O microbioma intestinal tem sido associado à sepse, causada por infecção, apresentando respostas imunológicas exacerbadas. O peptídeo antimicrobiano CRAMP atua na imunidade inata com característica ambígua, ora pró-inflamatória ora anti-inflamatória. Nesse estudo, a sepse foi induzida por modelo de ligadura e punção cecal (CLP) e, através de RT-qPCR, o DNA de amostras fecais de camundongos selvagens e deficientes em CRAMP foi analisado. A expressão de Alfa-defensina 5 e Beta-defensina 1 foi investigada em RT-qPCR. Técnicas de imunofluorescência, Elisa e Milliplex, foram utilizadas na quantificação de citocinas - IL-1Beta, IL-6, IL-10, MCP-1 e TNF-Alfa -, e Alfa-defensina 7 e Beta-defensina 1. Os resultados mostraram a intensificação da resposta imune, diante da sepse, com alterações pró-inflamatórias de IL-1Beta, IL-6, MCP-1 e TNF-Alfa e anti-inflamatória de IL-10. A Beta-defensina 1 teve expressão aumentada, enquanto a produção foi mantida ou reduzida nos tecidos, após CLP. A liberação de Alfa-defensina 7 foi ampliada no pulmão de animais selvagens durante a sepse, enquanto a expressão de Alfa-defensina 5 foi reduzida no íleo e cólon. A relação entre o microbioma intestinal e a sepse evidenciou-se com o crescimento da espécie Escherichia coli, enquanto o CRAMP apresentou associação com a espécie Bacteroides vulgatus. Novos estudos permitiram mais conhecimento sobre a interação entre sepse e microbioma intestinal, potencializando o uso de biomarcadores e nova terapêutica na recuperação intestinal, tal como transplante microbiológico fecal / The intestinal microbiome has been associated with sepsis, caused by infection, presenting exacerbated immune responses. The antimicrobial peptide CRAMP acts on innate immunity with ambiguous features, pro-inflammatory and anti-inflammatory. In this study, sepsis was induced by cecal ligation and puncture (CLP) model and, through RT-qPCR, the DNA of fecal samples from wild type and CRAMP-deficient mice was analyzed. Expression of Alpha-defensin 5 and Beta-defensin 1 was investigated in RT-qPCR. Immunofluorescence techniques, Elisa and Milliplex, were used to quantify cytokines - IL-1Beta, IL-6, IL-10, MCP-1 and TNF-Alpha -, and Alpha-defensin 7 and Beta-defensin 1. The results showed the enhancement of the immune response to sepsis with proinflammatory alterations of IL-1Beta, IL-6, MCP-1 and TNF-Alpha and anti-inflammatory IL-10. CRAMP and Beta-defensin 1 peptides had increased expression, while production was maintained or reduced in tissues after CLP. The release of Alpha-defensin 7 was amplified in the lungs of wild type animals during sepsis, while expression of Alpha-defensin 5 was reduced in the ileum and colon. The relationship between the intestinal microbiome and sepsis was evidenced by the growth of Escherichia coli, while CRAMP was associated with Bacteroides vulgatus. New studies have allowed more knowledge about the interaction between sepsis and intestinal microbiome, potentializing the use of biomarkers and new therapy in intestinal recovery, such as fecal microbiological transplantation

Campylobacter jejuni is a major cause of bacterial gastroenteritis in the developed world; however, many aspects of its biology remain poorly understood, including its colonization of the mucus layer lining the gastrointestinal tract. In this study, we utilized microarray transposon tracking to compile a list of 195 genes essential for the growth of C. jejuni in vitro under microaerophilic conditions. Then we characterized C. jejuni growing in an extracted intestinal mucus medium. We found that C. jejuni will grow efficiently in a medium comprised of either chick and piglet intestinal mucus, and that these media have a dramatic impact on its transcriptome. Within the genes identified as differentially expressed during growth in a mucus medium, we identified a single operon, (cj0481-cj0490), which we have subsequently characterized as being responsible for both the uptake and metabolism of L-fucose. This represents the first observation of carbohydrate metabolism by the otherwise asaccharolytic C. jejuni. We further found that the inability to utilize L-fucose puts C. jejuni at a competitive disadvantage when colonizing the piglet intestine, but not the chick cecum. Finally, we examined C. jejuni’s ability to utilize mucins as a carbon source while growing within the mucus layer. We found that despite mucins being a major source of L-fucose and amino acids within the intestine, C. jejuni has a minimal ability to degrade and utilize mucins on its own. However, close proximity to mucolytic bacteria within the microbiota of the intestine, allows for increased C. jejuni growth. Together, this paints the picture of an organism that is well adapted to survival within the mucus lining of the intestine and establishing itself as part of the intestinal microbiota.

Campylobacter jejuni is a major cause of bacterial gastroenteritis in the developed world; however, many aspects of its biology remain poorly understood, including its colonization of the mucus layer lining the gastrointestinal tract. In this study, we utilized microarray transposon tracking to compile a list of 195 genes essential for the growth of C. jejuni in vitro under microaerophilic conditions. Then we characterized C. jejuni growing in an extracted intestinal mucus medium. We found that C. jejuni will grow efficiently in a medium comprised of either chick and piglet intestinal mucus, and that these media have a dramatic impact on its transcriptome. Within the genes identified as differentially expressed during growth in a mucus medium, we identified a single operon, (cj0481-cj0490), which we have subsequently characterized as being responsible for both the uptake and metabolism of L-fucose. This represents the first observation of carbohydrate metabolism by the otherwise asaccharolytic C. jejuni. We further found that the inability to utilize L-fucose puts C. jejuni at a competitive disadvantage when colonizing the piglet intestine, but not the chick cecum. Finally, we examined C. jejuni’s ability to utilize mucins as a carbon source while growing within the mucus layer. We found that despite mucins being a major source of L-fucose and amino acids within the intestine, C. jejuni has a minimal ability to degrade and utilize mucins on its own. However, close proximity to mucolytic bacteria within the microbiota of the intestine, allows for increased C. jejuni growth. Together, this paints the picture of an organism that is well adapted to survival within the mucus lining of the intestine and establishing itself as part of the intestinal microbiota.