RESUMO
Strain-specific differences in the interaction of coxsackievirus B3 (CVB3) with the coxsackievirus-adenovirus receptor (CAR) and the decay-accelerating factor (DAF) co-receptor proteins were investigated using a non-haemagglutinating (CVB3) and a haemagglutinating (CVB3-HA) strain of CVB3. A panel of receptor-transfected hamster CHO cells, expressing either CAR (CHOCAR cells), DAF (CHODAF cells), or both receptor proteins (CHODC cells) were used to study the interplay of CAR and DAF receptor molecules with regard to binding and infection with CVB3 and CVB3-HA. Despite clear differences in their binding phenotypes, both virus strains were found to primarily depend on the CAR receptor protein for initialization of productive infections. Cytopathic effects induced by CVB3-HA were influenced by co-expression of DAF receptor proteins. The cardiotropic potential of both virus strains was investigated in A.BY/SnJ mice. Despite comparable virus replication of both CVB3 strains in individual myocytes, the number of infected heart muscle cells was significantly lower in CVB3-HA infected mice. Infections of pancreata correlated with myocardial infections. Together these data suggest that even small differences in virus-receptor interactions, influencing virus binding and virus spread, may have an impact on the pathogenesis of CVB-induced diseases.
Assuntos
Antígenos CD55/metabolismo , Enterovirus Humano B/classificação , Enterovirus Humano B/patogenicidade , Receptores Virais/metabolismo , Animais , Antígenos CD55/genética , Células CHO , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus , Cricetinae , Enterovirus Humano B/metabolismo , Células HeLa , Humanos , Camundongos , Miocardite/fisiopatologia , Miocardite/virologia , Pancreatite/fisiopatologia , Pancreatite/virologia , Receptores Virais/genética , TransfecçãoRESUMO
The diagnosis of pulmonary tuberculosis (TB) relies on the bacteriological examination of sputum. However, microscopy of smears made directly from sputum has a low sensitivity and there is an urgent need for improved methods. We have compared microscopy of smears made directly from sputum with microscopy after liquefaction of sputum with household bleach (NaOCl) and concentration of bacteria by centrifugation. In 3 studies performed in Ethiopia and India, the use of the NaOCl method increased the number of samples positive for acid-fast bacilli by more than 100%. The technique is appropriate for developing countries and its application would increase the efficiency of TB control programmes. As a potent disinfectant, NaOCl also has the advantage of lowering the risk of laboratory infection.
