microbiologia , Fagocitose/imunologia , Virulência/genética , Fatores de Virulência/genética , Peixe-ZebraRESUMO
Objetivo: Determinar el grado de conocimiento acerca de la prevención de osteoporosis (OP) en cesantes y jubilados del sector educación de Lambayeque. Material y Métodos: Estudio transversal, descriptivo, observacional, sobre 311 personas perteneciente al Fondo de cesantes y jubilados del sector de educación en Lambayeque, para el grado de conocimiento acerca de la OP se utilizó un cuestionario previamente validado y estructurado a partir del modelo OKAT. El Análisis estadístico se realizó con Excel y SPSS, nivel de confianza del 95% y significancia de 0, 05. Resultados: El 56,59% tenía un conocimiento apropiado de osteoporosis, con una calificación promedio de 12 preguntas acertadas. El 62,7% mencionaron haber recibido información previa sobre OP. El 57,23% afirma haber escuchado información acerca de la osteoporosis en la televisión, seguido del consultorio médico 24,76% . Solo el 10,93% afirma tener el hábito de fumar y el 13,18% afirma tener el hábito de consumir alcohol. Conclusiones: El grado de conocimiento sobre la osteoporosis es bajo en los cesantes y jubilados del sector educación. La información recibida sobre la enfermedad previamente es pobre. La información que reciben las personas sobre OP no proviene de los médicos. Las actitudes hacia la osteoporosis demandan mayor compromiso por el personal de salud para difundir un mejor conocimiento y evitar las complicaciones propias de esta enfermedad.
Objetive: Determine the extent of knowledge about the prevention of osteoporosis (OP) in unemployed and retired Lambayeque education sector. Materials and Methods: Cross-sectional non-experimental type, on a random sample of 311 people belonging to the Fund of Retirees of the education sector in Lambayeque. Information on the degree of knowledge about the OPwas obtained by a previously validated and structured from OKAT model questionnaire. Statistical analysis was performed using Excel and SPSS software, with a confidence level of 95% and a significance level of 0.5. Results: During the study 56.59% hadaproper understanding of osteoporosis, with an average score of 12 right questions. 62.7% mentioned having received prior information on OP. The 57.23% say they have heard about osteoporosis on television, followed by 24.76% medical office. Only 10.93% claims to have smoking and 13.18% say they have the habit of consuming alcohol. Conclusions: The level of knowledge about osteoporosis according to the questionnaire is low in unemployed and retired education sector. The reports of the disease is previously poor. The information received by people on OPcomes not from doctors. Attitudes towards osteoporosis demand greater commitment by health workers to spread a better understanding and to avoid the complications of this disease.
RESUMO
Oscar (Astronotus ocellatus) is an important fish from the Amazon Basin that has great potential for fish farming, human consumption, sport fishing and fish keeping. This study aimed to evaluate the effect of two hormonal treatments on the induction of artificial reproduction in broodstock and to describe the histological development of embryos and larvae. Broodstocks were selected and induced using two different hormones: (i) extract of carp pituitary (ECP); and (ii) synthetic human chorionic gonadotropin (hCG). Spawnings were transferred to hatcheries, collected at pre-established times, processed and analysed by histology. Astronotus ocellatus did not respond well to induced reproduction. From 16 couples of breeding fish, only five out of the eight females released oocytes after the hormonal action time, three with hCG and two with ECP; just one male responded positively to hCG. Oscar eggs were oval, and semi-adhesive, the yolk contained granules, and egg diameter was approximately 1.65 ± 0.057 to 1.98 ± 0.038 mm. Development from the initial collection (IC) point until the total absorption of the yolk lasted 315 h, at an average temperature of 27.45 ± 2.13°C. Several events marked embryonic and larval development, including the formation of the optic cup, forebrain, otic vesicle and cephalic divisions. The newly hatched larvae had non-pigmented eyes, and a closed mouth and anus, as well as the presence of adhesive glands on the head. Larval development was characterized by formation of the heart, liver, gaseous bladder, gills, pronephros, brain, fins and also the digestive tract. These results provide important information for the rearing and reproduction of A. ocellatus.
Assuntos
Gonadotropina Coriônica/farmacologia , Ciclídeos/embriologia , Ciclídeos/crescimento & desenvolvimento , Reprodução/efeitos dos fármacos , Animais , Aquicultura/métodos , Carpas , Ciclídeos/fisiologia , Embrião não Mamífero/citologia , Embrião não Mamífero/efeitos dos fármacos , Feminino , Larva/efeitos dos fármacos , Larva/fisiologia , Masculino , Oócitos/citologia , Oócitos/efeitos dos fármacos , Hipófise/química , Extratos de Tecidos/farmacologiaRESUMO
Astronotus ocellatus, popularly known as Oscar, is a cichlid fish from the Amazon basin (Brazil) with a great potential for fish farming. The aim of this research is to describe the morphology of eggs and larvae of A. ocellatus under stereomicroscopy and scanning electron microscopy. Eggs from natural spawnings were taken to hatcheries, collected at previously established time periods and then analysed. Oscar's eggs are demersal, adhesive and fragile to touch, with a slightly oval shape. The fertile eggs are yellowish in colour and when unfertilized are a white opaque colour. In the initial collection (IC), the majority of eggs were found to be at the gastrula phase with 30% epiboly. At 12 h after the IC, the formation of the embrionary axis and somites was observed, followed by differentiation of the tail and of the head. Fifteen hours after the IC, the emergence of the optic and otic vesicles, and of adhesive glands and the yolk pigmentation was observed. Larval hatching took place between 46 and 58 h after the first collection, at an average temperature of 27.45 ± 2.13°C. The larval stage was characterized by the development of the heart, fins, branchial apparatus, neuromasts, taste buds and adhesive glands on the head. Larval development to yolk absorption took a period of 257 h. These results provide important information for reproduction, rearing and preservation of A. ocellatus.