Comparison of Biofilm and Attachment Mechanisms of a Phytopathological and Clinical Isolate of Klebsiella pneumoniae

Some bacterial species can colonize humans and plants. It is almost impossible to prevent the contact of clinically pathogenic bacteria with food crops, and if they can persist there, they can reenter the human food chain and cause disease. On the leaf surface, microorganisms are exposed to a number of stress factors. It is unclear how they survive in such different environments. By increasing adhesion to diverse substrates, minimizing environmental differences, and providing protection against defence mechanisms, biofilms could provide part of the answer. Klebsiella pneumoniae subsp. pneumoniae is clinically important and also associated with fruit diseases, such as “pineapple fruit collapse.” We aimed to characterize biofilm formation and adhesion mechanisms of this species isolated from pineapple in comparison with a clinical isolate. No differences were found between the two isolates quantitatively or qualitatively. Both tested positive for capsule formation and were hydrophobic, but neither produced adherence fibres, which might account for their relatively weak adhesion compared to the positive control Staphylococcus epidermidis ATCC 35984. Both produced biofilms on glass and polystyrene, more consistently at 40°C than 35°C, confirmed by atomic force and high-vacuum scanning electron microscopy. Biofilm formation was maintained in an acidic environment, which may be relevant phytopathologically

Avaliação da produção editorial do Incaper sob a perspectiva do público interno: pesquisa, assistência técnica e extensão rural.

Publications produced by the team technique, since the 1950s, have been an instrument to support these methodologies, socializing knowledge, as well as for the professional updating of the technical staff. Considering the significant volume of Incaper's editorial production, the Editorial Coordination, together with the team from the Technology and Knowledge Transfer Management (GTTC) and professionals from the Research and Ater areas of the Institute, considered it important to evaluate the effectiveness and effectiveness of this production, especially related to access, content and language of publications, in accordance from the perspective of the target audience (internal and external). The research aimed to verify the perception of the Institute's employees, in relation to the publications and audiovisual materials used in the socialization of technologies generated and/or recommended by the Incaper technical team. As deployment, the purpose was also to improve scientific dissemination and support the transfer of technologies in action planning as a tool in knowledge management in Government of State

Physical Characteristics of the Leaves and Latex of Papaya Plants Infected with the Papaya meleira Virus

Sticky disease, which is caused by Papaya meleira virus (PMeV), is a significant papaya disease in Brazil and Mexico, where it has caused severe economic losses, and it seems to have spread to Central and South America. Studies assessing the pathogen-host interaction at the nano-histological level are needed to better understand the mechanisms that underlie natural resistance. In this study, the topography and mechanical properties of the leaf midribs and latex of healthy and PMeV-infected papaya plants were observed by atomic force microscopy and scanning electron microscopy. Healthy plants displayed a smooth surface with practically no roughness of the leaf midribs and the latex and a higher adhesion force than infected plants. PMeV promotes changes in the leaf midribs and latex, making them more fragile and susceptible to breakage. These changes, which are associated with increased water uptake and internal pressure in laticifers, causes cell disruption that leads to spontaneous exudation of the latex and facilitates the spread of PMeV to other laticifers. These results provide new insights into the papaya-PMeV interaction that could be helpful for controlling papaya sticky disease