RESUMO
We have previously reported that Salmonella infects B cells and survives within endosomal-lysosomal compartments. However, the mechanisms used by Salmonella to enter B cells remain unknown. In this study, we have shown that Salmonella induces its own entry by the induction of localized ruffling, macropinocytosis, and spacious phagosome formation. These events were associated with the rearrangement of actin and microtubule networks. The Salmonella pathogenesis island 1 (SPI-1) was necessary to invade B cells. In contrast to macrophages, B cells were highly resistant to cell death induced by Salmonella. These data demonstrate the ability of Salmonella to infect these non-professional phagocytic cells, where the bacterium can find an ideal intracellular niche to support persistence and the possible dissemination of infection.
Assuntos
Linfócitos B/microbiologia , Linfócitos B/fisiologia , Interações Hospedeiro-Patógeno , Fagossomos/microbiologia , Pinocitose , Salmonella/patogenicidade , Actinas/metabolismo , Animais , Proteínas de Bactérias , Células Cultivadas , Feminino , Macrófagos/microbiologia , Macrófagos/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Microtúbulos/metabolismo , Salmonella/genética , Fatores de Virulência/genética , Fatores de Virulência/metabolismoRESUMO
The aim of this study was to determine the frequency of cytomegalovirus (CMV) infection in children with postmortem study. The records of 1618 autopsies performed during 1980 - 1989 at the Hospital Infantil de Mexico Federico Gomez were reviewed. Characteristic cytomegalovirus inclusion bodies were identified, in one or several organs, in 47 cases (2.9 per cent of the autopsies). None of these cases was cultured for viruses prior to ar at the time of autopsy. Of the 47 cases, 24 (51 per cent) with CMV were younger than 3 months of age. In eight cases, the infection was juged as generalized and considered the cause of death. Two of these patients were premature and the infection was most probably intrauterine. The risk factor most frequently identified was secondary immunosuppression. The lung was the most common affected organ, followed by kidney, adrenals, pancreas, liver, brain and salivary glands. In seven cases the inclusion bodies were seen in the brain and in three others periventricular calcifications without inclusion bodies were observed. Although not a rarity in Mexico, CMV infection is not often suspected. Additional studies are needed in order to determine the prevalence of CMV infection in Mexico