Anti-Salmonella Polyclonal antibody

We present a case of vertebral osteomyelitis in a previously healthy, adolescent Caucasian female athlete. After months of lower back pain, spinal imaging demonstrated phlegmon and suspected osteomyelitis of the L4 vertebral body. A bone biopsy was obtained, and microbiologic cultures yielded pure growth of Salmonella enterica subsp. enterica serovar Poona (S. Poona), a member of the nontyphoid Salmonella group associated with food-borne gastroenteritis in the United States. This case represents the first reported association of S. Poona with osteomyelitis and is interesting in that the infection developed in a patient without traditional risk factors for invasive Salmonella disease (i.e. sickle cell disease). This case highlights the importance of keeping a broad differential diagnosis for lower back pain and emphasizes the value of obtaining specimens for microbiologic culture to aid in diagnosing non-traditional and potentially emerging bacterial pathogens.

Here, the authors show that Salmonella activates the cytosolic PRR Nod-like Receptor CARD 4 (NLRC4), which limits adaptive T-cell responses in a NLRP3-dependent manner. Modification of Salmonella flagellin reduces NLRC4 activation and enhances protective immunity. Pattern recognition receptors (PRRs) expressed in antigen-presenting cells are thought to shape pathogen-specific immunity by inducing secretion of costimulatory cytokines during T-cell activation, yet data to support this notion in vivo are scarce. Here, we show that the cytosolic PRR Nod-like Receptor CARD 4 (NLRC4) suppresses, rather than facilitates, effector and memory CD4(+) T-cell responses against Salmonella in mice. NLRC4 negatively regulates immunological memory by preventing delayed activation of the cytosolic PRR NLR pyrin domain 3 (NLRP3) that would otherwise amplify the production of cytokines important for the generation of Th1 immunity such as intereukin-18. Consistent with a role for NLRC4 in memory immunity, primary challenge with Salmonella expressing flagellin modified to largely evade NLRC4 recognition notably increases protection against lethal rechallenge. This finding suggests flagellin modification to reduce NLRC4 activation enhances protective immunity, which could have important implications for vaccine development against flagellated microbial pathogens.