Final answer:
The most severe septicemias are typically caused by gram-negative bacteria due to LPS-induced septic shock. Conditions such as puerperal fever and toxic shock syndrome are also serious, and therapies must support blood pressure and address the infection and inflammation.
Step-by-step explanation:
The most severe types of septicemias are often caused by gram-negative bacteria due to the release of lipopolysaccharides (LPS) into the bloodstream, which can trigger an overwhelming immune response known as septic shock. Additionally, conditions such as puerperal fever, toxic shock syndrome, and zoonotic diseases like bubonic plague are serious infections that can lead to sepsis. In cases of septic shock, therapies aimed at supporting the patient's blood pressure, combating the underlying infection with antibiotics, and managing the inflammatory response can be critical in stopping the dangerous events and outcomes associated with this condition.