Front Matter

The carbohydrate Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) is produced in all mammals except for humans, apes and old world monkeys that lost the ability to synthetize this carbohydrate. Therefore, humans can produce high antibody titers against α-Gal. Anti-α-Gal IgE antibodies have been associated with tick-induced allergy (i.e. α-Gal syndrome) and anti-α-Gal IgG/IgM antibodies may be involved in protection against malaria, leishmaniasis and Chagas disease. The α-Gal on tick salivary proteins plays an important role in the etiology of the α-Gal syndrome. However, whether ticks are able to produce endogenous α-Gal remains currently unknown. In this study, the Ixodes scapularis genome was searched for galactosyltransferases and three genes were identified as potentially involved in the synthesis of α-Gal. Heterologous gene expression in α-Gal-negative cells and gene knockdown in ticks confirmed that these genes were involved in α-Gal synthesis and are essential for tick feeding. Furthermore, these genes were shown to play an important role in tick-pathogen interactions. Results suggested that tick cells increased α-Gal levels in response to Anaplasma phagocytophilum infection to control bacterial infection. These results provided the molecular basis of endogenous α-Gal production in ticks and suggested that tick galactosyltransferases are involved in vector development, tick-pathogen interactions and possibly the etiology of α-Gal syndrome in humans.This research was supported by the Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185). JJV was supported by Project FIT (Pharmacology, Immunotherapy, nanoToxicology), funded by the European Regional Development Fund.Peer Reviewe

Infectious endocarditis from Streptococcus bovis associated with colonic carcinoma: case report and literature review Endocardite infecciosa por Streptococcus bovis associada com carcinoma cólico: relato de caso e revisão da literatura

BACKGROUND: Many studies in the literature have warned of the need for investigation of colonic lesions among patients, especially elderly ones, who have bacteremia and/or endocarditis from Streptococcus bovis. Bacteremia and infectious endocarditis from Streptococcus bovis may be related to the presence of neoplastic lesions in the large intestine and hepatic disease. AIM: This report describes a patient who presented infectious endocarditis from Streptococcus bovis associated with colonic carcinoma and tubular-villous adenomas. CONCLUSIONS: The finding of this bacterium among patients with septicemia and/or endocarditis is also related to the presence of villous or tubular-villous adenomas in the large intestine. For this reason, complete and detailed investigation of the large intestine must be performed in patients with infectious endocarditis, even in the absence of intestinal symptoms. An increased incidence of this condition or hepatic dysfunction has been reported among patients with infectious endocarditis from Streptococcus bovis. Patients with infectious endocarditis from Streptococcus bovis and normal colonoscopy may be included in the group at risk for developing colonic cancer. The knowledge that there is an association between endocarditis from Streptococcus bovis and carcinoma of the colon has important clinical implications. If the lesion can be discovered at an early stage, curative resection may become possible.<br>RACIONAL: Diferentes estudos na literatura têm alertado para a necessidade de investigação de lesões cólicas entre doentes, especialmente nos mais idosos, que apresentem bacteremia e/ou endocardite por Streptococcus bovis. A bacteremia e a endocardite infecciosa por S. bovis pode estar relacionada à presença de lesões neoplásicas do intestino grosso e a doença hepática. OBJETIVO: Descrição do caso de doente com endocardite infecciosa por S. bovis associada a carcinoma cólico e adenomas túbulo-vilosos. CONCLUSÕES: A detecção da bactéria nos pacientes com bacteremia e/ou endocardite também está relacionada com a presença de adenomas vilosos ou túbulo-vilosos no intestino grosso. A investigação minuciosa e completa do intestino grosso em doentes com endocardite infecciosa, mesmo na ausência de sintomas intestinais, deve ser realizada. O aumento da incidência da doença ou de disfunção hepática está sendo notado entre os pacientes com endocardite infecciosa por S. bovis. Doentes com endocardite infecciosa por S. bovis e colonoscopia normal podem ser incluídos em grupo de risco para o desenvolvimento de câncer cólico. O conhecimento desta associação entre endocardite por S. bovis e carcinoma de cólon tem aplicações clínicas importantes, pois se a lesão for descoberta num estádio inicial, a extirpação curativa pode ser possível