Dentro de las infecciones nosocomiales más frecuentes asociadas a bacterias multi-resistentes y de peor pronóstico, se encuentran las producidas por Pseudomonas aeruginosa. Esta bacteria posee una alta capacidad de adaptación a condiciones adversas como por ejemplo el pH y la osmolaridad de la orina. Pseudomonas aeruginosa es uno de los principales patógenos implicados en infecciones nosocomiales y de pacientes inmunosuprimidos. Esta bacteria se considera un agente infeccioso oportunista que posee diversos mecanismos de patogenicidad, así como de resistencia a antimicrobianos, lo que contribuye a la dificultad en el tratamiento de estas infecciones. En la presente revisión bibliográfica se analizan la taxonomía, los mecanismos de patogenicidad y genes de resistencia de P. aeruginosa. Así también, se abordan los factores microambientales de la infección urinaria producida por esta bacteria, haciendo un acercamiento al entendimiento de las bases fisiopatológicas de esta infección.

Dendritic cells (DCs) are a type of cells derived from bone marrow that represent 1% or less of the total hematopoietic cells of any lymphoid organ or of the total cell count of the blood or epithelia. Dendritic cells comprise a heterogeneous population of cells localized in different tissues where they act as sentinels continuously capturing antigens to present them to T cells. Dendritic cells are uniquely capable of attracting and activating naïve CD4⁺ and CD8⁺ T cells to initiate and modulate primary immune responses. They have the ability to coordinate tolerance or immunity depending on their activation status, which is why they are also considered as the orchestrating cells of the immune response. The purpose of this review is to provide a general overview of the current knowledge on ontogeny and subsets of human dendritic cells as well as their function and different biological roles.

There are many types of cell death, each involving multiple and complex molecular events. Cell death can occur accidentally when exposed to extreme physical, chemical, or mechanical conditions, or it can also be regulated, which involves a genetically coded complex machinery to carry out the process. Apoptosis is an example of the latter. Apoptotic cell death can be triggered through different intracellular signalling pathways that lead to morphological changes and eventually cell death. This is a normal and biological process carried out during maturation, remodelling, growth, and development in tissues. To maintain tissue homeostasis, regulatory, and inhibitory mechanisms must control apoptosis. Paradoxically, these same pathways are utilized during infection by distinct intracellular microorganisms to evade recognition by the immune system and therefore survive, reproduce and develop. In cancer, neoplastic cells inhibit apoptosis, thus allowing their survival and increasing their capability to invade different tissues and organs. The purpose of this work is to review the generalities of the molecular mechanisms and signalling pathways involved in apoptosis induction and inhibition. Additionally, we compile the current evidence of apoptosis modulation during cancer and Leishmania infection as a model of apoptosis regulation by an intracellular microorganism.