Video Experimental Relacionado
Updated: Apr 17, 2026
14:05
Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes
Published on: September 20, 2013
10.5K
La escisión de los prófagos activa los genes de competencia de Listeria que promueven el escape fagosómico y la
Lev Rabinovich1, Nadejda Sigal, Ilya Borovok
1Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel.
Cell
|August 21, 2012
Resumen
El sistema de competencia (Com) de Listeria monocytogenes, previamente considerado no funcional, es crucial para el escape bacteriano de las células huésped durante la infección. Un profago actúa como un interruptor genético, permitiendo que el sistema de comunicaciones funcione sin la transformación del ADN.
Área de la Ciencia:
- Microbiología Microbiología.
- La patogénesis bacteriana es la patogénesis bacteriana.
- Biología Molecular Biología Molecular
Sus antecedentes:
- El sistema de competencia (Com) en *Listeria monocytogenes* es ampliamente considerado no funcional, con un gen regulador maestro (comK) interrumpido debido a una propagación.
- No se han identificado condiciones para la transformación del ADN en este patógeno.
Objetivo del estudio:
- Para investigar el papel del sistema Com de Listeria monocytogenes durante la infección del huésped.
- Para dilucidar el mecanismo regulador que involucra el gen profago y comK.
Principales métodos:
- Análisis de la función del sistema Com durante el crecimiento bacteriano intracelular.
- Investigación de la escisión de la prófaga y su impacto en la integridad del gen comK.
- Evaluación del escape bacteriano de los fagosomas de los macrófagos.
Principales resultados:
- El sistema Com es esencial para que Listeria monocytogenes escape de los fagosomas de los macrófagos durante la infección, independientemente de la captación de ADN.
- La escisión de prófagos, inducida durante el crecimiento intracelular, restaura un gen comK funcional.
- La escisión de los prófagos ocurre sin la producción de partículas virales infecciosas, actuando como un interruptor genético específico.
Conclusiones:
- El sistema *Listeria monocytogenes* Com es un factor de virulencia activo, que no está involucrado en la transformación del ADN.
- Un profago templado actúa como un interruptor genético condicional, regulando la virulencia bacteriana durante la infección mediante el control de la expresión del gen comK.
Videos de Conceptos Relacionados
00:43Lysogenic Cycle of Bacteriophages
70.1K
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
70.1K
01:16Transduction
2.9K
Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome...
2.9K
01:20Viral Replication: Lytic Cycle
2.9K
Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
2.9K
01:16Viral Replication: Lysogenic Cycle
2.6K
The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects...
2.6K
01:25Colonisation of Pathogens
63
Pathogen colonization of host tissues is a critical step in the development of infectious diseases. Various pathogenic microorganisms, including bacteria, fungi, viruses, and protozoa, have evolved complex strategies to attach to, invade, and persist within host environments. These mechanisms enable pathogens to establish infections, evade immune responses, and resist antimicrobial treatments.Attachment to Host CellsIn bacteria, colonization typically begins with adherence to host epithelial...
63
01:28Regulation of Bacterial Virulence
59
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
59