Bacterial endotoxins are lipopolysaccharide (LPS) molecules found in the outer membrane of Gram-negative bacteria. The lipid A component is toxic and responsible for activating macrophages and the complement system, leading to fever, hypotension, disseminated intravascular coagulation (DIC), and septic shock.

Match each bacterial exotoxin to its causative organism and mechanism of pathogenesis. Focus on how these toxins act at the cellular level — whether they block neurotransmission, inhibit protein synthesis, or alter intracellular signaling (like cAMP). Understanding these mechanisms is essential for mastering microbiology concepts in USMLE Step 1 and clinical reasoning.

Der Anteil der Bakterien, die auch gegen Reserveantibiotika resistent sind, steigt weiter. Experten empfehlen eine intensivierte Überwachung.

Researchers from King's College London have called for urgent changes to the way new antibiotics are developed to address the growing problem of antimicrobial resistance (AMR).

Engineering synthetic consortia to perform distributed functions requires robust quorum sensing (QS) systems to facilitate communication between cells. However, the current QS toolbox lacks standardized implementations, which are particularly valuable for use in bacteria beyond the model species Escherichia coli. We developed a set of three QS systems encompassing both sender and receiver modules, constructed using backbones from the SEVA (Standard European Vector Architecture) plasmid collection. This increases versatility, allowing plasmid features like the origin of replication or antibiotic marker to be easily swapped. The systems were characterized using the synthetic biology chassis Pseudomonas putida. We first tested individual modules, then combined sender and receiver modules in the same host, and finally assessed the performance across separate cells to evaluate consortia dynamics. Alongside the QS set, we provide mathematical models and rate parameters to support the design efforts. Together, these tools advance the engineering of robust and predictable multicellular functions.

Für 2023 ist ein deutlicher Anstieg gramnegativer Krankenhauserreger festgestellt worden. Das hat Folgen auf verfügbare Therapieoptionen.